Control Systems of Rubber Dryer Machinery Components Using Programmable Logic Control (PLC)

NASA Astrophysics Data System (ADS)

Hendra; Yulianto, A. S.; Indriani, A.; Hernadewita; Hermiyetti

2018-02-01

Application of programmable logic control (PLC) is widely used on the control systems in the many field engineering such as automotive, aviation, food processing and other industries [1-2]. PLC is simply program to control many automatic activity, easy to use, flexible and others. PLC using the ladder program to solve and regulated the control system component. In previous research, PLC was used for control system of rotary dryer machine. In this paper PLC are used for control system of motion component in the rubber dryer machinery. Component of rubber dryer machine is motors, gearbox, sprocket, heater, drying chamber and bearing. Principle working of rubber dryer machinery is wet rubber moving into the drying chamber by sprocket. Sprocket is driven by motors that conducted by PLC to moving and set of wet rubber on the drying chamber. Drying system uses greenhouse effect by making hanger dryer design in the form of line path. In this paper focused on motion control system motors and sensors drying rubber using PLC. The results show that control system of rubber dryer machinery can work in accordance control input and the time required to dry the rubber.

Economic status, smoking, occupational exposure to rubber, and lung cancer: a case-cohort study.

PubMed

Li, Ke; Yu, Shunzhang

2002-05-01

Recent studies tend consistently to confirm the presence of a moderate excess risk of lung cancer in the rubber industry. However, the agent responsible for the excess of lung cancer is still obscure. Also, analyses without regard to the modifying effects of sex, economic status, and smoking habit are less than satisfactory. To explore these questions, we have conducted a case-cohort study using the data of 51 lung cancer deaths in 1973-1997 and a random sample (sub-cohort) of 188 from among 1598 subjects in a rubber factory in Shanghai, China. We computed the risks of lung cancer by economic status, smoking habit, coal fumes in home, and year of first employment. We assessed lung cancer risks for occupational exposures, unadjusted and adjusted for economic status and smoking. After confounding effects of smoking and economic status were controlled, we found that rate ratios were 1.43 (95% confidence interval (CI) 0.43-4.69), 1.79 (95% CI 0.64-5.03), and 3.76 (95% CI 1.44-9.86) for 1-14, 15-29, and 30-45 exposure-years in curing department, respectively. The data showed significant trends in increased risk of lung cancer with duration of exposure in tire-curing department (score test for trend:, P = 0.004). However, in front rubber processing (weighing and mixing, calendering, extruding, and milling), no significant excess risk of lung cancer was found. If it can be confirmed that nitrosamines are mainly generated in back rubber processing (curing and vulcanizing), it would be reasonable to conclude that excess risk of lung cancer in rubber industry is attributable, at least partially, to exposure to nitrosamines.

75 FR 28567 - New Pneumatic Off-the-Road Tires From the People's Republic of China: Notice of Partial...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-21

... Limited, Laizhou Xiongying Rubber Industry Co., Ltd., Qingdao Free Trade Zone Full World International Trading Co., Ltd., Qingdao Taifa Group Co., Ltd., and Weihai Zhongwei Rubber Co., Ltd. The Department then... Resources Limited, Laizhou Xiongying Rubber Industry Co., Ltd., Qingdao Free Trade Zone Full World...

The effect of carbon black (CB) loading on curing characteristics and mechanical properties of virgin acrylonitrile butadiene rubber (Nbrv)/recycled acrylonitrile butadiene rubber (Nbrr) blends

NASA Astrophysics Data System (ADS)

Husnan, M. A.; Ismail, H.; Shuib, R. K.

2018-02-01

Recently, the interest of polymer industry researchers have grown rapidly on the use of specific techniques which can reduce cost and utilize rubber waste into the processing form. The increasing of cognizance in environmental matters and the desire to sustain the resources had fortified the practice of recycling waste materials. In this work, the effect of carbon black loading on curing characteristics and mechanical properties of virgin acrylonitrile butadiene rubber/recycled acrylonitrile butadiene rubber (NBRv/NBRr) blends were studied. Cure time (t90), scorch time (tS2) and swelling percentage decreased but minimum torque (ML) and maximum torque (MH) increased with increasing carbon black (CB) loading in the blends. Increasing CB loading also increased tensile strength, tensile modulus (M100), hardness and compression set but decreased elongation at break (Eb) of NBRv/NBRr blends.

Rubber Plastics Processing Industry Training Board

ERIC Educational Resources Information Center

Industrial Training International, 1974

1974-01-01

The training adviser's role is changing from trainer to problem analyst. Some of the problems being dealt with include: (1) the school to industry transition, (2) new training methods for the 16 to 18 year old entry worker, (3) foreign language training, (4) safety programs, and (5) tire-fitter training. (MW)

Assessment  of  Genotoxicity  Among  Rubber  Industry Workers  Occupationally  Exposed  to  Toxic  Agents  Using Micronucleus  Assay.

PubMed

Gemitha, Gem; Sudha, Sellappa

2013-01-01

Occupational and environmental exposures mostly represent complexmixture of genotoxic agents, however there is a wide variation in the specificity of biomarkers. Exploration of correlations among biomarkers contributes to the further progress of molecular cancer epidemiology and to the selection of the optimal biomarkers for the investigation of human exposure to carcinogens. The aim of this study was to assess the potential cytogenetic damage associated with occupational exposure to toxic agents among rubber industry workers by using Micronucleus (MN) assay. In the present study 35 occupationally exposed rubber industry workers and 30 controls were investigated for genetic damage. Both the exposed and control individuals were selected from rural areas of South India. Exfoliated Buccal cells were collected from the study population and examined for the presence of MN. Rubber industry workers showed a significant increase in micronucleated cells when compared to controls with respect to their smoking and drinking habits (P< 0.05). The present study suggested that occupational exposure to toxic chemicals in rubber industry can cause genetic damage. MN formation reflects genetic changes and/or events associated with carcinogenesis. Therefore the results of this study indicate that rubber industry workers may be at the risk of cancer. Therefore, it is important to take appropriate measures to protect the workers from occupational hazards.

Cancer mortality in the British rubber industry.

PubMed

Parkes, H G; Veys, C A; Waterhouse, J A; Peters, A

1982-08-01

Although it is over 30 years since an excess of bladder cancer was first identified in British rubber workers, the fear has persisted that this hazard could still be affecting men working in the industry today. Furthermore, suspicions have also arisen that other and hitherto unsuspected excesses of cancer might be occurring. For these reasons 33 815 men, who first started work in the industry between 1 January 1946 and 31 December 1960, have been followed up to 31 December 1975 to ascertain the number of deaths attributable to malignant disease and to compare these with the expected number calculated from the published mortality rates applicable to the male population of England and Wales and Scotland. The findings confirm the absence of any excess mortality from bladder cancer among men entering the industry after 1 January 1951 (the presumed bladder carcinogens were withdrawn from production processes in July 1949), but they confirm also a statistically significant excess of both lung and stomach cancer mortality. A small excess of oesophageal cancer was also observed in both the tyre and general rubber goods manufacturing sectors. American reports of an excess of leukaemia among rubber workers receive only limited support from the present study, where a small numerical excess of deaths from leukaemia is not statistically significant. A special feature of the study is the adoption of an analytical method that permits taking into account the long latent period of induction of occupational cancer.

Cancer mortality in the British rubber industry.

PubMed Central

Parkes, H G; Veys, C A; Waterhouse, J A; Peters, A

1982-01-01

Although it is over 30 years since an excess of bladder cancer was first identified in British rubber workers, the fear has persisted that this hazard could still be affecting men working in the industry today. Furthermore, suspicions have also arisen that other and hitherto unsuspected excesses of cancer might be occurring. For these reasons 33 815 men, who first started work in the industry between 1 January 1946 and 31 December 1960, have been followed up to 31 December 1975 to ascertain the number of deaths attributable to malignant disease and to compare these with the expected number calculated from the published mortality rates applicable to the male population of England and Wales and Scotland. The findings confirm the absence of any excess mortality from bladder cancer among men entering the industry after 1 January 1951 (the presumed bladder carcinogens were withdrawn from production processes in July 1949), but they confirm also a statistically significant excess of both lung and stomach cancer mortality. A small excess of oesophageal cancer was also observed in both the tyre and general rubber goods manufacturing sectors. American reports of an excess of leukaemia among rubber workers receive only limited support from the present study, where a small numerical excess of deaths from leukaemia is not statistically significant. A special feature of the study is the adoption of an analytical method that permits taking into account the long latent period of induction of occupational cancer. PMID:7093147

Study on small molecular organic compounds pyrolysed from rubber seed oil and its sodium soap.

PubMed

Fernando, T L D; Prashantha, M A B; Amarasinghe, A D U S

2016-01-01

Rubber seed oil (RSO) and its sodium soap were pyrolysed in a batch reactor to obtain low molar mass organic substances. The pyrolitic oil of RSO was redistilled and the distillates were characterized by GC-MS and FTIR. Density, acid value, saponification value and ester values were also measured according to the ASTM standard methods. A similar analysis was done for samples taken out at different time intervals from the reaction mixture. Industrially important low molar mass alkanes, alkenes, aromatics, cyclic compounds and carboxylic acids were identified in the pyrolysis process of rubber seed oil. However, pyrolysis of the sodium soap of rubber seed oil gave a mixture of hydrocarbons in the range of C14-C17 and hence it has more applications as a fuel.

The functional analyses of the cis-prenyltransferase and the rubber elongation factor in rubber biosynthesis

USDA-ARS?s Scientific Manuscript database

Natural rubber (cis-1,4-polyisoprene) is an essential plant derived commodity required for the manufacture of numerous industrial, medical and household items. Rubber is synthesized and sequestered on cytsolic vesicles known as rubber particles. When provided with farnesyl pyrophosphate (FPP) and is...

Materials for the General Aviation Industry: Effect of Environment on Mechanical Properties of Glass Fabric/Rubber Toughened Vinyl Ester Laminates

NASA Technical Reports Server (NTRS)

McBride, Timothy M.

1995-01-01

A screening evaluation is being conducted to determine the performance of several glass fabric/vinyl ester composite material systems for use in primary General Aviation aircraft structures. In efforts to revitalize the General Aviation industry, the Integrated Design and Manufacturing Work Package for General Aviation Airframe and Propeller Structures is seeking to develop novel composite materials and low-cost manufacturing methods for lighter, safer and more affordable small aircraft. In support of this Work Package, this study is generating material properties for several glass fabric/rubber toughened vinyl ester composite systems and investigates the effect of environment on property retention. All laminates are made using the Seemann Composites Resin Infusion Molding Process (SCRIMP), a potential manufacturing method for the General Aviation industry.

Sister-chromatid exchanges and cell-cycle kinetics in the lymphocytes of workers occupationally exposed to a chemical mixture in the tyre industry.

PubMed

Sasiadek, M

1993-08-01

Cytogenetic studies of clinically healthy workers employed in the rubber industry showed an increase in chromosome aberrations (CAs), sister-chromatid exchanges (SCEs) and a decrease in proliferation indices (PIs). The aim of the present study was to establish, using the SCE and PI tests, genotoxic effects of hazardous chemicals in the rubber industry. An increase in mean SCEs in the lymphocytes of vulcanizers as compared to controls was observed. Since the PI in the exposed group was insignificantly decreased as compared to the controls, it could be concluded that the SCE test is the most sensitive cytogenetic test for the detection of a genotoxic effect of chemicals in the rubber industry. There was no evidence in the present study that the genotoxic effect of chemicals in the rubber industry was enhanced by cigarette smoking.

75 FR 11414 - Certain New Chemicals; Receipt and Status Information

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-10

... 01/25/10 04/24/10 CBI (S) Tackifier in the (G) Rosin, polymer rubber / tires with phenols and industry formaldehyde P-10-0191 01/25/10 04/24/10 CBI (S) Tackifier in the (G) Rosin, polymer rubber...) Rosin, polymer rubber / tires with phenols and industry formaldehyde P-10-0193 01/25/10 04/24/10 CBI (S...

Study on the Secant Segmentation Algorithm of Rubber Tree

NASA Astrophysics Data System (ADS)

Li, Shute; Zhang, Jie; Zhang, Jian; Sun, Liang; Liu, Yongna

2018-04-01

Natural rubber is one of the most important materials in the national defense and industry, and the tapping panel dryness (TPD) of the rubber tree is one of the most serious diseases that affect the production of rubber. Although considerable progress has been made in the more than 100 years of research on the TPD, there are still many areas to be improved. At present, the method of artificial observation is widely used to identify TPD, but the diversity of rubber tree secant symptoms leads to the inaccurate judgement of the level of TPD. In this paper, image processing technology is used to separate the secant and latex, so that we can get rid of the interference factors, get the exact secant and latex binary image. By calculating the area ratio of the corresponding binary images, the grade of TPD can be classified accurately. and can also provide an objective basis for the accurate identification of the tapping panel dryness (TPD) level.

Industrial viable process of making nanoparticles of various shapes and interior structures

NASA Astrophysics Data System (ADS)

Wang, Xiaorong

2008-03-01

Over the past 10 years, we attempted to develop industrial viable processes which were of significance in manufacturing the nanoparticles in good quality and large volume. Our effort relied on the self-assembly concepts of block macromolecules in solutions to prepare particles with a hard core made of crosslinked plastics and a soft shell made of low Tg elastomer. Depending on the type and microstructure of the copolymers, the solvent concentration and other process parameters chosen, a variety of shell-core nano-particles of different shapes (spheres, hollow spheres, ellipsoids, cylinders, linear and branched strings, disks and etc.) and sizes (5-100 nm diameter) were reproducibly synthesized. Scale-up studies led to an optimization of the manufacturing process and the production of nanoparticles in large quantities for various product application efforts. The unique performance of those nanoparticles as performance tuning additives and novel rubber reinforcing elements was explored in rubber compounds. This review describes the synthesis methods used to produce the polymer nanoparticles, the technology to modify the particles through functionalization, the means to optimize their performance for specific applications, and the methods to use those particles in rubber compounds. Collaborators: Victor J. Foltz, Kurasch Jessica, Chenchy J. Lin, Jeff Magestrelli, Sandra Warren, Alberto Scuratti, James E. Hall, Jim Krom, Mindaugas Rackaitis, Michael W. Hayes, Pat Sadhukhan, Georg G. A. Bohm

Mutagenicity of airborne particulates in the rubber industry.

PubMed

Barański, B; Indulski, J; Janik-Spiechowicz, E; Palus, J

1989-12-01

The aim of this work was to evaluate the mutagenic activity of airborne particulate matter in the rubber industry. Air was sucked through Whatman glass-fibre filters with Staplex pumps and adsorbed substances and fume particles were extracted with acetone or toluene for 2 h in a ultrasonic cleaner. After separation of the insoluble solid phase by filtration, solvent was evaporated at a temperature of 70 degrees C in an argon atmosphere. The residue was stored at -20 degrees C. Mutagenicity was determined by the Salmonella plate incorporation assay with the tester strain TA98 and activity is related either to the weight of aerosol (rev mg-1) or to the volume of atmospheric sample (rev m-3). The fumes emitted from the tyre tread line, calender feeding, and tyre vulcanizing processes, showed the highest mutagenic activity (55-211 rev mg-1, + S9). At these and at other workplaces (extruder mill, carbon black station, mixer loading), mutagenic activity related to the volume of air was in the range of 22-158 rev m-3, + S9. The results indicate the need to reduce and monitor mutagenic contamination in order to increase the safety of work in the rubber industry.

Hot air vulcanization of rubber profiles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gerlach, J.

1995-07-01

Elastomer profiles are deployed in quantity by the automobile industry as seals and wateproofing in coachwork. The high standards demanded by the industry; improvement in weather prediction, noise reduction, restriction of tolerances, together with powerful demand for EPDM force the rubber processing industry into development, particularly of elastomers. Complex proofing systems must also be achieved with extremely complicated profile forms. All too often such profiles have an extremely large surface together with a low cross-section density. They frequently consist of two or three rubber compounds and are steel reinforced. Sometimes they are flocked and coated with a low friction finish.more » Such high-tech seals require an adjustment of the vulcanization method. The consistent trend in the nineties towards lower quantities of elastomer per sealing unit and the dielectric factor, especially with EPDM, has brought an old fashioned vulcanization method once more to the fore, a method developed over the past years to an extremely high standard, namely the hot-air method. This paper describes various vulcanization and curing methods and their relative merits and disadvantages, the Gerlach hot-air concept, the hot air installation concept, and energy saving and efficiency afforded by this technique. 4 figs.« less

A green procedure using ozone for Cleaning-in-Place in the beverage industry.

PubMed

Nishijima, Wataru; Okuda, Tetsuji; Nakai, Satoshi; Okada, Mitsumasa

2014-06-01

Cleaning-in-Place (CIP) in the beverage industry is typically carried out in production lines with alkaline and acidic solutions with detergents. This cleaning not only produces alkaline and acidic wastewater with detergents but also takes significant time. One of the important targets for CIP is adsorbed odorous compounds on gaskets, hence, we have tried to establish a rapid and green CIP process to remove traces of such compounds, especially d-limonene, an odorous component of orange juice, using two approaches; an ozone cleaning method and a change of gasket material from ethylene propylene diene monomer (EPDM) rubber to silicone rubber. By changing the gasket material from EPDM rubber to silicone rubber, the removability of d-limonene by typical alkaline and acidic cleanings with detergents was improved. However, complete removal of 4 mg g(-1) of d-limonene on both EPDM and silicone gaskets could not be achieved even using a series of conventional cleaning procedures that included alkaline and acidic cleaning for 220 min. Ozone treatment dramatically improved the removability of d-limonene, removing 87% from the EPDM gasket at 60 min and 100% from the silicone gasket at 30 min. The combination of the silicone gasket and ozone treatment resulted in the most effective cleaning. The main removal mechanism for ozone treatment was confirmed to be oxidation by molecular ozone. Effectiveness of changing the gasket material from EPDM rubber to silicone rubber in reducing residual amounts of odorous compounds adsorbed on the gaskets was also confirmed for furfural and 4-vinylguaiacol. Copyright © 2014 Elsevier Ltd. All rights reserved.

Work environments and exposure to hazardous substances in korean tire manufacturing.

PubMed

Lee, Naroo; Lee, Byung-Kyu; Jeong, Sijeong; Yi, Gwang Yong; Shin, Jungah

2012-06-01

The purpose of this study is to evaluate the tire manufacturing work environments extensively and to identify workers' exposure to hazardous substances in various work processes. Personal air sampling was conducted to measure polycyclic aromatic hydrocarbons, carbon disulfide, 1,3-butadiene, styrene, methyl isobutyl ketone, methylcyclohexane, formaldehyde, sulfur dioxide, and rubber fume in tire manufacturing plants using the National Institute for Occupational Safety Health Manual of Analytical Methods. Noise, carbon monoxide, and heat stress exposure were evaluated using direct reading instruments. Past concentrations of rubber fume were assessed using regression analysis of total particulate data from 2003 to 2007, after identifying the correlation between the concentration of total particulate and rubber fume. Workers were exposed to rubber fume that exceeded 0.6 mg/m(3), the maximum exposure limit of the UK, in curing and production management processes. Forty-seven percent of workers were exposed to noise levels exceeding 85 dBA. Workers in the production management process were exposed to 28.1℃ (wet bulb globe temperature value, WBGT value) even when the outdoor atmosphere was 2.7℃ (WBGT value). Exposures to other substances were below the limit of detection or under a tenth of the threshold limit values given by the American Conference of Governmental Industrial Hygienists. To better classify exposure groups and to improve work environments, examining closely at rubber fume components and temperature as risk indicators in tire manufacturing is recommended.

Direct molding of pavement tiles made of ground tire rubber

NASA Astrophysics Data System (ADS)

Quadrini, Fabrizio; Gagliardi, Donatella; Tedde, Giovanni Matteo; Santo, Loredana; Musacchi, Ettore

2016-10-01

Large rubber products can be molded by using only ground tire rubber (GTR) without any additive or binder due to a new technology called "direct molding". Rubber granules and powders from tire recycling are compression molded at elevated temperatures and pressures. The feasibility of this process was clearly shown in laboratory but the step to the industrial scale was missing. Thanks to an European Project (SMART "Sustainable Molding of Articles from Recycled Tires") this step has been made and some results are reported in this study. The press used for compression molding is described. Some tests were made to measure the energy consumption so as to evaluate costs for production in comparison with conventional technologies for GTR molding (by using binders). Results show that 1 m2 tiles can be easily molded with several thicknesses in a reasonable low time. Energy consumption is higher than conventional technologies but it is lower than the cost for binders.

Source Hierarchy List. Volume 2. E through N

DTIC Science & Technology

1994-07-01

SEE CONTINENTAL AG HANNOVER (GERMANY F R) 421628 02 GENERAL TIRE AND RUBBER CO MARION IN 151750 02 GENERAL TIRE ANO RUBBER CO WABASH IN...151800 03 GENERAL TIRE AND RUBBER CO WABASH IN 151820 INDUSTRIAL PRODUCTS DIV...GENERAL TIRE AND RUBBER CO WABASH IN 151800 FOR HIGHEST ORGANIZATIONAL LEVEL SEE CONTINENTAL AG HANNOVER (GERMANY F R) G3 GENERAL TIRE AND RUBBER CO

Thermal behavior of silicone rubber-based ceramizable composites characterized by Fourier transform infrared (FT-IR) spectroscopy and microcalorimetry.

PubMed

Anyszka, Rafał; Bieliński, Dariusz M; Jędrzejczyk, Marcin

2013-12-01

Ceramizable (ceramifiable) silicone rubber-based composites are commonly used for cable insulation. These materials are able to create a protective ceramic layer during fire due to the ceramization process, which occurs at high temperature. When the temperature is increased, the polymer matrix is degraded and filler particles stick together by the fluxing agent, producing a solid, continuous ceramic phase that protects the copper wire from heat and mechanical stress. Despite increasing interest in these materials that has resulted in growing applications in the cable industry, their thermal behavior and ceramization process are still insufficiently described in the literature. In this paper, the thermal behavior of ceramizable silicone rubber-based composites is studied using microcalorimetry and Fourier transform infrared spectroscopy. The analysis of the experimental data made it possible to develop complete information on the mechanism of composite ceramization.

Cancer risk in the rubber industry: a review of the recent epidemiological evidence

PubMed Central

Kogevinas, M.; Sala, M.; Boffetta, P.; Kazerouni, N.; Kromhout, H.; Hoar-Zahm, S.

1998-01-01

OBJECTIVES: To examine the recent epidemiological evidence on cancer risk among workers in the rubber industry. METHODS: Epidemiological studies published after the last detailed review by the International Agency for Research on Cancer (IARC) in 1982 were reviewed. 12 cohort studies in nine countries that examined distinct populations of workers in the rubber industry, seven industry based nested case-control studies, 48 community based case-control studies in 16 countries, and 23 studies based on administrative data that reported risks for employment in the rubber industry were identified. RESULTS: Excess risks of bladder cancer, lung cancer, and leukaemia were found in most studies, with risks above 1.5 in about half of the studies. A moderate excess risk for laryngeal cancer was consistent across studies. Excess risks were found in a few studies for cancers of the oesophagus, stomach, colon, liver, pancreas, skin, prostate, kidney, brain, and thyroid, and for malignant lymphoma and multiple myeloma, but overall results were not consistent for these neoplasms. CONCLUSIONS: Magnitude of the observed risks varied considerably between studies, but overall the findings indicate the presence of a widespread moderate increased cancer risk among rubber workers. The most consistent results were for bladder, laryngeal, and lung cancer and for leukaemia. Excess risks were also found for other neoplasms but an evaluation of the consistency of the findings is difficult because of the possible selective reporting of results. Recent studies do not provide information associating specific exposures with cancer risk. The preventive measures taken in the rubber industry in recent years may decrease risks, but this has not been documented yet in epidemiological studies.   PMID:9536156

Application of mathematical planning in production of filled emulsion rubbers

NASA Astrophysics Data System (ADS)

Pugacheva, I. N.; Molokanova, L. V.; Popova, L. V.; Repin, P. S.

2018-05-01

The applicability of mathematical planning of experiment in the field of chemistry and chemical engineering, in particular in the industrial production of synthetic rubbers, is considered in the article. Possibility of using secondary material resources, which are waste products of light industry, in the production of elastomeric compositions is studied. The method of obtaining a powdered cellulose additive from wastes containing cellulose fiber is described. The best way of introducing the obtained additive into elastomeric compositions based on the emulsion rubber is established. Optimal conditions for obtaining filled emulsion rubber with the help of a powdered cellulose additive were established basing on the mathematical planning of experiment.

The design of an irradiator for the continuous processing of liquid latex

NASA Astrophysics Data System (ADS)

Reuter, O.; Langley, R.; Zn, Wan Manshol Bin W.

1998-06-01

This paper presents anew design concept for a gamma irradiation plant for the continuous processing of pumpable liquids. Typical applications of such a plant include ∗ the irradiation vulcanisation of natural latex rubber ∗ disinfection of municipal sewage sludge for agricultural use ∗ sterilisation of liquids in the pharmaceutical and cosmetics industries ∗ industrial processing of bulk liquids The authors describe the design and operation of the latex irradiator now operating on a small production scale in Malaysia and proposed developments. The design allows irradiation processing to be carried out under an inert or other gaseous environment. State-of-the-art computer control system ensures the fully automatic processing operation needed by industrial computers.

Recent achievements and research initiated in the Swedish plastics and rubber industry.

PubMed Central

Englund, A; Holmberg, B

1976-01-01

The improvement in exposure conditions in the Swedish vinyl chloride producing industry is reported. The article comments on the technology and control methods by which the vinyl chloride concentration has been lowered to less than 1 ppm vinyl chloride. Two epidemiological retrospective cohort studies are presently under way on workers in PVC-utilizing industries and in the rubber industry. Images FIGURE 1. FIGURE 2. FIGURE 3. PMID:1026411

40 CFR 60.540 - Applicability and designation of affected facilities.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Performance for the Rubber Tire Manufacturing Industry § 60.540 Applicability and designation of affected... each of the following affected facilities in rubber tire manufacturing plants that commence... cementing operation in rubber tire manufacturing plants that commenced construction, modification, or...

Thermoset recycling via high-pressure high-temperature sintering: Revisiting the effect of interchange chemistry

NASA Astrophysics Data System (ADS)

Morin, Jeremy Edward

In 1844 Charles Goodyear obtained U.S. Patent #3,633 for his "Gum Elastic Composition". In a published circular, which describes his patent for the sulfur vulcanization of gum elastic composition, he stated: "No degree of heat, without blaze, can melt it (rubber)... It resists the most powerful chemical reagents. Aquafortis (nitric acid), sulphuric acid, essential and common oils, turpentine and other solvents... ..." Goodyear's sulfur vulcanization of rubber fueled much of the industrial revolution and made transportation possible, as it exists today. In doing so, Goodyear created one of the most difficult materials to recycle. Rubber will not melt, dissolve, or lend itself to the usual methods of chemical decomposition. Ironically, Goodyear recognized this problem and in 1853 he patented the process of adding ground rubber to virgin material, now currently known as regrind blending. Today, scrap tires represent one of the most serious sources of pollution in the world. Studies estimate that there are roughly 2 billion scrap tires in U.S. landfills and more are being added at a rate of over 273 million tires per year. Current methods of recycling waste tires are crude, ineffective, and use rubber powder as a low cost filler instead of a new rubber. The groundwork for a very simple and effective method of producing high-quality rubber goods using 100% scrap rubber was discovered in 1944 by A. V. Tobolsky et al. This application, however, was not recognized until recently in our laboratory. The process as studied to date represents a method of creating quality, high-value added rubber goods with nothing other than heat and pressure. High pressure is required to obtain a void-free compaction of the rubber particles by forcing all of the free surfaces into intimate contact. High temperature then activates the chemical rearrangement, scission, and reformation of the chemical bonds thus providing new bridges between the once fractured interfaces. This occurs both within and between particles. The technique of high-pressure high-temperature sintering has worked on all types of thermoset materials. Typical mechanical properties for sintered SBR powder rubber are as follows: 1.3 MPa 100% Modulus, 12.0 MPa Tensile Strength and 300% Elongation at Break. The goal of this research is two-fold. First, to gain an understanding of the variables that control the process of high-pressure high-temperature sintering. Second, to study the factors governing the mechanism of fusion with the hope of controlling and exploiting this process so that tires can be recycled to produce high quality and high-value added products.

77 FR 38083 - Certain Rubber Resins and Processes for Manufacturing Same Institution of Investigation Pursuant...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-26

... by reason of misappropriation of trade secrets, the threat or effect of which is to destroy or... misappropriation of trade secrets, the threat or effect of which is to destroy or substantially injure an industry...

Rubber finger stripper harvester for green chile

USDA-ARS?s Scientific Manuscript database

Harvest mechanization as a system requires modifying or creating new components including cultivars, production practices, and harvest, transportation and processing plant machinery. New Mexican chile is one of the last segments of the pepper industry to still rely on hand labor. This paper reports ...

Supervision of Ethylene Propylene Diene M-Class (EPDM) Rubber Vulcanization and Recovery Processes Using Attenuated Total Reflection Fourier Transform Infrared (ATR FT-IR) Spectroscopy and Multivariate Analysis.

PubMed

Riba Ruiz, Jordi-Roger; Canals, Trini; Cantero, Rosa

2017-01-01

Ethylene propylene diene monomer (EPDM) rubber is widely used in a diverse type of applications, such as the automotive, industrial and construction sectors among others. Due to its appealing features, the consumption of vulcanized EPDM rubber is growing significantly. However, environmental issues are forcing the application of devulcanization processes to facilitate recovery, which has led rubber manufacturers to implement strict quality controls. Consequently, it is important to develop methods for supervising the vulcanizing and recovery processes of such products. This paper deals with the supervision process of EPDM compounds by means of Fourier transform mid-infrared (FT-IR) spectroscopy and suitable multivariate statistical methods. An expedited and nondestructive classification approach was applied to a sufficient number of EPDM samples with different applied processes, that is, with and without application of vulcanizing agents, vulcanized samples, and microwave treated samples. First the FT-IR spectra of the samples is acquired and next it is processed by applying suitable feature extraction methods, i.e., principal component analysis and canonical variate analysis to obtain the latent variables to be used for classifying test EPDM samples. Finally, the k nearest neighbor algorithm was used in the classification stage. Experimental results prove the accuracy of the proposed method and the potential of FT-IR spectroscopy in this area, since the classification accuracy can be as high as 100%.

Charcoal byproducts as potential styrene-butadiene rubber composte filler

USDA-ARS?s Scientific Manuscript database

Carbon black, a byproduct of the petroleum industry, is the world's most predominant filler for rubber composites. In this study, various renewable charcoals in the form of pyrolyzed agricultural byproducts were evaluted as potential carbon-based filler for rubber composites made with carboxylated s...

Evaluating Waste Charcoal as Potential Rubber Composite Filler

USDA-ARS?s Scientific Manuscript database

Carbon black, a byproduct of the petroleum industry, is the world's most predominant filler for rubber composites. In this study, charcoal in the form of pyrolyzed agricultural products was evaluated as potential carbon-based filler for rubber composites made with carboxylated styrene-butadiene lat...

Chrome-tanned leather shavings as a filler of butadiene-acrylonitrile rubber.

PubMed

Przepiórkowska, A; Chrońska, K; Zaborski, M

2007-03-06

The noxious wastes from the tanning industry such as chrome-tanned leather shavings were used as the only filler of rubber mixes containing carboxylated butadiene-acrylonitrile rubber (XNBR) or butadiene-acrylonitrile rubber (NBR), and a dispersing agent Limanol PEV (Schill & Seilacher). The best form addition of leather powder to the rubber mixes is mixed the waste protein with zinc oxide. The leather powder added to the rubber mixes improves the mechanical properties: tensile strength (T(s)), elongation at break (epsilon(b)) and increase the cross-linking density of carboxylated XNBR and NBR rubber mixes. Satisfactory results of these studies are presented in this work.

Occupational asthma induced by tall oil in the rubber tyre industry.

PubMed

Tarlo, S M

1992-01-01

A worker in the rubber tyre industry is described with occupational asthma from exposure to a solution of tall oil, a pine resin, confirmed by specific inhalation challenge. This supports studies of contact dermatitis which have suggested abietic and dehydroabietic acid oxidants to be the cause of colophony induced allergic reactions.

Occupational exposure to NDMA and NMor in the European rubber industry.

PubMed

de Vocht, F; Burstyn, I; Straif, K; Vermeulen, R; Jakobsson, K; Nichols, L; Peplonska, B; Taeger, D; Kromhout, H

2007-03-01

Many nitrosamines are suspected of being human carcinogens, with the highest concentrations in the environment being measured in the rubber industry. Time trends of personal exposure to N-nitrosodimethylamine (NDMA) and to N-nitrosomorpholine (NMor) during the past two decades in the German rubber industry were analysed and compared with cross-sectional studies in the same period in the Netherlands, Poland, the UK and Sweden. In the majority of the surveyed departments exposures reduced over time, but considerable heterogeneity was present between departments and sectors. Significant reductions were primarily found in curing and post-treating departments and ranged from -3% year(-1) to -19% year(-1). In contrast, NDMA levels increased (+13% year(-1)) in maintenance and engineering in the tyres industry. Average NDMA-levels in general rubber goods (GRG) and NMor-levels in tyre production in Germany did not decrease significantly in the past two decades, whereas NDMA-levels in tyre production (-10% year(-1)) and NMor-levels in GRG (-7% year(-1)) declined significantly after the introduction of an exposure limit for total nitrosamines in Germany in 1988. Confidence intervals of average exposures in other studied countries largely overlap trends observed in Germany. Exposure to N-nitrosamines decreased on average two-to-five fold in the German rubber industry with comparable concentration levels in other European countries. Although average levels are well below the current limits exposure has not been eliminated, and incidental high exposures do still occur.

A study of amino acid modifiers in guayule natural rubber

USDA-ARS?s Scientific Manuscript database

Natural rubber from the Hevea tree is a critical agricultural material vital to United States industry, medicine, and defense, yet the country is dependent on imports to meet domestic needs. Guayule, a desert shrub indigenous to the US, is under development as an alternative source of natural rubber...

A study of protein and amino acids in guayule natural rubber

USDA-ARS?s Scientific Manuscript database

Natural rubber (NR) from Hevea brasiliensis (the Hevea rubber tree) is a critical agricultural material vital to United States industry, medicine, and defense, yet the country is dependent on NR imports to meet domestic needs. Parthenium argentatum (guayule), a woody desert shrub indigenous to the U...

75 FR 68394 - Small Business Size Standards: Waiver of the Nonmanufacturer Rule

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-05

... Woven and Knit impregnated with Flat Dipped Rubber/Plastic Gloves. SUMMARY: The U. S. Small Business... Flat Dipped Rubber/Plastic Gloves, under North American Industry Classification System (NAICS) code... Rule for Woven and Knit impregnated with Flat Dipped Rubber/Plastic Gloves under PSC 9999...

Techno-economic analysis of guayule (parthenium argentatum) pyrolysis biorefining: production of biofuels from guayule bagasse via tail-gas reactive pyrolysis

USDA-ARS?s Scientific Manuscript database

The tire industry is currently considering natural rubber from guayule (Parthenium argentatum Gray) as a viable alternative to imported Hevea natural rubber, or petroleum-based synthetics, to meet expanding materials needs of the industry, however, only 5-10% of the harvested guayule plant is conver...

Reduced Order Models for Dynamic Behavior of Elastomer Damping Devices

NASA Astrophysics Data System (ADS)

Morin, B.; Legay, A.; Deü, J.-F.

2016-09-01

In the context of passive damping, various mechanical systems from the space industry use elastomer components (shock absorbers, silent blocks, flexible joints...). The material of these devices has frequency, temperature and amplitude dependent characteristics. The associated numerical models, using viscoelastic and hyperelastic constitutive behaviour, may become computationally too expensive during a design process. The aim of this work is to propose efficient reduced viscoelastic models of rubber devices. The first step is to choose an accurate material model that represent the viscoelasticity. The second step is to reduce the rubber device finite element model to a super-element that keeps the frequency dependence. This reduced model is first built by taking into account the fact that the device's interfaces are much more rigid than the rubber core. To make use of this difference, kinematical constraints enforce the rigid body motion of these interfaces reducing the rubber device model to twelve dofs only on the interfaces (three rotations and three translations per face). Then, the superelement is built by using a component mode synthesis method. As an application, the dynamic behavior of a structure supported by four hourglass shaped rubber devices under harmonic loads is analysed to show the efficiency of the proposed approach.

Characterization of some selected vulcanized and raw silicon rubber materials

NASA Astrophysics Data System (ADS)

Sasikala, A.; Kala, A.

2017-06-01

Silicone Rubber is a high need of importance of Medical devices, Implants, Aviation and Aerospace wiring applications. Silicone rubbers are widely used in industry, and there are in multiple formulations. A raw and vulcanized silicone rubber Chemical and Physical structures of particles was confirmed and mechanical strength has been analyzed by FTIR spectroscopy. Thermal properties studied from Thermo Gravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC) analysis. Activation energy of the rubber materials were calculated using Broido method, Piloyon-Novikova relation and coats-Red fern methods.

THERMOOXIDATIVE STUDY OF RAW NATURAL RUBBER FROM BRAZILIAN IAC 300 SERIES CLONES

USDA-ARS?s Scientific Manuscript database

The improvement of rubber tree species is of key importance due to the worldwide market demand of this renewable material essential for several types of industries. The thermal performance of natural rubber produced from new clones of IAC 300 series, and the Malaysian RRIM 600 clone (used as control...

Degradation of blending vulcanized natural rubber and nitril rubber (NR/NBR) by dimethyl ether through variation of elastomer ratio

NASA Astrophysics Data System (ADS)

Saputra, A. H.; Juneva, S.; Sari, T. I.; Cifriadi, A.

2018-04-01

Dimethyl ether can cause degradation of the rubber material seal in some applications. In order to use of natural rubber in industry, research about a blending of natural rubber (NR) and nitrile rubber (NBR) to produce rubber to meet the standard seal material application were conducted. This study will observe the degradation mechanisms that occur in the blending natural rubber and nitrile rubber (NR/NBR) by dimethyl ether. Nitrile rubber types used in this study is medium quality nitrile rubber with 33% of acrylonitrile content (NBR33). The observed parameters are percent change in mass, mechanical properties and surface morphology. This study is limited to see the effect of variation vulcanized blending ratio (NR/NBR33) against to swelling. The increase of nitrile rubber (NBR33) ratio of blending rubber vulcanized can reduce the tensile strength and elongation. The best elastomer variation was obtained after comparing with the standard feasibility material of seal is rubber vulcanized blending (NR/NBR33) with ratio 40:60 NR: NBR.

Interpretive Structural Model of Key Performance Indicators for Sustainable Maintenance Evaluatian in Rubber Industry

NASA Astrophysics Data System (ADS)

Amrina, E.; Yulianto, A.

2018-03-01

Sustainable maintenance is a new challenge for manufacturing companies to realize sustainable development. In this paper, an interpretive structural model is developed to evaluate sustainable maintenance in the rubber industry. The initial key performance indicators (KPIs) is identified and derived from literature and then validated by academic and industry experts. As a result, three factors of economic, social, and environmental dividing into a total of thirteen indicators are proposed as the KPIs for sustainable maintenance evaluation in rubber industry. Interpretive structural modeling (ISM) methodology is applied to develop a network structure model of the KPIs consisting of three levels. The results show the economic factor is regarded as the basic factor, the social factor as the intermediate factor, while the environmental factor indicated to be the leading factor. Two indicators of social factor i.e. labor relationship, and training and education have both high driver and dependence power, thus categorized as the unstable indicators which need further attention. All the indicators of environmental factor and one indicator of social factor are indicated as the most influencing indicator. The interpretive structural model hoped can aid the rubber companies in evaluating sustainable maintenance performance.

Industrial-hygiene walk-through survey report of Copolymer Rubber and Chemical Corporation, Baton Rouge, Louisiana. Industrywide study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Roberts, D.R.; Krishnan, E.R.

1986-06-01

A walk through survey was conducted at the Copolymer Rubber and Chemical Corporation, Baton Rouge, Louisiana. The facility produces 465 million pounds of styrene butadiene rubber (SBR) and 15 million pounds of nitrile butadiene rubber (NBR) annually, requiring 120 million pounds of 1,3-butadiene. Of 470 employees, 143 were directly involved in reaction, recovery, and finishing operations, and were potentially exposed to 1,3-butadiene 8 hours per day.

SUSTAINABILITY OF NATURAL RUBBER-PRODUCING CROPS IN THE UNITED STATES: APPLIED BIOTECHNOLOGY LESSONS 2000-2010

USDA-ARS?s Scientific Manuscript database

Natural rubber (NR) is a critical and strategic raw material for industrial manufacturing and national defense. Development of a US-based supply of NR is recognized in the Critical Agricultural Materials Act, Public Law 95–592. Domestic rubber-producing crops have been introduced in the US during ti...

Identification of a 3-hydroxy-3-methylglutaryl-CoA reductase gene highly expressed in the root tissue of Taraxacum kok-saghyz

USDA-ARS?s Scientific Manuscript database

Kazak dandelion (Taraxacum kok-saghyz, Tk) is a rubber-producing plant currently being investigated as a source of natural rubber for industrial applications. Like many other isoprenoids, rubber is a downstream product of the mevalonate pathway. The 3-hydroxy-3-methylglutaryl-CoA reductase (HMGR) en...

Identification of an exposure risk to heavy metals from pharmaceutical-grade rubber stoppers.

PubMed

Li, Xianghui; Qian, Pingping

2017-07-01

Exposure to low concentrations of heavy metals and metalloids represents a well-documented risk to animal and human health. However, current standards (European Pharmacopeia [EP], United States Pharmacopoeia [USP], International Organization for Standardization [ISO], YBB concerned with rubber closures) only require testing for Zn in pharmaceutical-grade rubber stoppers and then using only pure water as a solvent. We extracted and quantified heavy metals and trace elements from pharmaceutical-grade rubber stoppers under conditions that might occur during the preparation of drugs. Pure water, saline, 10% glucose, 3% acetic acid (w/v), 0.1 mol/L hydrochloric acid, and diethylenetriaminepentaacetic acid (4 mg/mL, 0.4 mg/mL, and 0.04 mg/mL) were used as extraction agents. We quantified the extracted arsenic, lead, antimony, iron, magnesium, aluminum, and zinc using inductively coupled plasma mass spectrometry. The concentration of extracted metals varied depending on the different extraction solutions used and between the different rubber stopper manufacturers. Rubber stoppers are ubiquitously used in the pharmaceutical industry for the storage and preparation of drugs. Extraction of heavy metals during the manufacturing and preparation of drugs represents a significant risk, suggesting a need for industry standards to focus on heavy metal migration from rubber stoppers. Copyright © 2016. Published by Elsevier B.V.

Durability of Fly Ash Based Geopolymer Concrete Infilled with Rubber Crumb in Seawater Exposure

NASA Astrophysics Data System (ADS)

Yahya, Z.; Abdullah, M. M. A. B.; Ramli, S. N. H.; Minciuna, M. G.; Razak, R. Abd

2018-06-01

Geopolymer is an alternative binder to replace Ordinary Portland Cement (OPC)in construction industry. Source materials that rich in silica (Si) and alumina (Al) were activated by using alkaline solution. Production of tires keep increasing every year and due to its non-biodegradable properties it causes problems for disposal process. In current scenario, waste materials should be used or recycled so that the existing natural resources can be saved and at the same times it can protected environment. In this paper, the effect of rubber crumb on fly ash based geopolymer concrete have been investigated by immersing the samples in seawater for 28 and 60 days. The rubber crumb was used to replace coarse aggregates from range 5% until 20%. The ratio of fly ash/alkaline activator and sodium silicate/sodium hydroxide(NaOH) ratio were fixed at 2.0 and 2.5. It has been shown that the compressive strength decreased when the content of rubber crumb increased. The highest compressive strength (39.6 MPa) was obtained at 5% replacement of rubber crumb when exposure to seawater for 28 days. The density of geopolymer samples also increased when immersed in seawater for all samples. The lack of bonding between rubber crumb and geoplymer paste cause increasing in porosity hence reduced the strength, increment in density and changes in weight of geopolymer samples.

Industrywide studies report of an in-depth survey at Copolymer Rubber and Chemical Corporation, Baton Rouge, Louisiana

DOE Office of Scientific and Technical Information (OSTI.GOV)

Krishnan, E.R.; Fajen, J.M.

1987-05-08

An in depth industrial hygiene survey was conducted at the Copolymer Rubber and Chemical Corporation located in Baton Rouge, Louisiana. The facility produced styrene-butadiene rubber and nitrile-butadiene rubber by continuous emulsion polymerization. The ultimate use of this product was for the manufacture of tire and rubber products. The authors recommend that leaking pumps which can present a potential for 1,3-butadiene exposure in the tank farm and recovery areas should be controlled through the use of dual mechanical seals. Employees assigned to maintenance tasks should use respirators with organic vapor cartridges.

Functional analysis of a regulator of G-protein signaling CgRGS1 in the rubber tree anthracnose fungus Colletotrichum gloeosporioides.

PubMed

Liu, Zhi-Qiang; Wu, Man-Li; Ke, Zhi-Jian; Liu, Wen-Bo; Li, Xiao-Yu

2018-04-01

Colletotrichum gloeosporioides is the causal agent of rubber anthracnose, which is also one of the important biological factors threatening the development of natural rubber industry in the world. Regulators of G-protein signaling (RGS) are key negative regulators of G-proteins, which play important roles in growth, development and pathogenic processes of plant pathogens. In this study, a RGS gene CgRGS1 was functionally characterized in C. gloeosporioides. Compared to the wild type, the CgRGS1 deletion mutant had slow vegetative growth, reduced conidia with multi-end germination, low appressorium formation rate, high resistance to oxidative stress and SDS. Moreover, the mutant was sensitive to osmotic pressure and showed decreased virulence. In conclusion, CgRGS1 is involved in regulation of vegetative growth, conidiation, germination, appressorium formation, oxidative stress, osmotic pressure response and pathogenicity in C. gloeosporioides.

On-demand tuned hazard free elastomeric composites: A green approach.

PubMed

Manoharan, Partheban; Chandra Das, Narayan; Naskar, Kinsuk

2017-07-01

Rising ecological concerns and depletion of the potentially harmful environmental impacts caused by rubber products, are of prime importance in the industry. Therefore, implementation of sustainable greener materials is required to minimize the detrimental influences. In this research, we investigated the beneficial influence of naturally derived bio-resin toward the effects of association with Zinc Oxide Nanoparticles in highly dispersible silica (HDS) reinforced Natural rubber (NR)/Epoxidized Natural Rubber (ENR)-based composites. This novel green composite offers impressive properties which were analyzed based on bound rubber content, transmission electron microscopy, physico-mechanical, dynamic mechanical, and cure characteristics. Nanoindentation studies demonstrated the enhanced hysteresis phenomenon of the green composites. The small angle X-ray scattering (SAXS) characterization has been studied by using a Beaucage model and results corroborates that the insertion of bio-resin exhibits ameliorated state of silica dispersion in the green composites. Overall, the study with the bio-resin has provided the impetus in employing it as an alternative to the expensive synthetic route of silane coupling agent and toxic process oil. © 2017 Wiley Periodicals, Inc.

Energy conservation: Industry. Citations from the NITS data base

NASA Astrophysics Data System (ADS)

Hundemann, A. S.

1980-07-01

The 335 citations, 37 of which are new entries, discuss potential methods of conserving energy. Many abstracts deal with reports that also cover processes used, amount of energy consumed, and environmental considerations of energy conserving options. Industries covered include food, paper, chemical, cement, metals, petroleum refining, contract construction, synthetic rubber, plastics, drug manufacturing, and stone, clay, and glass. Energy conservation through the use of waste heat is covered in a related Published Search entitled Waste Heat Utilization.

Securing the future of natural rubber – an American tire and bio-energy platform from guayule

USDA-ARS?s Scientific Manuscript database

There is a high level of interest in alternative sources of natural rubber for the tire industry due to both the price and supply volatility of Hevea brasiliensis. The guayule plant (Parthenium argentatum) has served as a major source of domestic natural rubber in the early 20th century and is being...

Design and thermal analysis of a mold used in the injection of elastomers

NASA Astrophysics Data System (ADS)

Fekiri, Nasser; Canto, Cécile; Madec, Yannick; Mousseau, Pierre; Plot, Christophe; Sarda, Alain

2017-10-01

In the process of injection molding of elastomers, improving the energy efficiency of the tools is a current challenge for industry in terms of energy consumption, productivity and product quality. In the rubber industry, 20% of the energy consumed by capital goods comes from heating processes; more than 50% of heat losses are linked to insufficient control and thermal insulation of Molds. The design of the tooling evolves in particular towards the reduction of the heated mass and the thermal insulation of the molds. In this paper, we present a complex tool composed, on one hand, of a multi-cavity mold designed by reducing the heated mass and equipped with independent control zones placed closest to each molding cavity and, on the other hand, of a regulated channel block (RCB) which makes it possible to limit the waste of rubber during the injection. The originality of this tool lies in thermally isolating the regulated channel block from the mold and the cavities between them in order to better control the temperature field in the material which is transformed. We present the design and the instrumentation of the experimental set-up. Experimental measurements allow us to understand the thermal of the tool and to show the thermal heterogeneities on the surface of the mold and in the various cavities. Tests of injection molding of the rubber and a thermal balance on the energy consumption of the tool are carried out.

Historical and Recent Achievements in the Field of Microbial Degradation of Natural and Synthetic Rubber

PubMed Central

Yikmis, Meral

2012-01-01

This review intends to provide an overview of historical and recent achievements in studies of microbial degradation of natural and synthetic rubber. The main scientific focus is on the key enzymes latex-clearing protein (Lcp) from the Gram-positive Streptomyces sp. strain K30 and rubber oxygenase A (RoxA) from the Gram-negative Xanthomonas sp. strain 35Y, which has been hitherto the only known rubber-degrading bacterium that does not belong to the actinomycetes. We also emphasize the importance of knowledge of biodegradation in industrial and environmental biotechnology for waste natural rubber disposal. PMID:22504822

Dynamic mechanical analysis of waste tyre rubber filled brake friction composite materials

NASA Astrophysics Data System (ADS)

Rathi, Mukesh Kumar; Singh, Tej; Chauhan, Ranchan

2018-05-01

In this research work, the dynamic mechanical properties of waste tyre rubber filled friction composites were studied. Four friction composites with varying amount of waste rubber (0, 4, 8, 12 wt.%) and barium sulphate (38, 42, 46, 50 wt.%) were designed and fabricated as per industrial norms. Dynamic mechanical analysis has been carried out to characterize the storage modulus, loss modulus and damping factor of the fabricated friction composite. Experimental results indicated that storage modulus decreases with increasing waste rubber content up to particular loading (4 wt.%), and after that it increases with further loading. The loss modulus of the composites increases steadily with increasing waste rubber content whereas, damping factor remain maximum for 12 wt.% waste rubber filled friction composites.

40 CFR 63.494 - Back-end process provisions-residual organic HAP and emission limitations.

Code of Federal Regulations, 2013 CFR

2013-07-01

... produced by the emulsion process, polybutadiene rubber and styrene butadiene rubber produced by the... styrene butadiene rubber produced by the emulsion process: (i) A monthly weighted average of 0.40 kg... than a solution or emulsion process, polybutadiene rubber produced by any process other than a solution...

A survey of occupational cancer in the rubber and cablemaking industries: results of five-year analysis, 1967-71

PubMed Central

Fox, A. J.; Lindars, D. C.; Owen, R.

1974-01-01

Fox, A. J., Lindars, D. C., and Owen, R. (1974).British Journal of Industrial Medicine,31, 140-151. A survey of occupational cancer in the rubber and cablemaking industries: results of five-year analysis, 1967-71. A mortality study of 40 867 subjects employed in the rubber and cablemaking industries on 1 February 1967 is reported. No evidence is found of a continued excess risk of neoplasms of the bladder in people who entered the industry after 1949. For those employed before that date, during the period when known bladder carcinogens were in use, the SMR is higher than predicted, indicating that men are still dying with occupationally induced tumours. An excess of all neoplasms was noted in the five years of the study. In certain sections of the industry (tyre manufacture, belting hose rubber with asbestos, and flooring industry) there is a particular excess of bronchial carcinoma. In those sections which use asbestos such an excess is not altogether surprising, but this does not apply to the tyre industry. The latter industry is sufficiently large (16 035 men in the study compared with 4 350 in the belting, hose rubber with asbestos, and flooring industry) for attention to be focused on particular operations. Two job groups are found to share the excess: moulding, press, autoclave, and pan curemen; and finished goods, packaging, and despatch. Job selection may play a part in the latter, as the work is generally considered suitable for older and perhaps less healthy people. Crude analyses have been undertaken to indicate whether the excesses are due to regional differences or to the population comprising an abnormally high proportion of smokers. No excesses are found in other smoking-related diseases. Although the effects of differences in smoking habit and regional differences cannot be ruled out, the indications are against these factors being the primary cause. The difficulties of this type of study are discussed. It is emphasized that the results can be used only as an indication of a problem area and the type of further study required. A more exact study would concentrate on five-year cohorts of people who left the industry between 1940 and 1960. A study of five-year cohorts of people who entered the industry in the same period would also be valuable. An attempt has been made to perform the latter, but it would be hazardous to draw too many conclusions from this because the population comprises those who `survive' in the industry until 1967. PMID:4830765

A Method for Calculating Industrial Mobilization Requirements Which Incorporates Production Process Times. Volume I. Main Report.

DTIC Science & Technology

1982-10-01

Synthetic Rubber .000019 234 67.0000 Radio/Television 13 9 00100 3Broadcasts 000000 8.0400.000050 Electric Utilities .007801 175 29.0000 brugs/ Cleaning ... Products .000588 236 68.0200 Gas Utilities .101653 176 30.0000 Paints .000008 237 68.0330 Water ltilities .000581 177 31.0100 Petroleum Oefinenies

Chemicals used in the rubber industry. An overview.

PubMed

Fishbein, L

1983-01-01

Hundreds of chemicals illustrative of many structural and use categories are employed in the rubber industry. The present overview has centered on the structural features of a number of compounds representative of several select use categories, eg, vulcanizing agents, accelerators, antioxidants, antiozonants, and blowing agents, with focus on the nature of their impurities, their chemical degradation, and by-products, as well as on those chemicals that can be converted to N-nitrosamines.

Nonaqueous ozonation of vulcanized rubber

DOEpatents

Serkiz, Steven M.

1999-01-01

A process and resulting product is provided in which a solid particulate, such as vulcanized crumb rubber, has the surface functional groups oxidized by ozonation using a nonpolar solvent. The ozonation process renders the treated crumb rubber more suitable for use in new rubber formulations. As a result, larger loading levels of the treated crumb rubber can be used in new rubber mixtures.

Experimental and Numerical Characterization of Polymer Nanocomposites for Solid Rocket Motor Internal Insulation

DTIC Science & Technology

2009-09-30

combustion chamber. Kevlar®-filled ethylene-propylene-diene rubber ( EPDM ) is the baseline insulation material for solid rocket motor cases. A novel...filled EPDM is the industry standard for this application. Since the elastic modulus of rubbers is low, they also act as absorbers during...Santoprene® thermoplastic rubber is already demonstrating their performance capability to replace EPDM in automotive weather seal applications [18]. An

Cancer mortality in cohorts of workers in the European rubber manufacturing industry first employed since 1975.

PubMed

Boniol, M; Koechlin, A; Świątkowska, B; Sorahan, T; Wellmann, J; Taeger, D; Jakobsson, K; Pira, E; Boffetta, P; La Vecchia, C; Pizot, C; Boyle, P

2016-05-01

Increased cancer risk has been reported among workers in the rubber manufacturing industry employed before the 1960s. It is unclear whether risk remains increased among workers hired subsequently. The present study focused on risk of cancer mortality for rubber workers first employed since 1975 in 64 factories. Anonymized data from cohorts of rubber workers employed for at least 1 year from Germany, Italy, Poland, Sweden, and the UK were pooled. Standardized mortality ratios (SMRs), based on country-specific death rates, were reported for bladder and lung cancer (primary outcomes of interest), for other selected cancer sites, and for cancer sites with a minimum of 10 deaths in men or women. Analyses stratified by type of industry, period, and duration of employment were carried out. A total of 38 457 individuals (29 768 men; 8689 women) contributed to 949 370 person-years. No increased risk of bladder cancer was observed [SMR = 0.80, 95% confidence interval (CI) 0.46; 1.38]. The risk of lung cancer death was reduced (SMR = 0.81, 95% CI 0.70; 0.94). No statistically significant increased risk was observed for any other cause of death. A reduced risk was evident for total cancer mortality (SMR = 0.81, 95% CI 0.76; 0.87). Risks were lower for workers in the tyre industry compared with workers in the general rubber goods sector. Analysis by employment duration showed a negative trend with SMRs decreasing with increasing duration of employment. In an analysis of secondary end points, when stratified by type of industry and period of first employment, excess risks of myeloma and gastric cancer were observed each due, essentially, to results from one centre. No consistent increased risk of cancer death was observed among rubber workers first employed since 1975, no overall analysis of the pooled cohort produced significantly increased risk. Continued surveillance of the present cohorts is required to confirm the absence of long-term risk. © The Author 2016. Published by Oxford University Press on behalf of the European Society for Medical Oncology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Water requirements of the carbon-black industry

USGS Publications Warehouse

Conklin, Howard L.

1956-01-01

Carbon blacks include an important group of industrial carbons used chiefly as a reinforcing agent in rubber tires. In 1953 more than 1,610 million pounds of carbon black was produced, of which approximately 1,134 million pounds was consumed by the rubber industry. The carbon-black industry uses small quantities of water as compared to some industries; however, the water requirements of the industry are important because of the dependence of the rubber-tire industry on carbon black.Two methods are used in the manufacture of carbon black - contact and furnace. The only process use of water in the contact method is that used in pelleting. Water is used also in the plant washhouse and for cleaning, and sometimes the company camp may be supplied by the plant. A survey made during the last quarter of 1953 showed that the average values of unit water use at contact plants for process use, all plant uses, and all uses including company camps are 0.08, 0.14, and 0.98 gallon of water per pound of carbon black respectively.In addition to use in wet pelleting, large quantities of water are required in continuous and cyclic furnace methods to reduce the temperature of the gases of decomposition in order to separate and collect the entrained carbon black. The 22 furnace plants in operation in 1953 used a total of 12.4 million gallons per day for process use. Four furnace plants generate electric power for plant use; condenser-cooling water for one such plant may nearly equal the requirements of the entire industry for process use. The average values of unit water use at furnace plants for process use, all plant uses and all uses including company camps but excluding power generation are 3.26, 3.34, and 3.45 gallons of water per pound of carbon black respectively.Carbon-black plants in remote, sparsely settled areas often must maintain company camps for employees. Twenty-one of twenty-seven contact plants surveyed in 1953 had company camps. These camps used large quantities of water: 0.84 gallon per pound of carbon black as compared to 0.14 gallon per pound used in the plants.Furnace plants can generally be located near a labor supply and, therefore, do not require company camps. Ten of the twenty-two furnace plants surveyed in 1953 had company camps.Because water used for pelleting and gas quenching is evaporated, leaving the dissolved minerals in the product as objectionable impurities, particular attention was paid to the quality of water available for use at the plants visited during the 1953 survey. Reports of chemical analyses of water samples were obtained at 23 plants. A study of these reports does not develop a pattern of the limits of tolerance of dissolved solids in water used in process or of the need for water treatment based on geographical location of the plant. However these analyses show that water used for quenching contains less dissolved solids than water used by the industry for any other purpose.Based on trends in the industry it is expected that the quantity of water used by the carbon-black industry will increase more rapidly than will the quantity of carbon black produced because of the increasing percentage produced in furnace plants, and that selection of sites for modern furnace plants will be influenced more by quantity and quality of the available water supply than was the case in selecting sites for contact plants for which low-cost natural gas was the primary consideration.

Study on cord/rubber interface at elevated temperatures by H-pull test method

NASA Astrophysics Data System (ADS)

Jamshidi, M.; Afshar, F.; Mohammadi, N.; Pourmahdian, S.

2005-08-01

Cords are used as reinforcing materials in rubber compounds. To increase cord/rubber interfacial adhesion, they are coated by an adhesive (usually based on resorcinol-formaldehyde-latex). These composites are used in many sectors such as tire and belt industries. Cord/rubber adhesion strength is an important aspect to determine the durability of system. Due to temperature increase during running tires, the adhesion energy becomes different from initial one. To study cord/rubber interface at elevated temperatures, H-adhesion test method was used. H-pull test is a simple method for adhesion evaluation at ambient temperature, so it is usually used for material quality control. In this research, cord/rubber systems were vulcanized at different temperatures and H-adhesion of samples were evaluated at elevated temperatures. Also cord/rubber interface was studied by ATR analyze to determine interfacial interactions kind.

Electricity remains a serious workplace hazard.

PubMed

Proctor, Laura; Kuchibotla, Srin

2013-08-01

Anyone who works in an industrial environment or is employed in the utility, mass transit, industrial goods manufacturing, or telecommunications industry - as well as many others - may be at risk for electrocution. Electric shock costs workers' lives and results in painful and debilitating injuries every year. Lockout/tagout procedures protect against electrocution, as do rubber insulating gloves, which must be worn any time workers are exposed to energized parts operating at 50 volts or higher. Some newer styles of rubber insulating gloves not only protect against electric shock, but also offer the dexterity and flexibility workers need for hours of comfortable wear.

Comprehensive evaluation of the long-term performance of rubberized pavement, phase I : laboratory study of rubberized asphalt mix performance.

DOT National Transportation Integrated Search

2012-12-01

Crumb rubber, made from scrap tires, has been introduced into the production of different types of hot : mix asphalt (HMA) in either a wet or dry process. In the wet process, the crumb rubber and binder are : completely mixed to form asphalt rubber (...

Test and Evaluation for Chemical Resistance of Gloves Worn for Protection against Exposure to H-70 Hydrazine.

DTIC Science & Technology

1980-07-01

Edmont-Wilson 37-165 NBR .056 (22) 10 J Edmont-Wilson 26-665 Rubber .046 (18) 10 K Edmont-Wilson 36-755 Rubber .102 (40) 10 L Surety 10-112L Nitrile...4367 Dickenson & Company Charleston SC 29405 Coshocton OH 43812 International Playtex Company Surety Rubber Company Industrial Gloves Division P.O. Box...B Pioneer A-10 Nitrile .025 (10) 9 C Pioneer A-15 Nitrile .038 (15) 9 D Norton NSN 8415-00-753-6551 Butyl rubber .076 (30) M E Norton NSN 8415-01-025

Influence of different functionalization on mechanical and interface behavior of MWCNTs/NBR sealing composites

NASA Astrophysics Data System (ADS)

Li, Kun; Gu, Boqin

2017-04-01

Rubber sealants are key components in processing industries. Carbon nanotubes (CNTs), which are randomly dispersed in polymer, are able to generate exciting effects. Focusing on mechanical properties of composites and interface characteristic between the fillers and matrix, carrying out SEM, DMA and uniaxial tensile tests, the tensile strength of the composites with 4 phr (parts by weight per hundred parts of rubber) multiwalled carbon nanotubes (MWNTs) is obviously improved. MWNTs with different functionalization have different influence on the viscoelastic and mechanical properties of the composites. Results indicate that MWNTs-COOH are broken when composites fractured. While MWNTs, MWNTs-OH and MWNTs-NH2 are pulled out from the matrix because interface debonds under the tensile failure. The interfacial shear stress (IFSS) is about 4.7 MPa in composites. The glass transition temperature (T g) shifts higher temperatures compared to pure NBR (Acrylonitrile-butadiene Rubber). The presence of the nanotubes limite the movement of NBR macromolecules.

Comparative numerical study on the optimal vulcanization of rubber compounds through traditional curing and microwaves

NASA Astrophysics Data System (ADS)

Milani, Gabriele; Milani, Federico

2012-12-01

The main problem in the industrial production process of thick EPM/EPDM elements is constituted by the different temperatures which undergo internal (cooler) and external regions. Indeed, while internal layers remain essentially under-vulcanized, external coating is always over-vulcanized, resulting in an overall average tensile strength insufficient to permit the utilization of the items in several applications where it is required a certain level of performance. Possible ways to improve rubber output mechanical properties include a careful calibration of exposition time and curing temperature in traditional heating or a vulcanization through innovative techniques, such as microwaves. In the present paper, a comprehensive numerical model able to give predictions on the optimized final mechanical properties of vulcanized 2D and 3D thick rubber items is presented and applied to a meaningful example of engineering interest. A detailed comparative numerical study is finally presented in order to establish pros and cons of traditional vulcanization vs microwaves curing.

40 CFR 63.494 - Back-end process provisions-residual organic HAP limitations.

Code of Federal Regulations, 2010 CFR

2010-07-01

... technology or control or recovery devices. (1) For styrene butadiene rubber produced by the emulsion process... rubber produced by any process other than a solution or emulsion process, polybutadiene rubber produced...

Environmental exposure to preformed nitroso compounds.

PubMed

Tricker, A R; Spiegelhalder, B; Preussmann, R

1989-01-01

In the human environment, nitrosatable amine precursors to N-nitroso compounds and nitrosating species such as nitrite and oxides of nitrogen are abundant. As a result, the formation of N-nitroso compounds and human exposure to these compounds show a rather complex pattern. The largest known human exposures to exogenous N-nitrosamines occur in the work place. This is particularly evident in the rubber and tyre manufacturing industry and in metal cutting and grinding shops. Nearly all industries which are concerned with the production and/or use of amines have a related nitrosamine problem. Outside the industrial environment, commodities such as cosmetics, pharmaceuticals, rubber and household products, which are either prepared from amines or contain high concentrations of amino compounds, may be subject to contamination by low concentrations of N-nitroso compounds. This contamination may result from the use of contaminated starting materials, in particular amines, or from the formation of N-nitroso compounds during manufacturing processes. A similar problem exists with agricultural chemicals. As our knowledge of the occurrence and formation of N-nitroso compounds in the environment increases, preventive measures can be introduced, particularly in manufacturing industries, to reduce the levels of human exposure to nitrosamines in the work place and to protect the consumer from nitrosamine exposure from household commodities.

Feasibility study on the utilization of rubber latex effluent for producing bacterial biopolymers.

PubMed

Tang, S N; Fakhru'l-Razi, A; Hassan, M A; Karim, M I

1999-01-01

Rubber latex effluent is a polluting source that has a high biochemical oxygen demand (BOD). It is estimated that about 100 million liters of effluent are discharged daily from rubber processing factories. Utilization of this effluent such as the use of a coupled system not only can reduce the cost of treatment but also yield a fermentation feedstock for the production of bioplastic. This study initially was carried out to increase the production of organic acids by anaerobic treatment of rubber latex effluent. It was found that through anaerobic treatment the concentration of organic acids did not increase. Consequently, separation of organic acids from rubber latex effluent by anion exchange resin was examined as a preliminary study of recovering acetic and propionic acids. However, the suspended solids (SS) content in the raw effluent was rather high which partially blocked the ion-exchange columns. Lime was used to remove the SS in the rubber latex effluent. After the lime precipitation process, organic acids were found to adsorb strongly onto the anion exchange resin. Less adsorption of organic acids onto the resin was observed before the lime precipitation. This was probably due to more sites being occupied by colloidal particles on the resin thus inhibiting the adsorption of organic acids. The initial concentration of organic acids in the raw effluent was 3.9 g/L. After ion exchange, the concentration of the organic acids increased to 27 g/L, which could be utilized for production of polyhydroxyalkanoates (PHA). For PHA accumulation stage, concentrated rubber latex effluent obtained from ion exchange resins and synthetic acetic acid were used as the carbon source. Quantitative analyses from fed batch culture via HPLC showed that the accumulation of PHA in Alcaligenes eutrophus was maximum with a concentration of 1.182 g/L when cultivated on synthetic acetic acid, corresponding to a yield of 87% based on its cell dry weight. The dry cell weight increased from 0.71 to 1.67 g/L. On the other hand, using concentrated rubber latex effluent containing acetic and propionic acids resulted in reduced PHA content by dry weight (14%) but the dry cell weight increased from 0.49 to 1.30 g/L. The results clearly indicated that the cells grow well in rubber latex effluent but no PHA was accumulated. This could be due to the high concentration of propionic acid in culture broth or other factors such as heavy metals. Thus further work is required before rubber latex effluent can be utilized as a substrate for PHA production industrially.

[Carcinogenic N-nitrosamines in the tire industry].

PubMed

Sokol?kaia, N N; Krivosheeva, L V; Khesing, A Ia; Piven, V A; Kavun, S M

1993-01-01

The level of volatile carcinogenic N-nitrosamines (NA) was studied in the air of various technological sites of tyre production. Reported total levels of NA in air exceeded MACs set in certain countries for the same enterprises. For example, German total MAC for 12 carcinogenic NA is 1 g/m3. N-nitrosomorpholine appeared to have the highest level (91 g/m3), probably, because its derivatives are used as raw material for technological process. Relative rate of volatile NA release from rubber samples containing 4-nitrosodiphenylamine (modifier) was studied. The parameter was reported to have no influence on NA outlet in conditions simulating technological process. NA was detected by means of gas chromatography with thermal energy detector TEA 502A provided by Thermo Electron Corporation, USA. The article necessitates regulation of NA in tyre production and better rubber mixtures to control the pollution of atmosphere.

Industrial waste treatment and application in rubber production

NASA Astrophysics Data System (ADS)

Pugacheva, I. N.; Popova, L. V.; Repin, P. S.; Molokanova, L. V.

2018-03-01

The paper provides for the relevance of various industrial waste treatment and application, as well as their secondary commercialization. It considers treatment of secondary polymer materials turning to additives applied in rubber production, in particular, in production of conveyor and V-type belts used in mechanical engineering. It is found that oligomers obtained from petroleum by-products can be used as an impregnating compound for fiber materials. Such adhesive treatment prior to introduction of impregnating compounds into elastomeric materials improves adhesion and complements performance of obtained composites.

Studies of the latex of Brazilian IAC series clones from Hevea brasiliensis

USDA-ARS?s Scientific Manuscript database

Natural rubber is an important commodity industrial crop that mainly derives from Hevea brasiliensis. Most natural rubber production is in Southeast Asia, but significant cultivar development takes place in Brazil, the original origin of current commercial H. brasiliensis cultivars. Thus it is criti...

Coal Producer's Rubber Waste Processing Development

NASA Astrophysics Data System (ADS)

Makarevich, Evgeniya; Papin, Andrey; Nevedrov, Alexander; Cherkasova, Tatyana; Ignatova, Alla

2017-11-01

A large amount of rubber-containing waste, the bulk of which are worn automobile tires and conveyor belts, is produced at coal mining and coal processing enterprises using automobile tires, conveyor belts, etc. The volume of waste generated increases every year and reaches enormous proportions. The methods for processing rubber waste can be divided into three categories: grinding, pyrolysis (high and low temperature), and decomposition by means of chemical solvents. One of the known techniques of processing the worn-out tires is their regeneration, aimed at producing the new rubber substitute used in the production of rubber goods. However, the number of worn tires used for the production of regenerate does not exceed 20% of their total quantity. The new method for processing rubber waste through the pyrolysis process is considered in this article. Experimental data on the upgrading of the carbon residue of pyrolysis by the methods of heavy media separation, magnetic and vibroseparation, and thermal processing are presented.

Silencing the lettuce homologs of small rubber particle protein does not influence natural rubber biosynthesis in lettuce (Lactuca sativa).

PubMed

Chakrabarty, Romit; Qu, Yang; Ro, Dae-Kyun

2015-05-01

Natural rubber, cis-1,4-polyisoprene, is an important raw material in chemical industries, but its biosynthetic mechanism remains elusive. Natural rubber is known to be synthesized in rubber particles suspended in laticifer cells in the Brazilian rubber tree (Hevea brasiliensis). In the rubber tree, rubber elongation factor (REF) and its homolog, small rubber particle protein (SRPP), were found to be the most abundant proteins in rubber particles, and they have been implicated in natural rubber biosynthesis. As lettuce (Lactuca sativa) can synthesize natural rubber, we utilized this annual, transformable plant to examine in planta roles of the lettuce REF/SRPP homologs by RNA interference. Among eight lettuce REF/SRPP homologs identified, transcripts of two genes (LsSRPP4 and LsSRPP8) accounted for more than 90% of total transcripts of REF/SRPP homologs in lettuce latex. LsSRPP4 displays a typical primary protein sequence as other REF/SRPP, while LsSRPP8 is twice as long as LsSRPP4. These two major LsSRPP transcripts were individually and simultaneously silenced by RNA interference, and relative abundance, polymer molecular weight, and polydispersity of natural rubber were analyzed from the LsSRPP4- and LsSRPP8-silenced transgenic lettuce. Despite previous data suggesting the implications of REF/SRPP in natural rubber biosynthesis, qualitative and quantitative alterations of natural rubber could not be observed in transgenic lettuce lines. It is concluded that lettuce REF/SRPP homologs are not critically important proteins in natural rubber biosynthesis in lettuce. Copyright © 2014 Elsevier Ltd. All rights reserved.

Method for co-processing waste rubber and carbonaceous material

DOEpatents

Farcasiu, Malvina; Smith, Charlene M.

1991-01-01

In a process for the co-processing of waste rubber and carbonaceous material to form a useful liquid product, the rubber and the carbonaceous material are combined and heated to the depolymerization temperature of the rubber in the presence of a source of hydrogen. The depolymerized rubber acts as a liquefying solvent for the carbonaceous material while a beneficial catalytic effect is obtained from the carbon black released on depolymerization the reinforced rubber. The reaction is carried out at liquefaction conditions of 380.degree.-600.degree. C. and 70-280 atmospheres hydrogen pressure. The resulting liquid is separated from residual solids and further processed such as by distillation or solvent extraction to provide a carbonaceous liquid useful for fuels and other purposes.

Radiation degradation of spent butyl rubbers

NASA Astrophysics Data System (ADS)

Telnov, A. V.; Zavyalov, N. V.; Khokhlov, Yu. A.; Sitnikov, N. P.; Smetanin, M. L.; Tarantasov, V. P.; Shadrin, D. N.; Shorikov, I. V.; Liakumovich, A. L.; Miryasova, F. K.

2002-03-01

Radiation methods of materials modification applied in technological chains can have significant economical and ecological advantages as compared to the established chemical, thermal and mechanical methods. Each year the problems of nature resources economy through the use of production and consumption wastes acquire a more significant value, as it allows to solve also ecological issues along with economical ones. This is mostly acute in relation to polymeric systems based on saturated rubbers, for example butyl rubber (BR) used in the tyre industry, as due to their high resistance to the action of oxygen, ozone, solar radiation and bacteria, they contaminate the environment for rather a long period. At VNIIEF and KSPU experiments were carried out on application of electron beams with energy from 6 to 10 MeV for radiation destruction of spent rubber based on BR. The radiation-degraded material was tested for re-use in the formulation of initial diaphragm mixture, rubber mixture for producing rubberized fabric and roofing.

Use of rubber and bentonite added fly ash as a liner material.

PubMed

Cokca, Erdal; Yilmaz, Zeka

2004-01-01

In many countries regulations require all hazardous waste disposal facilities to be lined with suitable impermeable barriers to protect against contamination. In this study, a series of laboratory tests on rubber and bentonite added fly ash were conducted. The aim of the tests was to evaluate the feasibility of utilizing fly ash, rubber and bentonite as a low hydraulic conductivity liner material. Type C fly ash was obtained from Soma thermal power plant in Turkey; rubber in pulverized form was waste from the retreading industry. To investigate the properties of rubber and bentonite added fly ash, hydraulic conductivity, leachate analysis, unconfined compression, split tensile strength, one-dimensional consolidation, swell and freeze/thaw cycle tests were performed. The overall evaluation of results have revealed that rubber and bentonite added fly ash showed good promise and a candidate for construction of a liner.

Nonlinear Viscoelastic Mechanics of Cross-linked Rubbers

NASA Technical Reports Server (NTRS)

Freed, Alan D.; Leonov, Arkady I.; Gray, Hugh R. (Technical Monitor)

2002-01-01

The paper develops a general theory for finite rubber viscoelasticity, and specifies it in the form, convenient for solving problems important for rubber, tire and space industries. Based on the quasi-linear approach of non-equilibrium thermodynamics, a general nonlinear theory has been developed for arbitrary nonisothermal deformations of viscoelastic solids. In this theory, the constitutive equations are presented as the sum of known equilibrium (rubber elastic) and non-equilibrium (liquid polymer viscoelastic) terms. These equations are then simplified using several modeling arguments. Stability constraints for the proposed constitutive equations are also discussed. It is shown that only strong ellipticity criteria are applicable for assessing stability of the equations governing viscoelastic solids.

Rapid Field Measurement of Rubber Content in Russian Dandelion

USDA-ARS?s Scientific Manuscript database

Natural rubber is a critical and strategic raw material for industrial manufacturing and national defense. In 2008, 10 million tons of NR were produced for commercial use, most of it from Hevea brasiliensis in tropical countries. The annual US import deficit for NR is approximately $1 billion. Devel...

Phenotypic variations, heritability and correlations in dry biomass, rubber and resin production among guayule germplasm

USDA-ARS?s Scientific Manuscript database

Gauyaule (Parthenium argentatum Gray) originated in the Southern Texas and northern Mexico deserts, which suggests it as a good candidate for arid and semi-arid sustainable agricultural systems to produce natural rubber and industrial byproducts. Continued improvement of guayule for higher biomass, ...

Amphiphilic semi-interpenetrating polymer networks using pulverized rubber

NASA Astrophysics Data System (ADS)

Shahidi, Nima

Scrap rubber materials provide a significant challenge to either reuse or safe disposal. Every year, millions of tires are discarded to landfills in the United States, consuming a staggering amount of land space, creating a high risk for large fires, breeding mosquitoes that spread diseases, and wasting the planet's natural resources. This situation cannot be sustained. The challenge of reusing scrap rubber materials is mainly due to the crosslinked structure of vulcanized rubber that prevent them from melting and further processing for reuse. The most feasible recycling approach is believed to be a process in which the vulcanized rubber is first pulverized into a fine powder and then incorporated into new products. The production of fine rubber particles is generally accomplished through the use of a cryogenic process that is costly. Therefore, development of a cost effective technology that utilizes a large quantity of the scrap rubber materials to produce high value added materials is an essential element in maintaining a sustainable solution to rubber recycling. In this research, a cost effective pulverization process, solid state shear extrusion (SSSE), was modified and used for continuous pulverization of the rubber into fine particles. In the modified SSSE process, pulverization takes place at high compressive shear forces and a controlled temperature. Furthermore, an innovative particle modification process was developed to enhance the chemical structure and surface properties of the rubber particles for manufacturing of high value added products. Modification of rubber particles was accomplished through the polymerization of a hydrophilic monomer mixture within the intermolecular structure of the hydrophobic rubber particles. The resulting composite particles are considered as amphiphilic particulate phase semi-interpenetrating polymer networks (PPSIPNs). The modified rubber particles are water dispersible and suitable for use in a variety of aqueous media applications such as additives to waterborne emulsions. This innovative process for the first time opened up the application of rubber particles in aqueous media. The kinetics of polymerization reaction of hydrophilic monomer mixture within the rubber particles was investigated based on the assumption of partitioning of acrylic acid monomer in the hydrophobic rubber particles. The produced PPSIPNs were used as additives to waterborne emulsions and the mechanical and physical properties of the prepared coatings were examined. It was observed that the PPSIPNs could be added in high quantities with an improvement in adhesion, enhancement of the impact strength, and hardness of the coatings. This approach aims to develop environmentally benign products from scrap rubber materials.

Adhesion of nitrile rubber to UV-assisted surface chemical modified PET fabric, part II: Interfacial characterization of MDI grafted PET

NASA Astrophysics Data System (ADS)

Razavizadeh, Mahmoud; Jamshidi, Masoud

2016-08-01

Fiber to rubber adhesion is an important subject in rubber industry. It is well known that surface treatment (i.e. physical, mechanical and chemical) is an effective method to improve interfacial bonding of fibers and/or fabrics to rubbers. UV irradiation is an effective method which has been used to increase fabric-rubber interfacial interactions. In this research UV assisted chemical modification of PET fabrics was used to increase PET to nitrile rubber (NBR) adhesion. Nitrile rubber is a perfect selection as fuel and oil resistant rubber. However it has weak bonding to PET fabric. For this purpose PET fabric was carboxylated under UV irradiation and then methylenediphenyl diisocyanate (MDI) was grafted on carboxylated PET. The chemical composition of the fabric before and after surface treatment was investigated by X-ray photoelectron spectroscopy (XPS). The sectional morphology of the experimental PET fibers and the interface between rubber compound and PET fabric was studied using scanning electron microscope (SEM). The morphology and structure of the product were analyzed by an energy dispersive X-ray spectrometer (EDX). FTIR-ATR and H NMR analysis were used to assess surface modifications on the PET irradiated fabrics.

40 CFR 63.494 - Back-end process provisions-residual organic HAP and emission limitations.

Code of Federal Regulations, 2011 CFR

2011-07-01

... producing butyl rubber, epichlorohydrin elastomer, neoprene, and nitrile butadiene rubber shall not exceed... processes at affected sources producing butyl rubber, epichlorohydrin elastomer, neoprene, and nitrile... submitted in accordance with § 63.499(f)(1). (i) For butyl rubber, the organic HAP emission limitation shall...

The rubber tree genome reveals new insights into rubber production and species adaptation.

PubMed

Tang, Chaorong; Yang, Meng; Fang, Yongjun; Luo, Yingfeng; Gao, Shenghan; Xiao, Xiaohu; An, Zewei; Zhou, Binhui; Zhang, Bing; Tan, Xinyu; Yeang, Hoong-Yeet; Qin, Yunxia; Yang, Jianghua; Lin, Qiang; Mei, Hailiang; Montoro, Pascal; Long, Xiangyu; Qi, Jiyan; Hua, Yuwei; He, Zilong; Sun, Min; Li, Wenjie; Zeng, Xia; Cheng, Han; Liu, Ying; Yang, Jin; Tian, Weimin; Zhuang, Nansheng; Zeng, Rizhong; Li, Dejun; He, Peng; Li, Zhe; Zou, Zhi; Li, Shuangli; Li, Chenji; Wang, Jixiang; Wei, Dong; Lai, Chao-Qiang; Luo, Wei; Yu, Jun; Hu, Songnian; Huang, Huasun

2016-05-23

The Para rubber tree (Hevea brasiliensis) is an economically important tropical tree species that produces natural rubber, an essential industrial raw material. Here we present a high-quality genome assembly of this species (1.37 Gb, scaffold N50 = 1.28 Mb) that covers 93.8% of the genome (1.47 Gb) and harbours 43,792 predicted protein-coding genes. A striking expansion of the REF/SRPP (rubber elongation factor/small rubber particle protein) gene family and its divergence into several laticifer-specific isoforms seem crucial for rubber biosynthesis. The REF/SRPP family has isoforms with sizes similar to or larger than SRPP1 (204 amino acids) in 17 other plants examined, but no isoforms with similar sizes to REF1 (138 amino acids), the predominant molecular variant. A pivotal point in Hevea evolution was the emergence of REF1, which is located on the surface of large rubber particles that account for 93% of rubber in the latex (despite constituting only 6% of total rubber particles, large and small). The stringent control of ethylene synthesis under active ethylene signalling and response in laticifers resolves a longstanding mystery of ethylene stimulation in rubber production. Our study, which includes the re-sequencing of five other Hevea cultivars and extensive RNA-seq data, provides a valuable resource for functional genomics and tools for breeding elite Hevea cultivars.

40 CFR 63.498 - Back-end process provisions-recordkeeping.

Code of Federal Regulations, 2010 CFR

2010-07-01

... be the crumb rubber dry weight of the rubber leaving the stripper. (iv) The organic HAP content of... stripper. (B) For solution processes, this quantity shall be the crumb rubber dry weight of the crumb rubber leaving the stripper. (iii) The hourly average of all stripper parameter results; (iv) If one or...

New sulfenamide accelerators derived from 'safe' amines for the rubber and tyre industry.

PubMed

Wacker, C D; Spiegelhalder, B; Preussmann, R

1991-01-01

A reduction of the high exposures to N-nitrosamines in the rubber and tyre industry is possible using the concept of 'safe' amines, in which vulcanization accelerators contain amine moieties that are both difficult to nitrosate and, on nitrosation, yield noncarcinogenic N-nitroso compounds. The toxicological and technological properties of more than 50 benzothiazole sulfenamides derived from 'safe' amines have been evaluated. Some of the new compounds show excellent vulcanization properties and seem suitable as replacements for traditional accelerators in this class of compounds.

40 CFR 721.4100 - Tris(disubstituted alkyl) het-er-o-cy-cle.

Code of Federal Regulations, 2010 CFR

2010-07-01

...) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for... substance is present in a plastic, an elastomer, a rubber matrix, or in a solution. (iii) Industrial... substance imported in a plastic, an elastomer, a rubber matrix, or in a solution, such that inhalation is...

40 CFR 721.4100 - Tris(disubstituted alkyl) het-er-o-cy-cle.

Code of Federal Regulations, 2011 CFR

2011-07-01

...) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for... substance is present in a plastic, an elastomer, a rubber matrix, or in a solution. (iii) Industrial... substance imported in a plastic, an elastomer, a rubber matrix, or in a solution, such that inhalation is...

Chemistry of rubber processing and disposal.

PubMed Central

Bebb, R L

1976-01-01

The major chemical changes during the processing of rubber occur with the breakdown in mastication and during vulcanization of the molded tire. There is little chemical change during the compounding, calendering, extrusion, and molding steps. Reclaiming is the process of converting scrap rubber into an unsaturated, processible product that can be vulcanized with sulfur. Pyrolysis of scrap rubber yields a complex mixture of liquids, gas, and residue in varying ratios dependent on the nature of the scrap and the conditions of pyrolysis. PMID:799964

Influence of association of "EVA-NBR" on indirect tensile strength of modified bituminous concrete

NASA Astrophysics Data System (ADS)

Chinoun, M.; Soudani, K.; Haddadi, S.

2016-04-01

The aim of this work is to contribute to the improvement of the mechanical properties of bituminous concrete by modification of bituminous concrete. In this study, we present the results of the indirect tensile strength "ITS" of modified bituminous concrete by the combination of two modifiers, one is a plastomer EVA (Ethylene Vinyl Acetate) and the other is a industrial waste from the shoe soles grinding NBR (Nitrile Butadiene Rubber) as crumb rubber. To modify the bitumen a wet process was used. The results show that the modification of bitumen by EVA-NBR combination increases their resistance to the indirect traction "ITS" compared to the bituminous concrete control. The mixture of 5% [50% EVA+ 50% NBR] is given the best result among the other associations.

Effects of preparation process on performance of rubber modified asphalt

NASA Astrophysics Data System (ADS)

Liu, Hanbing; Luo, Guobao; Wang, Xianqiang; Jiao, Yubo

2015-06-01

The rational utilization of waste rubber tire is essential for the environmental protection. Utilizing rubber particles to modify asphalt can not only improve asphalt performance, but also help the recycling of waste materials. Considering the effect of different preparation process parameters on the performance of rubber modified asphalt, this paper analyzes the effects of the shear temperature, shear time and shear rate on the performance of rubber modified asphalt, and provided a reference for its preparation.

A new mechanism for selective adsorption of rubber on carbon black surface caused by nano-confinement in SBR/NBR solution

NASA Astrophysics Data System (ADS)

Kawazoe, Masayuki

A novel mechanism of selective adsorption of rubber molecules onto carbon black surface in a binary immiscible rubber blend solution has been proposed in this dissertation. The phenomenon leads to uneven distribution of carbon black to the specific polymer in the blend and the obtained electrically conductive composite showed drastic reduction of percolation threshold concentration (PTC). The mechanism and the feature of conductive network formation have much potential concerning both fundamental understanding and industrial application to improve conductive polymer composites. In chapter I, carbon black filled conductive polymer composites are briefly reviewed. Then, in chapter II, a mechanism of rubber molecular confinement into carbon black aggregate structure is introduced to explain the selective adsorption of a specific rubber onto carbon black surface in an immiscible rubber solution blend (styrene butadiene rubber (SBR) and acrylonitrile butadiene rubber (NBR) with toluene or chloroform). Next, in chapters III and IV, polymers with various radius of gyration (Rg) and carbon blacks with various aggregate structure are examined to verify the selective adsorption mechanism. Finally, in chapter V, the novel mechanism was applied to create unique meso-/micro-unit conductive network in carbon black dispersed SBR/NBR composites.

Image Classification of Ribbed Smoked Sheet using Learning Vector Quantization

NASA Astrophysics Data System (ADS)

Rahmat, R. F.; Pulungan, A. F.; Faza, S.; Budiarto, R.

2017-01-01

Natural rubber is an important export commodity in Indonesia, which can be a major contributor to national economic development. One type of rubber used as rubber material exports is Ribbed Smoked Sheet (RSS). The quantity of RSS exports depends on the quality of RSS. RSS rubber quality has been assigned in SNI 06-001-1987 and the International Standards of Quality and Packing for Natural Rubber Grades (The Green Book). The determination of RSS quality is also known as the sorting process. In the rubber factones, the sorting process is still done manually by looking and detecting at the levels of air bubbles on the surface of the rubber sheet by naked eyes so that the result is subjective and not so good. Therefore, a method is required to classify RSS rubber automatically and precisely. We propose some image processing techniques for the pre-processing, zoning method for feature extraction and Learning Vector Quantization (LVQ) method for classifying RSS rubber into two grades, namely RSS1 and RSS3. We used 120 RSS images as training dataset and 60 RSS images as testing dataset. The result shows that our proposed method can give 89% of accuracy and the best perform epoch is in the fifteenth epoch.

Sapphire Multiple Filament and Large Plate Growth Processes

DTIC Science & Technology

1972-10-01

This is necessary to obtain proper belt tracking. The belts themselves are a silicone / glass fabric manufactured by Dodge Industries, Hoosick Falls...New York. This material is an extremely fine weave fiberglass cloth which is impregnated with silicone rubber. Its properties include high yield...by bonding together (with a silicone adhesive) two 0.010-in. thick strips of Dodge M301 silicone /glass fabric terminating in an angled butt joint to

Engineered TPEs: new materials of choice for health care?

PubMed

Decordier, J M

1992-03-01

Engineered thermoplastic elastomers (ETPEs) are a relatively young, fast-growing generation of products and have an important strategic influence on both the rubber and plastics market. Much has been written about the increasing usage of plastics in the design and manufacture of medical devices, and today we may add ETPEs to this list, with significant benefits possible for the plastics industry manufacturing elastomeric parts using plastics processing technology.

Construction of Pará rubber tree genome and multi-transcriptome database accelerates rubber researches.

PubMed

Makita, Yuko; Kawashima, Mika; Lau, Nyok Sean; Othman, Ahmad Sofiman; Matsui, Minami

2018-01-19

Natural rubber is an economically important material. Currently the Pará rubber tree, Hevea brasiliensis is the main commercial source. Little is known about rubber biosynthesis at the molecular level. Next-generation sequencing (NGS) technologies brought draft genomes of three rubber cultivars and a variety of RNA sequencing (RNA-seq) data. However, no current genome or transcriptome databases (DB) are organized by gene. A gene-oriented database is a valuable support for rubber research. Based on our original draft genome sequence of H. brasiliensis RRIM600, we constructed a rubber tree genome and transcriptome DB. Our DB provides genome information including gene functional annotations and multi-transcriptome data of RNA-seq, full-length cDNAs including PacBio Isoform sequencing (Iso-Seq), ESTs and genome wide transcription start sites (TSSs) derived from CAGE technology. Using our original and publically available RNA-seq data, we calculated co-expressed genes for identifying functionally related gene sets and/or genes regulated by the same transcription factor (TF). Users can access multi-transcriptome data through both a gene-oriented web page and a genome browser. For the gene searching system, we provide keyword search, sequence homology search and gene expression search; users can also select their expression threshold easily. The rubber genome and transcriptome DB provides rubber tree genome sequence and multi-transcriptomics data. This DB is useful for comprehensive understanding of the rubber transcriptome. This will assist both industrial and academic researchers for rubber and economically important close relatives such as R. communis, M. esculenta and J. curcas. The Rubber Transcriptome DB release 2017.03 is accessible at http://matsui-lab.riken.jp/rubber/ .

Effective utilizations of palm oil mill fly ash for synthetic amorphous silica and carbon zeolite composite synthesis

NASA Astrophysics Data System (ADS)

Utama, P. S.; Saputra, E.; Khairat

2018-04-01

Palm Oil Mill Fly Ash (POMFA) the solid waste of palm oil industry was used as a raw material for synthetic amorphous silica and carbon zeolite composite synthesis in order to minimize the wastes of palm oil industry. The alkaline extraction combine with the sol-gel precipitation and mechanical fragmentation was applied to produce synthetic amorphous silica. The byproduct, extracted POMFA was rich in carbon and silica content in a significant amount. The microwave heated hydrothermal process used to synthesize carbon zeolite composite from the byproduct. The obtained silica had chemical composition, specific surface area and the micrograph similar to commercial precipitated silica for rubber filler. The microwave heated hydrothermal process has a great potential for synthesizing carbon zeolite composite. The process only needs one-step and shorter time compare to conventional hydrothermal process.

5 MV 30 mA industrial electron processing system

NASA Astrophysics Data System (ADS)

Hoshi, Y.; Mizusawa, K.

1991-05-01

Industrial electron beam processing systems have been in use in various application fields such as: improving heat resistivity of wire insulation; controlling quality of automobile rubber tires and melt index characteristics of PE foams; and curing paintings or printing inks. Recently, there has come up a need for electron beam with an energy higher than 3 MV in order to disinfect salmonella in chicken meat, to kill bugs in fruits, and to sterilize medical disposables. To meet this need we developed a 5 MV 30 mA electron processing system with an X-ray conversion target. The machine was tested in NHV's plant in Kyoto at continuous operation of full voltage and full current. It proved to be very steady in operation with a high efficiency (as much as 72%). Also, the X-ray target was tested in a continuous run of 5 MV 30 mA (150 kW). It proved to be viable in industrial utilization. This paper introduces the process and the results of the development.

Effect of cellulose nanocrystals from corn cob with dispersion agent polyvinyl pyrrolidone in natural rubber latex film after aging treatment

NASA Astrophysics Data System (ADS)

Harahap, H.; Ridha, M.; Halimatuddahliana; Taslim; Iriany

2018-02-01

This study about the resistance of natural rubber latex films using nanocrystals cellulose filler from corn cob waste by aging treatment. Corn cob used as organic filler composed of cellulose, hemicellulose, and lignin. Each component has a potential for reuse, such as cellulose. Cellulose from corn cob has potential application as a filler prepared by hydrolysis process using a strong acid. The producing of natural rubber latex films through coagulant dowsing process. This research started with the pre-vulcanization process of natural rubber latex at 70 °C and followed by process of vulcanization at 110 °C for 20 minutes. Natural rubber latex films that have been produced continued with the aging treatment at 70 °C for 168 hours. The mechanical properties of natural rubber latex films after aging treatment are the tensile strength, elongation at break, M100 and M300 have performed.

Rubber Tire Dozer Operator. Open Pit Mining Job Training Series.

ERIC Educational Resources Information Center

British Columbia Dept. of Education, Victoria.

This training outline for rubber tire dozer operators, one in a series of eight outlines, is designed primarily for company training foremen or supervisors and for trainers to use as an industry-wide guideline for heavy equipment operator training in open pit mining in British Columbia. Intended as a guide for preparation of lesson plans both for…

The industrial production and use of 1,3-butadiene.

PubMed Central

Morrow, N L

1990-01-01

This presentation provides a brief overview of the production and use of 1,3-butadiene in the United States. Starting as a coproduct of ethylene, the 1,3-butadiene monomer is extracted and purified, then transferred to consumers. Major uses of 1,3-butadiene include the manufacture of styrene-butadiene rubber, polybutadiene rubber, and adiponitrile. PMID:2205493

Method for the addition of vulcanized waste rubber to virgin rubber products

DOEpatents

Romine, Robert A.; Snowden-Swan, Lesley J.

1997-01-01

The invention is a method of using enzymes from thiophyllic microbes for selectively breaking the sulfur rubber cross-link bonds in vulcanized rubber. The process is halted at the sulfoxide or sulfone step so that a devulcanized layer is reactive with virgin rubber.

Labor History and Industrial Relations: A Symposium.

ERIC Educational Resources Information Center

Salvatore, Nick; And Others

1989-01-01

Includes "Labor History, Industrial Relations, and the Crisis of American Labor" (Brody); "Reckoning with Company Unions: The Case of Thompson Products, 1934-1964" (Jacoby); "Managers and Nonunion Workers in the Rubber Industry: Union Avoidance Strategies in the 1930s" (Nelson); and "'Light Manufacturing': The…

Method for the addition of vulcanized waste rubber to virgin rubber products

DOEpatents

Romine, R.A.; Snowden-Swan, L.J.

1997-01-28

The invention is a method of using enzymes from thiophyllic microbes for selectively breaking the sulfur rubber cross-link bonds in vulcanized rubber. The process is halted at the sulfoxide or sulfone step so that a devulcanized layer is reactive with virgin rubber. 8 figs.

Diaphragmless shock wave generators for industrial applications of shock waves

NASA Astrophysics Data System (ADS)

Hariharan, M. S.; Janardhanraj, S.; Saravanan, S.; Jagadeesh, G.

2011-06-01

The prime focus of this study is to design a 50 mm internal diameter diaphragmless shock tube that can be used in an industrial facility for repeated loading of shock waves. The instantaneous rise in pressure and temperature of a medium can be used in a variety of industrial applications. We designed, fabricated and tested three different shock wave generators of which one system employs a highly elastic rubber membrane and the other systems use a fast acting pneumatic valve instead of conventional metal diaphragms. The valve opening speed is obtained with the help of a high speed camera. For shock generation systems with a pneumatic cylinder, it ranges from 0.325 to 1.15 m/s while it is around 8.3 m/s for the rubber membrane. Experiments are conducted using the three diaphragmless systems and the results obtained are analyzed carefully to obtain a relation between the opening speed of the valve and the amount of gas that is actually utilized in the generation of the shock wave for each system. The rubber membrane is not suitable for industrial applications because it needs to be replaced regularly and cannot withstand high driver pressures. The maximum shock Mach number obtained using the new diaphragmless system that uses the pneumatic valve is 2.125 ± 0.2%. This system shows much promise for automation in an industrial environment.

Composite theory applied to elastomers

NASA Technical Reports Server (NTRS)

Clark, S. K.

1986-01-01

Reinforced elastomers form the basis for most of the structural or load carrying applications of rubber products. Computer based structural analysis in the form of finite element codes was highly successful in refining structural design in both isotropic materials and rigid composites. This has lead the rubber industry to attempt to make use of such techniques in the design of structural cord-rubber composites. While such efforts appear promising, they were not easy to achieve for several reasons. Among these is a distinct lack of a clearly defined set of material property descriptors suitable for computer analysis. There are substantial differences between conventional steel, aluminum, or even rigid composites such as graphite-epoxy, and textile-cord reinforced rubber. These differences which are both conceptual and practical are discussed.

A cohort mortality and cancer incidence survey of recent entrants (1982-91) to the UK rubber industry: findings for 1983-2004.

PubMed

Dost, Abid; Straughan, Jk; Sorahan, Tom

2007-05-01

To monitor the occurrence of cancer in a recently defined cohort of UK rubber workers. A cohort of 8651 male and female workers from 41 UK rubber factories has been enumerated. All employees had a minimum of 12 months employment and were first employed at one of the participating factories in the period 1982-91. Mortality and cancer incidence data for the period 1983-2004 were compared with expected values based on appropriate national rates. Mortality from lung cancer was close to expectation for males [observed 22, standardized mortality ratio (SMR) 93] and females (observed 2, SMR 70). Mortality from stomach cancer was also unexceptional in males (observed 4, SMR 86) and females (observed 0, SMR 0). Although based on small numbers, significantly elevated mortality was shown for multiple myeloma in males (observed 5, SMR 385) and females (observed 2, SMR 952). All seven of these latter deaths occurred in workers from the general rubber goods (GRG) sector. The findings should be treated with caution as they relate to a relatively early period of follow-up. Nevertheless, they hold out the prospect that the elevated SMRs for stomach and lung cancers reported for historical cohorts of UK rubber workers will not be present in more recent cohorts. The elevated occurrence of multiple myeloma may represent no more than a chance finding. Alternatively, these findings may reflect the presence of an unrecognized occupational cancer hazard in parts of the GRG sector of the UK rubber industry.

Losses of soil carbon by converting tropical forest to plantations: erosion and decomposition estimated by δ(13) C.

PubMed

Guillaume, Thomas; Damris, Muhammad; Kuzyakov, Yakov

2015-09-01

Indonesia lost more tropical forest than all of Brazil in 2012, mainly driven by the rubber, oil palm, and timber industries. Nonetheless, the effects of converting forest to oil palm and rubber plantations on soil organic carbon (SOC) stocks remain unclear. We analyzed SOC losses after lowland rainforest conversion to oil palm, intensive rubber, and extensive rubber plantations in Jambi Province on Sumatra Island. The focus was on two processes: (1) erosion and (2) decomposition of soil organic matter. Carbon contents in the Ah horizon under oil palm and rubber plantations were strongly reduced up to 70% and 62%, respectively. The decrease was lower under extensive rubber plantations (41%). On average, converting forest to plantations led to a loss of 10 Mg C ha(-1) after about 15 years of conversion. The C content in the subsoil was similar under the forest and the plantations. We therefore assumed that a shift to higher δ(13) C values in plantation subsoil corresponds to the losses from the upper soil layer by erosion. Erosion was estimated by comparing the δ(13) C profiles in the soils under forest and under plantations. The estimated erosion was the strongest in oil palm (35 ± 8 cm) and rubber (33 ± 10 cm) plantations. The (13) C enrichment of SOC used as a proxy of its turnover indicates a decrease of SOC decomposition rate in the Ah horizon under oil palm plantations after forest conversion. Nonetheless, based on the lack of C input from litter, we expect further losses of SOC in oil palm plantations, which are a less sustainable land use compared to rubber plantations. We conclude that δ(13) C depth profiles may be a powerful tool to disentangle soil erosion and SOC mineralization after the conversion of natural ecosystems conversion to intensive plantations when soils show gradual increase of δ(13) C values with depth. © 2015 The Authors. Global Change Biology published by John Wiley & Sons Ltd.

Research on Extrusion of Rubber Composites Reinforced by Short Fibers Orientation Based on FEA

NASA Astrophysics Data System (ADS)

Zhang, Dewei; Wang, Chuansheng; Shen, Bo; Li, Shaoming; Bian, Huiguang

2018-06-01

In recent years, rubber composites reinforced by short fibers has been researched deeply, because of its good performances such as higher wear resistance, higher cut resistance and so on. Some research results indicated that if short fibers get orientation in rubber composites, the performances of rubber products could be promoted greatly. But how to make short fibers get orientation in rubber matrix during extrusion is still a real problem. And there are many parameters affect the short fibers orientation. So, in this paper, the effects of die structure including expansion-die and dam-expansion-die on extrusion flow field of short fiber and rubber composite material during extrusion process has been researched by Polyflow. And the FEA results about the pressure field, velocity field and the velocity vector of the rubber composites flow field indicate that, comparing with expansion-die and the dam-expansion-die, the latter one is better for the extrusion process of rubber composites and making short fibers get radial orientation in rubber matrix.

Chlorinolysis reclaims rubber of waste tires

NASA Technical Reports Server (NTRS)

Dufresne, E. R.; Tervet, J. H.; Hull, G. G.

1981-01-01

Process reclaims rubber and reduces sulfur content by using chlorine gas to oxidize sulfur bonds in preference to other bonds. Rubber does not have poor hysteresis and abrasion resistance like conventionally reclaimed rubber and is suitable for premium radial tires. Chlorinated rubber is less susceptible to swelling by oils and may be used as paint ingredient.

40 CFR 63.498 - Back-end process provisions-recordkeeping.

Code of Federal Regulations, 2011 CFR

2011-07-01

... be the crumb rubber dry weight of the rubber leaving the stripper. (iv) The organic HAP content of... be the crumb rubber dry weight of the crumb rubber leaving the stripper. (iii) The hourly average of... test runs. (1) The uncontrolled residual organic HAP content in the latex or dry crumb rubber, as...

40 CFR 63.498 - Back-end process provisions-recordkeeping.

Code of Federal Regulations, 2012 CFR

2012-07-01

... be the crumb rubber dry weight of the rubber leaving the stripper. (iv) The organic HAP content of... be the crumb rubber dry weight of the crumb rubber leaving the stripper. (iii) The hourly average of... test runs. (1) The uncontrolled residual organic HAP content in the latex or dry crumb rubber, as...

40 CFR 63.498 - Back-end process provisions-recordkeeping.

Code of Federal Regulations, 2014 CFR

2014-07-01

... be the crumb rubber dry weight of the rubber leaving the stripper. (iv) The organic HAP content of... be the crumb rubber dry weight of the crumb rubber leaving the stripper. (iii) The hourly average of... test runs. (1) The uncontrolled residual organic HAP content in the latex or dry crumb rubber, as...

40 CFR 63.498 - Back-end process provisions-recordkeeping.

Code of Federal Regulations, 2013 CFR

2013-07-01

... be the crumb rubber dry weight of the rubber leaving the stripper. (iv) The organic HAP content of... be the crumb rubber dry weight of the crumb rubber leaving the stripper. (iii) The hourly average of... test runs. (1) The uncontrolled residual organic HAP content in the latex or dry crumb rubber, as...

Biosorption of chromium (VI) from aqueous solutions and ANN modelling.

PubMed

Nag, Soma; Mondal, Abhijit; Bar, Nirjhar; Das, Sudip Kumar

2017-08-01

The use of sustainable, green and biodegradable natural wastes for Cr(VI) detoxification from the contaminated wastewater is considered as a challenging issue. The present research is aimed to assess the effectiveness of seven different natural biomaterials, such as jackfruit leaf, mango leaf, onion peel, garlic peel, bamboo leaf, acid treated rubber leaf and coconut shell powder, for Cr(VI) eradication from aqueous solution by biosorption process. Characterizations were conducted using SEM, BET and FTIR spectroscopy. The effects of operating parameters, viz., pH, initial Cr(VI) ion concentration, adsorbent dosages, contact time and temperature on metal removal efficiency, were studied. The biosorption mechanism was described by the pseudo-second-order model and Langmuir isotherm model. The biosorption process was exothermic, spontaneous and chemical (except garlic peel) in nature. The sequence of adsorption capacity was mango leaf > jackfruit leaf > acid treated rubber leaf > onion peel > bamboo leaf > garlic peel > coconut shell with maximum Langmuir adsorption capacity of 35.7 mg g -1 for mango leaf. The treated effluent can be reused. Desorption study suggested effective reuse of the adsorbents up to three cycles, and safe disposal method of the used adsorbents suggested biodegradability and sustainability of the process by reapplication of the spent adsorbent and ultimately leading towards zero wastages. The performances of the adsorbents were verified with wastewater from electroplating industry. The scale-up study reported for industrial applications. ANN modelling using multilayer perception with gradient descent (GD) and Levenberg-Marquart (LM) algorithm had been successfully used for prediction of Cr(VI) removal efficiency. The study explores the undiscovered potential of the natural waste materials for sustainable existence of small and medium sector industries, especially in the third world countries by protecting the environment by eco-innovation.

Projections of Demand for Waterborne Transportation, Ohio River Basin, 1980, 1990, 2000, 2020, 2040. Volume 14. Group XII. Rubber, Plastic, Nonmetallic Mineral Products, Nec.

DTIC Science & Technology

1980-12-01

thousand tons by the year 2040. Much of this increased consumption will be lime used in flue gas desulfurization . A. Market Areas In addition to local...increased consumption will result from lime consumed in lime and limestone flue gas desulfur - ization (FGD) installation processes. During the period 2000...is the use of lime and limestone in flue gas desulfu- rization processes. Lime scrubbers for power plants and other industrial plants have also

Proposed industrial recovered materials utilization targets for the metals and metal-products industry

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

1979-05-01

The introductory chapter provides a discussion of the factors that affect the recovery and reuse of secondary materials and the competition between the primary and secondary metals industries. It discusses these industries in terms of resource characteristics, industry technology, pollution control requirements, market structure, the economics of recycling, and the issues involved in econometrically estimating scrap supply response behavior. It further presents the methodology established by DOE for the metals, textiles, rubber, and pulp and paper industries. The areas in which government policies might have a significant impact on the utilization of primary and secondary metals and on any recyclingmore » targets between now and 1987 are noted. Chapter 3 presents general profiles for the major industrial segments comprising SIC 33. The profiles include such topics as industry structure, process technology, materials and recycling flow, and future trends. Chapter 4 specifically covers the evaluation of recycling targets for the ferrous, aluminum, copper, zinc, and lead industries. (MCW)« less

78 FR 15370 - Draft Guidance for Industry and Food and Drug Administration Staff: Recommendations for Labeling...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-11

... Product Container Is Not Made With Natural Rubber Latex.'' The purpose of this draft guidance is to make recommendations on the appropriate language to include in the labeling of a medical product to convey that natural... Products To Inform Users That the Product or Product Container Is Not Made With Natural Rubber Latex...

Guayule (parthenium argentatum) pyrolysis biorefining: fuels and chemicals contributed from guayule leaves via tail gas reactive pyrolysis

USDA-ARS?s Scientific Manuscript database

Guayule (Parthenium argentatum), a woody desert shrub cultivated in the southwestern United States, is a source of natural rubber and organic resins that promises to revolutionize the tire and rubber industry. Some 20,000 kg ha-1 yr-1 is reported to be harvested worldwide and expected to grow due to...

The rubber tree genome shows expansion of gene family associated with rubber biosynthesis.

PubMed

Lau, Nyok-Sean; Makita, Yuko; Kawashima, Mika; Taylor, Todd D; Kondo, Shinji; Othman, Ahmad Sofiman; Shu-Chien, Alexander Chong; Matsui, Minami

2016-06-24

Hevea brasiliensis Muell. Arg, a member of the family Euphorbiaceae, is the sole natural resource exploited for commercial production of high-quality natural rubber. The properties of natural rubber latex are almost irreplaceable by synthetic counterparts for many industrial applications. A paucity of knowledge on the molecular mechanisms of rubber biosynthesis in high yield traits still persists. Here we report the comprehensive genome-wide analysis of the widely planted H. brasiliensis clone, RRIM 600. The genome was assembled based on ~155-fold combined coverage with Illumina and PacBio sequence data and has a total length of 1.55 Gb with 72.5% comprising repetitive DNA sequences. A total of 84,440 high-confidence protein-coding genes were predicted. Comparative genomic analysis revealed strong synteny between H. brasiliensis and other Euphorbiaceae genomes. Our data suggest that H. brasiliensis's capacity to produce high levels of latex can be attributed to the expansion of rubber biosynthesis-related genes in its genome and the high expression of these genes in latex. Using cap analysis gene expression data, we illustrate the tissue-specific transcription profiles of rubber biosynthesis-related genes, revealing alternative means of transcriptional regulation. Our study adds to the understanding of H. brasiliensis biology and provides valuable genomic resources for future agronomic-related improvement of the rubber tree.

Microwave treatment of vulcanized rubber

DOEpatents

Wicks, George G [Aiken, SC; Schulz, Rebecca L [Aiken, SC; Clark, David E [Gainesville, FL; Folz, Diane C [Gainesville, FL

2002-07-16

A process and resulting product is provided in which a vulcanized solid particulate, such as vulcanized crumb rubber, has select chemical bonds broken by microwave radiation. The direct application of microwaves in combination with uniform heating of the crumb rubber renders the treated crumb rubber more suitable for use in new rubber formulations. As a result, larger particle sizes and/or loading levels of the treated crumb rubber can be used in new rubber mixtures to produce recycled composite products with good properties.

40 CFR 428.96 - Pretreatment standards for new sources.

Code of Federal Regulations, 2012 CFR

2012-07-01

... GUIDELINES AND STANDARDS (CONTINUED) RUBBER MANUFACTURING POINT SOURCE CATEGORY Pan, Dry Digestion, and... this section and attributable to pan, dry digestion, and mechanical reclaimed rubber processes which are integrated with a wet digestion reclaimed rubber process, which may be discharged to a publicly...

40 CFR 428.96 - Pretreatment standards for new sources.

Code of Federal Regulations, 2014 CFR

2014-07-01

... GUIDELINES AND STANDARDS (CONTINUED) RUBBER MANUFACTURING POINT SOURCE CATEGORY Pan, Dry Digestion, and... this section and attributable to pan, dry digestion, and mechanical reclaimed rubber processes which are integrated with a wet digestion reclaimed rubber process, which may be discharged to a publicly...

40 CFR 428.96 - Pretreatment standards for new sources.

Code of Federal Regulations, 2013 CFR

2013-07-01

... GUIDELINES AND STANDARDS (CONTINUED) RUBBER MANUFACTURING POINT SOURCE CATEGORY Pan, Dry Digestion, and... this section and attributable to pan, dry digestion, and mechanical reclaimed rubber processes which are integrated with a wet digestion reclaimed rubber process, which may be discharged to a publicly...

Workplace risk factors for cancer in the German rubber industry: Part 1. Mortality from respiratory cancers

PubMed Central

Weiland, S. K.; Straif, K.; Chambless, L.; Werner, B.; Mundt, K. A.; Bucher, A.; Birk, T.; Keil, U.

1998-01-01

OBJECTIVES: To determine the cancer specific mortality by work area among active and retired male workers in the German rubber industry. METHODS: A cohort of 11,663 male German workers was followed up for mortality from 1 January 1981 to 31 December 1991. Cohort members were classified as active (n = 7536) or retired (n = 4127) as of 1 January 1981 and had been employed for at least one year in one of five study plants producing tyres or technical rubber goods. Work histories were reconstructed with routinely documented "cost centre codes" which were classified into six categories: I preparation of materials; II production of technical rubber goods; III production of tyres; IV storage and dispatch; V maintenance; and VI others. Standardised mortality ratios (SMRs) adjusted for age and calendar year and 95% confidence intervals (95% CIs), stratified by work area (employment in respective work area for at least one year) and time related variables (year of hire, lagged years of employment in work area), were calculated from national reference rates. RESULTS: SMRs for laryngeal cancer were highest in work area I (SMR 253; 95% CI 93 to 551) and were significant among workers who were employed for > 10 years in this work area (SMR 330; 95% CI 107 to 779). Increased mortality rates from lung cancer were identified in work areas I (SMR 162; 95% CI 129 to 202), II (SMR 134; 95% CI 109 to 163), and V (SMR 131; 95% CI 102 to 167). Mortality from pleural cancer was increased in all six work areas, and significant excesses were found in work areas I (SMR 448; 95% CI 122 to 1146), II (SMR 505; 95% CI 202 to 1040), and V (SMR 554; 95% CI 179 to 1290). CONCLUSION: A causal relation between the excess of pleural cancer and exposure to asbestos among rubber workers is plausible and likely. In this study, the pattern of excess of lung cancer parallels the pattern of excess of pleural cancer. This points to asbestos as one risk factor for the excess deaths from lung cancer among rubber workers. The study provides further evidence for an increased mortality from laryngeal cancer among workers in the rubber industry, particularly in work area I.   PMID:9764109

Time-Dependent Testing Evaluation and Modeling for Rubber Stopper Seal Performance.

PubMed

Zeng, Qingyu; Zhao, Xia

2018-01-01

Sufficient rubber stopper sealing performance throughout the entire sealed product life cycle is essential for maintaining container closure integrity in the parenteral packaging industry. However, prior publications have lacked systematic considerations for the time-dependent influence on sealing performance that results from the viscoelastic characteristics of the rubber stoppers. In this paper, we report results of an effort to study these effects by applying both compression stress relaxation testing and residual seal force testing for time-dependent experimental data collection. These experiments were followed by modeling fit calculations based on the Maxwell-Wiechert theory modified with the Kohlrausch-Williams-Watts stretched exponential function, resulting in a nonlinear, time-dependent sealing force model. By employing both testing evaluations and modeling calculations, an in-depth understanding of the time-dependent effects on rubber stopper sealing force was developed. Both testing and modeling data show good consistency, demonstrating that the sealing force decays exponentially over time and eventually levels off because of the viscoelastic nature of the rubber stoppers. The nonlinearity of stress relaxation derives from the viscoelastic characteristics of the rubber stoppers coupled with the large stopper compression deformation into restrained geometry conditions. The modeling fit with capability to handle actual testing data can be employed as a tool to calculate the compression stress relaxation and residual seal force throughout the entire sealed product life cycle. In addition to being time-dependent, stress relaxation is also experimentally shown to be temperature-dependent. The present work provides a new, integrated methodology framework and some fresh insights to the parenteral packaging industry for practically and proactively considering, designing, setting up, controlling, and managing stopper sealing performance throughout the entire sealed product life cycle. LAY ABSTRACT: Historical publications in the parenteral packaging industry have lacked systematic considerations for the time-dependent influence on the sealing performance that results from effects of viscoelastic characteristic of the rubber stoppers. This study applied compression stress relaxation testing and residual seal force testing for time-dependent experimental data collection. These experiments were followed by modeling fit calculations based on the Maxwell-Wiechert theory modified with the Kohlrausch-Williams-Watts stretched exponential function, resulting in a nonlinear, time-dependent sealing force model. Experimental and modeling data show good consistency, demonstrating that sealing force decays exponentially over time and eventually levels off. The nonlinearity of stress relaxation derives from the viscoelastic characteristics of the rubber stoppers coupled with the large stopper compression deformation into restrained geometry conditions. In addition to being time-dependent stress relaxation, it is also experimentally shown to be temperature-dependent. The present work provides a new, integrated methodology framework and some fresh insights to the industry for practically and proactively considering, designing, setting up, controlling, and managing of the stopper sealing performance throughout the entire sealed product life cycle. © PDA, Inc. 2018.

40 CFR 428.93 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2014 CFR

2014-07-01

... Digestion, and Mechanical Reclaimed Rubber Subcategory § 428.93 Effluent limitations guidelines representing... pollutants or pollutant properties, controlled by this section, and attributable to pan, dry digestion, and mechanical reclaimed rubber processes which are integrated with a wet digestion reclaimed rubber process...

40 CFR 428.93 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2013 CFR

2013-07-01

... Digestion, and Mechanical Reclaimed Rubber Subcategory § 428.93 Effluent limitations guidelines representing... pollutants or pollutant properties, controlled by this section, and attributable to pan, dry digestion, and mechanical reclaimed rubber processes which are integrated with a wet digestion reclaimed rubber process...

40 CFR 428.93 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2012 CFR

2012-07-01

... Digestion, and Mechanical Reclaimed Rubber Subcategory § 428.93 Effluent limitations guidelines representing... pollutants or pollutant properties, controlled by this section, and attributable to pan, dry digestion, and mechanical reclaimed rubber processes which are integrated with a wet digestion reclaimed rubber process...

Applications of a job classification system in occupational epidemiology.

PubMed Central

Gamble, J F; Spirtas, R; Easter, P

1976-01-01

An occupational preventive medicine program attempts to control exposure so workers experience no detrimental effect on health. In a chemically complex industry, the definition of exposure is difficult because of the many different chemicals used and produced, the many different jobs and processes with qualitatively different exposures, and the movement of workers from job to job. Jobs have therefore been grouped on the basis of process or product into functionally homogeneous categories called occupational titles (OT's). Work experience can now be quantified independent of exposure (or by the dominant toxicants in each OT) and compared to health outcomes. Examples are discussed of the application of OT's to studies of the mortality and morbidity experience in the rubber industry, and the development of dose-response relations. PMID:961945

Toxicity evaluation of the process effluent streams of a petrochemical industry.

PubMed

Reis, J L R; Dezotti, M; Sant'Anna, G L

2007-02-01

The physico-chemical characteristics and the acute toxicity of several wastewater streams, generated in the industrial production of synthetic rubber, were determined. The acute toxicity was evaluated in bioassays using different organisms: Danio rerio (fish), Lactuca sativa (lettuce) and Brachionus calyciflorus (rotifer). The removal of toxicity attained in the industrial wastewater treatment plant was also determined upstream and downstream of the activated sludge process. The results obtained indicate that the critical streams in terms of acute toxicity are the effluents from the liquid polymer unit and the spent caustic butadiene washing stage. The biological treatment was able to partially remove the toxicity of the industrial wastewater. However, a residual toxicity level persisted in the biotreated wastewater. The results obtained with Lactuca sativa showed a high degree of reproducibility, using root length or germination index as evaluation parameters. The effect of volatile pollutants on the toxicity results obtained with lettuce seeds was assessed, using ethanol as a model compound. Modifications on the assay procedure were proposed. A strong correlation between the toxic responses of Lactuca sativa and Danio rerio was observed for most industrial effluent streams.

40 CFR 428.80 - Applicability; description of the wet digestion reclaimed rubber subcategory.

Code of Federal Regulations, 2014 CFR

2014-07-01

... digestion reclaimed rubber subcategory. 428.80 Section 428.80 Protection of Environment ENVIRONMENTAL... CATEGORY Wet Digestion Reclaimed Rubber Subcategory § 428.80 Applicability; description of the wet digestion reclaimed rubber subcategory. The provisions of this subpart are applicable to process waste water...

40 CFR 428.80 - Applicability; description of the wet digestion reclaimed rubber subcategory.

Code of Federal Regulations, 2010 CFR

2010-07-01

... digestion reclaimed rubber subcategory. 428.80 Section 428.80 Protection of Environment ENVIRONMENTAL... Wet Digestion Reclaimed Rubber Subcategory § 428.80 Applicability; description of the wet digestion... discharges resulting from the production of reclaimed rubber by use of the wet digestion process. ...

40 CFR 428.80 - Applicability; description of the wet digestion reclaimed rubber subcategory.

Code of Federal Regulations, 2012 CFR

2012-07-01

... digestion reclaimed rubber subcategory. 428.80 Section 428.80 Protection of Environment ENVIRONMENTAL... CATEGORY Wet Digestion Reclaimed Rubber Subcategory § 428.80 Applicability; description of the wet digestion reclaimed rubber subcategory. The provisions of this subpart are applicable to process waste water...

40 CFR 428.80 - Applicability; description of the wet digestion reclaimed rubber subcategory.

Code of Federal Regulations, 2011 CFR

2011-07-01

... digestion reclaimed rubber subcategory. 428.80 Section 428.80 Protection of Environment ENVIRONMENTAL... Wet Digestion Reclaimed Rubber Subcategory § 428.80 Applicability; description of the wet digestion... discharges resulting from the production of reclaimed rubber by use of the wet digestion process. ...

40 CFR 428.80 - Applicability; description of the wet digestion reclaimed rubber subcategory.

Code of Federal Regulations, 2013 CFR

2013-07-01

... digestion reclaimed rubber subcategory. 428.80 Section 428.80 Protection of Environment ENVIRONMENTAL... CATEGORY Wet Digestion Reclaimed Rubber Subcategory § 428.80 Applicability; description of the wet digestion reclaimed rubber subcategory. The provisions of this subpart are applicable to process waste water...

New understanding of microstructure formation of the rubber phase in thermoplastic vulcanizates (TPV).

PubMed

Wu, Hanguang; Tian, Ming; Zhang, Liqun; Tian, Hongchi; Wu, Youping; Ning, Nanying

2014-03-21

The breakup of the rubber phase in an ethylene-propylene-diene monomer (EPDM)/polypropylene (PP) blend at the early stage of dynamic vulcanization is similar to that in an unvulcanized EPDM/PP blend because of the low crosslink density of the EPDM phase. In this work, the minimum size of the rubber phase in the unvulcanized EPDM/PP blend was first calculated by using the critical breakup law of viscoelastic droplets in a matrix. The calculated results showed that the minimum size of the rubber phase in the unvulcanized blend was in the nanometer scale (25-46 nm), not the micrometer scale as reported in many works. Meanwhile, the actual size of the rubber phase in the thermoplastic vulcanizate (TPV) at both the early stage and the final stage of dynamic vulcanization was observed by using peak force tapping atomic force microscopy (PF-AFM). The results indicated that the EPDM phase indeed broke up into nanoparticles at the early stage of dynamic vulcanization, in good agreement with the calculated results. More interestingly, we first revealed that the micrometer-sized rubber particles commonly observed in TPV were actually the agglomerates of rubber nanoparticles with diameters between 40 and 60 nm. The mechanism for the formation of rubber nanoparticles and their agglomerates during dynamic vulcanization was then discussed. Our work provides guidance to control the microstructure of the rubber phase in TPV to prepare high performance TPV products for a wide range of applications in the automobile and electronic industries.

Influence of acrylonitrile butadiene rubber on recyclability of blends prepared from poly(vinyl chloride) and poly(methyl methacrylate).

PubMed

Suresh, Sunil S; Mohanty, Smita; Nayak, Sanjay K

2018-06-01

The current investigation deals with the recycling possibilities of poly(vinyl chloride) and poly(methyl methacrylate) in the presence of acrylonitrile butadiene rubber. Recycled blends of poly(vinyl chloride)/poly(methyl methacrylate) are successfully formed from the plastic constituents, those are recovered from waste computer products. However, lower impact performance of the blend and lower stability of the poly(vinyl chloride) phase in the recycled blend restricts its further usage in industrial purposes. Therefore, effective utilisation acrylonitrile butadiene rubber in a recycled blend was considered for improving mechanical and thermal performance. Incorporation of acrylonitrile butadiene rubber resulted in the improvement in impact performance as well as elongation-at-break of the recycled blend. The optimum impact performance was found in the blend with 9 wt% acrylonitrile butadiene rubber, which shows 363% of enhancement as compared with its parent blend. Moreover, incorporated acrylonitrile butadiene rubber also stabilises the poly(vinyl chloride) phase present in the recycled blend, similarly Fourier transform infrared spectroscopy studies indicate the interactions of various functionalities present in the recycled blend and acrylonitrile butadiene rubber. In addition to this, thermogravimetric analysis indicates the improvement in the thermal stability of the recycled blend after the addition of acrylonitrile butadiene rubber into it. The existence of partial miscibility in the recycled blend was identified using differential scanning calorimetry and scanning electron microscopy.

The rubber tree genome shows expansion of gene family associated with rubber biosynthesis

PubMed Central

Lau, Nyok-Sean; Makita, Yuko; Kawashima, Mika; Taylor, Todd D.; Kondo, Shinji; Othman, Ahmad Sofiman; Shu-Chien, Alexander Chong; Matsui, Minami

2016-01-01

Hevea brasiliensis Muell. Arg, a member of the family Euphorbiaceae, is the sole natural resource exploited for commercial production of high-quality natural rubber. The properties of natural rubber latex are almost irreplaceable by synthetic counterparts for many industrial applications. A paucity of knowledge on the molecular mechanisms of rubber biosynthesis in high yield traits still persists. Here we report the comprehensive genome-wide analysis of the widely planted H. brasiliensis clone, RRIM 600. The genome was assembled based on ~155-fold combined coverage with Illumina and PacBio sequence data and has a total length of 1.55 Gb with 72.5% comprising repetitive DNA sequences. A total of 84,440 high-confidence protein-coding genes were predicted. Comparative genomic analysis revealed strong synteny between H. brasiliensis and other Euphorbiaceae genomes. Our data suggest that H. brasiliensis’s capacity to produce high levels of latex can be attributed to the expansion of rubber biosynthesis-related genes in its genome and the high expression of these genes in latex. Using cap analysis gene expression data, we illustrate the tissue-specific transcription profiles of rubber biosynthesis-related genes, revealing alternative means of transcriptional regulation. Our study adds to the understanding of H. brasiliensis biology and provides valuable genomic resources for future agronomic-related improvement of the rubber tree. PMID:27339202

Effect of processing methods on the mechanical properties of natural rubber filled with stearic acid modified soy protein particles

USDA-ARS?s Scientific Manuscript database

Natural rubber was reinforced with stearic acid modified soy protein particles prepared with a microfluidizing and ball milling process. Longer ball milling time tends to increase tensile strength of the rubber composites. Elastic modulus of the composites increased with the increasing filler concen...

A case-control study of bladder cancer in the United States rubber and tyre industry.

PubMed

Checkoway, H; Smith, A H; McMichael, A J; Jones, F S; Monson, R R; Tyroler, H A

1981-08-01

A case-control study of bladder cancer was conducted in five United States rubber and tyre companies to determine if there were high-risk jobs and work areas within the industry. The study included 220 male cases of bladder cancer, of whom 107 were identified from hospital record reviews and 113 from death certificates. Each case was matched individually with two industry controls by sex, race, year of birth, and company. One control was matched additionally by year of hire and duration of employment. Comparisons of cases and controls not matched by year of hire and age of hire showed no differences for those variables, which suggests that age and calendar period of first exposure to the industry were not risk determinants. When the work histories of both cases and controls were contrasted it was found that cases were more likely than controls to have worked in milling (odds ratio (OR) = 1.91) and calender operation (OR = 2.21) jobs. The relative risk estimates for milling and calender operation both exhibited linear trends of increase with duration of exposure. Milling and calender operation jobs entail potential exposures to volatilised reaction products from heated rubber stock. A better understanding of aetiological associations with job type will require more detailed characterisation of the work environment with regard to the sources and levels of aromatic amines and other suspected bladder carcinogens.

A case-control study of bladder cancer in the United States rubber and tyre industry.

PubMed Central

Checkoway, H; Smith, A H; McMichael, A J; Jones, F S; Monson, R R; Tyroler, H A

1981-01-01

A case-control study of bladder cancer was conducted in five United States rubber and tyre companies to determine if there were high-risk jobs and work areas within the industry. The study included 220 male cases of bladder cancer, of whom 107 were identified from hospital record reviews and 113 from death certificates. Each case was matched individually with two industry controls by sex, race, year of birth, and company. One control was matched additionally by year of hire and duration of employment. Comparisons of cases and controls not matched by year of hire and age of hire showed no differences for those variables, which suggests that age and calendar period of first exposure to the industry were not risk determinants. When the work histories of both cases and controls were contrasted it was found that cases were more likely than controls to have worked in milling (odds ratio (OR) = 1.91) and calender operation (OR = 2.21) jobs. The relative risk estimates for milling and calender operation both exhibited linear trends of increase with duration of exposure. Milling and calender operation jobs entail potential exposures to volatilised reaction products from heated rubber stock. A better understanding of aetiological associations with job type will require more detailed characterisation of the work environment with regard to the sources and levels of aromatic amines and other suspected bladder carcinogens. PMID:7272236

A Thermodynamic Theory of Solid Viscoelasticity. Part II:; Nonlinear Thermo-viscoelasticity

NASA Technical Reports Server (NTRS)

Freed, Alan D.; Leonov, Arkady I.; Gray, Hugh R. (Technical Monitor)

2002-01-01

This paper, second in the series of three papers, develops a general, nonlinear, non-isothermal, compressible theory for finite rubber viscoelasticity and specifies it in a form convenient for solving problems important to the rubber, tire, automobile, and air-space industries, among others. Based on the quasi-linear approach of non-equilibrium thermodynamics, a general nonlinear theory of differential type has been developed for arbitrary non-isothermal deformations of viscoelastic solids. In this theory, the constitutive equations were presented as the sum of a rubber elastic (equilibrium) and a liquid type viscoelastic (non-equilibrium) terms. These equations have then been simplified using several modeling and simplicity arguments.

Enhancement of MCF Rubber Utilizing Electric and Magnetic Fields, and Clarification of Electrolytic Polymerization

PubMed Central

Shimada, Kunio

2017-01-01

Many sensors require mechanical durability to resist immense or impulsive pressure and large elasticity, so that they can be installed in or assimilated into the outer layer of artificial skin on robots. Given these demanding requirements, we adopted natural rubber (NR-latex) and developed a new method (NM) for curing NR-latex by the application of a magnetic field under electrolytic polymerization. The aim of the present work is to clarify the new manufacturing process for NR-latex embedded with magnetic compound fluid (MCF) as a conductive filler, and the contribution of the optimization of the new process for sensor. We first clarify the effect of the magnetic field on the enhancement of the NR-latex MCF rubber created by the alignment of magnetic clusters of MCF. Next, SEM, XRD, Raman spectroscopy, and XPS are used for morphological and microscopic observation of the electrolytically polymerized MCF rubber, and a chemical approach measuring pH and ORP of the MCF rubber liquid was used to investigate the process of electrolytic polymerization with a physical mode. We elucidate why the MCF rubber produced by the NM is enhanced with high sensitivity and long-term stability. This process of producing MCF rubber by the NM is closely related to the development of a highly sensitive sensor. PMID:28375182

The effect of carbon black loading and structure on tensile property of natural rubber composite

NASA Astrophysics Data System (ADS)

Savetlana, S.; Zulhendri; Sukmana, I.; Saputra, F. A.

2017-07-01

Natural rubber composite has been continuously developed due to its advantages such as a good combination of strength and damping property. Most of carbon black (CB)/Natural Rubber (NR) composite were used as material in tyre industry. The addition of CB in natural rubber is very important to enhance the strength of natural rubber. The particle loading and different structure of CB can affect the composite strength. The effects of CB particle loading of 20, 25 and 30 wt% and the effects of CB structures of N220, N330, N550 and N660 series on tensile property of composite were investigated. The result shows that the tensile strength and elastic modulus of natural rubber/CB composite was higher than pure natural rubber. From SEM observation the agglomeration of CB aggregate increases with particle loading. It leads to decrease of tensile strength of composite as more particle was added. High structure of CB particle i.e. N220 resulted in highest tensile stress. In fact, composite reinforced by N660 CB particle shown a comparable tensile strength and elastic modulus with N220 CB particle. SEM observation shows that agglomeration of CB aggregates of N330 and N550 results in lower stress of associate NR/CB composite.

Effect of synthesized ZnO nanoparticles on thermal conductivity and mechanical properties of natural rubber

NASA Astrophysics Data System (ADS)

Suntako, R.

2018-01-01

Zinc oxide (ZnO) is widely used in rubber industry as a cure activator for rubber vulcanization. In this work, comparison of cure characteristic, mechanical properties, thermal conductivity and volume swell testing in oil no.1 and oil no.3 between natural rubber (NR) filled synthesized ZnO nanoparticles (sZnO) by precipitation method and NR filled conventional ZnO (cZnO). The particle size of sZnO is 41.50 nm and specific area of 27.92 m2/g, the particle size of cZnO is 312.92 nm and specific surface area of 1.35 m2/g. It has been found that NR filled sZnO not only improves rubber mechanical properties, volume swell testing but also improves thermal conductivity and better than NR filled cZnO. Thermal conductivity of NR filled sZnO increases by 10.34%, 12.90% and 20.00%, respectively when compared with NR filled cZnO in same loading content (various concentrations of ZnO at 5, 8 and 10 parts per hundred parts of rubber). This is due to small particle size and large specific surface area of sZnO which lead to an increase in crosslinking in rubber chain and enhance heat transfer performance.

Functionalized Materials From Elastomers to High Performance Thermoplastics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Salazar, Laura Ann

Synthesis and incorporation of functionalized materials continues to generate significant research interest in academia and in industry. If chosen correctly, a functional group when incorporated into a polymer can deliver enhanced properties, such as adhesion, water solubility, thermal stability, etc. The utility of these new materials has been demonstrated in drug-delivery systems, coatings, membranes and compatibilizers. Two approaches exist to functionalize a material. The desired moiety can be added to the monomer either before or after polymerization. The polymers used range from low glass transition temperature elastomers to high glass transition temperature, high performance materials. One industrial example of themore » first approach is the synthesis of Teflon(reg. sign). Poly(tetrafluoroethylene) (PTFE or Teflon(reg. sign)) is synthesized from tetrafluoroethylene, a functionalized monomer. The resulting material has significant property differences from the parent, poly(ethylene). Due to the fluorine in the polymer, PTFE has excellent solvent and heat resistance, a low surface energy and a low coefficient of friction. This allows the material to be used in high temperature applications where the surface needs to be nonabrasive and nonstick. This material has a wide spread use in the cooking industry because it allows for ease of cooking and cleaning as a nonstick coating on cookware. One of the best examples of the second approach, functionalization after polymerization, is the vulcanization process used to make tires. Natural rubber (from the Hevea brasiliensis) has a very low glass transition temperature, is very tacky and would not be useful to make tires without synthetic alteration. Goodyear's invention was the vulcanization of polyisoprene by crosslinking the material with sulfur to create a rubber that was tough enough to withstand the elements of weather and road conditions. Due to the development of polymerization techniques to make cis-polyisoprene, natural rubber is no longer needed for the manufacturing of tires, but vulcanization is still utilized.« less

[Preface for special issue on bio-based materials (2016)].

PubMed

Weng, Yunxuan

2016-06-25

Bio-based materials are new materials or chemicals with renewable biomass as raw materials such as grain, legume, straw, bamboo and wood powder. This class of materials includes bio-based polymer, biobased fiber, glycotechnology products, biobased rubber and plastics produced by biomass thermoplastic processing and basic biobased chemicals, for instance, bio-alcohols, organic acids, alkanes, and alkenes, obtained by bio-synthesis, bio-processing and bio-refinery. Owing to its environmental friendly and resource conservation, bio-based materials are becoming a new dominant industry taking the lead in the world scientific and technological innovation and economic development. An overview of bio-based materials development is reported in this special issue, and the industrial status and research progress of the following aspects, including biobased fiber, polyhydroxyalkanoates, biodegradable mulching film, bio-based polyamide, protein based biomedical materials, bio-based polyurethane, and modification and processing of poly(lactic acid), are introduced.

Basic Rheology and Its Application to Nitrocellulose Propellant Processing by Screw Mix-Extruders

DTIC Science & Technology

1990-09-01

plastics and rubber industries. In its raw state NC retains much of the supermolecular structure of the precursor cellulose , and it exists in the form of...they have a cholesteric liquid crystal structure, in common with many other cellulosic materials(ref.8). It has been postulated that thermal...and molecules, see figure 19. Fibrils are about 25 plm in diameter, and are made up of ordered bundles of microfibrils which are about 3 jim in

Occupational nitrosamine exposure. 1. Rubber and tyre industry.

PubMed

Spiegelhalder, B; Preussmann, R

1983-09-01

To determine the role of N-nitrosamines in the known increased cancer risk of rubber workers, air concentrations of such carcinogens were measured by area sampling or personal monitoring in 19 factories. N-Nitrosodimethylamine (NDMA) and N-nitrosomorpholine (NMOR) were found regularly, the air concentrations varying between 0.1 and 380 micrograms/m3 personal monitoring. The mean concentration was usually in the range of 1-10 micrograms/m3. Several other nitrosamines could be detected in certain production branches. In retail shops and storage rooms of tyres NDMA and NMOR were found. Most rubber chemicals based on amines are contaminated with N-nitrosamines, but this contamination cannot explain the air concentrations of nitrosamines found. The occurrence of nitrosamines mainly depends upon their formation during production of rubber and rubber products from used vulcanisation accelerators based on amines and the presence of nitrosating agents, such as diphenylnitrosamine (retarder A) and of nitrous gases, in products or production areas. Elimination of one or both precursors for nitrosamine formation resulted in significant reduction of airial contamination of nitrosamines. The results are discussed in regard to the mechanisms of nitrosamine formation during rubber production, as basis for future epidemiological studies and their potential for exposure prevention.

Nonlinear Elasticity

NASA Astrophysics Data System (ADS)

Fu, Y. B.; Ogden, R. W.

2001-05-01

This collection of papers by leading researchers in the field of finite, nonlinear elasticity concerns itself with the behavior of objects that deform when external forces or temperature gradients are applied. This process is extremely important in many industrial settings, such as aerospace and rubber industries. This book covers the various aspects of the subject comprehensively with careful explanations of the basic theories and individual chapters each covering a different research direction. The authors discuss the use of symbolic manipulation software as well as computer algorithm issues. The emphasis is placed firmly on covering modern, recent developments, rather than the very theoretical approach often found. The book will be an excellent reference for both beginners and specialists in engineering, applied mathematics and physics.

Micro-organisms in latex and natural rubber coagula of Hevea brasiliensis and their impact on rubber composition, structure and properties.

PubMed

Salomez, M; Subileau, M; Intapun, J; Bonfils, F; Sainte-Beuve, J; Vaysse, L; Dubreucq, E

2014-10-01

Natural rubber, produced by coagulation of the latex from the tree Hevea brasiliensis, is an important biopolymer used in many applications for its outstanding properties. Besides polyisoprene, latex is rich in many nonisoprene components such as carbohydrates, proteins and lipids and thereby constitutes a favourable medium for the development of micro-organisms. The fresh rubber coagula obtained by latex coagulation are not immediately processed, allowing the development of various microbial communities. The time period between tree tapping and coagula processing is called maturation, during which an evolution of the properties of the corresponding dry natural rubber occurs. This evolution is partly related to the activity of micro-organisms and to the modification of the biochemical composition. This review synthesizes the current knowledge on microbial populations in latex and natural rubber coagula of H. brasiliensis and the changes they induce on the biochemistry and technical properties of natural rubber during maturation. © 2014 The Society for Applied Microbiology.

Aerosol particle and organic vapor concentrations at industrial work sites in Malaysia.

PubMed

Armstrong, R W; Rood, M J; Sani, S; Mohamed, M; Rashid, M; Jab, A T; Landsberger, S

2001-01-01

The objective of this study was to establish baseline data about air pollutants potentially related to nasopharyngeal carcinoma (NPC) in the Federal Territory and Selangor, Malaysia. During 1991-1993, ambient air quality was monitored at 42 work sites representing ten industrial sectors: adhesive manufacturing, foundries, latex processing, metalworking, plywood/veneer milling, ricemilling, rubber tire manufacturing, sawmilling, shoemaking, and textile related industries. At each work site, aerosol particle size distributions and concentrations of formaldehyde, benzene, toluene, isopropyl alcohol, and furfural were measured. Mean aerosol particle concentrations ranged from 61 micrograms/m3 in foundries to 5,578 micrograms/m3 in ricemills, with five industries (adhesives, metalworking, ricemilling, sawmilling, and shoemaking) exceeding the US EPA 24-hr ambient air standard for PM-10. Formaldehyde concentrations exceeded the threshold limit value (TLV) in adhesives factories. Other vapours and elements measured were well below TLVs.

Combination biological and microwave treatments of used rubber products

DOEpatents

Fliermans, Carl B.; Wicks, George G.

2002-01-01

A process and resulting product is provided in which a vulcanized solid particulate, such as vulcanized crumb rubber, has select chemical bonds altered by biotreatment with thermophillic microorganisms selected from natural isolates from hot sulfur springs. Following the biotreatment, microwave radiation is used to further treat the surface and to treat the bulk interior of the crumb rubber. The resulting combined treatments render the treated crumb rubber more suitable for use in new rubber formulations. As a result, larger loading levels and sizes of the treated crumb rubber can be used in new rubber mixtures and good properties obtained from the new recycled products.

Criteria for asphalt-rubber concrete in civil airport pavements: Mixture design

NASA Astrophysics Data System (ADS)

Roberts, F. L.; Lytton, R. L.; Hoyt, D.

1986-07-01

A mixture design procedure is developed to allow the use of asphalt-rubber binders in concrete for flexible airport pavement. The asphalt-rubber is produced by reacting asphalt with ground, scrap tire rubber to produce the binder for the asphalt-rubber concrete. Procedures for laboratory preparation of alsphalt-rubber binders using an equipment setup that was found by researchers to produce laboratory binders with similar properties to field processes are included. The rubber-asphalt concrete mixture design procedure includes adjustments to the aggregate gradation to permit space for the rubber particles in the asphalt-rubber binder as well as suggested mixing and compaction temperatures, and compaction efforts. While the procedure was used in the laboratory to successfully produce asphalt-rubber concrete mixtures, it should be evaluated in the field to ensure that consistent results can be achieved in a production environment.

Use of recycled chunk rubber asphalt concrete (CRAC) on low volume roads and use of recycled crumb rubber modifier in asphalt pavements. Final report, June 1993-June 1995

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hossain, M.; Funk, L.P.; Sadeq, M.A.

1995-06-01

The major objective of this project was to formulate a Chunk Rubber Asphalt Concrete (CRAC) mix for use on low volume roads. CRAC is a rubber modified asphalt concrete product produced by the `dry process` where rubber chunks of 1/2 inch size are used as aggregate in a cold mix with a type C fly ash. The second objective of this project was to develop guidelines concerning the use of rubber modified asphalt concrete hot mix to include: (1) Design methods for use of asphalt-rubber mix for new construction and overlay, (2) Mix design method for asphalt-rubber, and (3) Testmore » method for determining the amount of rubber in an asphalt-rubber concrete for quality control purposes.« less

Cream concentrated latex for foam rubber products

NASA Astrophysics Data System (ADS)

Suksup, R.; Imkaew, C.; Smitthipong, W.

2017-12-01

Fresh natural latex (around 40% rubber and 60% water) can be transformed to concentrated natural latex (around 60% rubber and 40% water) in order to realise economical transportation and easier latex product’s preparation. The concentrated natural latex is an extremely valuable material. It can be applied for many types of products, for example, foam rubber as pillow and mattress, elastic band, etc. Industrially, the concentrated natural latex can be prepared by centrifugation which requires an enormous expensive machine. From the eco-friendly products point of view, most of rubber entrepreneurs in the world try to develop a green rubber product. So, the main objective of this study is to prepare the cream concentrated latex without any sophisticated machine. Thus, we work on a simple, cheap and green method that does not use any expensive machine but uses water-based chemical as sodium alginate to prepare the cream concentrated latex. The optimal amount of sodium alginate in the latex was studied. The main characteristics of the cream concentrated latex were tested by various technics, such as alkalinity, total solid content (TSC), dry rubber content (DRC), etc. We found that there are no significant differences of results between fresh natural latex and cream concentrated latex, except for the TSC and DRC. The TSC and DRC of cream latex are higher than those of fresh natural latex. Finally, we propose a model of natural rubber particle and sodium alginate to form the cream concentrated latex.

Federal Research Action Plan on Recycled Tire Crumb Used ...

EPA Pesticide Factsheets

Over the past several years, parents, athletes, schools, and communities have raised concerns about the safety of recycled tire crumb rubber used as infill for playing fields and playgrounds in the United States. The public has expressed concerns that the use of these fields could potentially be related to certain health effects. Studies to date have not shown an elevated health risk from playing on fields with tire crumb rubber, but these studies have limitations and do not comprehensively evaluate the concerns about health risks from exposure to tire crumb rubber. This status report provides a summary of activities to date, including: (1) stakeholder outreach, (2) the tire crumb rubber manufacturing industry, (3) the final peer-reviewed Literature Review/Gaps Analysis (LRGA), (4) progress on the research activities, and (5) next steps and a timeline for completion of the final report. The status report does not include research findings.

29 CFR 520.300 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... representative. Shoe manufacturing industry means the manufacture or partial manufacture of footwear from any... manufacturing also includes the manufacture of heels from any material except molded rubber, but not including... industry means the manufacturing of the following products as referred to in subpart D of this part: (1...

Subcellular proteome profiles of different latex fractions revealed washed solutions from rubber particles contain crucial enzymes for natural rubber biosynthesis.

PubMed

Wang, Dan; Sun, Yong; Chang, Lili; Tong, Zheng; Xie, Quanliang; Jin, Xiang; Zhu, Liping; He, Peng; Li, Hongbin; Wang, Xuchu

2018-06-30

Rubber particle (RP) is a specific organelle for natural rubber biosynthesis (NRB) and storage in rubber tree Hevea brasiliensis. NRB is processed by RP membrane-localized proteins, which were traditionally purified by repeated washing. However, we noticed many proteins in the discarded washing solutions (WS) from RP. Here, we compared the proteome profiles of WS, C-serum (CS) and RP by 2-DE, and identified 233 abundant proteins from WS by mass spectrometry. Many spots on 2-DE gels were identified as different protein species. We further performed shotgun analysis of CS, WS and RP and identified 1837, 1799 and 1020 unique proteins, respectively. Together with 2-DE, we finally identified 1825 proteins from WS, 246 were WS-specific. These WS-specific proteins were annotated in Gene Ontology, indicating most abundant pathways are organic substance metabolic process, protein degradation, primary metabolic process, and energy metabolism. Protein-protein interaction analysis revealed these WS-specific proteins are mainly involved in ribosomal metabolism, proteasome system, vacuolar protein sorting and endocytosis. Label free and Western blotting revealed many WS-specific proteins and protein complexes are crucial for NRB initiation. These findings not only deepen our understanding of WS proteome, but also provide new evidences on the roles of RP membrane proteins in NRB. Natural rubber is stored in rubber particle from the rubber tree. Rubber particles were traditionally purified by repeated washing, but many proteins were identified from the washing solutions (WS). We obtained the first visualization proteome profiles with 1825 proteins from WS, including 246 WS-specific ones. These WS proteins contain almost all enzymes for polyisoprene initiation and may play important roles in rubber biosynthesis. Copyright © 2018 Elsevier B.V. All rights reserved.

Injection molding of high precision optics for LED applications made of liquid silicone rubber

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hopmann, Christian; Röbig, Malte

Light Emitting Diodes (LED) conquer the growing global market of lighting technologies. Due to their advantages, they are increasingly used in consumer products, in lighting applications in the home and in the mobility sector as well as in industrial applications. Particularly, with regard to the increasing use of high-power LED (HP-LED) the materials in the surrounding area of the light emitting semiconductor chip are of utmost importance. While the materials behind the semiconductor chip are optimized for maximum heat dissipation, the materials currently used for the encapsulation of the semiconductor chip (primary optics) and the secondary optics encounter their limitsmore » due to the high temperatures. In addition certain amounts of blue UV radiation degrade the currently used materials such as epoxy resins or polyurethanes for primary optics. In the context of an ongoing joint research project with various partners from the industry, an innovative manufacturing method for high precision optics for LED applications made of liquid silicone rubber (LSR) is analyzed at the Institut of Plastics Processing (IKV), Aachen. The aim of this project is to utilize the material-specific advantages of high transparent LSR, especially the excellent high temperature resistance and the great freedom in design. Therefore, a high integrated injection molding process is developed. For the production of combined LED primary and secondary optics a LED board is placed in an injection mold and overmolded with LSR. Due to the integrated process and the reduction of subcomponents like the secondary optics the economics of the production process can be improved significantly. Furthermore combined LED optics offer an improved effectiveness, because there are no losses of the light power at the transition of the primary and secondary optics.« less

Progress in radiation processing of polymers

NASA Astrophysics Data System (ADS)

Chmielewski, Andrzej G.; Haji-Saeid, Mohammad; Ahmed, Shamshad

2005-07-01

Modification in polymeric structure of plastic material can be brought either by conventional chemical means or by exposure to ionization radiation from ether radioactive sources or highly accelerated electrons. The prominent drawbacks of chemical cross-linking typically involve the generation of noxious fumes and by products of peroxide degradation. Both the irradiation sources have their merits and limitations. Increased utilization of electron beams for modification and enhancement of polymer materials has been in particular witnessed over the past 40 years. The paper highlights several recent cases of EB utilization to improve key properties of selected plastic products. In paper is provided a survey of radiation processing methods of industrial interest, encompassing technologies which are already commercially well established, through developments in the active R&D stage which show pronounced promise for future commercial use. Radiation cross-linking technologies discussed include: application in cable and wire, application in rubber tyres, radiation vulcanization of rubber latex, development of radiation crosslinked SiC fiber, polymer recycling, development of gamma compatible pp, hydrogels etc. Over the years, remarkable advancement has been achieved in radiation processing of natural polymers. Role of radiation in improving the processing of temperature of PCL for use as biodegradable polymer, in accelerated breakdown of cellulose into viscose and enhancement in yields of chitin/chitosan from sea-food waste, is described.

Cancer mortality in the British rubber industry: 1946-80.

PubMed Central

Sorahan, T; Parkes, H G; Veys, C A; Waterhouse, J A

1986-01-01

The mortality experienced by a cohort of 36445 rubber workers during 1946-80 has been investigated. These workers were all male operatives first employed in any one of the 13 participating factories in 1946-60; all had worked continuously in the industry for a minimum period of one year. Compared with the general population, statistically significant excesses relating to cancer mortality were found for cancer of the stomach (E = 245.9, O = 282, SMR = 115), primary cancer of the liver (E = 12.8, O = 22, SMR = 172), cancer of the lung (E = 892.7, O = 1191, SMR = 133), and all neoplasms (E = 2165.2, O = 2487, SMR = 115). Statistically significant deficits were found for cancer of the prostate (E = 79.7, O = 59, SMR = 74) and cancer of the testis (E = 10.3, O = 4, SMR = 39). The method of regression models in life tables (RMLT) was used to compare the duration of employment in the industry, the duration in "dust exposed" jobs, and the duration in "fume and/or solvent exposed" jobs of those dying from causes of interest with those of all matching survivors. Significant positive associations were found only for cancer of the stomach and cancer of the lung. The results of the RMLT analysis are independent of those from the SMR analysis, and the study has provided further evidence of a causal association between the risks of lung and stomach cancer and certain occupational exposures in the rubber industry. PMID:3718880

The use of smoke acid as an alternative coagulating agent for natural rubber sheets' production.

PubMed

Ferreira, Vanda S; Rêgo, Ione N C; Pastore, Floriano; Mandai, Mariana M; Mendes, Leonardo S; Santos, Karin A M; Rubim, Joel C; Suarez, Paulo A Z

2005-03-01

A comparative study of rubber sheets obtained using formic, acetic, and smoke acid as coagulants is shown for latex obtained from native Amazonian trees and also from commercial cultivated trees. The evaluation of both processes of coagulation was carried out by spectroscopic and physical-chemical analysis, showing no differences in the rubber sheets obtained. This new method of rubber sheet preparation was introduced into Amazonian rainforest rubber tapper communities, which are actually producing in large scale. The physical-mechanical properties were similar among a large sheets made by different rubber tapper communities using this new method.

Sulfur Mustard Penetration of Thermoplastic Elastomers

DTIC Science & Technology

2008-10-01

blend of polypropylene and finely dispersed, highly vulcanised EPDM rubber [4]. However its exact composition is a trade secret. The Santoprene grade... rubber or silicone rubber . Compared to thermoplastic elastomers, these thermosetting elastomers are expensive and difficult to process. Therefore a...the last few decades, CBR respirators have generally been manufactured from either butyl rubber (as in the British and Australian S10), or silicone

Chronic diseases in the rubber industry

PubMed Central

Tyroler, H. A.; Andjelkovic, Dragana; Harris, Robert; Lednar, Wayne; McMichael, Anthony; Symons, Mike

1976-01-01

An overview is presented of epidemiologic studies of chronic diseases in the rubber industry. Analyses of the mortality experience during the period 1964-1972 of workers age 40–64 and retirees age 65–84 of two large rubber and tire manufacturing companies consistently disclosed excesses of deaths attributed to leukemia and lymphosarcoma, and for cancers of the stomach, large intestine, and prostate. The relation of site-specific malignancies to work histories and grouped occupational titles as surrogate measures of work-related exposures to possible carcinogens is described. There was no evidence of company-wide, sizable, consistent excess for the other major chronic diseases causes of death. Although a total cohort deficit in the mortality rate for lung cancer was found, there was a history of increased frequency of exposure to certain work areas among lung cancer decedents. Morbidity studies, including analysis of disability retirements, and ad hoc questionnaire and health testing surveys, disclosed excesses of chronic pulmonary diseases. There was evidence of an interactive effect in the association of work and smoking histories with pulmonary disability retirement. PMID:1026398

Analysis of temperature profile and electric field in natural rubber glove due to microwave heating: effects of waveguide position

NASA Astrophysics Data System (ADS)

Keangin, P.; Narumitbowonkul, U.; Rattanadecho, P.

2018-01-01

Natural rubber (NR) is the key raw material used in the manufacture of other products such as rubber band, tire and shoes. Recently, the NR is used in natural rubber glove ( NRG) manufacturing in the industrial and medical fields. This research aims to investigate the electromagnetic wave propagation and heat transfer in NRG due to heating with microwave energy within the microwave oven at a microwave frequency of 2.45 GHz. Three-dimensional model of NRG and microwave oven are considered in this work. The comparative effects of waveguide position on the electric field and temperature profile in NRG when subjected to microwave energy are discussed. The finite element method (FEM) is used to solve the transient Maxwell’s equation coupled with the transient heat transfer equation. The simulation results with computer programs are validated with experimental results. The placement of waveguides in three cases are left hand side of microwave oven, right hand side of microwave oven and left and right hand sides of microwave oven are investigated. The findings revealed that the placing the waveguide on the right side of the microwave oven gives the highest electric field and temperature profile. The values obtained provide an indication toward understanding the study of heat transfer in NRG during microwave heating in the industry.

Industrial recovered-materials-utilization targets for the textile-mill-products industry

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

1979-01-01

The Congress, in the National Energy Conservation and Policy Act of 1978 (NECPA), directed the Department of Energy to establish materials recovery targets for the metals and metal products, paper and allied products, rubber, and textile-mill-products industries. The targets were developed to provide incentives for using energy-saving recorded materials and to provied a yardstick for measuring progress and improvement in this endeavor. The NECPA indicates that the targets should represent the maximum technically and economically feasible increase in the use of energy-saving recovered materials that each industry can achieve progressively by January 1, 1987. Materials affected by recovered-materials targets includemore » and are limited to aluminum, copper, lead, zinc, iron, steel, paper and associated products, textile-mill, products, and rubber. Using information gathered from the textile-mill-products industry and from other textile-relaed sources, DOE has developed recovered materials targets for that industry. This report presents those targets and their basis and justification. Following an overview of the textile industry, the chapters are: Textile-Mill-Products Industry Operations; Economic Analysis of the Textile-Mill-Products Industry; Governmental and Regulatory Influence on the US Textile Industry; Current Mill Use of Recovered Materials in the Textile-Mill-Products Industry; Limitations on the Use of Recovered Materials in the US Textile-Mill-Products Industry; Materials-Recovery Targets; and Government and Industry Actions That Could Increase the Use of Recovered Materials.« less

Ground tire rubber as a stabilizer for subgrade soils.

DOT National Transportation Integrated Search

2014-05-01

Over 250 million scrap tires are generated annually in the U.S. Historically, a significant portion of these tires : have been processed into finely ground tire rubber (GTR), or crumb rubber, for use as an additive in hot mix asphalt : (HMA) pavement...

In-depth proteome analysis of the rubber particle of Hevea brasiliensis (para rubber tree).

PubMed

Dai, Longjun; Kang, Guijuan; Li, Yu; Nie, Zhiyi; Duan, Cuifang; Zeng, Rizhong

2013-05-01

The rubber particle is a special organelle in which natural rubber is synthesised and stored in the laticifers of Hevea brasiliensis. To better understand the biological functions of rubber particles and to identify the candidate rubber biosynthesis-related proteins, a comprehensive proteome analysis was performed on H. brasiliensis rubber particles using shotgun tandem mass spectrometry profiling approaches-resulting in a thorough report on the rubber particle proteins. A total of 186 rubber particle proteins were identified, with a range in relative molecular mass of 3.9-194.2 kDa and in isoelectric point values of 4.0-11.2. The rubber particle proteins were analysed for gene ontology and could be categorised into eight major groups according to their functions: including rubber biosynthesis, stress- or defence-related responses, protein processing and folding, signal transduction and cellular transport. In addition to well-known rubber biosynthesis-related proteins such as rubber elongation factor (REF), small rubber particle protein (SRPP) and cis-prenyl transferase (CPT), many proteins were firstly identified to be on the rubber particles, including cyclophilin, phospholipase D, cytochrome P450, small GTP-binding protein, clathrin, eukaryotic translation initiation factor, annexin, ABC transporter, translationally controlled tumour protein, ubiquitin-conjugating enzymes, and several homologues of REF, SRPP and CPT. A procedure of multiple reaction monitoring was established for further protein validation. This comprehensive proteome data of rubber particles would facilitate investigation into molecular mechanisms of biogenesis, self-homeostasis and rubber biosynthesis of the rubber particle, and might serve as valuable biomarkers in molecular breeding studies of H. brasiliensis and other alternative rubber-producing species.

Health aspects of the curing of synthetic rubbers.

PubMed Central

Fraser, D A; Rappaport, S

1976-01-01

A commonly used tread rubber formulation was cured in the laboratory under conditions simulating vulcanization in the Bag-O-Matic press. Volatile emissions were collected on charcoal and analyzed by combined GC-mass spectrometry. The compounds identified were either contaminants present in the raw material or reaction products. Some of these compounds were also identified in charcoal tube samples collected in the atmosphere of the industrial operations. Estimates based on the loss of weight of rubber during curing were used to predict airborne concentrations and compared to the concentrations actually found. The literature of the toxicity of raw materials and effluents was reviewed, and no acute or chronic toxicological effects would be anticipated. Information concerning potential carcinogenicity was not available and could not be evaluated. PMID:1026417

Natural rubber, a potential alternative source for the synthesis of renewable fuels via Hydrous Pyrolysis

NASA Astrophysics Data System (ADS)

Ahmad, N.; Dayana, S. A. S.; Abnisa, F.; Mohd, W. A. W. D.

2018-03-01

Natural rubber is a humid agricultural harvest, which mostly contains hydrocarbon cis-1, 4-Poly isoprene. Through depolymerisation technology, the natural rubber can be changed into liquid product, and then it can be subsequently utilized as a fuel or chemical feedstock. This article aims to provide an outlook on the natural rubber and its sources, which are available globally. Numerous depolymerisation processes, which include pyrolysis, gasification, chemical degradation, catalytic cracking and hydrogenation, were introduced in this paper, while the focus of discussion was emphasized on the hydrous pyrolysis process. Many studies have shown that the use of hydrous pyrolysis able to improve the depolymerisation process, e.g. the raw material can be feed without drying, the process can be carried out at lower temperature, only the water is used as the reaction medium, and it is easy to separate the water from oil product. The effect of operating parameters such as temperature, water to rubber mass ratio, reaction time and type of gases on the product yield and composition were reviewed in this paper. In addition, this paper also highlighted the eco-friendly and economic viability of the hydrous pyrolysis process.

Selection of a Non-ODC Solvent for Rubber Processing Equipment Cleaning

NASA Technical Reports Server (NTRS)

Morgan, R. E.; Thornton, T. N.; Semmel, L.; Selvidge, S. A.; Cash, Steve (Technical Monitor)

2002-01-01

NASA/MSFC has recently acquired new equipment for the manufacture and processing of rubber and rubber containing items that are used in the RSRM (Reusable Solid Rocket Motor) system. Work with a previous generation of rubber equipment at MSFC (Marshall Space Flight Center) in the 1970's had involved the use of ODC's such as 1,1,1-Trichloroethane or VOC's such as Toluene as the solvents of choice in cleaning the equipment. Neither of these options is practical today. This paper addresses the selection and screening of candidate cleaning solvents that are not only effective, but also meet the new environmental standards.

Selection of a Non-ODC Solvent for Rubber Processing Equipment Cleaning

NASA Technical Reports Server (NTRS)

Morgan, R. E.; Thornton, T. N.; Semmel, L.; Selvidge, S. A.

2003-01-01

NASA/MSFC has recently acquired new equipment for the manufacture and processing of rubber and rubber containing items that are used in the Redesigned Solid Rocket Motor (RSRM) system. Work with a previous generation of rubber equipment at MSFC in the 1970's had involved the use of Oxygen Deficient Center (ODC's) such as 1,1,1-Trichloroethane or VOC's such as Toluene as the solvents of choice in cleaning the equipment. Neither of these options is practical today. This paper addresses the selection and screening of candidate cleaning solvents that are not only effective, but also meet the new environmental standards.

Ground tire rubber as a stabilizer for subgrade soils : [summary].

DOT National Transportation Integrated Search

2014-05-01

Over 250 million scrap tires are generated : annually in the U.S. Historically, a significant : portion of these tires have been processed into : finely ground tire rubber (GTR), or crumb rubber, : for use as an additive in hot mix asphalt (HMA) : pa...

Innovative technologies of waste recycling with production of high performance products

NASA Astrophysics Data System (ADS)

Gilmanshin, R.; Ferenets, A. V.; Azimov, Yu I.; Galeeva, A. I.; Gilmanshina, S. I.

2015-06-01

The innovative ways of recycling wastes as a tool for sustainable development are presented in the article. The technology of the production of a composite material based on the rubber fiber composite waste tire industry is presented. The results of experimental use of the products in the real conditions. The comparative characteristics of the composite material rubber fiber composite are given. The production technology of construction and repairing materials on the basis of foamed glass is presented.

Studies on gamma irradiated rubber materials

NASA Astrophysics Data System (ADS)

Lungu, I. B.; Stelescu, M. D.; Cutrubinis, M.

2018-01-01

Due to the increase in use and production of polymer materials, there is a constant pressure of finding a solution to more environmental friendly composites. Beside the constant effort of recycling used materials, it seems more appropriate to manufacture and use biodegradable and renewable row materials. Natural polymers like starch, cellulose, lignin etc are ideal for preparing biodegradable composites. Some of the dynamic markets that use polymer materials are the food and pharmaceutical industries. Because of their desinfastation and sometimes sterility requirements, different treatment processes are applied, one of it being radiation treatment. The scope of this paper is to analyze the mechanical behaviour of rubber based materials irradiated with gamma rays at four medium doses, 30.1 kGy, 60.6 kGy, 91 kGy and 121.8 kGy. The objectives are the following: to identify the optimum radiation dose in order to obtain a good mechanical behaviour and to identify the mechanical behaviour of the material when adding different quantities of natural filler (20 phr, 60 phr and 100 phr).

JPRS Report, East Europe

DTIC Science & Technology

1987-12-03

is also surprising in the film and television industry . It often happens that Slovak actors play in our films and always speak Czech badly (with...Metallurgical Pro- cessing Industry in Liberec, the Tesla in Holesovice, the Bytex in Liberec, the Plastika in Nitra, the First of May Rubber Plants in...Presov. [Question] Could you describe their share in our national economy? [Answer] In the centrally managed industry these orga- nizations share

23 CFR 751.7 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-04-01

... not nonconforming junkyards. (b) Junk. Old or scrap metal, rope, rags, batteries, paper, trash, rubber... relative to Outdoor Advertising Control shall apply insofar as industrial zones are concerned. (e) Unzoned...

Reinforcement of latex rubber by the incorporation of amphiphilic particles

USDA-ARS?s Scientific Manuscript database

Latex rubbers are fabricated from latex suspensions. During the fabrication process, latex particles are bound together while water is removed from the suspension. This report shows that the mechanical properties of latex rubbers can be improved by incorporating a small amount of amphiphilic submicr...

Rubber friction on road surfaces: Experiment and theory for low sliding speeds

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lorenz, B.; Persson, B. N. J.; Oh, Y. R.

We study rubber friction for tire tread compounds on asphalt road surfaces. The road surface topographies are measured using a stylus instrument and atomic force microscopy, and the surface roughness power spectra are calculated. The rubber viscoelastic modulus mastercurves are obtained from dynamic mechanical analysis measurements and the large-strain effective modulus is obtained from strain sweep data. The rubber friction is measured at different temperatures and sliding velocities, and is compared to the calculated data obtained using the Persson contact mechanics theory. We conclude that in addition to the viscoelastic deformations of the rubber surface by the road asperities, theremore » is an important contribution to the rubber friction from shear processes in the area of contact. The analysis shows that the latter contribution may arise from rubber molecules (or patches of rubber) undergoing bonding-stretching-debonding cycles as discussed in a classic paper by Schallamach.« less

New rubber qualification for the igniter adapter

NASA Technical Reports Server (NTRS)

Humpherys, Mark A.

1994-01-01

Kirkhill Rubber Company (KRC) has informed Thiokol Corporation that two raw materials used in the asbestos and silica filled acrylonitrile butadience rubber (NBR) formulation per STW 2621 are no longer available from their vendors. Agerite White (Di-beta-naphthyl-paraphenylene diamine), manufactured by B. F. Goodrich, is an antioxidant used in NBR. This raw material makes up roughly 1-2 percent of the finished product. KRC proposed that this raw material be replaced by Agerite Stalite S (mixture of octylated diphenylamines) distributed by R. T. Vanderbilt Co. Protox-166 zinc oxide, manufactured by Zinc Corporation of America, is an activator currently used in NBR. This material also makes up about 1-2 percent of the finished material. Protox-166 is an American process grade zinc oxide. It is proposed by KRC to replace Protox-166 with Kadox-930C, a French process grade zinc oxide. American process grades have an ASTM minimum purity of 99.0 percent; the French process grades have a minimum purity of 99.5 percent. Previous testing per WTP-0270 has demonstrated that the mechanical and thermal properties of the rubber with the new ingredients are comparable to the 'old' rubber. The test results are reported in TWR-61790. One igniter adapter, Part no. 7U77562-02 serial no. 2 was insulated per ETP-1206 using the new rubber formulation and a modified lay up and cure method to demonstrate that there is no impact on this process. The results of this demonstration are reported.

Electron linear accelerator system for natural rubber vulcanization

NASA Astrophysics Data System (ADS)

Rimjaem, S.; Kongmon, E.; Rhodes, M. W.; Saisut, J.; Thongbai, C.

2017-09-01

Development of an electron accelerator system, beam diagnostic instruments, an irradiation apparatus and electron beam processing methodology for natural rubber vulcanization is underway at the Plasma and Beam Physics Research Facility, Chiang Mai University, Thailand. The project is carried out with the aims to improve the qualities of natural rubber products. The system consists of a DC thermionic electron gun, 5-cell standing-wave radio-frequency (RF) linear accelerator (linac) with side-coupling cavities and an electron beam irradiation apparatus. This system is used to produce electron beams with an adjustable energy between 0.5 and 4 MeV and a pulse current of 10-100 mA at a pulse repetition rate of 20-400 Hz. An average absorbed dose between 160 and 640 Gy is expected to be archived for 4 MeV electron beam when the accelerator is operated at 400 Hz. The research activities focus firstly on assembling of the accelerator system, study on accelerator properties and electron beam dynamic simulations. The resonant frequency of the RF linac in π/2 operating mode is 2996.82 MHz for the operating temperature of 35 °C. The beam dynamic simulations were conducted by using the code ASTRA. Simulation results suggest that electron beams with an average energy of 4.002 MeV can be obtained when the linac accelerating gradient is 41.7 MV/m. The rms transverse beam size and normalized rms transverse emittance at the linac exit are 0.91 mm and 10.48 π mm·mrad, respectively. This information can then be used as the input data for Monte Carlo simulations to estimate the electron beam penetration depth and dose distribution in the natural rubber latex. The study results from this research will be used to define optimal conditions for natural rubber vulcanization with different electron beam energies and doses. This is very useful for development of future practical industrial accelerator units.

Losses of soil organic carbon by converting tropical forest to plantations: Assessment of erosion and decomposition by new δ13C approach

NASA Astrophysics Data System (ADS)

Guillaume, Thomas; Muhammad, Damris; Kuzyakov, Yakov

2015-04-01

Indonesia lost more tropical forest than all of Brazil in 2012, mainly driven by the rubber, oil palm and timber industries. Nonetheless, the effects of converting forest to oil palm and rubber plantations on soil organic carbon (SOC) stocks remain unclear. We analyzed SOC losses after lowland rainforest conversion to oil palm, intensive rubber and extensive rubber plantations in Jambi province on Sumatra Island. We developed and applied a new δ13C based approach to assess and separate two processes: 1) erosion and 2) decomposition. Carbon contents in the Ah horizon under oil palm and rubber plantations were strongly reduced: up to 70% and 62%, respectively. The decrease was lower under extensive rubber plantations (41%). The C content in the subsoil was similar in the forest and the plantations. We therefore assumed that a shift to higher δ13C values in the subsoil of the plantations corresponds to the losses of the upper soil layer by erosion. Erosion was estimated by comparing the δ13C profiles in the undisturbed soils under forest with the disturbed soils under plantations. The estimated erosion was the strongest in oil palm (35±8 cm) and rubber (33±10 cm) plantations. The 13C enrichment of SOC used as a proxy of its turnover indicates a decrease of SOC decomposition rate in the Ah horizon under oil palm plantations after forest conversion. SOC availability, measured by microbial respiration rate and Fourier Transformed Infrared Spectroscopy, was lower under oil palm plantations. Despite similar trends in C losses and erosion in intensive plantations, our results indicate that microorganisms in oil palm plantations mineralized mainly the old C stabilized prior to conversion, whereas microorganisms under rubber plantations mineralized the fresh C from the litter, leaving the old C pool mainly untouched. Based on the lack of C input from litter, we expect further losses of SOC under oil palm plantations, which therefore are a less sustainable land-use compared to rubber plantations. Finally, we discussed the advantages and limitations of the new δ13C based approach to assess erosion and decomposition as well as possibilities for its development and broader application. The reestablishment of new oil palm plantations has just started in the studied region. We therefore advise 1) to reduce the period without soil protection by planting cover crops at the early stage of the establishment to reduce soil erosion and 2) to leave a maximum of the biomass from the old palm trees on site and/or to keep the land lying fallow for a few years to enable the reconstruction of the SOC pool for the next oil palm generation.

Design of Self-Healing Supramolecular Rubbers by Introducing Ionic Cross-Links into Natural Rubber via a Controlled Vulcanization.

PubMed

Xu, Chuanhui; Cao, Liming; Lin, Baofeng; Liang, Xingquan; Chen, Yukun

2016-07-13

Introducing ionic associations is one of the most effective approaches to realize a self-healing behavior for rubbers. However, most of commercial rubbers are nonpolar rubbers without now available functional groups to be converted into ionic groups. In this paper, our strategy was based on a controlled peroxide-induced vulcanization to generate massive ionic cross-links via polymerization of zinc dimethacrylate (ZDMA) in natural rubber (NR) and exploited it as a potential self-healable material. We controlled vulcanization process to retard the formation of covalent cross-link network, and successfully generated a reversible supramolecular network mainly constructed by ionic cross-links. Without the restriction of covalent cross-linkings, the NR chains in ionic supramolecular network had good flexibility and mobility. The nature that the ionic cross-links was easily reconstructed and rearranged facilitating the self-healing behavior, thereby enabling a fully cut sample to rejoin and retain to its original properties after a suitable self-healing process at ambient temperature. This study thus demonstrates a feasible approach to impart an ionic association induced self-healing function to commercial rubbers without ionic functional groups.

The effects of plasma spray parameters and atmosphere on the properties and microstructure of WC-Co coatings

NASA Astrophysics Data System (ADS)

Ghosh, D.; Lamy, D.; Sopkow, T.; Smuga-Otto, I.

Wear- and corrosion-resistant coatings deposited by plasma spray process are increasingly used in severe environments in resource industries, such as oil and gas, oil sands, mining, pulp and paper, etc. While there is a large volume of literature in the area of plasma spray coatings, comparatively few papers deal with the co-relation between coating properties and microstructure as a function of plasma spray processing parameters. In this study, the effect of some plasma spray processing variables and atmosphere (air or inert gas) on the microstructure and the properties of WC-Co coatings were studied. The properties of the coatings measured include: microhardness, porosity by image analysis, wear resistance by dry sand/rubber wheel abrasion test (ASTM G 65-91) and corrosion properties by AC impedance technique. Phase analyses of the coatings were also performed by X-ray diffraction. From the above, optimized coatings were developed for oil and gas industry applications.

Leaching of nitroso rubber material removes uncured polymer

NASA Technical Reports Server (NTRS)

Bratfisch, W. A.; Gonzalez, R.

1972-01-01

New leaching process removes uncured polymer from nitroso rubber, elastomer used in presence of nitrogen tetroxide. Uncured portion is removed by controlled soaking of polymer slab in Freon TF. Leaching with Freon TF prevents nitroso rubber from adhering to adjoining surfaces and limiting its usefulness in either static or dynamic applications.

Comprehensive evaluation of the long-term performance of rubberized pavement, phase II : the influence of rubber and asphalt interaction on mixture durability.

DOT National Transportation Integrated Search

2014-12-01

This project investigated the long-term performance of hot asphalt mixes containing crumb rubber : modifiers (CRM) added in dry or wet processes. A total of eight asphalt mixturesfour Porous : European Mixtures (PEMs) and four Stone Matrix Asphalt...

Effect of microfluidized and stearic acid modified soy protein in natural rubber

USDA-ARS?s Scientific Manuscript database

Microfluidized and stearic acid modified soy protein aggregates were used to reinforced natural rubber. The size of soy protein particles was reduced with a microfluidizing and ball milling process. Filler size reduction with longer ball milling time tends to increase tensile strength of the rubber ...

Cancer by industry: analysis of a population-based cancer registry with an emphasis on blue-collar workers.

PubMed

Hall, N E; Rosenman, K D

1991-01-01

This paper uses information on occupation and industry routinely collected in a state-based cancer registry to assess potential associations between work place exposures and cancer incidence. Industry-specific proportional cancer incidence ratios (PCIR) were calculated by race and sex for all individuals and for white males with blue-collar occupations. Expected numbers of cancers were derived both from cancers occurring among all occupations and just among blue-collar occupations. This latter analysis was done as a control for differences in the prevalence of life-style habits between blue- and white-collar workers. Increased lung cancer PCIR were seen in most industries previously reported to be associated with lung cancer risk. The effects of socioeconomic status on these results are discussed. Other results include an increased ratio of melanoma in blue-collar white male rubber and plastic product workers, an increased ratio of non-Hodgkin's lymphomas in motor vehicle manufacture workers, and an increased PCIR of chronic lymphocytic leukemia in general construction workers. Uterine cancer was increased in proportion in white females for a number of industries including rubber and plastic product manufacture, apparel manufacture, and electrical equipment manufacture.

The reclaiming of butyl rubber and in-situ compatibilization of thermoplastic elastomer by power ultrasound

NASA Astrophysics Data System (ADS)

Feng, Wenlai

This is a study of the continuous ultrasound aided extrusion process for the in-situ compatibilization of isotactic polypropylene (iPP)/ethylene-propylene diene rubber (EPDM) thermoplastic elastomer (TPE) using a newly developed ultrasonic treatment reactor. The rheological, mechanical properties and morphology of the TPE with and without ultrasonic treatment were studied. In-situ compatibilization in the ultrasonically treated blends was observed as evident by their more stable morphology after annealing, improved mechanical properties and IR spectra. The obtained results indicated that ultrasonic treatment induced the thermo-mechanical degradations and led to the possibility of enhanced molecular transport and chemical reactions at the interfaces. Processing conditions were established for enhanced in situ compatibilization of the PP/EPDM TPE. The ultrasonic treatments of butyl rubber gum and ultrasonic devulcanization of butyl rubber, tire-curing bladder during extrusion using a grooved barrel ultrasonic reactor were carried out. The ultrasonic treatment of gum caused degradation of the polymer main chain leading to lower molecular weight, broader molecular weight distribution, less unsaturation and changes in physical properties. The devulcanization of butyl rubber was successfully accomplished only at severe conditions of ultrasonic treatment. The mechanical properties of vulcanizates prepared from devulcanized butyl rubber are comparable to that of the virgin vulcanizate. The molecular characterization of sol fraction of devulcanized butyl rubber showed the devulcanization and degradation of butyl rubber occurred simultaneously. 1H NMR transverse relaxation was also used to study butyl rubber gum before and after ultrasonic treatment, and ultrasonically devulcanized unfilled butyl rubber. The T2 relaxation decays were successfully described using a two-component model. The recyclability of tire-curing bladder was also investigated. Gel fraction, crosslink density, cure behavior, dynamic properties and mechanical properties were measured. Good mechanical properties of revulcanized rubber were achieved by blending devulcanized rubber with the carbon black filled virgin butyl rubber. The structural characteristics of devulcanized butyl rubber were simulated using the Dobson-Gordon theory of rubber network statistics. A fairly good agreement between experimental data and theoretical prediction on normalized gel fraction vs. normalized crosslink density was achieved. The simulation of devulcanized butyl rubber indicated that the rate of crosslink rupture is much higher than that of the main chain.

CHEMICAL RECLAMATION OF SCRAP RUBBER

EPA Science Inventory

A conceptual, commercial-scale plant design was formulated for processing 22,500 t/yr of scrap rubber tires to hydrocarbon fuel gases, oils, petrochemicals (principally ethylene and aromatic liquids), and carbon black. The process is based upon molten salt (zinc chloride) pyrolys...

The effect of antioxidant concentration of N-isopropyl-N-phenyl-p-phenylenediamine, and 2,2,4-trimethyl-1,2-dihydroquinoline and mixing time of physical properties, thermal properties, mechanical properties and microstructure on natural rubber compound

NASA Astrophysics Data System (ADS)

Budiarto

2017-03-01

Study the influence of high concentrations of antioxidants N-isopropyl-N-phenyl-p-phenylenediamine (IPPD) and 2,2,4-trimethyl-1,2-dihydroquinoline (TMQ) and the mixing time of the vulcanization physical properties, thermal properties, mechanical properties and structure micro on natural rubber compound has been done. The purpose of this study is to compare the effect of anti-oxidants types IPPD and TMQ and mixing time of vulcanization of the physical properties, mechanical properties, microstructure and elemental composition of the synthesis of natural rubber compound. Processes of vulcanization with variations in the concentration of antioxidant IPPD and TMQ: 2, 3, and 4 grams and mixing time: 20, 30, and 40 minutes. Analysis characterization of physical properties and mechanical properties of natural rubber compound showed that the maturity value 0,499Nm (TMQ) and 0.489 Nm (IPPD), Mooney viscosity value of 26.7 (TMQ) and 20.8 (IPPD), the value of the elongation at break 583.75 % (IPPD), and 552.63% (TMQ) as well as the value of tensile strength of 28.108 M.Pa (TMQ), and 27.986 M.Pa (IPPD). Analysis of thermal properties of natural rubber compound antioxidant IPPD with DTA shows there are three endothermic peak on the curve that is temperature 405°C, 550°C and 660°C and tested by TGA showed that the curve of the total reduction in the sample are 81.745% and compound rubber antioxidant TMQ with the analysis of DTA also contained 3 endothermic peak at a temperature 397,21°C, 514,02°C, and 610,27°C and TGA analysis shows the curve of the total sample of 82.356% reduction. Gsi fun group analysis rubber-antioxidant compound IPPD / TMQ with FTIR spectrophotometer shows some typical infrared absorption peak at the wave number (1 / λ) 833-895 cm-1 for cluster / CH bonds, 1,313 cm-1 for group / single bond Si-O, 1368 cm-1 to g ugus / single bond CC, 1507 cm-1, for cluster / bond C = C, 1665 cm-1For cluster / bond-C = O, 2128 cm-1 is the group / bond CN single, 3371cm-1 for group-OH, 3506 cm-1 for cluster / CH3 bond and 3585 cm-1 showed the presence of vibration in the cluster / bond-NH. The results of morphological observation with SEM produces uneven surface (homogeneous) and are compatible at 2000 times magnification, as well as the test composition by EDX spectroscopy showed that the biggest element in the rubber compound is carbon and Zn, S, Ca, Si, Mg, Al, N. This shows that the natural rubber compound antioxidant IPPD / TMQ meet the standard of "Mechanical Properties of Industrial Tyre rubber Compounds".

[The airborne 1,3-butadiene concentrations in rubber and plastic processing plants].

PubMed

Yoshida, Toshiaki; Tainaka, Hidetsugu; Matsunaga, Ichiro; Goto, Sumio

2002-03-01

Environment pollution by 1,3-butadiene had considerably increased in Japan. The main cause of the pollution is the automotive exhaust gas, and leaks from factories, smoking, and burning of rubber and plastic products are considered to be minor sources. The object of this study was to determine the contamination levels of airborne 1,3-butadiene in factories processing rubber and plastics containing 1,3-butadiene. The concentrations of airborne 1,3-butadiene were measured in 21 plants (10 rubber processing plants and 11 plastics processing plants) in Osaka. 1,3-Butadiene in air was collected for 10 minutes with a charcoal tube and a portable small pump adjusted to a 250 ml/min flow rate. In each plant, indoor air samples at five points and an outdoor air sample at one point outside the plant were collected. The samples were subjected to gas chromatography/mass spectrometry after thermal desorption from the charcoal. The concentrations of airborne 1,3-butadiene in the rubber processing plants and the plastics processing plants were 0.14-2.20 micrograms/m3 (geometric mean: 0.48 microgram/m3) and 0.23-4.51 micrograms/m3 (geometric mean: 0.80 microgram/m3), respectively. In all plants examined, indoor 1,3-butadiene concentrations were higher than the outdoor concentrations around the plants. Therefore, 1,3-butadiene was considered to arise from the processing of rubber or plastics, but the indoor 1,3-butadiene concentrations were much lower than the PEL-TWA (1 ppm = 2.21 mg/m3) of OSHA and the TLV-TWA (2 ppm) of ACGIH. The concentrations in the plants with closed room conditions without ventilation were higher than the concentrations in the other plants. It was suggested that ventilation affected the 1,3-butadiene concentration in the plants.

Infrared Spectroscopic Study on Structural Change and Interfacial Interaction in Rubber Composites Filled with Silica-Kaolin Hybrid Fillers

NASA Astrophysics Data System (ADS)

Chen, Y.; Guan, J.; Hu, H.; Gao, H.; Zhang, L.

2016-07-01

A series of natural rubber/styrene butadiene rubber/polybutadiene rubber composites was prepared with nanometer silica and micron kaolin by a dry modification process, mechanical compounding, and mold vulcanization. Fourier transform infrared spectroscopy and a scanning electron microscope were used to investigate the structural changes and interfacial interactions in composites. The results showed that the "seesaw" structure was formed particularly with the incorporation of silica particles in the preparation process, which would be beneficial to the dispersibility of fillers in the rubber matrix. The kaolinite platelets were generally arranged in directional alignment. Kaolinite with smaller particle size and low-defect structure was more stable in preparation, but kaolinite with larger particle size and high defect structure tended to change the crystal structure. The composite prepared in this research exhibited excellent mechanical and thermal properties.

Application of radiation processing in asia and the pacific region: Focus on malaysia

NASA Astrophysics Data System (ADS)

Mohd Dahlan, Khairul Zaman HJ.

1995-09-01

Applications of radiation processing in Malaysia and other developing countries in Asia and the Pacific region is increasing as the countries move toward industrialisation. At present, there are more than 85 gamma facilities and 334 electron accelerators in Asia and the Pacific region which are mainly in Japan, Rep. of Korea and China. The main applications which are in the interest of the region are radiation sterilisation of medical products; radiation crosslinking of wire and cable, heat shrinkable film and tube, and foam; radiation curing of surface coatings, printing inks and adhesive; radiation vulcanisation of natural rubber latex; radiation processing of agro-industrial waste; radiation treatment of sewage sludge and municipal waste; food irradiation; tissue grafts and radiation synthesis of bioactive materials.

78 FR 56734 - Certain Rubber Resins and Processes for Manufacturing Same; Commission Determination To Review...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-09-13

... INTERNATIONAL TRADE COMMISSION [Investigation No. 337-TA-849] Certain Rubber Resins and Processes... Administrative Law Judge; Schedule for Filing Written Submissions on Review AGENCY: U.S. International Trade Commission. ACTION: Notice. [[Page 56735

Casting Technology.

ERIC Educational Resources Information Center

Wright, Michael D.; And Others

1992-01-01

Three articles discuss (1) casting technology as it relates to industry, with comparisons of shell casting, shell molding, and die casting; (2) evaporative pattern casting for metals; and (3) high technological casting with silicone rubber. (JOW)

Mechanical properties of melt-processed polymer blend of amorphous corn flour composite filler and styrene-butadiene rubber

USDA-ARS?s Scientific Manuscript database

The corn flour composite fillers were prepared by blending corn flour with rubber latex, dried, and cryogenically ground into powders, which were then melt-blended with rubber polymers in an internal mixer to form composites with enhanced mechanical properties. The composites prepared with melt-blen...

Fabrication of Wood-Rubber Composites Using Rubber Compound as a Bonding Agent Instead of Adhesives

PubMed Central

Shao, Dongwei; Xu, Min; Cai, Liping; Shi, Sheldon Q.

2016-01-01

Differing from the hot-pressing method in the manufacturing of traditional wood-rubber composites (WRCs), this study was aimed at fabricating WRCs using rubber processing to improve water resistance and mechanical properties. Three steps were used to make WRCs, namely, fiber-rubber mixing, tabletting, and the vulcanization molding process. Ninety-six WRC panels were made with wood fiber contents of 0%–50% at rotor rotational speeds of 15–45 rpm and filled coefficients of 0.55–0.75. Four regression equations, i.e., the tensile strength (Ts), elongation at break (Eb), hardness (Ha) and rebound resilience (Rr) as functions of fiber contents, rotational speed and filled coefficient, were derived and a nonlinear programming model were developed to obtain the optimum composite properties. Although the Ts, Eb and Rr of the panels were reduced, Ha was considerably increased by 17%–58% because of the wood fiber addition. Scanning electron microscope images indicated that fibers were well embedded in rubber matrix. The 24 h water absorption was only 1%–3%, which was much lower than commercial wood-based composites. PMID:28773591

Extracting distribution and expansion of rubber plantations from Landsat imagery using the C5.0 decision tree method

NASA Astrophysics Data System (ADS)

Sun, Zhongchang; Leinenkugel, Patrick; Guo, Huadong; Huang, Chong; Kuenzer, Claudia

2017-04-01

Natural tropical rainforests in China's Xishuangbanna region have undergone dramatic conversion to rubber plantations in recent decades, resulting in altering the region's environment and ecological systems. Therefore, it is of great importance for local environmental and ecological protection agencies to research the distribution and expansion of rubber plantations. The objective of this paper is to monitor dynamic changes of rubber plantations in China's Xishuangbanna region based on multitemporal Landsat images (acquired in 1989, 2000, and 2013) using a C5.0-based decision-tree method. A practical and semiautomatic data processing procedure for mapping rubber plantations was proposed. Especially, haze removal and deshadowing were proposed to perform atmospheric and topographic correction and reduce the effects of haze, shadow, and terrain. Our results showed that the atmospheric and topographic correction could improve the extraction accuracy of rubber plantations, especially in mountainous areas. The overall classification accuracies were 84.2%, 83.9%, and 86.5% for the Landsat images acquired in 1989, 2000, and 2013, respectively. This study also found that the Landsat-8 images could provide significant improvement in the ability to identify rubber plantations. The extracted maps showed the selected study area underwent rapid conversion of natural and seminatural forest to a rubber plantations from 1989 to 2013. The rubber plantation area increased from 2.8% in 1989 to 17.8% in 2013, while the forest/woodland area decreased from 75.6% in 1989 to 44.8% in 2013. The proposed data processing procedure is a promising approach to mapping the spatial distribution and temporal dynamics of rubber plantations on a regional scale.

Microbial communities in natural rubber coagula during maturation: impacts on technological properties of dry natural rubber.

PubMed

Salomez, M; Subileau, M; Vallaeys, T; Santoni, S; Bonfils, F; Sainte-Beuve, J; Intapun, J; Granet, F; Vaysse, L; Dubreucq, É

2018-02-01

To characterize microbial communities present in natural rubber (NR) coagula from Hevea brasiliensis latex during maturation and identify microbial taxa (bacteria and fungi) having an impact on dry NR properties. Microbial community dynamics in NR coagula maturated under controlled conditions were compared and related with the evolution of dry NR properties. The pyrosequencing of 16S (119 837 effective reads) and 18S (131 879 effective reads) rRNA gene regions was performed on 21 samples covering different maturation times and two aeration conditions. Results showed a relatively high bacterial richness (Chao1 estimates of 200-1000) associated with significant bacterial dynamics. Lactic acid bacteria (LAB) were dominant in the first days of maturation. Then, in aerobic conditions, development of Actinobacteria represented by the family Microbacteriaceae was associated with alkalinization of the samples and a higher sensitivity of NR to thermo-oxidation as evaluated by its plasticity retention index (PRI). In anaerobiosis, the reduced development of bacteria, mostly LAB present, was associated with improved NR properties (higher initial plasticity P 0 and PRI). The involvement of micro-organisms in the evolution of dry NR properties during the maturation of NR coagula was confirmed. The importance of the structure and dynamics of microbial communities is specifically highlighted. Natural rubber is a key elastomer for the tyre industry and for a variety of other applications. The majority of raw NR is obtained by natural coagulation of H. brasiliensis latex under the activity of micro-organisms. An improved understanding of the microbial communities involved in the maturation of NR coagula may lead to an improvement in the production process of raw NR to provide a better consistency in NR quality. © 2017 The Society for Applied Microbiology.

[Type IV contact allergies in the food processing industry: an update].

PubMed

Bauer, A; Schubert, S; Geier, J; Mahler, V

2018-06-01

The food sector is one of the high-risk areas for occupational irritative and allergic contact eczema. The present work provides an overview of the main allergens as well as sensitization frequencies and risk in various food industry occupations. The literature on type IV sensitization in the food sector is summarized. The relative risk of developing a work-related eczema in food processing is increased by more than 3 times. The comparison group was calculated on the basis of the proportion of documented cases in the IVDK (Informationsverbund Dermatologischer Kliniken) network per 100,000 working persons in relation to the average of the years 2005 and 2010. For this purpose, the average risk of all patients was set as reference to 1. Bakers, pastry chefs, cooks and meat and fish processors are mainly affected. In addition to irritant contact eczema, allergic contact eczema and protein contact dermatitis often occur. Leading haptens (main allergens) are rubber ingredients, but also disinfectants and compositae. Only a few contact allergens are responsible for the majority of job-relevant sensitizations in the food industry.

32 CFR 256.8 - Land use compatibility guidelines for accident potential.

Code of Federal Regulations, 2010 CFR

2010-07-01

... industries ......do ......do Do. Rubber and miscellaneous plastic goods ......do ......do Do. Stone, clay..., explosive characteristics, air pollution. 4 No passenger terminals and no major above ground transmission...

32 CFR 256.8 - Land use compatibility guidelines for accident potential.

Code of Federal Regulations, 2011 CFR

2011-07-01

... industries ......do ......do Do. Rubber and miscellaneous plastic goods ......do ......do Do. Stone, clay..., explosive characteristics, air pollution. 4 No passenger terminals and no major above ground transmission...

Respiratory and skin effects of exposure to wood dust from the rubber tree Hevea brasiliensis.

PubMed

Sripaiboonkij, P; Phanprasit, W; Jaakkola, M S

2009-07-01

Potential health effects related to wood dust from the rubber tree, which produces natural rubber latex, have not been previously investigated. The main aim of this study was to investigate the relations of rubber tree dust exposure to respiratory and skin symptoms, asthma and lung function. A cross-sectional study was conducted among 103 workers (response rate 89%) in a rubber tree furniture factory and 76 office workers (73%) in four factories in Thailand. All participants answered a questionnaire and performed spirometry. Inhalable dust levels were measured in different work areas. Factory workers showed increased risk of wheezing, nasal symptoms and asthma compared to office workers. There was a dose-dependent increase in wheeze and skin symptoms in relation to dust level. Significantly increased risks of nasal symptoms (adj OR 3.67, 95% CI 1.45 to 9.28) and asthma (8.41, 1.06 to 66.60) were detected in the low exposure category. Workers exposed to ethyl cyanoacrylate glue had significantly increased risk of cough, breathlessness and nasal symptoms. There was dose-dependent reduction in spirometric lung function with wood dust level. This study provides new evidence that workers exposed to wood dust from the rubber tree experience increased risk of nasal symptoms, wheeze, asthma and skin symptoms and have reduced spirometric lung function. Exposure to cyanoacrylate is related to significantly increased respiratory symptoms. Results suggest that the furniture industry using rubber tree wood should implement appropriate exposure control measures to reduce wood dust exposure and cyanoacrylate glue exposure to protect their employees.

75 FR 17827 - Goodyear Tire & Rubber Company, Grant of Petition for Decision of Inconsequential Noncompliance

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-07

... measurable effect on the safety of the tire retread, repair, and recycling industries. The use of steel cord... effect of the noncompliance on the operational safety of vehicles on which these tires are mounted. The safety of people working in the tire retread, repair, and recycling industries must also be considered...

The comparison of properties and cost of material use of natural rubber and sand in manufacturing cement mortar for construction sub-base layer

NASA Astrophysics Data System (ADS)

Rahman, R.; Nemmang, M. S.; Hazurina, Nor; Shahidan, S.; Khairul Tajuddin Jemain, Raden; Abdullah, M. E.; Hassan, M. F.

2017-11-01

The main issue related to this research was to examine the feasibility of natural rubber SMR 20 in the manufacturing of cement mortar for sub-base layer construction. Subbase layers have certain functions that need to be fulfilled in order to assure strong and adequate permeability of pavement performance. In a pavement structure, sub-base is below the base and serves as the foundation for the overall pavement structure, transmitting traffic loads to the sub-grade and providing drainage. Based on this research, the natural rubber, SMR 20 was with the percentages of 0%, 5%, 10% and 15% to mix with sand in the manufacture of the cement mortar. This research describes some of the properties and cost of the materials for the natural rubber and sand in cement mortar manufacturing by laboratory testing. Effects of the natural rubber replacement on mechanical properties of mortar were investigated by laboratory testing such as compressive strength test and density. This study obtained the 5% of natural rubber replaced in sand can achieved the strength of normal mortar after 7 days and 28 days. The strength of cement mortar depends on the density of cement mortar. According to the cost of both materials, sand shows the lower cost in material for the cement mortar manufacturing than the uses of natural rubber. Thus, the convectional cement mortar which used sand need lower cost than the modified rubber cement mortar and the most economical to apply in industrial. As conclusion, the percentage of 5% natural rubber in the cement mortar would have the same with normal cement mortar in terms of the strength. However, in terms of the cost of the construction, it will increase higher than cost of normal cement mortar production. So that, this modified cement mortar is not economical for the road sub-base construction.

Audit Technical of Kori Rubber Dam in the River of Keyang District of Ponorogo East Java Province

NASA Astrophysics Data System (ADS)

Murnianto, E.; Suprapto, M.; Ikhsan, C.

2018-03-01

The development of science and technology for the utilization and protection of rivers has embodied various types of river infrastructure. Without proper maintenance, rapid river sediments undergo physical degradation and function. Problems that occur in Kori Rubber Dam, among others, the damage to the body of the rubber dam that is made of rubber, so that the function of flower deflection is not optimal. This happens because of limited operational and maintenance activities (OM). A technical audit is a process of identifying problems, analyzing, and evaluating ones conducted independently, objectively and professionally on the basis of examination, to assess the truth, accuracy, credibility, and reliability of information about a job. In this case an assessment of the Kori Rubber Dam, which is basically a benchmarking activity. Assessment of rubber dam components includes the physical conditions and functions that affect the weir. This research is expected to know the performance of Kori rubber Dam as a recommendation material in the implementation of OM Rubber Dam activities.

Biodiesel production methods of rubber seed oil: a review

NASA Astrophysics Data System (ADS)

Ulfah, M.; Mulyazmi; Burmawi; Praputri, E.; Sundari, E.; Firdaus

2018-03-01

The utilization of rubber seed as raw material of biodiesel production is seen highly potential in Indonesia. The availability of rubber seeds in Indonesia is estimated about 5 million tons per annum, which can yield rubber seed oil about 2 million tons per year. Due to the demand of edible oils as a food source is tremendous and the edible oil feedstock costs are far expensive to be used as fuel, production of biodiesel from non-edible oils such as rubber seed is an effective way to overcome all the associated problems with edible oils. Various methods for producing biodiesel from rubber seed oil have been reported. This paper introduces an optimum condition of biodiesel production methods from rubber seed oil. This article was written to be a reference in the selection of methods and the further development of biodiesel production from rubber seed oil. Biodiesel production methods for rubber seed oils has been developed by means of homogeneous catalysts, heterogeneous catalysts, supercritical method, ultrasound, in-situ and enzymatic processes. Production of biodiesel from rubber seed oil using clinker loaded sodium methoxide as catalyst is very interesting to be studied and developed further.

Silver nanoprisms/silicone hybrid rubber materials and their optical limiting property to femtosecond laser

NASA Astrophysics Data System (ADS)

Li, Chunfang; Liu, Miao; Jiang, Nengkai; Wang, Chunlei; Lin, Weihong; Li, Dongxiang

2017-08-01

Optical limiters against femtosecond laser are essential for eye and sensor protection in optical processing system with femtosecond laser as light source. Anisotropic Ag nanoparticles are expected to develop into optical limiting materials for femtosecond laser pulses. Herein, silver nanoprisms are prepared and coated by silica layer, which are then doped into silicone rubber to obtain hybrid rubber sheets. The silver nanoprisms/silicone hybrid rubber sheets exhibit good optical limiting property to femtosecond laser mainly due to nonlinear optical absorption.

Studies of Contaminated Runways,

DTIC Science & Technology

1980-01-01

slide friction we refer to the friction which is produced due to the relative motion between a rubber tyre and a hard runway. tThis type of friction is... rubber planing" and a tyre exposed to such a process shows damages in form of a local sticky surface or a locally worn-off layer. The steam, which...macrostructure causes when dry together with a rubber tyre brake numbers Prom 0.7 to 1.1 depending on the rubber mixture and inflation pressure. On this type of

Preparation and characterization of zinc sulphide nanocomposites based on acrylonitrile butadiene rubber

NASA Astrophysics Data System (ADS)

Ramesan, M. T.; Nihmath, A.; Francis, Joseph

2013-06-01

Rubber composite based on acrylonitrile butadiene rubber (NBR) reinforced with nano zinc sulphide (ZnS) have been prepared via vulcanization process and characterized by several techniques. Processing characteristics such as scorch time, optimum cure time decreases with increase in concentration of nano filler in acrylonitrile butadiene rubber. Mechanical properties such as tensile and tear strength increases with increase in concentration of nano filler up to 7 phr of loading thereafter the value decreases, whereas hardness, and flame resistance increases with the dosage of fillers. These enhanced properties are due to the homogenous dispersion of nano fillers in NBR matrix, which is evidenced from the structure that evaluated using X-ray diffraction (XRD) and scanning electron microscopy (SEM).

Occupational asthma due to colophony in non-industrial environments.

PubMed

Mariano, A; Paredes, I; Nuti, R; Innocenti, A

1993-01-01

Colophony is largely used in industrial environments, like the electronics and the rubber tyre industries, but it is also present in non-industrial environments as a constituent of glues and paper. For this reason it is one of the commonest skin sensitizers. Many cases of occupational asthma due to colophony have been described, but reports apart from electronic industry are not common. The case is described of a subject employed in administrative work who developed asthma due to colophony from using sealing wax to seal samples of food packages.

Roughness Perception during the Rubber Hand Illusion

ERIC Educational Resources Information Center

Schutz-Bosbach, Simone; Tausche, Peggy; Weiss, Carmen

2009-01-01

Watching a rubber hand being stroked by a paintbrush while feeling identical stroking of one's own occluded hand can create a compelling illusion that the seen hand becomes part of one's own body. It has been suggested that this so-called rubber hand illusion (RHI) does not simply reflect a bottom-up multisensory integration process but that the…

Mortality in the British rubber industry 1946-85.

PubMed Central

Sorahan, T; Parkes, H G; Veys, C A; Waterhouse, J A; Straughan, J K; Nutt, A

1989-01-01

The mortality experienced by a cohort of 36,691 rubber workers during 1946-85 has been investigated. These workers were all male operatives first employed in any one of the 13 participating factories in 1946-60; all had worked continuously in the industry for a minimum period of one year. Compared with the general population, statistically significant excesses relating to cancer mortality were found for cancer of the pharynx (E = 20.2, O = 30, SMR = 149), oesophagus (E = 87.6, O = 107, SMR = 122), stomach (E = 316.5, O = 359, SMR = 113), lung (E = 1219.2, O = 1592, SMR = 131), and all neoplasms (E = 2965.6, O = 3344, SMR = 113). Statistically significant deficits were found for cancer of the prostate. (E = 128.2, O = 91, SMR = 71), testis (E = 11.0, O = 4, SMR = 36), and Hodgkin's disease (E = 26.9, O = 16, SMR = 59). Involvement of occupational exposures was assessed by the method of regression models and life tables (RMLT). This method was used to compare the duration of employment in the industry, the duration in "dust exposed" jobs, and the duration in "fume and/or solvent exposed" jobs of those dying from causes of interest with those of all matching survivors. Positive associations (approaching formal levels of statistical significance) were found only for cancers of the stomach and the lung. The results of the RMLT analysis are independent of those from the SMR analysis, and the study continues to provide limited evidence of a causal association between the risks of stomach cancer and dust exposures, and the risks of lung cancer and fume or solvent exposures in the rubber industry during the period under study. PMID:2920137

[To-day exposure to occupational carcinogens and their effects. The experience of the rubber industry, iron metallurgy, asphalt work and aviculture].

PubMed

Barbieri, Pietro Gino

2009-01-01

While the progressive improvement of hygiene situations in the workplaces has taken to a reduction of chemical carcinogens exposure, in recent years in Italy the number of compensated occupational cancer resulting from carcinogens exposures of distant decades, has been increasing. Nevertheless, several experiences suggest that the proportion of occupational cancers unrecognised and not notified, as required by law, still remains important. This contribution concerns some experiences, performed between 2004-2008 by the Local Occupational Health Service (SPSAL) located in a highly industrialised province, on the working sector of rubber, iron and steel industry, the asphalt working and the poultry stock-breeders. This work concerns the following issues: - the evaluation of carcinogens exposure; - technical preventive measures and personal protection; - the level of workers' information and formation and the registration of exposed workers; - the characterization of work-related cancer. The results of the 5 years of activity allow us to underline that, in the most of 49 plants involved in the study, the carcinogens exposure evaluation and the prevention and protection measures were lacking. Information of workers was largely deficient and the registration of exposed workers was absent. A major attention to detect and to evaluate the work-related cancer has allowed us to recognize 50 new cases in the iron-steel industries and 21 new cases in a rubber industry. Although this experience concerns only few occupational fields, it provides the basis to call for a greater commitment of SPSAL addressed to companies and general practitioners to both, the promotion and surveillance of the correct procedures of carcinogens exposure evaluation and his prevention, and the active detection of occupational cancer, still missing.

The Effect of Temperature on the Production of Nitrobenzene

NASA Astrophysics Data System (ADS)

Agustriyanto, R.; Sapei, L.; Rosaline, G.; Setiawan, R.

2017-02-01

Nitrobenzene is a compound derived from benzene and quite fundamental in the petrochemical industry. One of which is in the manufacture of aniline. Aniline has an important role as dyes, synthetic rubber materials, rocket fuels and pharmaceuticals. Nitrobenzene can be synthesized by the nitration reaction of benzene. The purpose of the research is to design synthesis process of nitrobenzene by using Aspen Hysys simulator. The effect of changes in operating condition on nitrobenzene will be investigated. The benefits of the research are to obtain the optimum operating temperature for nitrobenzene production so that the use of utility can be minimized.

Occupational exposure to rubber vulcanization products during repair of rubber conveyor belts in a brown coal mine.

PubMed

Gromiec, Jan P; Wesołowski, Wiktor; Brzeźnicki, Sławomir; Wróblewska-Jakubowska, Krystyna; Kucharska, Małgorzata

2002-12-01

Several hundred chemical compounds were found in workroom environments in the rubber industry, but most of the published exposure data relate to the production of tyres; information from the "non-tyre" sections are very limited, if any. This study was carried out to identify chemical substances and measure their air concentrations in the repair shop of a brown coal mine in which damaged rubber conveyor belts were repaired. GC-MS and HPLC analysis of stationary air samples resulted in identification of aliphatic and aromatic hydrocarbons to C12, PAHs, alcohols, phenols, ketones, heterocyclic nitrogen and sulfur compounds. Quantitative evaluation of occupational exposure included determination of organic compound vapours collected on charcoal (GC-MSD), polycyclic aromatic hydrocarbons (HPLC), N-nitrosoamines and other amines (GC-NPD) and DNPH derivatives of aldehydes (HPLC) in the breathing zone of workers representing all job titles. The concentrations of investigated compounds were very low. Carcinogenic substances: N-nitrosoamines, benzene, PAHs were not present in workroom air in concentrations exceeding limits of detection of the analytical methods being applied; concentrations of methylisobutylketone, tetrachloroethylene, naphtha, aromatic hydrocarbons, phthalates and aldehydes were much lower than the respective occupational exposure limit values. The results indicate much lower exposure than that reported in the production of tyres and other fabricated rubber products.

Interfacial interaction between the epoxidized natural rubber and silica in natural rubber/silica composites

NASA Astrophysics Data System (ADS)

Xu, Tiwen; Jia, Zhixin; Luo, Yuanfang; Jia, Demin; Peng, Zheng

2015-02-01

The epoxidized natural rubber (ENR) as an interfacial modifier was used to improve the mechanical and dynamical mechanical properties of NR/silica composites. In order to reveal the interaction mechanism between ENR and silica, the ENR/Silica model compound was prepared by using an open mill and the interfacial interaction of ENR with silica was investigated by Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), X-ray diffraction (XRD) and stress-strain testing. The results indicated that the ring-opening reaction occurs between the epoxy groups of ENR chains and Si-OH groups on the silica surfaces and the covalent bonds are formed between two phases, which can improve the dispersion of silica in the rubber matrix and enhance the interfacial combination between rubber and silica. The ring-opening reaction occurs not only in vulcanization process but also in mixing process, meanwhile, the latter seems to be more important due to the simultaneous effects of mechanical force and temperature.

77 FR 10615 - Cooper Tire & Rubber Tire Company, Grant of Petition for Decision of Inconsequential Noncompliance

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-22

... measurable effect on the safety of the tire retread, repair, and recycling industries. The use of steel cord... no effect of the noncompliances on the operational safety of the vehicles on which these tires are mounted. The safety of people working in the tire retread, repair, and recycling industries must also be...

76 FR 73007 - Goodyear Tire and Rubber Company, Grant of Petition for Decision of Inconsequential Noncompliance

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-28

... measurable effect on the safety of the tire retread, repair, and recycling industries. The use of steel cord... true measure of inconsequentiality to motor vehicle safety in this case is that there is no effect of... safety of people working in the tire retread, repair, and recycling industries must also be considered...

The guayule plant : a renewable, domestic source of binder materials for flexible pavement mixtures.

DOT National Transportation Integrated Search

2013-01-01

The guayule (pronounced 'why-YOU-lee') plant grows in arid and semi-arid regions (e.g. the southwestern U.S.) and is a source of natural rubber. It was cultivated and processed during the World War II rubber shortage and is currently being processed ...

40 CFR 428.96 - Pretreatment standards for new sources.

Code of Federal Regulations, 2010 CFR

2010-07-01

... GUIDELINES AND STANDARDS RUBBER MANUFACTURING POINT SOURCE CATEGORY Pan, Dry Digestion, and Mechanical... and attributable to pan, dry digestion, and mechanical reclaimed rubber processes which are integrated...

Liquefaction of ground tire rubber at low temperature.

PubMed

Cheng, Xiangyun; Song, Pan; Zhao, Xinyu; Peng, Zonglin; Wang, Shifeng

2018-01-01

Low-temperature liquefaction has been investigated as a novel method for recycling ground tire rubber (GTR) into liquid using an environmentally benign process. The liquefaction was carried out at different temperatures (140, 160 and 180 °C) over variable time ranges (2-24 h) by blending the GTR with aromatic oil in a range from 0 to 100 parts per hundred rubber (phr). The liquefied GTR was separated into sol (the soluble fraction of rubber which can be extracted with toluene) and gel fractions (the solid fraction obtained after extraction) to evaluate the reclaiming efficiency. It was discovered that the percentage of the sol fraction increased with time, swelling ratio and temperature. Liquefied rubber was obtained with a high sol fraction (68.34 wt%) at 140 °C. Simultaneously, separation of nano-sized carbon black from the rubber networks occurred. The separation of carbon black from the network is the result of significant damage to the cross-linked-network that occurs throughout the liquefaction process. During liquefaction, a competitive reaction between main chain scission and cross-link bond breakage takes place. Copyright © 2017 Elsevier Ltd. All rights reserved.

Fabrication of Wood-Rubber Composites Using Rubber Compound as a Bonding Agent Instead of Adhesives.

PubMed

Shao, Dongwei; Xu, Min; Cai, Liping; Shi, Sheldon Q

2016-06-14

Differing from the hot-pressing method in the manufacturing of traditional wood-rubber composites (WRCs), this study was aimed at fabricating WRCs using rubber processing to improve water resistance and mechanical properties. Three steps were used to make WRCs, namely, fiber-rubber mixing, tabletting, and the vulcanization molding process. Ninety-six WRC panels were made with wood fiber contents of 0%-50% at rotor rotational speeds of 15-45 rpm and filled coefficients of 0.55-0.75. Four regression equations, i.e. , the tensile strength ( T s), elongation at break ( E b), hardness ( H a) and rebound resilience ( R r) as functions of fiber contents, rotational speed and filled coefficient, were derived and a nonlinear programming model were developed to obtain the optimum composite properties. Although the T s, E b and R r of the panels were reduced, H a was considerably increased by 17%-58% because of the wood fiber addition. Scanning electron microscope images indicated that fibers were well embedded in rubber matrix. The 24 h water absorption was only 1%-3%, which was much lower than commercial wood-based composites.

Onset of frictional sliding of rubber–glass contact under dry and lubricated conditions

PubMed Central

Tuononen, Ari J.

2016-01-01

Rubber friction is critical in many applications ranging from automotive tyres to cylinder seals. The process where a static rubber sample transitions to frictional sliding is particularly poorly understood. The experimental and simulation results in this paper show a completely different detachment process from the static situation to sliding motion under dry and lubricated conditions. The results underline the contribution of the rubber bulk properties to the static friction force. In fact, simple Amontons’ law is sufficient as a local friction law to produce the correct detachment pattern when the rubber material and loading conditions are modelled properly. Simulations show that micro-sliding due to vertical loading can release initial shear stresses and lead to a high static/dynamic friction coefficient ratio, as observed in the measurements. PMID:27291939

The use of Benford's law for evaluation of quality of occupational hygiene data.

PubMed

De Vocht, Frank; Kromhout, Hans

2013-04-01

Benford's law is the contra-intuitive empirical observation that the digits 1-9 are not equally likely to appear as the initial digit in numbers resulting from the same phenomenon. Manipulated, unrelated, or created numbers usually do not follow Benford's law, and as such this law has been used in the investigation of fraudulent data in, for example, accounting and to identify errors in data sets due to, for example, data transfer. We describe the use of Benford's law to screen occupational hygiene measurement data sets using exposure data from the European rubber manufacturing industry as an illustration. Two rubber process dust measurement data sets added to the European Union ExAsRub project but initially collected by the UK Health and Safety Executive (HSE) and British Rubber Manufacturers' Association (BRMA) and one pre- and one post-treatment n-nitrosamines data set collated in the German MEGA database and also added to the ExAsRub database were compared with the expected first-digit (1BL) and second-digit (2BL) Benford distributions. Evaluation indicated only small deviations from the expected 1BL and 2BL distributions for the data sets collated by the UK HSE and industry (BRMA), respectively, while for the MEGA data larger deviations were observed. To a large extent the latter could be attributed to imputation and replacement by a constant of n-nitrosamine measurements below the limit of detection, but further evaluation of these data to determine why other deviations from 1BL and 2BL expected distributions exist may be beneficial. Benford's law is a straightforward and easy-to-implement analytical tool to evaluate the quality of occupational hygiene data sets, and as such can be used to detect potential problems in large data sets that may be caused by malcontent a priori or a posteriori manipulation of data sets and by issues like treatment of observations below the limit of detection, rounding and transfer of data.

Glove permeation by semiconductor processing mixtures containing glycol-ether derivatives.

PubMed

Zellers, E T; Ke, H Q; Smigiel, D; Sulewski, R; Patrash, S J; Han, M W; Zhang, G Z

1992-02-01

Results of permeation tests of several glove materials challenged with semiconductor processing formulations containing glycolether derivatives are described. Commercial glove samples of nitrile rubber (Edmont), natural rubber (Edmont and Baxter), butyl rubber (North), PVC Baxter), a natural rubber/neoprene/nitrile blend (Pioneer), and a natural rubber/neoprene blend (Playtex) were tested according to the ASTM F739-85 permeation test method (open-loop configuration). The liquid formulations examined included a positive photoresist thinner containing 2-ethoxyethyl acetate (2-EEA), n-butyl acetate, and xylene; a positive photoresist containing 2-EEA, n-butyl acetate, xylene, polymer resins, and photoactive compounds; a negative photoresist containing 2-methoxyethanol (2-ME), xylene, and cyclized poly(isoprene); and pure 2-methoxyethyl acetate (2-MEA), which is the solvent used in a commercial electron-beam resist. With the exception of the negative photoresist, butyl rubber provided the highest level of protection against the solvent mixtures tested, with no breakthrough observed after 4 hr of continuous exposure at 25 degrees C. Nitrile rubber provided the highest level of protection against the negative photoresist and reasonably good protection against initial exposure to the other solvent mixtures. Gloves consisting of natural rubber or natural rubber blends provided less protection against the mixtures than either nitrile or butyl rubber. For most of the glove samples, permeation of the glycol-ether derivatives contained in the mixtures was faster than that predicted from the permeation of the pure solvents. Increasing the exposure temperature from 25 to 37 degrees C did not significantly affect the performance of the butyl rubber glove. For the other gloves, however, exposures at 37 degrees C resulted in decreases in breakthrough times of 25-75% and increases in steady-state permeation rates of 80-457% relative to values obtained at 25 degrees C. Repeated exposure of nitrile rubber samples resulted in shorter breakthrough times for all mixture components. In fact, exposure for as little as one-half of the nominal breakthrough time followed by air drying overnight resulted in measurable quantities of one or more of the component solvents at the inner surface of the gloves at the beginning of the next exposure. This effect was not observed with the butyl rubber samples. With the exception of the negative photoresist, heating previously exposed nitrile rubber samples at 70 degrees C for 20 hr prior to retesting reduced or eliminated the effects of residual solvents, permitting reuse of the gloves. The use of thin PVC or natural rubber gloves adjacent to the nitrile gloves provided moderate increases in permeation resistance.(ABSTRACT TRUNCATED AT 400 WORDS)

The outgassing characteristic research of the silicone rubber in high power laser system

NASA Astrophysics Data System (ADS)

Wu, Qipeng; Lv, Haibing; Dong, Meng; Fu, Zhaohui

2016-11-01

The outgassing characteristic of the silicone rubber which is the main material of non-metallic materials in high power laser system was studied outgassing rates of the silicone rubber and the baked-out silicone rubber which was performed at 80°C4 hours were measured by the constant volume process method and outgassing properties of them were analyzed by the quadrupole mass spectrometer. The results show that the outgassing rate of the silicone rubber and the baked-out silicone rubber is 2.69×10-7 Pa·m3s-1cm-2 and 6.47×10-8 Pa·m3s-1cm-2 respectively. All of them give out condensable volatile matter in vacuum. The outgassing rate and condensable volatile matter of the baked-out silicone rubber are less an order of magnitude compared with the silicone rubber, and the outgassing rate of the silicone rubber is less than 1×10-7 Pa·m3s-1cm-2, which is fit for non-metallic material of the high power laser system. This paper also discusses the method of reducing the outgassing rate and condensable volatile matter of the silicone rubber in high power laser system.

End Restraints for Impact-Energy-Absorbing Tube Specimens

NASA Technical Reports Server (NTRS)

Farley, G. L.; Modlin, J. T.

1985-01-01

Inexpensive device developed that eliminates tipping problem without affecting crushing process. Device consists of soft sponge-rubber insert approximately 0.5 inches (1.3 centimeters) thick, cut to same diameter as internal diameter of tube specimen. Metal washer, slightly smaller than internal diameter of tube, placed on top of rubber insert. Screw passed through washer and rubber insert and threaded into base of test machine. As screw tightened against washer, rubber insert compressed and expands radially. Radial expansion applies pressure against internal wall of tube specimen, which provides sufficient support to tube to prevent tipping.

Quality control in the recycling stream of PVC from window frames by hyperspectral imaging

NASA Astrophysics Data System (ADS)

Luciani, Valentina; Serranti, Silvia; Bonifazi, Giuseppe; Di Maio, Francesco; Rem, Peter

2013-05-01

Polyvinyl chloride (PVC) is one of the most commonly used thermoplastic materials in respect to the worldwide polymer consumption. PVC is mainly used in the building and construction sector, products such as pipes, window frames, cable insulation, floors, coverings, roofing sheets, etc. are realised utilising this material. In recent years, the problem of PVC waste disposal gained increasing importance in the public discussion. The quantity of used PVC items entering the waste stream is gradually increased as progressively greater numbers of PVC products approach to the end of their useful economic lives. The quality of the recycled PVC depends on the characteristics of the recycling process and the quality of the input waste. Not all PVC-containing waste streams have the same economic value. A transparent relation between value and composition is required to decide if the recycling process is cost effective for a particular waste stream. An objective and reliable quality control technique is needed in the recycling industry for the monitoring of both recycled flow streams and final products in the plant. In this work hyperspectral imaging technique in the near infrared (NIR) range (1000-1700 nm) was applied to identify unwanted plastic contaminants and rubber present in PVC coming from windows frame waste in order to assess a quality control procedure during its recycling process. Results showed as PVC, PE and rubber can be identified adopting the NIR-HSI approach.

40 CFR 428.95 - Standards of performance for new sources.

Code of Federal Regulations, 2012 CFR

2012-07-01

...) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) RUBBER MANUFACTURING POINT SOURCE CATEGORY Pan, Dry Digestion..., dry digestion, and mechanical reclaimed rubber processes which are integrated with a wet digestion...

40 CFR 428.95 - Standards of performance for new sources.

Code of Federal Regulations, 2014 CFR

2014-07-01

...) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) RUBBER MANUFACTURING POINT SOURCE CATEGORY Pan, Dry Digestion..., dry digestion, and mechanical reclaimed rubber processes which are integrated with a wet digestion...

40 CFR 428.95 - Standards of performance for new sources.

Code of Federal Regulations, 2013 CFR

2013-07-01

...) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) RUBBER MANUFACTURING POINT SOURCE CATEGORY Pan, Dry Digestion..., dry digestion, and mechanical reclaimed rubber processes which are integrated with a wet digestion...

Fluorination of silicone rubber by plasma polymerization

NASA Astrophysics Data System (ADS)

Fielding, Jennifer Chase

Plasma polymerized fluorocarbon (PPFC) films were deposited onto various silicone rubber substrates, including O-rings, to decrease oil uptake. Depositions were performed using a radio frequency (rf)-powered plasma reactor and various fluorocarbon monomers, such as C2F6, C2F 5H, C3F6, and 1H,1H,2H-perfluoro-1-dodecene. PPFC films which were most promising for inhibiting oil uptake were deposited with 1H,1H,2H-perfluoro-1-dodecene, and were composed predominantly of perfluoromethylene (CF2) species. These films displayed low critical surface energies (as low as 2.7 mJ/m2), and high contact angles with oil (84°), which were correlated with the amount of CF2 species present in the film. For the films with the highest degree of CF2 (up to 67%), CF2 chains may have been oriented slightly perpendicular to the substrate and terminated by CF3 species. Adhesion of the PPFC films directly to silicone rubber was found to be poor. However, when a plasma polymerized hydrocarbon interlayer was deposited on the silicone rubber prior to the fluorocarbon films, adhesion was excellent. O-rings coated with multilayer fluorocarbon films showed 2.6% oil uptake after soaking in oil for 100 hrs at 100°C. Due to variability in data, and the low quality of the industrial grade silicone rubber, the oil uptake mechanism was determined to be from oil flowing through flaws in the film due to defects within the substrate, not from generalized diffusion through the film. This mechanism was confirmed using higher quality silicone rubber, which showed little or no oil diffusion. Therefore, this film may perform well as an oil-repelling barrier when deposited on a high quality silicone rubber.

The use of diamond-filled polymers as thermally conductive composites

NASA Astrophysics Data System (ADS)

Morlidge, Christopher Patrick

A need for a material that combines excellent thermal conductivity with high electrical resistivity has been identified in the electrical industry. As many materials currently exist that conduct both materials the investigation was carried out into a ceramic filled polymer. Diamond was chosen as the filling material due to its exceptionally high thermal conductivity. Three polymer materials were investigated as matrices for this material. The materials used were silicone rubber, polyester and a paint based on poly vinyl chloride. A study of method of production and mixing was first carried out to find the best route to produce the composite by ensuring even dispersion and ease of application. Various examination techniques were employed to find the success of the different processes. These methods were calibrated and optimised. The best methods of mixing and choice of filling material was established. Thermal conductivity tests carried out on the composite materials showed that there was a marked increase in the thermal conductivity of the materials. The strength and thermal expansion of the silicone rubber based material were also increased.

Trapped rubber processing for advanced composites

NASA Technical Reports Server (NTRS)

Marra, P. J.

1976-01-01

Trapped rubber processing is a molding technique for composites in which precast silicone rubber is placed within a closed cavity where it thermally expands against the composite's surface supported by the vessel walls. The method has been applied by the Douglas Aircraft Company, under contract to NASA-Langley, to the design and fabrication of 10 DC-10 graphite/epoxy upper aft rudder assemblies. A three-bay development tool form mold die has been designed and manufactured, and tooling parameters have been established. Fabrication procedures include graphite layup, assembly of details in the tool, and a cure cycle. The technique has made it possible for the cocured fabrication of complex primary box structures otherwise impracticable via standard composite material processes.

29 CFR Appendix A to Part 510 - Manufacturing Industries Eligible for Minimum Wage Phase-In

Code of Federal Regulations, 2014 CFR

2014-07-01

... resins, and nonvulcanizable elastomers. 2822 2 Synthetic rubber (vulcanizable elastomers). 283 1 Drugs... shops). 3444 2 Sheet metal work. 3446 3 Architectural and ornamental metal work. 3449 2 Miscellaneous...

29 CFR Appendix A to Part 510 - Manufacturing Industries Eligible for Minimum Wage Phase-In

Code of Federal Regulations, 2013 CFR

2013-07-01

... resins, and nonvulcanizable elastomers. 2822 2 Synthetic rubber (vulcanizable elastomers). 283 1 Drugs... shops). 3444 2 Sheet metal work. 3446 3 Architectural and ornamental metal work. 3449 2 Miscellaneous...

29 CFR Appendix A to Part 510 - Manufacturing Industries Eligible for Minimum Wage Phase-In

Code of Federal Regulations, 2012 CFR

2012-07-01

... resins, and nonvulcanizable elastomers. 2822 2 Synthetic rubber (vulcanizable elastomers). 283 1 Drugs... shops). 3444 2 Sheet metal work. 3446 3 Architectural and ornamental metal work. 3449 2 Miscellaneous...

40 CFR 60.751 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-07-01

...; organic chemicals; plastics and resins manufacturing; pulp and paper industry; rubber and miscellaneous plastic products; stone, glass, clay, and concrete products; textile manufacturing; transportation..., water supply treatment plant, or air pollution control facility, exclusive of the treated effluent from...

Efficiency of butyl rubber sorbent to remove the PAH toxicity.

PubMed

Okay, O S; Özdemir, P; Yakan, S D

2011-01-01

Large amounts of polycyclic aromatic hydrocarbons (PAHs) have been released to the marine environment as a result of oil spills and from other sources including wastewaters, surface runoff, industrial processes, atmospheric deposition, biosynthesis, and natural events such as forest fires. PAHs have been known to affect a variety of biological processes and can be potent cell mutagens/carcinogens and toxic. In this study, PAH toxicity removal was investigated by using a novel macroporous butyl rubber (BR) sorbent. To find out the toxicity removal efficiency of the sorbents, the toxicity tests with Vibrio fisheri (luminescence bacteria) and Phaeodactylum tricornutum (marine algae) were applied to the acenaphthene (Ace) and phenanthrene (Phen) solutions in seawater (Ace: 500- 1000 μg/L; Phen; 100-1000 μg/L) before and after sorbent applications. Additionally, lysosomal stability and filtration rate biomarker techniques were applied to the mussels (Mytilus galloprovincialis) exposed to 1000 μg/L Phen solution and bioaccumulation was measured. The results showed that the toxicity of the PAH solutions decreased 50-100 percent depending on the concentration of the solutions and organisms. Phaeodactylum was found as the most sensitive organism to Phen and Ace. Since the application of BR sorbent removed the Phen from the solution, the bioaccumulated Phen amount in the mussels decreased accordingly.

Opportunities and challenges in industrial plantation mapping in big data era

NASA Astrophysics Data System (ADS)

Dong, J.; Xiao, X.; Qin, Y.; Chen, B.; Wang, J.; Kou, W.; Zhai, D.

2017-12-01

With the increasing demand in timer, rubber, palm oil in the world market, industrial plantations have dramatically expanded, especially in Southeast Asia; which have been affecting ecosystem services and human wellbeing. However, existing efforts on plantation mapping are still limited and blocked our understanding about the magnitude of plantation expansion and their potential environmental effects. Here we would present a literature review about the existing efforts on plantation mapping based on one or multiple remote sensing sources, including rubber, oil palm, and eucalyptus plantations. The biophysical features and spectral characteristics of plantations will be introduced first, a comparison on existing algorithms in terms of different plantation types. Based on that, we proposed potential improvements in large scale plantation mapping based on the virtual constellation of multiple sensors, citizen science tools, and cloud computing technology. Based on the literature review, we discussed a series of issues for future scale operational paddy rice mapping.

[Has N-isopropyl-N'-phenylparaphenylenediamine a place among standard allergens? Importance of this allergen in rubber intolerance].

PubMed

Foussereau, J; Cavelier, C

1977-01-01

Allergic contact dermatitis to N-isopropyl-N'-phenylparaphenylenediamine (IPPD) from rubber is far from being exceptional. Out of a total of 56 cases of allergic contact dermatitis to IPPD, 42 were considered as caused by occupational contacts: 17 cases were found in tyre manufacturers, 9 in car-mechanics, 9 in drivers, and 7 in various industrial branches. Out of the 56 cases, 23 also reacted allergically to mercaptobenzothiazole or to tetramethylthiuramdisulphide, or to both of these substances. In a chromatographic analysis of samples of 9 different tyre brands, IPPD was found in 8 cases.

Accelerated lifetime test of vibration isolator made of Metal Rubber material

NASA Astrophysics Data System (ADS)

Ao, Hongrui; Ma, Yong; Wang, Xianbiao; Chen, Jianye; Jiang, Hongyuan

2017-01-01

The Metal Rubber material (MR) is a kind of material with nonlinear damping characteristics for its application in the field of aerospace, petrochemical industry and so on. The study on the lifetime of MR material is impendent to its application in engineering. Based on the dynamic characteristic of MR, the accelerated lifetime experiments of vibration isolators made of MR working under random vibration load were conducted. The effects of structural parameters of MR components on the lifetime of isolators were studied and modelled with the fitting curves of degradation data. The lifetime prediction methods were proposed based on the models.

ODC-Free Solvent Implementation Issues for Vulcanized Rubber and Bond Systems

NASA Technical Reports Server (NTRS)

Hodgson, James R.; McCool, Alex (Technical Monitor)

2001-01-01

Thiokol Propulsion has worked extensively to replace 1,1,1-trichloroethane (TCA) with ozone depleting chemicals (ODC)-free solvents for use in the manufacture of the Reusable Solid Rocket Motor (RSRM) for the Space Shuttle Program. As Thiokol has transitioned from sub-scale to full-scale testing and implementation of these new solvents, issues have been discovered which have required special attention. The original intent of Thiokol's solvent replacement strategy was to replace TCA with a single drop-in solvent for all equivalent applications. We have learned that a single candidate does not exist for replacing TCA. Solvent incompatibility with process materials has caused us to seek for niche solvents and/or processing changes that provide an ODC-free solution for special applications. This paper addresses some of the solvent incompatibilities, which have lead to processes changes and possible niche solvent usage. These incompatibilities were discovered during full-scale testing of ODC-free solvents and relate to vulcanized rubber and bond systems in the RSRM. Specifically, the following items are presented: (1) Cure effects of d-limonene based solvents on Silica Filled Ethylene Propylene Diene Monomer (SF-EPDM) rubber. During full-scale test operations, Thiokol discovered that d-limonene (terpene) based solvents inhibit the cure of EPDM rubber. Subsequent testing showed the same issue with Nitrile Butadiene Rubber (NBR). Also discussed are efforts to minimize uncured rubber exposure to solvents; and (2) Cured bond system sensitivity to ODC-free solvents. During full scale testing it was discovered that a natural rubber to steel vulcanized bond could degrade after prolonged exposure to ODC-free solvents. Follow on testing showed that low vapor pressure and residence time seemed to be most likely cause for failure.

Determination of thermophysical characteristics of vulcanizable rubber products by the mathematical modeling method

NASA Astrophysics Data System (ADS)

Tikhomirov, S. G.; Pyatakov, Y. V.; Karmanova, O. V.; Maslov, A. A.

2018-03-01

The studies of the vulcanization kinetics of elastomers were carried out using a Truck tyre tread rubber compound. The formal kinetic scheme of vulcanization of rubbers sulfur-accelerator curing system was used which generalizes the set of reactions occurring in the curing process. A mathematical model is developed for determining the thermal parameters vulcanizable mixture comprising algorithms for solving direct and inverse problems for system of equations of heat conduction and kinetics of the curing process. The performance of the model is confirmed by the results of numerical experiments on model examples.

40 CFR 428.92 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2013 CFR

2013-07-01

... CATEGORY Pan, Dry Digestion, and Mechanical Reclaimed Rubber Subcategory § 428.92 Effluent limitations... pan, dry digestion, and mechanical reclaimed rubber processes which are integrated with a wet digestion reclaimed process, which may be discharged by a point source subject to the provisions of this...

40 CFR 428.92 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2012 CFR

2012-07-01

... CATEGORY Pan, Dry Digestion, and Mechanical Reclaimed Rubber Subcategory § 428.92 Effluent limitations... pan, dry digestion, and mechanical reclaimed rubber processes which are integrated with a wet digestion reclaimed process, which may be discharged by a point source subject to the provisions of this...

40 CFR 428.92 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2014 CFR

2014-07-01

... CATEGORY Pan, Dry Digestion, and Mechanical Reclaimed Rubber Subcategory § 428.92 Effluent limitations... pan, dry digestion, and mechanical reclaimed rubber processes which are integrated with a wet digestion reclaimed process, which may be discharged by a point source subject to the provisions of this...

The Rubber Hand Illusion Reveals Proprioceptive and Sensorimotor Differences in Autism Spectrum Disorders

ERIC Educational Resources Information Center

Paton, Bryan; Hohwy, Jakob; Enticott, Peter G.

2012-01-01

Autism spectrum disorder (ASD) is characterised by differences in unimodal and multimodal sensory and proprioceptive processing, with complex biases towards local over global processing. Many of these elements are implicated in versions of the rubber hand illusion (RHI), which were therefore studied in high-functioning individuals with ASD and a…

Urine cytology screening of French workers exposed to occupational urinary tract carcinogens: a prospective cohort study over a 20-year period

PubMed Central

Rouanet, Lucile; Mulliez, Aurélien; Naughton, Geraldine; Fontana, Luc; Druet-Cabanac, Michel; Moustafa, Farès; Chamoux, Alain

2017-01-01

Objectives To demonstrate that urine cytology screening can provide relevant epidemiological data for earlier detection of urothelial cancer caused by occupational exposure. Design Prospective cohort study. Setting Industries using urothelial carcinogens in France. Urine samples were collected on site, after a work week and were analysed at the University Hospital of Clermont-Ferrand, France. Participants Participants were workers exposed to urothelial carcinogens. Women and current smokers at time of study recruitment were exclusion criteria. Outcomes Urine cells atypia were ranged into three classes: negative/normal, atypical/suspicious/dysplasia or positive/malignant. Results We included 2020 workers over a period of 20 years from 1993 to 2013: 606 worked in rubber manufacturing, 692 from metal processing, 245 in chemical industry and 477 in roadwork and building industry. Workers had a mean exposure of 15.2±10.4 years before their first urine cytology screening. There was a mean of 3.4±4.3 urine cytology screenings per worker between 1993 and 2013. 6478 cytology were normal, 462 suspicious and 13 malignant. Suspicious and malignant cytology occurred in 4.8% of workers exposed for 1–10 years, 6.2% for 11–20 years of exposure, 7.6% for 21–30 years and 8.6% for >30 years (p<0.001). Using exposure for 1–10 years as reference, the adjusted OR of receiving a suspicious or malignant diagnosis increased with duration of exposure: OR=1.50 (95% CI 1.10 to 2.05, p=0.01) for 21–30 years and OR=1.78 (95% CI 1.23 to 2.56, p=0.002) for >30 years of exposure. Using metal processing as reference, the risk of pathological urine cytology results increased for rubber manufacturing (OR=1.32, 95% CI 1.05 to 1.65, p=0.02), with a trend for roadwork and building industry (OR=1.39, 95% CI 0.98 to 1.97, p=0.07) and for chemical industry (OR=1.34, 95% CI 0.94 to 1.93, p=0.11). Conclusions Urine cytology is a useful tool in occupational medicine. We promote new guidelines with an early screening of urothelial cancer by cytology, starting with beginning of exposure. PMID:28939575

Reinforcement of natural rubber hybrid composites based on marble sludge/Silica and marble sludge/rice husk derived silica

PubMed Central

Ahmed, Khalil; Nizami, Shaikh Sirajuddin; Riza, Nudrat Zahid

2013-01-01

A research has been carried out to develop natural rubber (NR) hybrid composites reinforced with marble sludge (MS)/Silica and MS/rice husk derived silica (RHS). The primary aim of this development is to scrutinize the cure characteristics, mechanical and swelling properties of such hybrid composite. The use of both industrial and agricultural waste such as marble sludge and rice husk derived silica has the primary advantage of being eco-friendly, low cost and easily available as compared to other expensive fillers. The results from this study showed that the performance of NR hybrid composites with MS/Silica and MS/RHS as fillers is extremely better in mechanical and swelling properties as compared with the case where MS used as single filler. The study suggests that the use of recently developed silica and marble sludge as industrial and agricultural waste is accomplished to provide a probable cost effective, industrially prospective, and attractive replacement to the in general purpose used fillers like china clay, calcium carbonate, and talc. PMID:25685484

Levels and distribution of dissolved hydrophobic organic contaminants in the Morava river in Zlín district, Czech Republic as derived from their accumulation in silicone rubber passive samplers.

PubMed

Prokeš, Roman; Vrana, Branislav; Klánová, Jana

2012-07-01

Dissolved waterborne polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) were assessed over a period of one year at five sampling sites in a model industrial region in the Czech Republic using silicone rubber passive samplers. The spatial variability of POPs in the studied region in water was small and diffusive pollution sources predominate. Concentrations of the most volatile PAHs decreased with increasing water temperature in the whole region, which reflects the seasonality in atmospheric deposition. The dissolved concentrations of more hydrophobic PAHs, PCBs and OCPs in and downstream the industrial zone are related to desorption from suspended particles. Upstream the industrial area, a positive correlation of dissolved and particle-bound contamination was observed only for DDT metabolites and hexachlorobenzene. Calculated fugacities in water and bottom sediment indicated a fair degree of equilibrium between these compartments for OCPs and PCBs, whereas sediment represented a potential source of PAHs. Copyright © 2012 Elsevier Ltd. All rights reserved.

40 CFR 428.95 - Standards of performance for new sources.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Mechanical Reclaimed Rubber Subcategory § 428.95 Standards of performance for new sources. (a) The following..., dry digestion, and mechanical reclaimed rubber processes which are integrated with a wet digestion...

Crumb rubber filtration: a potential technology for ballast water treatment.

PubMed

Tang, Zhijian; Butkus, Michael A; Xie, Yuefeng F

2006-05-01

The removal of turbidity, particles, phytoplankton and zooplankton in water by crumb rubber filtration was investigated. A substantial reduction was achieved. Of the three variables, filter depth, media size and filtration rate, media size had the most significant influence. Smaller media size favored higher removal efficiency of all targeted matter. There was no apparent relationship between removal efficiency and filter depth. Higher filtration rate resulted in lower removal efficiency and higher head loss. Compared with conventional granular media filters, crumb rubber filters required less backwash, and developed lower head loss. Consequently crumb rubber filters could be run for a longer time or allow a higher filtration rate. The results also indicate that the crumb rubber filtration alone did not achieve the target removal of invasive species. However, crumb rubber filtration could potentially be used as a primary treatment technology to enhance the efficiency of a secondary treatment process (e.g., disinfection).

Prevalence and risk factors of musculoskeletal disorders among Sri Lankan rubber tappers

PubMed Central

de Silva, Vijitha; Tharindra, Hemajith; Ostbye, Truls

2016-01-01

Background Rubber tapping exposes workers to risk factors for musculoskeletal disorders (MSDs). Objectives This cross-sectional study assessed the prevalence and factors associated with MSDs among Sri Lankan rubber tappers. Methods Questionnaires were administered to 300 rubber tappers to measure MSDs and potential associated factors. Ergonomic exposure levels were measured for 90 tappers using the Quick Exposure Check instrument. MSD prevalence and prevalence ratios were calculated using log-binomial regression. Results In the past 12 months, 66% of rubber tappers in our sample experienced an MSD. Ergonomic exposure levels were high or very high in the back (94.4%), shoulders (96.7%), and neck (83.3%). Being female, older, Tamil, working two jobs, alternating tapping hands, and depression were significantly associated with increased risk of MSDs. Conclusions MSDs are common among rubber tappers in Sri Lanka. These results suggest a need for work process modifications to prevent MSDs. PMID:27092589

40 CFR 60.751 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... collection and control systems are required under this subpart as a result of the nonmethane organic... generation; fertilizer/agricultural chemicals; food and related products/by-products; inorganic chemicals...; organic chemicals; plastics and resins manufacturing; pulp and paper industry; rubber and miscellaneous...

40 CFR 52.122 - Negative declarations.

Code of Federal Regulations, 2010 CFR

2010-07-01

...) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS Arizona § 52.122 Negative declarations. (a) The following... negative declarations are approved as additional information to the State Implementation Plan. (1) Maricopa... Operations, Rubber Tire Manufacturing, Polymer Manufacturing, Industrial Wastewater, Ship Building and Repair...

40 CFR 52.122 - Negative declarations.

Code of Federal Regulations, 2012 CFR

2012-07-01

...) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS Arizona § 52.122 Negative declarations. (a) The following... negative declarations are approved as additional information to the State Implementation Plan. (1) Maricopa... Operations, Rubber Tire Manufacturing, Polymer Manufacturing, Industrial Wastewater, Ship Building and Repair...

40 CFR 52.122 - Negative declarations.

Code of Federal Regulations, 2013 CFR

2013-07-01

...) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS Arizona § 52.122 Negative declarations. (a) The following... negative declarations are approved as additional information to the State Implementation Plan. (1) Maricopa... Operations, Rubber Tire Manufacturing, Polymer Manufacturing, Industrial Wastewater, Ship Building and Repair...

40 CFR 52.122 - Negative declarations.

Code of Federal Regulations, 2014 CFR

2014-07-01

...) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS Arizona § 52.122 Negative declarations. (a) The following... negative declarations are approved as additional information to the State Implementation Plan. (1) Maricopa... Operations, Rubber Tire Manufacturing, Polymer Manufacturing, Industrial Wastewater, Ship Building and Repair...

40 CFR 52.122 - Negative declarations.

Code of Federal Regulations, 2011 CFR

2011-07-01

...) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS Arizona § 52.122 Negative declarations. (a) The following... negative declarations are approved as additional information to the State Implementation Plan. (1) Maricopa... Operations, Rubber Tire Manufacturing, Polymer Manufacturing, Industrial Wastewater, Ship Building and Repair...

40 CFR 258.2 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-07-01

...; plastics and resins manufacturing; pulp and paper industry; rubber and miscellaneous plastic products... wastewater treatment plant, water supply treatment plant, or air pollution control facility exclusive of the... a wastewater treatment plant, water supply treatment plant, or air pollution control facility and...

40 CFR 60.751 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... generation; fertilizer/agricultural chemicals; food and related products/by-products; inorganic chemicals...; organic chemicals; plastics and resins manufacturing; pulp and paper industry; rubber and miscellaneous... of this title. Lateral expansion means a horizontal expansion of the waste boundaries of an existing...

40 CFR 60.751 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... generation; fertilizer/agricultural chemicals; food and related products/by-products; inorganic chemicals...; organic chemicals; plastics and resins manufacturing; pulp and paper industry; rubber and miscellaneous... of this title. Lateral expansion means a horizontal expansion of the waste boundaries of an existing...

40 CFR 60.751 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... generation; fertilizer/agricultural chemicals; food and related products/by-products; inorganic chemicals...; organic chemicals; plastics and resins manufacturing; pulp and paper industry; rubber and miscellaneous... of this title. Lateral expansion means a horizontal expansion of the waste boundaries of an existing...

Adhesion of nitrile rubber (NBR) to polyethylene terephthalate (PET) fabric. Part 1: PET surface modification by methylenediphenyl di-isocyanate (MDI)

NASA Astrophysics Data System (ADS)

Razavizadeh, Mahmoud; Jamshidi, Masoud

2016-01-01

Fiber to rubber adhesion is an important subject in rubber composite industry. It is well known that surface physical, mechanical and chemical treatments are effective methods to improve interfacial bonding. Ultra violet (UV) light irradiation is an efficient method which is used to increase interfacial interactions. In this research UV assisted chemical modification of PET fabric was used to increase its bonding to nitrile rubber (NBR). NBR is perfect selection to produce fuel and oil resistant rubber parts but it has weak bonding to fabrics. For this purpose at first, the PET fabric was carboxylated under UV irradiation and then methylenediphenyl diisocyanate (MDI) was reacted and grafted to carboxylated PET. T-peel test was used to evaluate PET fabric to NBR bonding strength. Attenuated total reflectance-Fourier transform infrared spectroscopy (FTIR-AT) was used to assess surface modifications of the PET fabrics. The chemical composition of the PET surfaces before and after carboxylation and MDI grafting was investigated by X-ray photoelectron spectroscopy (XPS). It was found that at vulcanizing temperature of 150 °C, carboxylation in contrary to MDI grafting, improved considerably PET to NBR adhesion. Finally effect of curing temperature on PET to NBR bonding strength was determined. It was found that increasing vulcanizing temperature to 170 °C caused considerable improvement (about 134%) in bonding strength.

An analytical approach for the non-invasive selection of consolidants in rubber artworks.

PubMed

Manfredi, Marcello; Barberis, Elettra; Rava, Antonio; Poli, Tommaso; Chiantore, Oscar; Marengo, Emilio

2016-08-01

The effectiveness of five polymeric materials for the long-term conservation and restoration of rubber artworks was evaluated by accelerated photo-oxidative degradation studies. Two different ethylene vinyl-acetate resins, generally used in industry and uncommon in conservation field, a new water-based polyurethane, and two ethylene butyl-acrylate resins were assessed for the consolidation of rubber. By monitoring their degradation along time with LED imaging coupled to statistics and Fourier transform infrared spectroscopy (FTIR), the polymeric materials with the best properties that ensure the protection and security of the artwork were identified. The degradation was performed in solar box simulating the light exposure in a museum, under controlled temperature at no more than 35 °C in order to exclude the thermal effects that could influence the ageing of polymers. The mechanical stress of the treated samples was also investigated. The spectroscopic analyses, the chromatic changes study, and the mechanical degradation were used as indicators of the consolidant stability, allowing the evaluation of the materials selected for the consolidation and conservation of rubber. The ethylene-vinyl acetate copolymers resulted the most stable and suitable for the conservation of rubber artworks. Lastly, the conservation treatment identified in this research was employed for the restoration of the contemporary artwork "Presagi di Birnam" made with bicycle inner tubes by the artist Carol Rama.

Fast and robust method for the determination of microstructure and composition in butadiene, styrene-butadiene, and isoprene rubber by near-infrared spectroscopy.

PubMed

Vilmin, Franck; Dussap, Claude; Coste, Nathalie

2006-06-01

In the tire industry, synthetic styrene-butadiene rubber (SBR), butadiene rubber (BR), and isoprene rubber (IR) elastomers are essential for conferring to the product its properties of grip and rolling resistance. Their physical properties depend on their chemical composition, i. e., their microstructure and styrene content, which must be accurately controlled. This paper describes a fast, robust, and highly reproducible near-infrared analytical method for the quantitative determination of the microstructure and styrene content. The quantitative models are calculated with the help of pure spectral profiles estimated from a partial least squares (PLS) regression, using (13)C nuclear magnetic resonance (NMR) as the reference method. This versatile approach allows the models to be applied over a large range of compositions, from a single BR to an SBR-IR blend. The resulting quantitative predictions are independent of the sample path length. As a consequence, the sample preparation is solvent free and simplified with a very fast (five minutes) hot filming step of a bulk polymer piece. No precise thickness control is required. Thus, the operator effect becomes negligible and the method is easily transferable. The root mean square error of prediction, depending on the rubber composition, is between 0.7% and 1.3%. The reproducibility standard error is less than 0.2% in every case.

Promoting the use of crumb rubber concrete in developing countries.

PubMed

Batayneh, Malek K; Marie, Iqbal; Asi, Ibrahim

2008-11-01

The use of accumulated waste materials in third world countries is still in its early phases. It will take courage for contractors and others in the construction industry to recycle selected types of waste materials in the concrete mixes. This paper addresses the recycling of rubber tires accumulated every year in Jordan to be used in concrete mixes. The main objectives of this research were to provide more scientific evidence to support the use of legislation or incentive-based schemes to promote the reuse of accumulated waste tires. This research focused on using crumb tires as a replacement for a percentage of the local fine aggregates used in the concrete mixes in Jordan. Different concrete specimens were prepared and tested in terms of uniaxial compression and splitting tension. The main variable in the mixture was the volumetric percentage of crumb tires used in the mix. The test results showed that even though the compressive strength is reduced when using the crumb tires, it can meet the strength requirements of light weight concrete. In addition, test results and observations indicated that the addition of crumb rubber to the mix has a limited effect toward reducing the workability of the mixtures. The mechanical test results demonstrated that the tested specimens of the crumb rubber concrete remained relatively intact after failure compared to the conventional concrete specimens. It is also concluded that modified concrete would contribute to the disposal of the non-decaying scrap tires, since the amount being accumulated in third world countries is creating a challenge for proper disposal. Thus, obliging authorities to invest in facilitating the use of waste tires in concrete, a fundamental material to the booming construction industry in theses countries, serves two purposes.

Mechanical Parameters of Rubber-Sand Mixtures for Numerical Analysis of a Road Embankment

NASA Astrophysics Data System (ADS)

Kowalska, Magdalena; Chmielewski, Maciej

2017-10-01

Waste production is one of the greatest problems of the modern world. It is inevitably related to the increase of industrialization. One of the most difficult, and growing in amounts, waste is scrap tyres. The most common method of utilization of end-of-life tyres by their incineration raises much concern in terms of air pollution. More sustainable seems to reuse the tyre derived products - rubber in particular - in civil engineering, where the interesting properties of this material may be effectively utilized. This paper presents results of direct shear strength tests on sand-rubber mixtures, which were next applied to a numerical FEM (finite element method) model of a road embankment built on soft ground. The laboratory tests, conducted for two types of scrap tyre rubber granulates (0.5 - 2 mm and 1 - 5 mm in size) mixed with medium fluvial sand in various proportions (5, 10, 30 and 50% by weight), proved that the unit weight of the mixtures is distinctly smaller that the unit weight of sand alone and at 50% rubber content it drops by half. The internal angle of friction stays almost unchanged for the mixtures with up to 10% of rubber (33 - 37°), but decreases by about 10° when the rubber content increases to 50%. In most of the cases analysed, the cohesion intercept is higher in case of sand-rubber mixtures when compared to sand alone. The numerical model simulated a 4.5 m high embankment with a 3 m thick layer made of sand-rubber mixtures, containing 0%, 10% or 30% of the waste product, founded on a weak subsoil (with a 3 m layer of organic soil). The results showed that stability factor of the structure built with the layer containing 30% of the coarser rubber granulate has increased from 1.60 - for sand only, to 2.15. The embankment was also able to carry load increased from 32 kPa to 45.5 kPa and its base showed much smaller settlement. The results prove that the use of tyre derived aggregates in embankment construction is not only an effective way of utilization of this problematic waste, but can also improve behaviour of such a structure.

New Green Polymeric Composites Based on Hemp and Natural Rubber Processed by Electron Beam Irradiation

PubMed Central

Stelescu, Maria-Daniela; Craciun, Gabriela; Dumitrascu, Maria

2014-01-01

A new polymeric composite based on natural rubber reinforced with hemp has been processed by electron beam irradiation and characterized by several methods. The mechanical characteristics: gel fraction, crosslink density, water uptake, swelling parameters, and FTIR of natural rubber/hemp fiber composites have been investigated as a function of the hemp content and absorbed dose. Physical and mechanical properties present a significant improvement as a result of adding hemp fibres in blends. Our experiments showed that the hemp fibers have a reinforcing effect on natural rubber similar to mineral fillers (chalk, carbon black, silica). The crosslinking rates of samples, measured using the Flory-Rehner equation, increase as a result of the amount of hemp in blends and the electron beam irradiation dose increasing. The swelling parameters of samples significantly depend on the amount of hemp in blends, because the latter have hydrophilic characteristics. PMID:24688419

New green polymeric composites based on hemp and natural rubber processed by electron beam irradiation.

PubMed

Stelescu, Maria-Daniela; Manaila, Elena; Craciun, Gabriela; Dumitrascu, Maria

2014-01-01

A new polymeric composite based on natural rubber reinforced with hemp has been processed by electron beam irradiation and characterized by several methods. The mechanical characteristics: gel fraction, crosslink density, water uptake, swelling parameters, and FTIR of natural rubber/hemp fiber composites have been investigated as a function of the hemp content and absorbed dose. Physical and mechanical properties present a significant improvement as a result of adding hemp fibres in blends. Our experiments showed that the hemp fibers have a reinforcing effect on natural rubber similar to mineral fillers (chalk, carbon black, silica). The crosslinking rates of samples, measured using the Flory-Rehner equation, increase as a result of the amount of hemp in blends and the electron beam irradiation dose increasing. The swelling parameters of samples significantly depend on the amount of hemp in blends, because the latter have hydrophilic characteristics.

The Auto

ERIC Educational Resources Information Center

Novick, Sheldon

1976-01-01

The basic automobile design has persisted for fifty years with innovations only in production and marketing. Complex interrelationships among steel, oil, rubber, road building, and automobile industries perpetuate the "modern Model T's." Efforts to alter design to meet safety and environmental standards face tremendous resistance from a…

Microstructure evolution and tribological properties of acrylonitrile-butadiene rubber surface modified by atmospheric plasma treatment

NASA Astrophysics Data System (ADS)

Shen, Ming-xue; Zhang, Zhao-xiang; Peng, Xu-dong; Lin, Xiu-zhou

2017-09-01

For the purpose of prolonging the service life for rubber sealing elements, the frictional behavior of acrylonitrile-butadiene rubber (NBR) surface by dielectric barrier discharge plasma treatments was investigated in this paper. Surface microstructure and chemical composition were measured by atomic force microscopy, field-emission scanning electron microscopy, and X-ray photoelectron spectroscopy, respectively. Water contact angles of the modified rubber surface were also measured to evaluate the correlation between surface wettability and tribological properties. The results show that plasma treatments can improve the properties of the NBR against friction and wear effectively, the surface microstructure and roughness of plasma-modified NBR surface had an important influence on the surface tribological behavior, and the wear depth first decreased and then increased along with the change of plasma treatment time. It was found that the wettability of the modified surface was gradually improved, which was mainly due to the change of the chemical composition after the treatment. This study suggests that the plasma treatment could effectively improve the tribological properties of the NBR surface, and also provides information for developing wear-resistant NBR for industrial applications.

Kansei engineering as a tool for the design of in-vehicle rubber keypads.

PubMed

Vieira, Joana; Osório, Joana Maria A; Mouta, Sandra; Delgado, Pedro; Portinha, Aníbal; Meireles, José Filipe; Santos, Jorge Almeida

2017-05-01

Manufacturers are currently adopting a consumer-centered philosophy which poses the challenge of developing differentiating products in a context of constant innovation and competitiveness. To merge both function and experience in a product, it is necessary to understand customers' experience when interacting with interfaces. This paper describes the use of Kansei methodology as a tool to evaluate the subjective perception of rubber keypads. Participants evaluated eleven rubber keys with different values of force, stroke and snap ratio, according to seven Kansei words ranging from "pleasantness" to "clickiness". Evaluation data was collected using the semantic differential technique and compared with data from the physical properties of the keys. Kansei proved to be a robust method to evaluate the qualitative traits of products, and a new physical parameter for the tactile feel of "clickiness" is suggested, having obtained better results than the commonly used Snap Ratio. It was possible to establish very strong relations between Kansei words and all physical properties. This approach will result in guidance to the industry for the design of in-vehicle rubber keypads with user-centered concerns. Copyright © 2017 Elsevier Ltd. All rights reserved.

Responses of rubber leaf phenology to climatic variations in Southwest China

NASA Astrophysics Data System (ADS)

Zhai, De-Li; Yu, Haiying; Chen, Si-Chong; Ranjitkar, Sailesh; Xu, Jianchu

2017-11-01

The phenology of rubber trees (Hevea brasiliensis) could be influenced by meteorological factors and exhibits significant changes under different geoclimates. In the sub-optimal environment in Xishuangbanna, rubber trees undergo lengthy periods of defoliation and refoliation. The timing of refoliation from budburst to leaf aging could be affected by powdery mildew disease (Oidium heveae), which negatively impacts seed and latex production. Rubber trees are most susceptible to powdery mildew disease at the copper and leaf changing stages. Understanding and predicting leaf phenology of rubber trees are helpful to develop effective means of controlling the disease. This research investigated the effect of several meteorological factors on different leaf phenological stages in a sub-optimal environment for rubber cultivation in Jinghong, Yunnan in Southwest China. Partial least square regression was used to quantify the relationship between meteorological factors and recorded rubber phenologies from 2003 to 2011. Minimum temperature in December was found to be the critical factor for the leaf phenology development of rubber trees. Comparing the delayed effects of minimum temperature, the maximum temperature, diurnal temperature range, and sunshine hours were found to advancing leaf phenologies. A comparatively lower minimum temperature in December would facilitate the advancing of leaf phenologies of rubber trees. Higher levels of precipitation in February delayed the light green and the entire process of leaf aging. Delayed leaf phenology was found to be related to severe rubber powdery mildew disease. These results were used to build predictive models that could be applied to early warning systems of rubber powdery mildew disease.

The IBA Easy-E-Beam™ Integrated Processing System

NASA Astrophysics Data System (ADS)

Cleland, Marshall R.; Galloway, Richard A.; Lisanti, Thomas F.

2011-06-01

IBA Industrial Inc., (formerly known as Radiation Dynamics, Inc.) has been making high-energy and medium-energy, direct-current proton and electron accelerators for research and industrial applications for many years. Some industrial applications of high-power electron accelerators are the crosslinking of polymeric materials and products, such as the insulation on electrical wires, multi-conductor cable jackets, heat-shrinkable plastic tubing and film, plastic pipe, foam and pellets, the partial curing of rubber sheet for automobile tire components, and the sterilization of disposable medical devices. The curing (polymerization and crosslinking) of carbon and glass fiber-reinforced composite plastic parts, the preservation of foods and the treatment of waste materials are attractive possibilities for future applications. With electron energies above 1.0 MeV, the radiation protection for operating personnel is usually provided by surrounding the accelerator facility with thick concrete walls. With lower energies, steel and lead panels can be used, which are substantially thinner and more compact than the equivalent concrete walls. IBA has developed a series of electron processing systems called Easy-e-Beam™ for the medium energy range from 300 keV to 1000 keV. These systems include the shielding as an integral part of a complete radiation processing facility. The basic concepts of the electron accelerator, the product processing equipment, the programmable control system, the configuration of the radiation shielding and some performance characteristics are described in this paper.

Mass, energy and material balances of SRF production process. Part 1: SRF produced from commercial and industrial waste.

PubMed

Nasrullah, Muhammad; Vainikka, Pasi; Hannula, Janne; Hurme, Markku; Kärki, Janne

2014-08-01

This paper presents the mass, energy and material balances of a solid recovered fuel (SRF) production process. The SRF is produced from commercial and industrial waste (C&IW) through mechanical treatment (MT). In this work various streams of material produced in SRF production process are analyzed for their proximate and ultimate analysis. Based on this analysis and composition of process streams their mass, energy and material balances are established for SRF production process. Here mass balance describes the overall mass flow of input waste material in the various output streams, whereas material balance describes the mass flow of components of input waste stream (such as paper and cardboard, wood, plastic (soft), plastic (hard), textile and rubber) in the various output streams of SRF production process. A commercial scale experimental campaign was conducted on an MT waste sorting plant to produce SRF from C&IW. All the process streams (input and output) produced in this MT plant were sampled and treated according to the CEN standard methods for SRF: EN 15442 and EN 15443. The results from the mass balance of SRF production process showed that of the total input C&IW material to MT waste sorting plant, 62% was recovered in the form of SRF, 4% as ferrous metal, 1% as non-ferrous metal and 21% was sorted out as reject material, 11.6% as fine fraction, and 0.4% as heavy fraction. The energy flow balance in various process streams of this SRF production process showed that of the total input energy content of C&IW to MT plant, 75% energy was recovered in the form of SRF, 20% belonged to the reject material stream and rest 5% belonged with the streams of fine fraction and heavy fraction. In the material balances, mass fractions of plastic (soft), plastic (hard), paper and cardboard and wood recovered in the SRF stream were 88%, 70%, 72% and 60% respectively of their input masses to MT plant. A high mass fraction of plastic (PVC), rubber material and non-combustibles (such as stone/rock and glass particles), was found in the reject material stream. Copyright © 2014 Elsevier Ltd. All rights reserved.

Characterization of rubber particles and rubber chain elongation in Taraxacum koksaghyz

PubMed Central

2010-01-01

Background Natural rubber is a biopolymer with exceptional qualities that cannot be completely replaced using synthetic alternatives. Although several key enzymes in the rubber biosynthetic pathway have been isolated, mainly from plants such as Hevea brasiliensis, Ficus spec. and the desert shrub Parthenium argentatum, there have been no in planta functional studies, e.g. by RNA interference, due to the absence of efficient and reproducible protocols for genetic engineering. In contrast, the Russian dandelion Taraxacum koksaghyz, which has long been considered as a potential alternative source of low-cost natural rubber, has a rapid life cycle and can be genetically transformed using a simple and reliable procedure. However, there is very little molecular data available for either the rubber polymer itself or its biosynthesis in T. koksaghyz. Results We established a method for the purification of rubber particles - the active sites of rubber biosynthesis - from T. koksaghyz latex. Photon correlation spectroscopy and transmission electron microscopy revealed an average particle size of 320 nm, and 13C nuclear magnetic resonance (NMR) spectroscopy confirmed that isolated rubber particles contain poly(cis-1,4-isoprene) with a purity >95%. Size exclusion chromatography indicated that the weight average molecular mass (w) of T. koksaghyz natural rubber is 4,000-5,000 kDa. Rubber particles showed rubber transferase activity of 0.2 pmol min-1 mg-1. Ex vivo rubber biosynthesis experiments resulted in a skewed unimodal distribution of [1-14C]isopentenyl pyrophosphate (IPP) incorporation at a w of 2,500 kDa. Characterization of recently isolated cis-prenyltransferases (CPTs) from T. koksaghyz revealed that these enzymes are associated with rubber particles and are able to produce long-chain polyprenols in yeast. Conclusions T. koksaghyz rubber particles are similar to those described for H. brasiliensis. They contain very pure, high molecular mass poly(cis-1,4-isoprene) and the chain elongation process can be studied ex vivo. Because of their localization on rubber particles and their activity in yeast, we propose that the recently described T. koksaghyz CPTs are the major rubber chain elongating enzymes in this species. T. koksaghyz is amenable to genetic analysis and modification, and therefore could be used as a model species for the investigation and comparison of rubber biosynthesis. PMID:20170509

Occupation and gastric cancer

PubMed Central

Raj, A; Mayberry, J; Podas, T

2003-01-01

Gastric cancer is a cause of significant morbidity and mortality. There are several risk factors, with occupation emerging as one of these. There is considerable evidence that occupations in coal and tin mining, metal processing, particularly steel and iron, and rubber manufacturing industries lead to an increased risk of gastric cancer. Other "dusty" occupations—for example, wood processing, or work in high temperature environments have also been implicated but the evidence is not strong. The mechanism of pathogenesis of gastric cancer is unclear and the identification of causative agents can be difficult. Dust is thought to be a contributor to the pathological process, but well known carcinogens such as N-nitroso compounds have been detected in some environments. Further research on responsible agents is necessary and screening for detection of precursor gastric cancer lesions at the workplace merits consideration. PMID:12782770

Fixture for mounting small parts for processing

DOEpatents

Foreman, Larry R.; Gomez, Veronica M.; Thomas, Michael H.

1990-01-01

A fixture for mounting small parts, such as fusion target spheres or microelectronic components. A glass stalk is drawn and truncated near its tip. The truncated end of the glass stalk is dipped into silicone rubber forming an extending streamer. After the rubber cures for approximately 24 hours, a small part is touched to the streamer, and will be held securely throughout processing.

Properties of Vulcanized Polyisoprene Rubber Composites Filled with Opalized White Tuff and Precipitated Silica

PubMed Central

Zeković, Ivana; Marinović-Cincović, Milena

2014-01-01

Opalized white tuff (OWT) with 40 μm average particle size and 39.3 m2/g specific surface area has been introduced into polyisoprene rubber (NR). Their reinforcing effects were evaluated by comparisons with those from precipitated silica (PSi). The cure characteristic, apparent activation energy of cross-link (E ac) and reversion (E ar), and mechanical properties of a variety of composites based on these rubbers were studied. This was done using vulcanization techniques, mechanical testing, and scanning electron microscopy (SEM). The results showed that OWT can greatly improve the vulcanizing process by shortening the time of optimum cure (t c90) and the scorch time (t s2) of cross-linked rubber composites, which improves production efficiency and operational security. The rubber composites filled with 50 phr of OWT were found to have good mechanical and elastomeric properties. The tensile strengths of the NR/OWT composites are close to those of NR/PSi composites, but the tear strength and modulus are not as good as the corresponding properties of those containing precipitated silica. Morphology results revealed that the OWT is poorly dispersed in the rubber matrix. According to that, the lower interactions between OWT and polyisoprene rubber macromolecules are obtained, but similar mechanical properties of NR/OWT (100/50) rubber composites compared with NR/PSi (100/50) rubber composites are resulted. PMID:24672391

A comparative study of ground tire rubber devulcanization using twin screw extruder and internal mixer

NASA Astrophysics Data System (ADS)

Ujianto, O.; Putri, D. B.; Jayatin; AWinarto, D.

2017-07-01

Devulcanization of ground tire rubber (GTR) was done using twin screw extruder (TSE) and internal mixer (IM). Processing parameters were varied to analyze its effect on gel content. Fourier Transform Infrared Spectroscopy (FTIR) analysis was performed as qualitative technique to confirm structural change. The devulcanized rubbers with the least gel content percentage produced in both TSE and IM were then used as filler in natural rubber (NR)/coconut coir (CC) composite preparation. Effects of gel content percentage on NR/CC composite tensile strength and elongation at break were analyzed. The results show that the gel content decreased by 41% for sample processed in TSE and 50% in IM compared to control sample. Overall, the devulcanization is influenced by high energy generated by thermal or thermo-mechanical process. FTIR spectra show chemically structural changes of GTR as C=C, CH2, CH3 with higher intensity for IM sample than its counterpart indicated devulcanization. The replacement of GTR to DGTR on NR/CC/GTR composites provided less network structures and resulted better tensile strength and elongation at break.

40 CFR 721.9740 - Brominated triazine derivative.

Code of Federal Regulations, 2010 CFR

2010-07-01

....9740 Section 721.9740 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC... plastic, elastomer, rubber matrix, or in solution. (iii) Industrial, commercial, and consumer activities. Requirements as specified in section 721.80(q). Any amount of the PMN substance imported in a plastic...

40 CFR 721.9740 - Brominated triazine derivative.

Code of Federal Regulations, 2011 CFR

2011-07-01

....9740 Section 721.9740 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC... plastic, elastomer, rubber matrix, or in solution. (iii) Industrial, commercial, and consumer activities. Requirements as specified in section 721.80(q). Any amount of the PMN substance imported in a plastic...

Comparative studies of industrial grade carbon black powders

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chawla, Komal, E-mail: komalchawla.rs@gmail.com; Chauhan, Alok P. S., E-mail: chauhan.alok@gmail.com, E-mail: alok.chauhan@alumni.stonybrook.edu

Comparative studies of two dissimilar industrial grade Carbon Black (CB) powders (N375 and N405) were conducted. The structure, surface area and particle size are the three important characteristics of CB powder that determine their processability and application as filler in preparing rubber compounds. The powders were characterized for their structure using dibutyl phthalate absorption (DBPA), particle size via laser particle size analyzer and surface area by nitrogen adsorption method. The structural characterization showed that N405 had lower DBPA in comparison to N375, confirming low structure of N405 grade CB powder. It was observed from the particle size analysis that N375more » was coarser than N405 grade CB. The total surface area values were determined by the BET method based on the cross sectional area of the nitrogen molecule. N375, a coarse grade CB powder with high structure, depicted less surface area as compared to N405.« less

Cancer incidence in cohorts of workers in the rubber manufacturing industry first employed since 1975 in the UK and Sweden.

PubMed

Boniol, M; Koechlin, A; Sorahan, T; Jakobsson, K; Boyle, P

2017-06-01

Increased cancer risks have been reported among workers in the rubber manufacturing industry employed before the 1960s, but it is unclear for workers hired subsequently. The present study focused on cancer incidence among rubber workers first employed after 1975 in Sweden and the UK. Two cohorts of rubber workers employed for at least 1 year were analysed. Standardised incidence ratios (SIRs), based on country-specific and period-specific incidence rates, were analysed for all cancers combined (except non-melanoma skin), bladder, lung, stomach cancer, leukaemia, non-Hodgkin's lymphoma and multiple myeloma. Exploratory analyses were conducted for other cancers with a minimum of 10 cases in both genders combined. 16 026 individuals (12 441 men; 3585 women) contributed to 397 975 person-years of observation, with 846 cancers observed overall (437 in the UK, 409 in Sweden). No statistically significant increased risk was observed for any site of cancer. A reduced risk was evident for all cancers combined (SIR=0.83, 95% CI (0.74 to 0.92)), lung cancer (SIR=0.74, 95% CI (0.59 to 0.93)), non-Hodgkin's lymphoma (SIR=0.67, 95% CI (0.45 to 1.00)) and prostate cancer (SIR=0.77, 95% CI (0.64 to 0.92)). For stomach cancer and multiple myeloma, SIRs were 0.93 (95% CI (0.61 to 1.43)) and 0.92 (95% CI 0.44 to 1.91), respectively. No increased risk of bladder cancer was observed (SIR=0.88, 95% CI (0.61 to 1.28)). No significantly increased risk of cancer incidence was observed in the combined cohort of rubber workers first employed since 1975. Continued surveillance of the present cohorts is required to confirm absence of long-term risk and confirmatory findings from other cohorts would be important. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Crumb rubber modified asphalt concrete in Oregon : summary report.

DOT National Transportation Integrated Search

1995-07-01

Over the last nine years, the Oregon Department of Transportation (ODOT) has constructed 13 projects using crumb rubber modifiers (CRMs) in asphalt concrete pavements using both the wet and dry process. Three of the projects included more than one ty...

Silicone absorption of elastomeric closures--an accelerated study.

PubMed

Degrazio, F L; Hlobik, T; Vaughan, S

1998-01-01

There is a trend in the parenteral industry to move from the use of elastomeric closures which are washed, siliconized, dried and sterilized in-house at the pharmaceutical manufacturers' site to pre-prepared closures purchased from the closure supplier. This preparation can consist of washing to reduce particle-load and bioburden, siliconization, placement in ready-to-sterilize bags and may eventually extend to sterilization by steam autoclave or gamma irradiation. Since silicone oil lubrication is critical to the processability/machinability of closures, research was designed to investigate this phenomenon in closures prepared using the Westar RS (Ready-to-Sterilize) process. This paper presents the data gathered in a study of the characteristic of silicone absorption into elastomeric closures under accelerated conditions. Variables such as silicone viscosity, rubber formulation, effect of sterilization and others are considered.

Fixture for mounting small parts for processing

DOEpatents

Foreman, L.R.; Gomez, V.M.; Thomas, M.H.

1990-05-29

A fixture for mounting small parts, such as fusion target spheres or microelectronic components is disclosed. A glass stalk is drawn and truncated near its tip. The truncated end of the glass stalk is dipped into silicone rubber forming an extending streamer. After the rubber cures for approximately 24 hours, a small part is touched to the streamer, and will be held securely throughout processing. 5 figs.

Tech Transfer Office discusses the finer points of tire recycling

NASA Technical Reports Server (NTRS)

1995-01-01

NASA's Technology Transfer Office at Stennis worked with a tire recycling company in St. Francisville, La., to help the company make better use of the cryogenics, or supercold fluids, in its recycling process. The process separates the rubber from the steel belts and other particles. The rubber is broken down into a material called crumb. Other parts of the tire particle removed is called fluff.

[Chromosome aberration frequency in workers in tire and industrial ruber manufacture].

PubMed

Aleksandrov, S E

1982-01-01

A cytogenetic study was carried out with the view to analyse blood and embryonic tissue cultures taken from female workers of various shops of tyre and rubber industry. In workers of preparation shops the level of chromosome aberrations in blood was equal to 2.63%, while in embryonic tissues the value was 6.33%. The number of aberrations on blood and embryonic tissue exhibited by workers of chemical shops was equal to 1.34 and 2.79%, respectively. No specific differences were observed in the sub-group of women having been in frequent contacts with gasoline or curing gases, as compared with the group on the whole. Curing accelerators which are ingredients of toxic dust in preparation shops of tyre and rubber industry cause a sharp increase in the number of chromosome aberrations both in blood and in the embryonic tissues of women. Data on induced abortions may be used for evaluation of the influence of chemicals on the developing fetus and can serve as a test models of mutagenic and embryotoxic effect. They also may be regarded as a part of the general system of the evaluation of mutagenic effects of chemicals in humans.

Upscaling of a Batch De-Vulcanization Process for Ground Car Tire Rubber to a Continuous Process in a Twin Screw Extruder.

PubMed

Saiwari, Sitisaiyidah; van Hoek, Johannes W; Dierkes, Wilma K; Reuvekamp, Louis E A M; Heideman, Geert; Blume, Anke; Noordermeer, Jacques W M

2016-08-24

As a means to decrease the amount of waste tires and to re-use tire rubber for new tires, devulcanization of ground passenger car tires is a promising process. Being an established process for NR and EPDM, earlier work has shown that for ground passenger car tire rubber with a relatively high amount of SBR, a devulcanization process can be formulated, as well. This was proven for a laboratory-scale batch process in an internal mixer, using diphenyl disulfide as the devulcanization aid and powder-sized material. In this paper, the devulcanization process for passenger car tire rubber is upscaled from 15 g per batch and transformed into a continuous process in a co-rotating twin screw extruder with a capacity of 2 kg/h. As SBR is rather sensitive to devulcanization process conditions, such as thermal and mechanical energy input, the screw design was based on a low shear concept. A granulate with particle sizes from 1-3.5 mm was chosen for purity, as well as economic reasons. The devulcanization process conditions were fine-tuned in terms of: devulcanization conditions (time/temperature profile, concentration of devulcanization aid), extruder parameters (screw configuration, screw speed, fill factor) and ancillary equipment (pre-treatment, extrudate handling). The influence of these parameters on the devulcanization efficiency and the quality of the final product will be discussed. The ratio of random to crosslink scission as determined by a Horikx plot was taken for the evaluation of the process and material. A best practice for continuous devulcanization will be given.

Upscaling of a Batch De-Vulcanization Process for Ground Car Tire Rubber to a Continuous Process in a Twin Screw Extruder

PubMed Central

Saiwari, Sitisaiyidah; van Hoek, Johannes W.; Dierkes, Wilma K.; Reuvekamp, Louis E.A.M.; Heideman, Geert; Blume, Anke; Noordermeer, Jacques W.M.

2016-01-01

As a means to decrease the amount of waste tires and to re-use tire rubber for new tires, devulcanization of ground passenger car tires is a promising process. Being an established process for NR and EPDM, earlier work has shown that for ground passenger car tire rubber with a relatively high amount of SBR, a devulcanization process can be formulated, as well. This was proven for a laboratory-scale batch process in an internal mixer, using diphenyl disulfide as the devulcanization aid and powder-sized material. In this paper, the devulcanization process for passenger car tire rubber is upscaled from 15 g per batch and transformed into a continuous process in a co-rotating twin screw extruder with a capacity of 2 kg/h. As SBR is rather sensitive to devulcanization process conditions, such as thermal and mechanical energy input, the screw design was based on a low shear concept. A granulate with particle sizes from 1–3.5 mm was chosen for purity, as well as economic reasons. The devulcanization process conditions were fine-tuned in terms of: devulcanization conditions (time/temperature profile, concentration of devulcanization aid), extruder parameters (screw configuration, screw speed, fill factor) and ancillary equipment (pre-treatment, extrudate handling). The influence of these parameters on the devulcanization efficiency and the quality of the final product will be discussed. The ratio of random to crosslink scission as determined by a Horikx plot was taken for the evaluation of the process and material. A best practice for continuous devulcanization will be given. PMID:28773843

1,3-Butadiene

Cancer.gov

Learn about 1,3-butadiene, exposure to which can raise your risk of leukemia. 1,3-Butadiene is a gas used to produce synthetic rubber products, such as tires, resins, and plastics. Other sources of exposure include car exhaust; tobacco smoke; and polluted air and water near industrial facilities.

Ghana: Background and U.S. Relations

DTIC Science & Technology

2009-07-08

increased access to credit and markets to diverse types of agricultural infrastructure growth. The key cocoa industry, as well as the cotton, cashew ...rubber, oil palm, soy, fruit, shea nut , timber, and coconut crop sectors, along with bio-fuel and medicinal plants and fisheries, are especially

Collective Bargaining and Labor-Management Relations in 1988.

ERIC Educational Resources Information Center

Ruben, George

1989-01-01

Reviews labor contracts renegotiated during 1988, placing emphasis on labor-management relations. Provides information on negotiations in the following industries: (1) trucking, (2) air transportation, (3) automobile manufacturing, (4) steel and other metals, (5) rubber, (6) bituminous coal, (7) forest products, and (8) shipbuilding. Covers…

[Destruction of the solid-cast rubber tyres by microscopic fungi].

PubMed

Chuienko, A I; Subbota, A H; Zhdanova, N M

2010-01-01

Resistance to the action of standard test-cultures of fungi (in accordance with GOST 9.049-91 of the former U.S.S.R.) and species, isolated from rubber substrates of two types of the poured rubber tyres, which contained natural and synthetic plasticizer, have been investigated. It has been shown that the strains, isolated from rubber materials have an ability to deteriorate rubber tyres of two types, in contrast to standard species, which caused deterioration only to the tyres, containing the synthetic plasticizer. It has been described in our investigations that fungal resistance of studied tyres decrease with time (on the 28th and 365th day, accordingly), that is shown in full overgrowing of tyre samples, in destruction of their surfaces and in changing of their hardness. Such changes are accompanied by processes of oxidation of rubber, degradation of plasticizer, and by deleaching of such inorganic components of rubber as calcium carbonate, kaolin and zeolite. This information is presented on IR-spectrograms of investigated samples as the absence or presence of absorption frequencies of different intensity that corresponded to aromatic, hydroxyl, ester, alcohol, nitrile and inorganic groups. The paper is presented in Ukrainian.

Toward 3D Printing of Medical Implants: Reduced Lateral Droplet Spreading of Silicone Rubber under Intense IR Curing.

PubMed

Stieghorst, Jan; Majaura, Daniel; Wevering, Hendrik; Doll, Theodor

2016-03-01

The direct fabrication of silicone-rubber-based individually shaped active neural implants requires high-speed-curing systems in order to prevent extensive spreading of the viscous silicone rubber materials during vulcanization. Therefore, an infrared-laser-based test setup was developed to cure the silicone rubber materials rapidly and to evaluate the resulting spreading in relation to its initial viscosity, the absorbed infrared radiation, and the surface tensions of the fabrication bed's material. Different low-adhesion materials (polyimide, Parylene-C, polytetrafluoroethylene, and fluorinated ethylenepropylene) were used as bed materials to reduce the spreading of the silicone rubber materials by means of their well-known weak surface tensions. Further, O2-plasma treatment was performed on the bed materials to reduce the surface tensions. To calculate the absorbed radiation, the emittance of the laser was measured, and the absorptances of the materials were investigated with Fourier transform infrared spectroscopy in attenuated total reflection mode. A minimum silicone rubber spreading of 3.24% was achieved after 2 s curing time, indicating the potential usability of the presented high-speed-curing process for the direct fabrication of thermal-curing silicone rubbers.

Evaluation of mix ingredients on the performance of rubber-modified asphalt mixtures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Takallou, H.B.

1987-01-01

In rubber-modified asphalt pavements ground recycled tire particles are added to a gap-graded aggregate and then mixed with hot asphalt cement. In view of the significant reductions in wintertime stopping distances under icy or frosty road surface conditions, the use of coarse rubber in asphalt pavements should be seriously considered. This research project consisted of a laboratory study of mix properties as a function of variables such as rubber gradation and content, void content, aggregate graduation, mix process, temperature, and asphalt content. Twenty different mix combinations were evaluated for diametral modulus and fatigue at two different temperatures. Also, five differentmore » mix combinations were evaluated for static creep and permanent deformation. The findings of the laboratory study indicate that the rubber gradation and content, aggregate gradation, and use of surcharge during sample preparation have considerable effect on modulus and fatigue life of the mix. The results of static creep and permanent deformation tests indicate that the rubber asphalt mixes had low stability and high elasticity. Also, due to greater allowable tensile strain in rubber-modified mixtures, the thickness of the modified mixture can be reduced, using a layer equivalency of 1.4 to 1.0« less

Ethylene-Propylene Terpolymer Rubber Processing by Electron Beam Irradiation

NASA Astrophysics Data System (ADS)

Manaila, Elena N.; Zuga, Maria Daniela T.; Martin, Diana I.; Craciun, Gabriela D.; Ighigeanu, Daniel I.; Matei, Constantin I.

2007-04-01

The investigations on the cross-linking by accelerated electrons of 6.23 MeV in lowly unsaturated elastomers of EPDM (ethylene-propylene terpolymer rubber) type are presented. Two rubber blends based EPDM were prepared and irradiated at different doses up to 250kGy: blend A - based on EPDM maleinized with polyethylene, zinc oxide, plasticizers, filler, and blend B - based on EPDM / PE (50 % EPDM and 50% polyethylene). Blends were prepared on a laboratory electrically heated rubber mill at temperatures of 150-160°C to enable the polyethylene (PE) melting to be reached. Plates of 150 × 150 × 2 mm were obtained in a laboratory electrical press at 170°C.

Toughening of thermosetting polyimides

NASA Technical Reports Server (NTRS)

Gollob, D. S.; Mandell, J. F.; Mcgarry, F. J.

1979-01-01

Work directed toward increasing the resistance to crack propagation of thermoset polyimides is described. Rubber modification and Teflon microfiber impregnation techniques for increasing fracture toughness are investigated. Unmodified Kerimid 601 has a fracture surface work value of 0.20 in-lbs/sq in. Dispersed particles of amine terminated butadiene acrylonitrile liquid rubber or of silicone rubber do not raise this value much. By contrast, 5 percent of well fibrillated Teflon produces an eight-fold increase in fracture toughness. Further process improvements should increase this factor to 20-30.

An investigation on chloroprene-compatibilized acrylonitrile butadiene rubber/high density polyethylene blends.

PubMed

Ahmed, Khalil

2015-11-01

Blends of acrylonitrile butadiene rubber/high density polyethylene (NBR/HDPE) compatibilized by Chloroprene rubber (CR) were prepared. A fixed quantity of industrial waste such as marble waste (MW, 40 phr) was also included. The effect of the blend ratio and CR on cure characteristics, mechanical and swelling properties of MW-filled NBR/HDPE blends was investigated. The results showed that the MW-filled NBR/HDPE blends revealed an increase in tensile strength, tear, modulus, hardness and cross-link density for increasing weight ratio of HDPE. The minimum torque (M L) and maximum torque (M H) of blends increased with increasing weight ratio of HDPE while scorch time (ts2) cure time (tc90), compression set and abrasion loss of blends decreased with increasing weight ratio of HDPE. The blends also showed a continuous reduction in elongation at break as well as swelling coefficient with increasing HDPE amount in blends. MW filled blends based on CR provided the most encouraging balance values of overall properties.

An investigation on chloroprene-compatibilized acrylonitrile butadiene rubber/high density polyethylene blends

PubMed Central

Ahmed, Khalil

2014-01-01

Blends of acrylonitrile butadiene rubber/high density polyethylene (NBR/HDPE) compatibilized by Chloroprene rubber (CR) were prepared. A fixed quantity of industrial waste such as marble waste (MW, 40 phr) was also included. The effect of the blend ratio and CR on cure characteristics, mechanical and swelling properties of MW-filled NBR/HDPE blends was investigated. The results showed that the MW-filled NBR/HDPE blends revealed an increase in tensile strength, tear, modulus, hardness and cross-link density for increasing weight ratio of HDPE. The minimum torque (ML) and maximum torque (MH) of blends increased with increasing weight ratio of HDPE while scorch time (ts2) cure time (tc90), compression set and abrasion loss of blends decreased with increasing weight ratio of HDPE. The blends also showed a continuous reduction in elongation at break as well as swelling coefficient with increasing HDPE amount in blends. MW filled blends based on CR provided the most encouraging balance values of overall properties. PMID:26644917

Enhancement of carbon-steel peel adhesion to rubber blend using atmospheric pressure plasma

NASA Astrophysics Data System (ADS)

Kršková, Jana; Skácelová, Dana; Kováčik, Dušan; Ráhel', Jozef; Pret'o, Jozef; Černák, Mirko

2016-08-01

The surface of carbon-steel plates was modified by non-equilibrium plasma of diffuse coplanar surface barrier discharge (DCSBD) in order to improve the adhesive properties to the NR (natural rubber) green rubber compound. The effect of different treatment times as well as different input power and frequency of supplied high voltage was investigated. The samples were characterized using contact angle and surface free energy measurement, measurement of adhesive properties, scanning electron microscopy (SEM) and atomic force microscopy (AFM). Surface chemical composition was studied by energy-dispersive X-ray spectroscopy (EDX). Significant increase in wettability was observed even after 2 s of plasma exposure. The surface modification was confirmed also by peel test, where the best results were obtained for 6 s of plasma treatment. In addition the ageing effect was studied to investigate the durability of modification, which is crucial for the industrial applications. Contribution to the topical issue "6th Central European Symposium on Plasma Chemistry (CESPC-6)", edited by Nicolas Gherardi, Ester Marotta and Cristina Paradisi

Polymer Research at NBS-NIST

NASA Astrophysics Data System (ADS)

Han, Charles

2001-03-01

Research on Polymers at NBS-NIST can be traced back to the World War I era.. During World War II, rubber and other organic materials testing and characterization started to play an important role in the nation's war effort. Since the 1940's, the rubber and plastic industry has transformed our lives. Rubber and plastic becomes a part of nearly every aspect of our daily life, including clothing, housing, transportation, and even food. The standards, testing methods, and basic physics research results produced at NBS-NIST had extensive influences and impacts on science and technology development during the post WWII period. Although sometimes controversial, the research in polymer crystallization, in linear and non-linear visco-elasticity, in surface adsorption, in piezoelectrical and pyroelectrical properties, in light scattering and neutron scattering, in polymer blends and alloys, and in dental applications, has made important contributions in the establishment of the current technology base. The challenge is to set the correct course in the future. We can learn many things by simply looking back at our past.

Piezoelectric ribbons printed onto rubber for flexible energy conversion.

PubMed

Qi, Yi; Jafferis, Noah T; Lyons, Kenneth; Lee, Christine M; Ahmad, Habib; McAlpine, Michael C

2010-02-10

The development of a method for integrating highly efficient energy conversion materials onto stretchable, biocompatible rubbers could yield breakthroughs in implantable or wearable energy harvesting systems. Being electromechanically coupled, piezoelectric crystals represent a particularly interesting subset of smart materials that function as sensors/actuators, bioMEMS devices, and energy converters. Yet, the crystallization of these materials generally requires high temperatures for maximally efficient performance, rendering them incompatible with temperature-sensitive plastics and rubbers. Here, we overcome these limitations by presenting a scalable and parallel process for transferring crystalline piezoelectric nanothick ribbons of lead zirconate titanate from host substrates onto flexible rubbers over macroscopic areas. Fundamental characterization of the ribbons by piezo-force microscopy indicates that their electromechanical energy conversion metrics are among the highest reported on a flexible medium. The excellent performance of the piezo-ribbon assemblies coupled with stretchable, biocompatible rubber may enable a host of exciting avenues in fundamental research and novel applications.

Effect of carbon black composition with sludge palm oil on the curing characteristic and mechanical properties of natural rubber/styrene butadiene rubber compound

NASA Astrophysics Data System (ADS)

Mohamed, R.; Nurazzi, N. Mohd; Huzaifah, M.

2017-07-01

This study was conducted to investigate the possibility of utilizing sludge palm oil (SPO) as processing oil, with various amount of carbon black as its reinforcing filler, and its effects on the curing characteristics and mechanical properties of natural rubber/styrene butadiene rubber (NR/SBR) compound. Rubber compound with fixed 15 pphr of SPO loading, and different carbon black loading from 20 to 50 pphr, was prepared using two roll mills. The cure characteristics and mechanical tests that have been conducted are the scorch and cure time analysis, tensile strength and tear strength. Scorch time (ts5) and cure time (t90) of the compound increases with the increasing carbon black loading. The mechanical properties of NR/SBR compound viz. the tensile strength, modulus at 300% strain and tear strength were also improved by the increasing carbon black loading.

Enhanced performance of crumb rubber filtration for ballast water treatment.

PubMed

Tang, Zhijian; Butkus, Michael A; Xie, Yuefeng F

2009-03-01

Waste-tire-derived crumb rubber was utilized as filter media to develop an efficient filter for ballast water treatment. In this study, the effects of coagulation, pressure filtration and dual-media (gravity) filtration on the performance of the crumb rubber filtration were investigated. The removal efficiencies of turbidity, phytoplankton and zooplankton, and head loss development were monitored during the filtration process. The addition of a coagulant enhanced the removal efficiencies of all targeted matter, but resulted in substantial increase of head loss. Pressure filtration increased filtration rates to 220 m(3)h(-1)m(-2) for 8-h operation and improved the zooplankton removal. Dual-media (crumb rubber/sand) gravity filtration also improved the removal efficiencies of phytoplankton and zooplankton over mono-media gravity crumb rubber filtration. However, these filtration techniques alone did not meet the criteria for removing indigenous organisms from ballast water. A combination of filtration and disinfection is suggested for future studies.

Industrial energy-efficiency improvement program

NASA Astrophysics Data System (ADS)

1980-12-01

The industrial energy efficiency improvement program to accelerate market penetration of new and emerging industrial technologies is described. Practices which will improve energy efficiency, encourage substitution of more plentiful domestic fuels, and enhance recovery of energy and materials from industrial waste streams are enumerated. Specific reports from the chemicals and allied products; primary metals; petroleum and coal products; stone, clay, and glass, paper and allied products; food and kindred products; fabricated metals; transportation equipment; machinery (except electrical); textile mill products; rubber and miscellaneous plastics; electrical and electronic equipment; lumber and wood; and tobacco products are discussed. A summary on progress in the utilization of recovered materials, and an analysis of industrial fuel mix is presented.

The effect of ultrasonic processing of multi-wall carbon nanotubes on properties of elastomeric compositions on the basis of synthetic isoprene rubber

NASA Astrophysics Data System (ADS)

Mitryaeva, N. S.; Myshlyavtsev, A. V.; Akimenko, S. S.

2017-08-01

The paper studies the effect of ultrasonic processing on the vulcanizing, physical, mechanical and electrophysical properties of elastomeric compositions based on synthetic isoprene rubber. Microscopic studies of multi-wall carbon nanotubes samples before and after ultrasonic processing are carried out. Due to the research, the applied ultrasonic processing method provides splitting of bundles formed from multi-wall carbon nanotubes. This results in elastomeric material with increased strength and high electrical conductivity with a low concentration of nanofiller.

Process simulation and techno economic analysis of renewable diesel production via catalytic decarboxylation of rubber seed oil - A case study in Malaysia.

PubMed

Cheah, Kin Wai; Yusup, Suzana; Gurdeep Singh, Haswin Kaur; Uemura, Yoshimitsu; Lam, Hon Loong

2017-12-01

This work describes the economic feasibility of hydroprocessed diesel fuel production via catalytic decarboxylation of rubber seed oil in Malaysia. A comprehensive techno-economic assessment is developed using Aspen HYSYS V8.0 software for process modelling and economic cost estimates. The profitability profile and minimum fuels selling price of this synthetic fuels production using rubber seed oil as biomass feedstock are assessed under a set of assumptions for what can be plausibly be achieved in 10-years framework. In this study, renewable diesel processing facility is modelled to be capable of processing 65,000 L of inedible oil per day and producing a total of 20 million litre of renewable diesel product per annual with assumed annual operational days of 347. With the forecasted renewable diesel retail price of 3.64 RM per kg, the pioneering renewable diesel project investment offers an assuring return of investment of 12.1% and net return as high as 1.35 million RM. Sensitivity analysis conducted showed that renewable diesel production cost is most sensitive to rubber seed oil price and hydrogen gas price, reflecting on the relative importance of feedstock prices in the overall profitability profile. Copyright © 2017 Elsevier Ltd. All rights reserved.

Proteins and amino acids as biobased polymer modifiers

USDA-ARS?s Scientific Manuscript database

Natural rubber (NR) is a critical agricultural material vital to industry, medicine, and defense, yet global supply is largely limited to latex from Hevea brasiliensis cultivated in tropical regions. Guayule (Parthenium argentatum), a woody desert shrub indigenous to the U.S. and Mexico, is under de...

76 FR 29007 - Certain Aluminum Extrusions From China

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-19

... Aluminum Extrusions From China Determinations On the basis of the record \\1\\ developed in the subject...), that an industry in the United States is materially injured by reason of imports of certain aluminum... by Aluminum Extrusions Fair Trade Committee and the United Steel, Paper and Forestry, Rubber...

Expression of the cytoplasmic mevalonate pathway in chloroplasts

USDA-ARS?s Scientific Manuscript database

Parthenium argentatum, commonly known as guayule, is a shrub in the Asteraceae family that is native to the southwestern United States and northern Mexico. P. argentatum produces high quality rubber in bark tissue. As an industrial crop that grows in temperate climates, P. argentatum represents a vi...

Hazardous Waste Cleanup: Hyatt Clark Industries in Clark, New Jersey

EPA Pesticide Factsheets

The Former Hyatt Clark site was located at 3100 Raritan Road in Clark, New Jersey. The site was comprised of 32 acres of manufacturing areas, 32 acres of parking lots, and 23 acres of woodland. The plant originally manufactured hard-rubber products, such a

Zinc Leaching from Tire Crumb Rubber

NASA Astrophysics Data System (ADS)

Rhodes, E. P.; Ren, J.; Mays, D. C.

2010-12-01

Recent estimates indicate that more than 2 billion scrap tires are currently stockpiled in the United States and approximately 280 million more tires are added annually. Various engineering applications utilize recycled tires in the form of shredded tire crumb rubber. However, the use of tire crumb rubber may have negative environmental impacts, especially when the rubber comes into contact with water. A review of the literature indicates that leaching of zinc from tire crumb rubber is the most significant water quality concern associated with using this material. Zinc is generally used in tire manufacturing, representing approximately 1.3% of the final product by mass. This study will report results from the U.S. Environmental Protection Agency’s (EPA’s) Synthetic Precipitation Leaching Procedure, batch leaching tests, and column leaching tests performed to quantify the process by which zinc leaches from tire crumb rubber into water. Results are interpreted with a first-order kinetic attachment/detachment model, implemented with the U.S. Agricultural Research Service software HYDRUS-1D, in order to determine the circumstances when zinc leaching from tire crumb rubber would be expected to comply with the applicable discharge limits. One potential application for recycled tires is replacing sand with tire crumb rubber in granular media filters used for stormwater pollution control. For this to be a viable application, the total zinc in the stormwater discharge must be below the EPA’s benchmark value of 0.117 mg/L.

Evaluation of Permanent Deformation of CRM-Reinforced SMA and Its Correlation with Dynamic Stiffness and Dynamic Creep

PubMed Central

Mashaan, Nuha Salim; Karim, Mohamed Rehan

2013-01-01

Today, rapid economic and industrial growth generates increasing amounts of waste materials such as waste tyre rubber. Attempts to inspire a green technology which is more environmentally friendly that can produce economic value are a major consideration in the utilization of waste materials. The aim of this study is to evaluate the effect of waste tyre rubber (crumb rubber modifier (CRM)), in stone mastic asphalt (SMA 20) performance. The virgin bitumen (80/100) penetration grade was used, modified with crumb rubber at four different modification levels, namely, 6%, 12%, 16%, and 20% by weight of the bitumen. The testing undertaken on the asphalt mix comprises the indirect tensile (dynamic stiffness), dynamic creep, and wheel tracking tests. By the experimentation, the appropriate amount of CRM was found to be 16% by weight of bitumen. The results show that the addition of CRM into the mixture has an obvious significant effect on the performance properties of SMA which could improve the mixture's resistance against permanent deformation. Further, higher correlation coefficient was obtained between the rut depth and permanent strain as compared to resilient modulus; thus dynamic creep test might be a more reliable test in evaluating the rut resistance of asphalt mixture. PMID:24302883

Evaluation of permanent deformation of CRM-reinforced SMA and its correlation with dynamic stiffness and dynamic creep.

PubMed

Mashaan, Nuha Salim; Karim, Mohamed Rehan

2013-01-01

Today, rapid economic and industrial growth generates increasing amounts of waste materials such as waste tyre rubber. Attempts to inspire a green technology which is more environmentally friendly that can produce economic value are a major consideration in the utilization of waste materials. The aim of this study is to evaluate the effect of waste tyre rubber (crumb rubber modifier (CRM)), in stone mastic asphalt (SMA 20) performance. The virgin bitumen (80/100) penetration grade was used, modified with crumb rubber at four different modification levels, namely, 6%, 12%, 16%, and 20% by weight of the bitumen. The testing undertaken on the asphalt mix comprises the indirect tensile (dynamic stiffness), dynamic creep, and wheel tracking tests. By the experimentation, the appropriate amount of CRM was found to be 16% by weight of bitumen. The results show that the addition of CRM into the mixture has an obvious significant effect on the performance properties of SMA which could improve the mixture's resistance against permanent deformation. Further, higher correlation coefficient was obtained between the rut depth and permanent strain as compared to resilient modulus; thus dynamic creep test might be a more reliable test in evaluating the rut resistance of asphalt mixture.

Studies on nitrile rubber degradation in zinc bromide completion fluid and its prevention by surface fluorination

NASA Astrophysics Data System (ADS)

Vega-Cantu, Yadira Itzel

Poly(acrylonitrile-co-butadiene) or nitrile-butadiene rubber (NBR) is frequently used as an O-ring material in the oil extraction industry due to its excellent chemical properties and resistance to oil. However, degradation of NBR gaskets is known to occur during the well completion and oil extraction process where packers are exposed to completion fluids such as ZnBr2 brine. Under these conditions NBR exhibits accelerated chemical degradation resulting in embrittlement and cracking. Samples of NBR, poly(acrylonitrile) (PAN) and poly(butadiene) (PB) have been exposed to ZnBr2 based completion fluid, and analyzed by ATR and diffuse reflectance IR. Analysis shows the ZnBr2 based completion fluid promotes hydrolysis of the nitrile group to form amides and carboxylic groups. Analysis also shows that carbon-carbon double bonds in NBR are unaffected after short exposure to zinc bromide based completion fluid, but are quickly hydrolyzed in acidic bromide mixtures. Although fluoropolymers have excellent chemical resistance, their strength is less than nitrile rubber and replacing the usual gasket materials with fluoroelastomers is expensive. However, a fluoropolymer surface on a nitrile elastomer can provide the needed chemical resistance while retaining their strength. In this study, we have shown that this can be achieved by direct fluorination, a rather easy and inexpensive process. Samples of NBR O-rings have been fluorinated by exposure to F2 and F2/HF mixtures at various temperatures. Fluorination with F 2 produces the desired fluoropolymer layer; however, fluorination by F2/HF mixtures gave a smoother fluorinated layer at lower temperatures and shorter times. Fluorinated samples were exposed to ZnBr2 drilling fluid and solvents. Elemental analysis shows that the fluorinated layer eliminates ZnBr2 diffusion into the NBR polymeric matrix. It was also found that surface fluorination significantly retards the loss of mechanical properties such as elasticity, tensile strength, toughness and compression set of nitrile rubber when exposed to zinc bromide fluid. This surface fluorination can be applied to extend the useful life of O-rings and packers in the field during oil extraction. The extended life can save millions of dollars by limiting the downtime of the well.

Morphology study of peroxide-induced dynamically vulcanized polypropylene/ethylene-propylene-diene monomer/zinc dimethacrylate blends during tensile deformation.

PubMed

Chen, Yukun; Xu, Chuanhui; Cao, Liming; Wang, Yanpeng; Fang, Liming

2013-06-27

Polypropylene (PP)/ethylene-propylene-diene monomer (EPDM)/zinc dimethacrylate (ZDMA) blend (EPDM/PP ratio of 30/70) with remarkable extensibility was successfully prepared via peroxide dynamic vulcanization. The uniaxial tensile properties, crystallization behavior, structure, and morphology during stretching were investigated. The tensile process study showed that the PP/EPDM/ZDMA blend exhibited the rubbery-like behavior with an elongation beyond 600%. The ZDMA graft-product domain increased the compatibility and interfacial adhesion between rubber and PP phases, while it reduced the crystallinity of the PP phase. On the basis of TEM and SEM analyses, we found that the cross-linked rubber particles could be elongated and oriented along the tensile direction, whereas the ZDMA graft-product domain "encapsulated" rubber phase together, acting as a "bridge" between elongated rubber phases and the PP phase during uniaxial stretching. The stress could be effectively transferred from the PP phase to the numerous elongated rubber phases due to the excellent compatibility and interfacial adhesion between rubber and PP phases, resulting in the rubbery-like behavior.

The detection and quantification of the defects in adhesive bonded joints of the piezoelectric sensors by infrared thermographic nondestructive testing

NASA Astrophysics Data System (ADS)

Vinod, P. N.; Joseph, Sherin; John, Reji

2017-04-01

In this paper, efficacy of pulsed thermography technique has been explored for the first time for the detection and quantification of the subsurface defects present in the rubber-encapsulated piezoelectric sensors. Initial experiments were performed on adhesively bonded joints of the rubber/Al or rubber/PZT control samples to find out an optimum acquisition time for the 3-mm rubber encapsulants. Thermographic measurements were performed in the reflection mode and acquired thermal images were analysed and processed images were described in terms of the phase images. The defective regions are identified as delamination of the adhesive joints at the interface of rubber and PZT stacks, and presence of porosity in the encapsulation in the inspected hydrophone. The defect depths of the observed anomalies were calculated empirically from the plots of the peak time of thermal contrast (tmax) maximum and thermal contrast maximum (Cmax) for a particular defect. The estimated defect depths of the prominent porosity observed in the PZT hydrophone are found nearly 1 mm from the surface.

Experimental and numerical modeling research of rubber material during microwave heating process

NASA Astrophysics Data System (ADS)

Chen, Hailong; Li, Tao; Li, Kunling; Li, Qingling

2018-05-01

This paper aims to investigate the heating behaviors of block rubber by experimental and simulated method. The COMSOL Multiphysics 5.0 software was utilized in numerical simulation work. The effects of microwave frequency, power and sample size on temperature distribution are examined. The effect of frequency on temperature distribution is obvious. The maximum and minimum temperatures of block rubber increase first and then decrease with frequency increasing. The microwave heating efficiency is maximum in the microwave frequency of 2450 MHz. However, more uniform temperature distribution is presented in other microwave frequencies. The influence of microwave power on temperature distribution is also remarkable. The smaller the power, the more uniform the temperature distribution on the block rubber. The effect of power on microwave heating efficiency is not obvious. The effect of sample size on temperature distribution is evidently found. The smaller the sample size, the more uniform the temperature distribution on the block rubber. However, the smaller the sample size, the lower the microwave heating efficiency. The results can serve as references for the research on heating rubber material by microwave technology.

Positron Annihilation Spectroscopy during physical aging of carbon-black filled rubber composites

NASA Astrophysics Data System (ADS)

Jobando, Vincent; Wang, Jingyi; Quarles, C. A.

2004-10-01

We have used positron annihilation spectroscopy to investigate the relaxation behavior of vulcanized and un-vulcanized rubber-carbon black composites. The samples were studied at temperatures above their glassy transitions. Changes in o-Ps intensity and S-parameter are indicative of the structural relaxation process. We have found that at room temperature, both vulcanized and un-vulcanized rubber showed no changes after ageing for about two months. While within the same period, un-vulcanized samples heated at 60^oC and allowed to age at room -temperature showed a decrease in o-Ps intensity and S-parameter. The o-Ps lifetime also decreased after this heat treatment for the un-vulcanized samples while the vulcanized ones remained unchanged. The changes seen were reversible however when we stopped heating the samples. We proposed that heat disordered the system and on cooling, rubber molecules formed more ordered regions, which we interpreted as crystallization. Vulcanized samples remained unchanged. We also found out that free volume decreases during physical deformation of pure rubber, but rubber with carbon black showed a significant rise in free volume. The lifetimes however remained unchanged.

Urine cytology screening of French workers exposed to occupational urinary tract carcinogens: a prospective cohort study over a 20-year period.

PubMed

Dutheil, Frederic; Rouanet, Lucile; Mulliez, Aurélien; Naughton, Geraldine; Fontana, Luc; Druet-Cabanac, Michel; Moustafa, Farès; Chamoux, Alain

2017-09-21

To demonstrate that urine cytology screening can provide relevant epidemiological data for earlier detection of urothelial cancer caused by occupational exposure. Prospective cohort study. Industries using urothelial carcinogens in France. Urine samples were collected on site, after a work week and were analysed at the University Hospital of Clermont-Ferrand, France. Participants were workers exposed to urothelial carcinogens. Women and current smokers at time of study recruitment were exclusion criteria. Urine cells atypia were ranged into three classes: negative/normal, atypical/suspicious/dysplasia or positive/malignant. We included 2020 workers over a period of 20 years from 1993 to 2013: 606 worked in rubber manufacturing, 692 from metal processing, 245 in chemical industry and 477 in roadwork and building industry. Workers had a mean exposure of 15.2±10.4 years before their first urine cytology screening. There was a mean of 3.4±4.3 urine cytology screenings per worker between 1993 and 2013. 6478 cytology were normal, 462 suspicious and 13 malignant. Suspicious and malignant cytology occurred in 4.8% of workers exposed for 1-10 years, 6.2% for 11-20 years of exposure, 7.6% for 21-30 years and 8.6% for >30 years (p<0.001). Using exposure for 1-10 years as reference, the adjusted OR of receiving a suspicious or malignant diagnosis increased with duration of exposure: OR=1.50 (95% CI 1.10 to 2.05, p=0.01) for 21-30 years and OR=1.78 (95% CI 1.23 to 2.56, p=0.002) for >30 years of exposure. Using metal processing as reference, the risk of pathological urine cytology results increased for rubber manufacturing (OR=1.32, 95% CI 1.05 to 1.65, p=0.02), with a trend for roadwork and building industry (OR=1.39, 95% CI 0.98 to 1.97, p=0.07) and for chemical industry (OR=1.34, 95% CI 0.94 to 1.93, p=0.11). Urine cytology is a useful tool in occupational medicine. We promote new guidelines with an early screening of urothelial cancer by cytology, starting with beginning of exposure. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

On the realization of the bulk modulus bounds for two-phase viscoelastic composites

NASA Astrophysics Data System (ADS)

Andreasen, Casper Schousboe; Andreassen, Erik; Jensen, Jakob Søndergaard; Sigmund, Ole

2014-02-01

Materials with good vibration damping properties and high stiffness are of great industrial interest. In this paper the bounds for viscoelastic composites are investigated and material microstructures that realize the upper bound are obtained by topology optimization. These viscoelastic composites can be realized by additive manufacturing technologies followed by an infiltration process. Viscoelastic composites consisting of a relatively stiff elastic phase, e.g. steel, and a relatively lossy viscoelastic phase, e.g. silicone rubber, have non-connected stiff regions when optimized for maximum damping. In order to ensure manufacturability of such composites the connectivity of the matrix is ensured by imposing a conductivity constraint and the influence on the bounds is discussed.

Quality improvement of pyrolysis oil from waste rubber by adding sawdust.

PubMed

Wang, Wen-liang; Chang, Jian-min; Cai, Li-ping; Shi, Sheldon Q

2014-12-01

This work was aimed at improving the pyrolysis oil quality of waste rubber by adding larch sawdust. Using a 1 kg/h stainless pyrolysis reactor, the contents of sawdust in rubber were gradually increased from 0%, 50%, 100% and 200% (wt%) during the pyrolysis process. Using a thermo-gravimetric (TG) analyzer coupled with Fourier transform infrared (FTIR) analysis of evolving products (TG-FTIR), the weight loss characteristics of the heat under different mixtures of sawdust/rubber were observed. Using the pyrolysis-gas chromatography (GC)-mass spectrometry (Py-GC/MS), the vapors from the pyrolysis processes were collected and the compositions of the vapors were examined. During the pyrolysis process, the recovery of the pyrolysis gas and its composition were measured in-situ at a reaction temperature of 450 °C and a retaining time of 1.2s. The results indicated that the efficiency of pyrolysis was increased and the residual carbon was reduced as the percentage of sawdust increased. The adding of sawdust significantly improved the pyrolysis oil quality by reducing the polycyclic aromatic hydrocarbons (PAHs) and nitrogen and sulfur compounds contents, resulting in an improvement in the combustion efficiency of the pyrolysis oil. Copyright © 2014 Elsevier Ltd. All rights reserved.

Troubleshooting for the observed problems in processing latex concentrate from natural resource

NASA Astrophysics Data System (ADS)

Afreen, S.; Haque, K. R.; Huda, M. K.

2013-06-01

Natural latex has special importance in the rubber industry for manufacturing different types of goods like gloves, balloons, male contraceptive and similar thin walled articles. This natural latex is much more sensitive a liquid to handle since it can easily become contaminated and thereby coagulated which makes it unfavourable for centrifuge and getting concentrate from it. Some other related measures also are included in consideration during the processing of concentrate latex from the natural raw latex. The problems that are being faced in a concentrate latex processing plant can be categorized in different groups like, problems related to the latex property, mechanical problems, electrical problems, handling and storage problems, transformation problems, problems related to environmental issues, etc. Among them, the most common and vital problems frequently observed in a concentrate latex processing plant are discussed here with a view to finding the measures for solution which will help to maintain the latex property in any latex processing plant.

29 CFR 1910.216 - Mills and calenders in the rubber and plastics industries.

Code of Federal Regulations, 2011 CFR

2011-07-01

... readily by pressure of the mill operator's body. (ii) Safety triprod. Installed in the front and in the.... 1910.216 Section 1910.216 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR OCCUPATIONAL SAFETY AND HEALTH STANDARDS Machinery and Machine...

Kent and Riegel's Handbook of industrial chemistry and biotechnology. 11th ed.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kent, James A.

2007-07-01

This handbook provides extensive information on plastics, rubber, adhesives, textile fibers, pharmaceutical chemistry, synthetic organic chemicals, soaps and detergents, as well as various other major classes of industrial chemistry. There is detailed coverage of coal utilization technology, dyes and dye intermediates, chlor-alkali and heavy chemicals, paints and pigments, chemical explosives, propellants, petroleum and petrochemicals, natural gas, industrial gases, synthetic nitrogen products, fats and oils, sulfur and sulfuric acid, phosphorous and phosphates, wood products, and sweeteners. The chapter on coal is entitled: coal technology for power, liquid fuels and chemicals. 100 ills.

Spontaneous abortions and reproductive selection mechanisms in the rubber and leather industry in Finland

PubMed Central

Hemminki, K; Niemi, Marja-Liisa; Kyyrönen, P; Kilpikari, I; Vainio, H

1983-01-01

ABSTRACT Spontaneous abortions in hospitals were analysed from two sources—membership files of the Union of Rubber and Leather Workers (about 10 000 women) and records of the personnel of a rubber factory (about 1600 women). Two frequencies of spontaneous abortions were calculated for each population analysed: rate (No spontaneous abortions X 100/No pregnancies) and ratio (No spontaneous abortions X 100/No births). The two frequencies were increased for all union members compared with all Finnish women. The frequencies, however, did not appreciably differ when the pregnancies occurred during union membership as compared with the pregnancies before or after membership. The frequency of spontaneous abortions was higher for the short-time union members than for those employed for longer periods, but the increased frequency did not correlate with union membership. The employees of a rubber factory had slightly fewer spontaneous abortions on average than the community population. The women employed in the rubber factory for three to 23 months were found to have appreciably higher frequencies of spontaneous abortions than the women employed for longer periods. The present study showed the feasibility of using cases of spontaneous abortions in hospitals in an occupational study with longitudinal employment data. Women with short periods of employment appeared to have more spontaneous abortions than those with longer periods of employment suggesting the presence of selection mechanisms, perhaps with some analogies to the “healthy worker effect” in occupational mortality studies. The presence of such selection mechanisms deserve serious consideration in occupational reproductive epidemiology. PMID:6824605

Exposure to high concentrations of nitrosamines and cancer mortality among a cohort of rubber workers

PubMed Central

Straif, K.; Weiland, S.; Bungers, M.; Holthenrich, D.; Taeger, D.; Yi, S.; Keil, U.

2000-01-01

OBJECTIVES—To examine if the occurrence of different cancers was increased among rubber workers, as the highest known exposures of humans to nitrosamines have occurred in the rubber industry.
METHODS—A cohort of 8933 rubber workers (hired after 1 January 1950, still active or retired on 1 January 1981 and employed for at least 1 year in one of five study factories) was followed up for mortality from 1 January 1981 to 31 December 1991. Work histories were reconstructed with routinely documented cost centre codes, which allowed identification by employment in specific work areas. For each cost centre code time and factory specific, semi-quantitative exposures to nitrosamines (three levels: low, medium, high) and other compounds were estimated by industrial hygienists. Rate ratios for medium (RRm) and high (RRh) exposures and 95% confidence intervals (95% CIs) were calculated with Cox's proportional hazards models with the low exposure as reference.
RESULTS—Exposure to nitrosamines was significantly associated with an increased mortality from cancers of the oesophagus (13 deaths: RRm 1.7, 95% CI 0.3 to 10.3; RRh 7.3, 95% CI 1.9 to 27.8) and of the oral cavity and pharynx (17 deaths: RRm 0.8, 95% CI 0.2 to 4.1; RRh 3.9, 95% CI 1.4 to 11.1). A non-significant trend of increasing mortality with exposure to higher concentrations of nitrosamines was found for mortality from cancer of the prostate (26 deaths: RRm 1.4, 95% CI 0.5 to 3.8; RRh 2.2, 95% CI 0.9 to 5.6), and the brain (six deaths: RRm 3.9, 95% CI 0.3 to 42.6; RRh 6.0, 95% CI 0.6 to 57.6). No association was found between exposure to nitrosamines and cancer of the stomach (RRm 0.8, 95% CI 0.4 to 1.8; RRh 1.2, 95% CI 0.5 to 2.5) or lung (RRm 1.0, 95% CI 0.6 to 1.5; RRh 1.0, 95% CI 0.7 to 1.6).
CONCLUSIONS—Exposure to high concentrations of nitrosamines is associated with increased mortality from cancers of the oesophagus, oral cavity, and pharynx, but not with increased mortality from cancers of the stomach or lung.


Keywords: nitrosamines; cancer mortality; rubber industry PMID:10810100

A novel use of bio-based natural fibers, polymers, and rubbers for composite materials

NASA Astrophysics Data System (ADS)

Modi, Sunny Jitendra

The composites, materials, and packaging industries are searching for alternative materials to attain environmental sustainability. Bio-plastics are highly desired and current microbially-derived bio-plastics, such as PHA (poly-(hydroxy alkanoate)), PHB (poly-(hydroxybutyrate)), and PHBV (poly-(beta-hydroxy butyrate-co-valerate)) could be engineered to have similar properties to conventional thermoplastics. Poly-(hydroxybutyrate) (PHB) is a bio-degradable aliphatic polyester that is produced by a wide range of microorganisms. Basic PHB has relatively high glass transition and melting temperatures. To improve flexibility for potential packaging applications, PHB is synthesized with various co-polymers such as Poly-(3-hydroxyvalerate) (HV) to decrease the glass and melting temperatures and, since there is improved melt stability at lower processing temperatures, broaden the processing window. However, previous work has shown that this polymer is too brittle, temperature-sensitive, and hydrophilic to meet packaging material physical requirements. Therefore, the proposed work focuses on addressing the needs for bio-derived and bio-degradable materials by creating a range of composite materials using natural fibers as reinforcement agents in bio-polymers and bio- plastic-rubber matrices. The new materials should possess properties lacking in PHBV and broaden the processing capabilities, elasticity, and improve the mechanical properties. The first approach was to create novel composites using poly-(beta-hydroxy butyrate-co-valerate) (PHBV) combined with fibers from invasive plants such as common reed (Phragmites australis), reed canary grass (Phalaris arundinacea), and water celery ( Vallisneria americana). The composites were manufactured using traditional processing techniques of extrusion compounding followed by injection molding of ASTM type I parts. The effects of each bio-fiber at 2, 5, and 10% loading on the mechanical, morphological, rheological, and thermal properties of PHBV were investigated. Many of the composites showed miscible blends between the fibers and PHBV. The SEM analysis showed finely dispersed water celery bio-fibers into the PHBV matrix indicating compatibility between this fiber and the PHBV matrix. The finely ground water celery fibers increased the fiber-matrix interactions without the use of additives or compatibilizers. When the mechanical properties of the composites were compared to pure PHBV, the composites showed improvements in the tensile modulus, while limited changes were observed in the tensile strength and elongation at break. Also, improvements in the viscosity at 170¨¬C over pure PHBV were observed with the addition of 10% by weight bio-fibers due to fiber-fiber and fiber-matrix interactions. With these improvements in the melt stability, the composites can be processed above the melting temperature of 165-170°C, a marked benefit over pure PHBV. The brittle nature of PHBV and its relatively high water transmission rates making it unsuitable for packaging applications. New blends of PHBV with high molecular weight natural rubber of matched viscosity were developed. The mechanical, rheological, and thermal properties of the blends with 5, 10, 15, and 25% by weight high molecular weight natural rubber (HMW-NR) were characterized; in addition, the water vapor transmission rates of these blends was determined. The results showed increased thermal stability and more uniform melting peaks for the blends compared to pure PHBV. The water permeation decreased with the addition of HMW-NR, and the permeation rates were similar to that of traditional thermoplastics. The addition of rubber increased the elongation at break without adversely affecting the Young's modulus for the blends. The complex viscosity of the blends was improved by one log over pure PHBV at 170ºC suggesting improved thermal stability of the blends. During creep and recovery testing, higher compliance values of the blends suggest increased entanglements network of PHBV and rubber micro-fibrils preventing the blends from developing permanent deformation. Therefore, these blends can potentially be used in-place of transitional thermoplastics in casting sheets and thermoforming.

Simulation of Canopy CO2/H2O Fluxes for a Rubber (Hevea Brasiliensis) Plantation in Central Cambodia: The Effect of the Regular Spacing of Planted Trees

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kumagai, Tomo'omi; Mudd, Ryan; Miyazawa, Yoshiyuki

We developed a soil-vegetation-atmosphere transfer (SVAT) model applicable to simulating CO2 and H2O fluxes from the canopies of rubber plantations, which are characterized by distinct canopy clumping produced by regular spacing of plantation trees. Rubber (Hevea brasiliensis Müll. Arg.) plantations, which are rapidly expanding into both climatically optimal and sub-optimal environments throughout mainland Southeast Asia, potentially change the partitioning of water, energy, and carbon at multiple scales, compared with traditional land covers it is replacing. Describing the biosphere-atmosphere exchange in rubber plantations via SVAT modeling is therefore essential to understanding the impacts on environmental processes. The regular spacing of plantationmore » trees creates a peculiar canopy structure that is not well represented in most SVAT models, which generally assumes a non-uniform spacing of vegetation. Herein we develop a SVAT model applicable to rubber plantation and an evaluation method for its canopy structure, and examine how the peculiar canopy structure of rubber plantations affects canopy CO2 and H2O exchanges. Model results are compared with measurements collected at a field site in central Cambodia. Our findings suggest that it is crucial to account for intensive canopy clumping in order to reproduce observed rubber plantation fluxes. These results suggest a potentially optimal spacing of rubber trees to produce high productivity and water use efficiency.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Magdalena Zaharia; Veena Sahajwalla; Byong-Chul Kim

The present study investigates the effect of addition of waste rubber tires on the combustion behavior of its blends with coke for carbon injection in electric arc furnace steelmaking. Waste rubber tires were mixed in different proportions with metallurgical coke (MC) (10:90, 20:80, 30:70) for combustion and pyrolysis at 1473 K in a drop tube furnace (DTF) and thermogravimetric analyzer (TGA), respectively. Under experimental conditions most of the rubber blends indicated higher combustion efficiencies compared to those of the constituent coke. In the early stage of combustion the weight loss rate of the blends is much faster compared to thatmore » of the raw coke due to the higher volatile yield of rubber. The presence of rubber in the blends may have had an impact upon the structure during the release and combustion of their high volatile matter (VM) and hence increased char burnout. Measurements of micropore surface area and bulk density of the chars collected after combustion support the higher combustion efficiency of the blends in comparison to coke alone. The surface morphology of the 30% rubber blend revealed pores in the residual char that might be attributed to volatile evolution during high temperature reaction in oxygen atmosphere. Physical properties and VM appear to have a major effect upon the measured combustion efficiency of rubber blends. The study demonstrates that waste rubber tires can be successfully co-injected with metallurgical coke in electric arc furnace steelmaking process to provide additional energy from combustion. 44 refs., 11 figs., 2 tabs.« less

Recycling and processing of several typical crosslinked polymer scraps with enhanced mechanical properties based on solid-state mechanochemical milling

NASA Astrophysics Data System (ADS)

Lu, Canhui; Zhang, Xinxing; Zhang, Wei

2015-05-01

The partially devulcanization or de-crosslinking of ground tire rubber (GTR), post-vulcanized fluororubber scraps and crosslinked polyethylene from cable scraps through high-shear mechanochemical milling (HSMM) was conducted by a modified solid-state mechanochemical reactor. The results indicated that the HSMM treated crosslinked polymer scraps can be reprocessed as virgin rubbers or thermoplastics to produce materials with high performance. The foamed composites of low density polyethylene/GTR and the blend of post-vulcanized flurorubber (FKM) with polyacrylate rubber (ACM) with better processability and mechanical properties were obtained. The morphology observation showed that the dispersion and compatibility between de-crosslinked polymer scraps and matrix were enhanced. The results demonstrated that HSMM is a feasible alternative technology for recycling post-vulcanized or crosslinked polymer scraps.

Bulk Viscoelastic Contribution to the Wet Sliding Friction of Rubber Compounds

NASA Astrophysics Data System (ADS)

Pan, Xiao-Dong

2002-03-01

An efficient stopping of an automobile on a wet highway in a rainy day is of obvious importance to the safety of the driving public. Here tire tread made of filled rubber compounds plays an essential role in detremining the wet traction performance. Even though significant progress has been made in improving this tire performance character and much knowledge has been accumulated, there still lacks a coherent fundamental understanding on this dynamic process. Consequently there currently exist no accurate guidelines for designing rubber compounds for better wet traction, and for predicting the wet traction performance of a rubber compound. In this experimental study, a portable British Pendulum Skid Tester has been employed to examine in the laboratory how the rubber compound material properties affect its wet sliding friction on a concrete surface. A dramatic dispaly of the impacts from the compound bulk viscoelastic properties has been observed for the first time. This observation will be discussed in relation to previous results discussed in the literature.

Soil methane and CO2 fluxes in rainforest and rubber plantations

NASA Astrophysics Data System (ADS)

Lang, Rong; Blagodatsky, Sergey; Goldberg, Stefanie; Xu, Jianchu

2017-04-01

Expansion of rubber plantations in South-East Asia has been a land use transformation trend leading to losses of natural forest cover in the region. Besides impact on ecosystem carbon stocks, this conversion influences the dynamics of greenhouse gas fluxes from soil driven by microbial activity, which has been insufficiently studied. Aimed to understand how land use change affects the soil CO2 and CH4 fluxes, we measured surface gas fluxes, gas concentration gradient, and 13C signature in CH4 and soil organic matter in profiles in a transect in Xishuangbanna, including a rainforest site and three rubber plantation sites with age gradient. Gas fluxes were measured by static chamber method and open chamber respiration system. Soil gases were sampled from installed gas samplers at 5, 10, 30, and 75cm depth at representative time in dry and rainy season. The soil CO2 flux was comparable in rainforest and old rubber plantations, while young rubber plantation had the lowest rate. Total carbon content in the surface soil well explained the difference of soil CO2 flux between sites. All sites were CH4 sinks in dry season and uptake decreased in the order of rainforest, old rubber plantations and young rubber plantation. From dry season to rainy season, CH4 consumption decreased with increasing CH4 concentration in the soil profile at all depths. The enrichment of methane by 13CH4 shifted towards to lowerδ13C, being the evidence of enhanced CH4 production process while net surface methane flux reflected the consumption in wet condition. Increment of CH4 concentration in the profile from dry to rainy season was higher in old rubber plantation compared to rainforest, while the shifting of δ13CH4 was larger in rainforest than rubber sites. Turnover rates of soil CO2 and CH4 suggested that the 0-5 cm surface soil was the most active layer for gaseous carbon exchange. δ13C in soil organic matter and soil moisture increased from rainforest, young rubber plantation to old rubber plantations. Conversion the forest into rubber plantation decreased soil respiration in young plantation and it recovered during rubber development. However, the CH4consumption by tropical upland forest soil decreased in converted rubber plantations of all ages, with more decrement in old plantation. Change forest into rubber plantations weakened the soil function as CH4 sink.

Development of downflow hanging sponge (DHS) reactor as post treatment of existing combined anaerobic tank treating natural rubber processing wastewater.

PubMed

Watari, Takahiro; Cuong Mai, Trung; Tanikawa, Daisuke; Hirakata, Yuga; Hatamoto, Masashi; Syutsubo, Kazuaki; Fukuda, Masao; Nguyen, Ngoc Bich; Yamaguchi, Takashi

2017-01-01

Conventional aerated tank technology is widely applied for post treatment of natural rubber processing wastewater in Southeast Asia; however, a long hydraulic retention time (HRT) is required and the effluent standards are exceeded. In this study, a downflow hanging sponge (DHS) reactor was installed as post treatment of anaerobic tank effluent in a natural rubber factory in South Vietnam and the process performance was evaluated. The DHS reactor demonstrated removal efficiencies of 64.2 ± 7.5% and 55.3 ± 19.2% for total chemical oxygen demand (COD) and total nitrogen, respectively, with an organic loading rate of 0.97 ± 0.03 kg-COD m -3 day -1 and a nitrogen loading rate of 0.57 ± 0.21 kg-N m -3 day -1 . 16S rRNA gene sequencing analysis of the sludge retained in the DHS also corresponded to the result of reactor performance, and both nitrifying and denitrifying bacteria were detected in the sponge carrier. In addition, anammox bacteria was found in the retained sludge. The DHS reactor reduced the HRT of 30 days to 4.8 h compared with the existing algal tank. This result indicates that the DHS reactor could be an appropriate post treatment for the existing anaerobic tank for natural rubber processing wastewater treatment.

Novel percolation phenomena and mechanism of strengthening elastomers by nanofillers.

PubMed

Wang, Zhenhua; Liu, Jun; Wu, Sizhu; Wang, Wenchuan; Zhang, Liqun

2010-03-28

Nano-strengthening by employing nanoparticles is necessary for high-efficiency strengthening of elastomers, which has already been validated by numerous researches and industrial applications, but the underlying mechanism is still an open challenge. In this work, we mainly focus our attention on studying the variation of the tensile strength of nanofilled elastomers by gradually increasing the filler content, within a low loading range. Interestingly, the percolation phenomenon is observed in the relationship between the tensile strength and the filler loading, which shares some similarities with the percolation phenomenon occurring in rubber toughened plastics. That is, as the loading of nanofillers (carbon black, zinc oxide) increases, the tensile strength of rubber nanocomposites (SBR, EPDM) increases slowly at first, then increases abruptly and finally levels off. Meanwhile, the bigger the particle size, the higher the filler content at the percolation point, and the lower the corresponding tensile strength of rubber nanocomposites. The concept of a critical particle-particle distance (CPD) is proposed to explain the observed percolation phenomenon. It is suggested that rubber strengthening through nanoparticles is attributed to the formation of stretched straight polymer chains between neighbor particles, induced by the slippage of adsorbed polymer chains on the filler surface during tension. Meanwhile, the factors to govern this CPD and the critical minimum particle size (CMPS) figured out in this work are both discussed and analyzed in detail. Within the framework of this percolation phenomenon, this paper also clearly answers two important and intriguing issues: (1) why is it necessary and essential to strengthen elastomers through nanofillers; (2) why does it need enough loading of nanofillers to effectively strengthen elastomers. Moreover, on the basis of the percolation phenomenon, we give out some guidance for reinforcement design of rubbery materials: the interfacial interactions between rubber and fillers cannot be complete chemical bonding, and partial physical absorption of macromolecular chains on the filler surface is necessary, otherwise the formation of stretched straight chains would be seriously hindered. There should exist such an optimum crosslinking density for a certain filler reinforced rubber system, and as well an optimum filler loading for rubber strengthening. Additionally, the different percolation behaviors of Young's modulus, the tensile strength and the electrical conductivity are compared and analyzed in our work. Lastly, molecular simulation indicates that it is not possible to strengthen glassy or hard polymer matrices by incorporating spherical nanoparticles. In general, by providing substantial experimental data and detailed analyses, this work is believed to promote the fundamental understanding of rubber reinforcement, as well provide better guidance for the design of high-performance and multi-functional rubber nanocomposites.

Synthesis of a novel alginate-rubber joint immobilization strains H-1 and its application in removal of Pb (II) from aqueous solution

NASA Astrophysics Data System (ADS)

Li, Huidong; Huo, Kaili; Li, Xiaolei; Zhang, Lin; Yun, Yueqing; Song, Lei; Bai, Runying; Liu, Yuhong

2018-02-01

In this study, a novel alginate-rubber-strains immobilized beads (ARSIBs) was synthesized at the optimum conditions that the concentration of sodium alginate was 4%; the volume of bacterial suspension was 75%; the quality of rubber powder was 3.2%; the crosslinking time was 24 h by the orthogonal experiments. The optimum conditions for Pb (II) adsorption were 1.2% ARSIBs, 100 mg L-1 initial concentrations, pH 5 and 3 h contact time. The equilibrium data were well fitted by the Freundlich isotherm model. The biosorption process was nearly consistent with the pseudo-second-order model. Meanwhile, the biosorption mechanism could be that Pb (II) was adsorbed by the hydroxyl and carboxyl, finally precipitated with phosphate in the form of NaPb4(PO4)3, Pb5(PO4)3(OH) and Pb(H2PO4)2 based on the spectra of FTIR and XRD, respectively. In addition, the stability of ARSIBs was enhanced due to the addition to the rubber powder in the process of wastewater treatment.

Degradation of polyisoprene rubber by newly isolated Bacillus sp. AF-666 from soil.

PubMed

Shah, A A; Hasan, F; Shah, Z; Mutiullah; Hameed, A

2012-01-01

Various microorganisms were screened for their ability to degrade polyisoprene rubber (natural rubber latex gloves). Strain AF-666, newly isolated from a soil sample, was selected as the best strain having the ability to grow on polyisoprene containing plates. The strain identified as Bacillus sp. AF-666, was found to degrade polyisoprene rubber, both on basal agar plates (latex overlay) as well as in liquid medium. Qualitative analysis of degradation was done through scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy SEM showed changes in surface morphology, like appearance of pits and cracks, and marked difference in transmittance spectra of test and control due to changes in the functional groups, was detected through FTIR. CO2 evolution as a result of rubber degradation, was calculated gravimetrically by Sturm Test. About 4.43 g/1 of CO2 was produced in case of test, whereas, 1.57 g/1 in case of control. The viable number of cells (CFU/ml) was also higher in test than in control. Present study may provide an opportunity for further studies on the applications of biotechnological processes as a tool for rubber waste management.

Quality improvement of pyrolysis oil from waste rubber by adding sawdust

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Wen-liang; Chang, Jian-min, E-mail: cjianmin@bjfu.edu.cn; Cai, Li-ping

Highlights: • Rubber-pyrolysis oil is difficult to be fuel due to high proportion of PAHs. • The efficiency of pyrolysis was increased as the percentage of sawdust increased. • The adding of sawdust improved pyrolysis oil quality by reducing the PAHs content. • Adding sawdust reduced nitrogen/sulfur in oil and was easier to convert to diesel. - Abstract: This work was aimed at improving the pyrolysis oil quality of waste rubber by adding larch sawdust. Using a 1 kg/h stainless pyrolysis reactor, the contents of sawdust in rubber were gradually increased from 0%, 50%, 100% and 200% (wt%) during themore » pyrolysis process. Using a thermo-gravimetric (TG) analyzer coupled with Fourier transform infrared (FTIR) analysis of evolving products (TG–FTIR), the weight loss characteristics of the heat under different mixtures of sawdust/rubber were observed. Using the pyrolysis–gas chromatography (GC)–mass spectrometry (Py–GC/MS), the vapors from the pyrolysis processes were collected and the compositions of the vapors were examined. During the pyrolysis process, the recovery of the pyrolysis gas and its composition were measured in-situ at a reaction temperature of 450 °C and a retaining time of 1.2 s. The results indicated that the efficiency of pyrolysis was increased and the residual carbon was reduced as the percentage of sawdust increased. The adding of sawdust significantly improved the pyrolysis oil quality by reducing the polycyclic aromatic hydrocarbons (PAHs) and nitrogen and sulfur compounds contents, resulting in an improvement in the combustion efficiency of the pyrolysis oil.« less

Understanding the effects of decompaction maintenance on the infill state and play performance of third-generation artificial grass pitches

PubMed Central

Forrester, Stephanie E; McLaren, Nicholas J

2015-01-01

Third generation artificial grass pitches have been observed to get harder over time. The maintenance technique of rubber infill decompaction is intended to help slow, or reverse, this process. At present, little is understood about either the science of the infill compaction process or the efficacy of decompaction maintenance. The objective of this study was to measure the changes in rubber infill net bulk density, force reduction (impact absorption) and vertical ball rebound under various levels of compactive effort in controlled laboratory-based testing. The assessments were repeated after the systems had been raked to simulate the decompaction maintenance techniques. These tests defined the limits of compaction (loose to maximally compacted) in terms of the change in rubber infill net bulk density, force reduction and vertical ball rebound. Site testing was also undertaken at four third generation pitches immediately pre and post decompaction, to determine the measurable effects in the less well controlled field environment. Rubber infill net bulk density was found to increase as compactive effort increased, resulting in increased hardness. Decompacting the surface was found to approximately fully reverse these effects. In comparison, the site measurements demonstrated similar but notably smaller magnitudes of change following the decompaction process suggesting that the field state pre and post decompaction did not reach the extremes obtained in the laboratory. The findings suggest that rubber infill net bulk density is an important parameter influencing the hardness of artificial grass and that decompactions can be an effective method to reverse compaction related hardness changes. PMID:29708108

Geographic patterns of industry in the United States. An aid to the study of occupational disease.

PubMed

Stone, B J; Blot, W J; Fraumeni, J F

1978-07-01

The geographic location of 18 major manufacturing industries within the United States is illustrated by a series of computer-generated county maps. The metal and machinery industries, the two largest employers, an the transportation and rubber industries are concentrated in the northeastern quadrant of the United States, while most counties with textile, apparel, tobacco, and furniture manufacturing are in the South. Other industries had different patterns. The counties where industry was concentrated tended to be more urban and to have higher levels of income and education. The maps and associated demographic data on industrial counties may prove a useful adjunct to county maps illustrating mortality patterns for cancer and other diseases. Despite obvious limitations, the visual patterns and correlation analyses may help to generate and formulate hypothese concerning occupationally induced diease.

Directions for material recovery of used tires and their use in the production of new products intended for the industry of civil construction and pavements

NASA Astrophysics Data System (ADS)

Bulei, C.; Todor, M. P.; Heput, T.; Kiss, I.

2018-01-01

The management of waste from used tires is one of the major principles of recycling and reuse, which involves encouraging a high level of material recovery components, preferably by recycling. Given the current pressure on natural resources on a global scale we must fully take into account the waste in a broader framework defined by the flow of raw materials and their sustainable use. Thus, the opportunity to use various waste from used tires as raw material in order to support economic activities becomes a priority. The recycling of raw materials from waste products and their use in new production processes for their material capitalization is becoming a sustainable approach. Used tire recycling, is the process of recycling waste tires that are no longer suitable for use on vehicles due to wear or irreparable damage. These tires are a problematic source of waste, due to the large volume produced, the durability of the tires, and the components in the tire that are ecologically problematic. Although tires are usually burnt, not recycled, efforts are continuing to find value. Tires can be recycled into, among other things, typically as crumb rubber modifier in recycled pavement. The paper presents aspects of the product resulting from crushing of used tires (powder), which can be used properly valued in the street furniture field or building materials containing rubber.

[Etiology of pathogen-induced changes between the toes in patients working under moist conditions].

PubMed

Gründer, K; Kroker, A; Heppner, M; Marre, R

1988-11-15

Referring to recent studies, we discuss the epidemiology of tinea pedis and its position within the range of polyetiological foot infections caused by microbial agents. 201 industrial workers used to wear rubber boots because of moist working conditions were examined with regard to their feet. 107 of them showed clinically altered toe web; in 45 cases, we found ringworm infection (22.4%), in correlation to increased daily wearing time of rubber boots. 85 workers showed colonization of pathogenic bacteria (42.4%), especially gram-negative species (25.8%). Frequently, mixed infections were found. The clinical picture not always allows definite conclusions as to the causal agents. The symptom "maceration" is seen in each of the 3 pathogenic groups of germs (fungi, gram-positive pathogenic cocci, gram-negative bacteria), frequently in bacterial foot infections, especially gram-negative infections. Marked clinical symptoms involve increased infection rates. The predisposing factors to foot infection such as interdigital maceration and the promoting role of rubber boots have been confirmed. The final diagnosis is to be reassured by cultural investigations, in order to set up a specific treatment.

Study for the degumming pretreatment of rubber seed oil

NASA Astrophysics Data System (ADS)

Li, X. Y.; Chen, Y. B.; Zhang, X.; Souliyathai, D.; Yang, S. P.; Wang, Q.

2017-11-01

With the rapid development of the aviation industry, appearing of the aviation carbon tax and the increasingly serious environmental problems have forced the world to research the development of renewable bio-aviation fuel. Renewable biological aviation fuel contains phosphorus that could reduce the synthesis of noble metal catalysts such as Pd, Pt activity. In order to get low content of phosphorus in degummed oil of non-edible vegetable oil, in this paper, with rubber seed oil as raw material, making the experiment of single factor at the influence of temperature, stirring speed, adding amount of monoethanolamine (MEA) and water amount. The experimental results show that the added amount of MEA is 2.5% in the weight of oil, and temperature is 60°C, while the amount of added water is 2% in the weight of oil, reaction time is 40 min, and stirring speed is 200 r/min. Under these conditions, the phosphorus content of rubber seed oil can be reduced to below 3 mg/kg, degumming rate is 91.37%, and the degumming effects are obvious, which also provides some foundation for follow-up studies.

Pattern of occupational allergic dermatitis in the Dermatology Clinic, Hospital Kuala Lumpur.

PubMed

Rohna, R; Ganesapillai, T; Salbiah, D; Zaiton, I

1999-03-01

A two years retrospective analysis of patients diagnosed as contact allergic dermatitis with positive patch test attending the Dermatology clinic was performed. Of the 346 patients with a positive patch test, 14% had occupational dermatitis. This condition affected mainly young and inexperienced workers. An inverse relationship was seen between age and prevalence of occupational allergic dermatitis. Allergic hand dermatitis was the commonest presentation in occupational allergic dermatitis. This was followed by dermatitis of the exposed skin (face, neck, hands and forearms). The common sensitising agents identified were rubber chemicals and nickel. The two main groups at risk were factory workers and medical personnel. The common allergens found in factory workers were epoxy resin, pewter, nickel and rubber chemicals. Exposure dermatitis occurred in patients working in the pewter industry. Two thirds of medical personnel with hand dermatitis were allergic to rubber gloves. One year follow up after patch testing showed that 19% of patients still suffered from chronic dermatitis. Dermatitis improved in 34% of patients. Forty-seven percent were cured and stopped attending the clinic after patch testing and adequate counselling.

Plasma-modified graphene nanoplatelets and multiwalled carbon nanotubes as fillers for advanced rubber composites

NASA Astrophysics Data System (ADS)

Sicinski, M.; Gozdek, T.; Bielinski, D. M.; Szymanowski, H.; Kleczewska, J.; Piatkowska, A.

2015-07-01

In modern rubber industry, there still is a room for new fillers, which can improve the mechanical properties of the composites, or introduce a new function to the material. Modern fillers like carbon nanotubes or graphene nanoplatelets (GnP), are increasingly applied in advanced polymer composites technology. However, it might be hard to obtain a well dispersed system for such systems. The polymer matrix often exhibits higher surface free energy (SFE) level with the filler, which can cause problems with polymer-filler interphase adhesion. Filler particles are not wet properly by the polymer, and thus are easier to agglomerate. As a consequence, improvement in the mechanical properties is lower than expected. In this work, multi-walled carbon nanotubes (MWCNT) and GnP surface were modified with low-temperature plasma. Attempts were made to graft some functionalizing species on plasma-activated filler surface. The analysis of virgin and modified fillers’ SFE was carried out. MWCNT and GnP rubber composites were produced, and ultimately, their morphology and mechanical properties were studied.

Coal as a Substitute for Carbon Black

NASA Technical Reports Server (NTRS)

Kushida, R. O.

1982-01-01

New proposal shows sprayed coal powder formed by extrusion of coal heated to plastic state may be inexpensive substitute for carbon black. Carbon black is used extensively in rubber industry as reinforcing agent in such articles as tires and hoses. It is made from natural gas and petroleum, both of which are in short supply.

Tire Production and Pollution Control. Environmental Education Curriculum. Revised.

ERIC Educational Resources Information Center

Topeka Public Schools, KS.

This unit was developed to introduce secondary students to the many facets of a typical, large manufacturing plant - the Topeka Goodyear Tire and Rubber Company - in an effort to increase awareness of sound environmental practices in industry. Its five major foci include the production of tires and quality control procedures; applications of…

75 FR 62110 - Notice of Petitions by Firms for Determination of Eligibility To Apply for Trade Adjustment...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-07

... passive and electro- mechanical component parts. Knickerbocker Machine Shop, Inc. dba 611 Union Boulevard... manufactures Memphis, TX 79245. components of cast steel products. Pequea Machine, Inc 200 Jalyn Drive, P.O..., Warren, PA 16365. manufacturer of solid polyurethane and rubber industrial wear products. Any party...

Outline of Vocational Training in Ceylon.

ERIC Educational Resources Information Center

Australian Dept. of Labour and National Service, Perth.

The island of Ceylon had a 1963 population of 10,625,000 and an agricultural economy based upon tea, rubber, coconuts, and rice. Fishing and industrial expansion are receiving emphasis. Economic problems include a declining rate of growth in gross national product, unemployment, and a limited range of exports. Education, under control of the…

76 FR 76143 - Tapered Roller Bearings and Parts Thereof, Finished and Unfinished, From the People's Republic of...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-06

..., the United Steel, Paper and Forestry, Rubber, Manufacturing, Energy, Allied Industrial and Service... from Blackstone OTR LLC and OTR Wheel Engineering, Inc. (collectively, ``Blackstone OTR''), the... Ruling on Blackstone OTR LLC and OTR Wheel Engineering, Inc.'s Wheel Hub Assemblies and TRBs,'' dated...

40 CFR 60.542a - Alternate standard for volatile organic compounds.

Code of Federal Regulations, 2010 CFR

2010-07-01

... PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for the Rubber Tire Manufacturing Industry § 60.542a Alternate standard for volatile organic compounds. (a) On and after the date on which the initial performance test, required by § 60.8, is completed, but no...

Combined effects of microwaves, electron beams and polyfunctional monomers on rubber vulcanization.

PubMed

Manaila, Elena; Martin, Diana; Stelescu, Daniela Zuga; Craciun, Gabriela; Ighigeanu, Daniel; Matei, Constantin

2009-01-01

This paper presents comparative results obtained by conventional vulcanization with benzoyl peroxide (CV-BP), separate electron beam vulcanization (EB-V) and simultaneous electron beam and microwave vulcanization (EB+MW-V) applied to two kind of rubber samples: EVA (ethylene vinyl acetate) rubber-sample (EVA-sample) and EPDM (ethylene-propylene terpolymer) rubber-sample (EPDM-sample). The EVA-samples contain 61.54% EVA Elvax 260, 30.77% carbon black, 1.85% TAC (triallylcyanurate) polyfunctional monomer and 5.84% filler (zinc oxide, stearic acid, polyethylene glycol and antioxidant). The EPDM-samples contain 61.54% EPDM Nordel 4760, 30.77% carbon black, 1.85% TMPT (trimethylopropane trimethacrylate) polyfunctional monomer and 5.84% filler (zinc oxide, stearic acid, polyethylene glycol and antioxidant). The rubber samples designed for different vulcanization methods were obtained from raw rubber mixtures, as compressed sheets of 2 mm in the polyethylene foils to minimize oxidation. For EB and EB + MW treatments the sheets were cut in rectangular shape 0.15 x 0.15 m2. The physical properties of samples obtained by CV-BP EV-Vand EB + MW-V methods were evaluated by measuring the tearing strength, residual elongation, elongation at break, tensile strength, 300% modulus, 100% modulus, elasticity and hardness. The obtained results demonstrate an improvement of rubber several properties obtained by EB and EB + MW processing as compared to classical procedure using benzoyl peroxide.

Effect of crumb-rubber particle size on mechanical response of polyurethane foam composites

NASA Astrophysics Data System (ADS)

Sanjay, Omer Sheik

The compression properties of foam are governed by by three factors: i) cell edge bending ii) compression of cell fluid iii) membrane stresses in the cell faces. The effect of reinforcement, granular form of scrap tire rubber on contribution of each of these effects along with the physical properties of polyurethane foam is investigated. It is seen that the addition of crumb-rubber hinders the formation of cell membranes during the foaming process. Four different sizes of particles were chosen to closely study the effect of particle size on the physical properties of the foam composite. There is a definite pattern seen in each of the physical property of the composite with change in the particle size. Addition of crumb-rubber decreases the compressive strength but in turn increases the elastic modulus of the composite. The rubber particles act as the sites for stress concentration and hence the inclusion of rubber particles induces the capability to transfer the axial load laterally along the surface of the foam. Also, the filler material induces porosity into the foam, which is seen in the SEM images, and hence the addition of rubber particles induces brittleness, which makes the foam composites extensively applicable for structural application in sandwich components. The lightweight composite therefore is a potential substitute to the heavier metal foams and honeycombs as a protective layer.

Para rubber seed oil: new promising unconventional oil for cosmetics.

PubMed

Lourith, Nattaya; Kanlayavattanakul, Mayuree; Sucontphunt, Apirada; Ondee, Thunnicha

2014-01-01

Para rubber seed was macerated in petroleum ether and n-hexane, individually, for 30 min. The extraction was additionally performed by reflux and soxhlet for 6 h with the same solvent and proportion. Soxhlet extraction by petroleum ether afforded the greatest extractive yield (22.90 ± 0.92%). Although antioxidant activity by means of 1, 1-diphenyl-2-picrylhydrazyl (DPPH) assay was insignificantly differed in soxhleted (8.90 ± 1.15%) and refluxed (9.02 ± 0.71%) by n-hexane, soxhlet extraction by n-hexane was significantly (p < 0.05) potent scavenged 2,2'-azino-bis(3-ethylbenzothaiazoline)-6-sulfonic acid) or ABTS radical with trolox equivalent antioxidant capacity (TEAC) of 66.54 ± 6.88 mg/100 g oil. This extract was non cytotoxic towards normal human fibroblast cells. In addition, oleic acid and palmitic acid were determined at a greater content than in the seed of para rubber cultivated in Malaysia, although linoleic and stearic acid contents were not differed. This bright yellow extract was further evaluated on other physicochemical characters. The determined specific gravity, refractive index, iodine value, peroxide value and saponification value were in the range of commercialized vegetable oils used as cosmetic raw material. Therefore, Para rubber seed oil is highlighted as the promising ecological ingredient appraisal for cosmetics. Transforming of the seed that is by-product of the important industrial crop of Thailand into cosmetics is encouraged accordingly.

Quantification of 5'-deoxy-5'-methylthioadenosine in heat-treated natural rubber latex serum.

PubMed

Pitakpornpreecha, Thanawat; Plubrukarn, Anuchit; Wititsuwannakul, Rapepun

2012-01-01

5'-Deoxy-5'-methylthioadenosine (MTA) is one of the biologically active components found in natural rubber latex (NRL) serum, a common waste product from rubber plantations. In this study the contents of MTA in heat-treated NRL serum were measured in order to assess the potential of the serum as an alternative source of MTA. To devise an HPLC/UV-based quantitative analytical protocol for the determination of MTA, and to determine the effect of heat treatment on the content of MTA in NRL serum from various sources. An HPLC/UV-based determination of MTA using an acidic eluant was devised and validated. In the heat treatment, the effect of refluxing times on MTA liberation was evaluated. The quantification protocol was validated with satisfying linearity, limits of detection and quantitation, precisions for peak areas and recovery percentages from intra- and inter-day operations. The amounts of MTA in the NRL sera from various sources increased with heat treatment to yield 5-12 μg MTA/mL of serum. The devised protocol was found to be satisfyingly applicable to the routine determination of MTA in NRL serum. The effect of heat treatment on the content of MTA also indicated another possible use for NRL serum, normally discarded in vast amounts by the rubber industry, as an alternative source of MTA. Copyright © 2011 John Wiley & Sons, Ltd.

Effect of rubber stopper composition, preservative pretreatment and rinse water temperature on the moist heat resistance of Bacillus stearothermophilus ATCC 12980.

PubMed

Rubio, S L; Moldenhauer, J E

1995-01-01

Bacillus stearothermophilus spores (liquid suspension) were inoculated onto rubber stoppers and exposed to sublethal steam sterilization cycles at 120 degrees C. The D-values were determined using the fraction-negative method. An increase in heat resistance (D-value) of 200%-400% was observed when the spore suspension was inoculated onto rubber stoppers. The D-values ranged from 4.90-6.96 minutes 120 degrees C. No significant effect was seen when different preservatives were added to the stoppers nor when hot or cold rinse water temperatures were used after processing.

Reduced adherence of Candida to silane-treated silicone rubber.

PubMed

Price, C L; Williams, D W; Waters, M G J; Coulthwaite, L; Verran, J; Taylor, R L; Stickler, D; Lewis, M A O

2005-07-01

Silicone rubber is widely used in the construction of medical devices that can provide an essential role in the treatment of human illness. However, subsequent microbial colonization of silicone rubber can result in clinical infection or device failure. The objective of this study was to determine the effectiveness of a novel silane-treated silicone rubber in inhibiting microbial adherence and material penetration. Test material was prepared by a combination of argon plasma discharge treatment and fluorinated silane coupling. Chemicophysical changes were then confirmed by X-ray photoelectron spectroscopy, contact-angle measurement, and atomic force microscopy. Two separate adherence assays and a material penetration assay assessed the performance of the new material against four strains of Candida species. Results showed a significant reduction (p < 0.01) of Candida albicans GDH 2346 adherence to silane-treated silicone compared with untreated controls. This reduction was still evident after the incorporation of saliva into the assay. Adherence inhibition also occurred with Candida tropicalis MMU and Candida krusei NCYC, although this was assay dependent. Reduced penetration of silane-treated silicone by Candida was evident when compared to untreated controls, plaster-processed silicone, and acrylic-processed silicone. To summarize, a novel silicone rubber material is described that inhibits both candidal adherence and material penetration. The clinical benefit and performance of this material remains to be determined. Copyright 2005 Wiley Periodicals, Inc.

Evaluation of rice husk ash as filler in tread compounds

NASA Astrophysics Data System (ADS)

Fernandes, M. R. S.; Furtado, C. R. G.; de Sousa, A. M. F.

2014-05-01

Rice which is one of the largest agriculture crops produces around 22% of rice rusk during its milling process. This material is mainly used as fuel for energy generation, which results in an ash, which disposal represents an environmental issue. The rice husk ash (RHA) contains over than 70% of silica in an amorphous form and a lot of applications is being developed for it all over the world. The use of silica as a filler in the tire industry is growing since it contributes significantly to the reduction of fuel consumption of the automobiles, allowing at the same time better traction (safety). This paper presents an evaluation of the use of RHA as filler in rubber tread compounds prepared in lab scale and compares its performance with compounds prepared with commercial silica and carbon black, the fillers normally used in tire industry. Mechanical and rheological properties are evaluated, with emphasis for tan delta as an indicator of tread performance related with rolling resistance (fuel consumption) and wet grip/traction (safety).

Influence of engine coolant composition on the electrochemical degradation behavior of EPDM radiator hoses

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vroomen, G.L.M.; Lievens, S.S.; Maes, J.P.

1999-08-01

EPDM (ethylene-propylene rubber) has been used for more than 25 years as the main elastomer in radiator hoses because it offers a well-balanced price/performance ratio in this field of application. Some years ago the automotive and rubber industry became aware of a problem called electrochemical degradation and cracking. Cooling systems broke down due to a typical cracking failure of some radiator hoses. Different test methods were developed to simulate and solve the problem on laboratory scale. The influence of different variables with respect to the electrochemical degradation and cracking. Cooling systems broke down due to a typical cracking failure ofmore » some radiator hoses. Different test methods were developed to simulate and solve the problem on laboratory scale. The influence of different variables with respect to the electrochemical degradation process has been investigated, but until recently the influence of the engine coolant was ignored. Using a test method developed by DSM elastomers, the influence of the composition of the engine coolant as well as of the EPDM composition has now been evaluated. This paper gives an overview of test results with different coolant technologies and offers a plausible explanation of the degradation mechanisms as a function of the elastomer composition.« less

A survey of occupational cancer in the rubber and cablemaking industries: analysis of deaths occurring in 1972-74.

PubMed Central

Fox, A J; Collier, P F

1976-01-01

The records of 40 867 men employed for at least one year in the rubber and cablemaking industries have now been observed for eight years. This analysis compares the mortality pattern for 1972-74 with that previously reported for 1968-71. It indicates a significant excess of deaths due to cancer of the bladder throughout the industry including men who had not been exposed to acknowledged bladder carcinogens. This excess is in deaths occurring in 1973 and 1974 in the 45-64 and 65 years plus age groups. The two sectors of the industry where this excess is significant are footwear and footwear supplies except adhesives, and the tyre sector. The excess of all cancers taken together previously noted throughout the study population for 1968-71 is confirmed for 1972-74 as is the excess for lung cancers. The greater excess in the tyre sector is also confirmed, particularly in those men in the 55-64 year age group and those who entered the industry between 1950 and 1960. While men employed in 1967 on moulding, press, autoclave, and pan curing, and workers in finished goods, stores, packaging, and despatch continue to have more lung cancer deaths than expected for 1972-74, the excess is no longer statistically significant. An excess of cancer of the stomach which was overlooked in 1968-71 is not confirmed in 1972-74 but is nevertheless high when the total period of study 1968-74 is considered. The limitations of the study are discussed with particular reference to extrapolating the results to the whole industry. We conclude that there is a higher rate of lung cancer in the tyre sector of the industry and that immediate investigations are required to test the hypothesis concerning the recent excess of bladder cancers. Attention should now be paid to the control of exposures to all potential hazards in the industry. PMID:999799

A survey of occupational cancer in the rubber and cablemaking industries: analysis of deaths occurring in 1972-74.

PubMed

Fox, A J; Collier, P F

1976-11-01

The records of 40 867 men employed for at least one year in the rubber and cablemaking industries have now been observed for eight years. This analysis compares the mortality pattern for 1972-74 with that previously reported for 1968-71. It indicates a significant excess of deaths due to cancer of the bladder throughout the industry including men who had not been exposed to acknowledged bladder carcinogens. This excess is in deaths occurring in 1973 and 1974 in the 45-64 and 65 years plus age groups. The two sectors of the industry where this excess is significant are footwear and footwear supplies except adhesives, and the tyre sector. The excess of all cancers taken together previously noted throughout the study population for 1968-71 is confirmed for 1972-74 as is the excess for lung cancers. The greater excess in the tyre sector is also confirmed, particularly in those men in the 55-64 year age group and those who entered the industry between 1950 and 1960. While men employed in 1967 on moulding, press, autoclave, and pan curing, and workers in finished goods, stores, packaging, and despatch continue to have more lung cancer deaths than expected for 1972-74, the excess is no longer statistically significant. An excess of cancer of the stomach which was overlooked in 1968-71 is not confirmed in 1972-74 but is nevertheless high when the total period of study 1968-74 is considered. The limitations of the study are discussed with particular reference to extrapolating the results to the whole industry. We conclude that there is a higher rate of lung cancer in the tyre sector of the industry and that immediate investigations are required to test the hypothesis concerning the recent excess of bladder cancers. Attention should now be paid to the control of exposures to all potential hazards in the industry.

Impulse Measurement Using an Arduíno

ERIC Educational Resources Information Center

Espindola, P. R.; Cena, C. R.; Alves, D. C. B.; Bozano, D. F.; Goncalves, A. M. B.

2018-01-01

In this paper, we propose a simple experimental apparatus that can measure the force variation over time to study the impulse-momentum theorem. In this proposal, a body attached to a rubber string falls freely from rest until it stretches and changes the linear momentum. During that process the force due to the tension on the rubber string is…

Recycling and processing of several typical crosslinked polymer scraps with enhanced mechanical properties based on solid-state mechanochemical milling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lu, Canhui; Zhang, Xinxing; Zhang, Wei

The partially devulcanization or de-crosslinking of ground tire rubber (GTR), post-vulcanized fluororubber scraps and crosslinked polyethylene from cable scraps through high-shear mechanochemical milling (HSMM) was conducted by a modified solid-state mechanochemical reactor. The results indicated that the HSMM treated crosslinked polymer scraps can be reprocessed as virgin rubbers or thermoplastics to produce materials with high performance. The foamed composites of low density polyethylene/GTR and the blend of post-vulcanized flurorubber (FKM) with polyacrylate rubber (ACM) with better processability and mechanical properties were obtained. The morphology observation showed that the dispersion and compatibility between de-crosslinked polymer scraps and matrix were enhanced. Themore » results demonstrated that HSMM is a feasible alternative technology for recycling post-vulcanized or crosslinked polymer scraps.« less

Effects of different processing techniques on multi-walled carbon nanotubes/silicone rubber nanocomposite on tensile strength properties

NASA Astrophysics Data System (ADS)

Mazlan, N.; Jaafar, M.; Aziz, A.; Ismail, H.; Busfield, J. J. C.

2016-10-01

In this work, two different processing techniques were approached to identify the properties of the multi-walled carbon nanotubes (MWCNT) reinforced polydimethylsiloxane (PDMS). The MWCNT was dispersed in the polymer by using the ultrasonic and twin screw extruder mixer. The final composite showed different manner of dispersed tubes in the silicone rubber matrix. High shear twin screw extruder tends to fragment the tubes during processing compound, which can be observed by scanning electron microscope (SEM). Tensile strength of the extrusion MWCNT/PDMS nanocomposites was found to be higher compared to ultrasonic MWCNT/PDMS nanocomposites.

REACTOR COOLANT TUBE SEAL

DOEpatents

Morris, W.J.

1958-12-01

A plle-flattenlng control element and a fluid seal therefore to permit movement of the element into a liquld contnining region of a neutronlc reactor are described. The device consists of flattened, thin-walled aluminum tubing contalnlng a uniform mixture of thermal neutron absorbing material, and a number of soft rubber closures for the process tubes, having silts capable of passing the flattened elements therethrough, but effectively sealing the process tubes against fluld leaknge by compression of the rubber. The flattened tubing is sufficiently flexible to enable it to conform to the configuratlon of the annular spacing surrounding the fuel elements ln the process tubes.

Malaysian made condoms sold locally as well as exported.

PubMed

1979-01-01

Malaysia, famous for its natural rubber, is also producing condoms made from local rubber. About 40,000 gross of condoms a month are being produced by a factory with about 30 female workers. 30-40% of the production is exported to Europe, Middle East, Asia, Japan, Singapore and South America. The size of the condoms conform to international standards, 49 mm and 52 mm. As there is a greater demand for the 52 mm. condoms overseas, the company produces more of this than the 49 mm. condoms. In April 1975, the Standard Institution and Industrial Research of Malaysia gave its quality control approval to a condom which can hold 5 gallons of water and with thickness varying from 0.03 mm, 0.06 mm. and 0.05-0.07 mm. A 10% tax/piece and a 5% surtax are imposed on imported condoms to protect the local industry from foreign competition. Local condoms are sold tax-free. Pink and black colored condoms appear to be popular among consumers. Although complaints are few, 1 in 10,000 users may suffer from allergic problems because of the silicone oil treatment of the condoms. Another local condom factory which uses Malaysian rubber for condom manufacture is located in Klang, approximately 24 miles from Kuala Lumpur; the factory has 25 workers producing 12,000 gross of lubricated and non-lubricated condoms for local consumption only. There is increasing evidence that condoms are increasing in popularity in Malaysia and that the average consumer is now being more selective in choosing contraceptive methods.

The regulation of crystalline silica: an industry perspective.

PubMed

Elzea, J M

1997-01-01

Silica is ubiquitous in the earth's crust. It occurs in trace to large quantities in rocks and soil. Because it is so common, the regulation of silica has affected a large number of industries, including the mining industry and any industry that uses quartz in the manufacture of a products. Mineral commodities that contain silica include diatomite, bentonite, kaolinite, talc, pyrophyllite, sand and gravel, perlite, pumice, dimension stone, and barite. Products that contain minerals, many of which are associated with silica, include paint, paper, rubber, plastic, pharmaceuticals, food, cement, plaster, cat litter, potting soil, plaster board, and miscellaneous construction materials. In collaboration with some agencies and academic centers, the silica industry is supporting research to lower health risks and to improve the methods of detecting this common material.

Customer relationship management implementation in the small and medium enterprise

NASA Astrophysics Data System (ADS)

Nugroho, Agus; Suharmanto, Agus; Masugino

2018-03-01

To win the global competition and sustain the business, small and medium enterprise shall implement a reliable information technology application to support their customer data base, production and sales as well as marketing management. This paper addresses the implementation of Customer Relationship Management (CRM) in small and medium enterprise, CV. Densuko Jaya. It is a small and medium enterprises in Semarang, Central Java, Republic of Indonesia deal with rubber processing industry supply chain. ADDIE model utilized in study to setup the CRM functionality at these enterprises. The aim of the authors is to present the benefits resulting from the application of CRM technologies at these enterprises to solve their chronicle issues in the field of integrated customer data base, production management process and sales automation in order to boost their business in the near future. Training and coaching have been delivered to the enterprises staffs and management to ensure that they can execute the system.

Locus of decision making in multinational corporations and its relationship to subsidiary performance

DOE Office of Scientific and Technical Information (OSTI.GOV)

Goehle, D.G.

1978-01-01

A conceptual model was developed which drew from the existing research in organization theory, comparative management, and international business which assisted in the delineation of the relevant variables and suggested the nature of their relationship to the locus of decision making. The conceptual model incorporated certain corporate and subsidiary factors considered an influence on the determination of the locus of decision making. Corporate factors included product line or industry, size and complexity of international operations, organization structure, availability of managerial talent, and corporate philosophy. Subsidiary characteristics included subsidiary age and size, availability of local managerial talent, geographic distance from headquartersmore » and other affiliated units, and subsidiary environmental characteristics. The locus of desicion making was measured by the level of participation the headquarters and subsidiary management had in decision making for twenty-nine decisions, representing six functional areas. Levels of participation for headquarters and subsidiary managers were measured for each decision based on responses to a five-point scale of decision process categories which indicated varying levels of headquarters and subsidiary participation. The sample included ten US multinational corporations representing five industries: pharmaceuticals, tire and rubber, automobiles, capital equipment, and food processing.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smith, F. G.; Daniels, E. J.

This report summarizes an assessment conducted by Environmental Technologies Alternatives, Inc., under a subcontract to Argonne National Laboratory. The project was conducted in two phases. An assessment of alternative technologies for recycling of prompt non-tire rubber was conducted in the first phase, and an experimental program focusing on a new technology called the catalytic Regeneration Process offered the greatest opportunity for recovery of high-value recyclable rubber material. An experimental and large-scale test program was undertaken to further delineate the economic potential as an essential step leading to commercial deployment and to determine the course of continued development of the technologymore » by the private sector. The experimental program defined process-operating conditions for the technology and verified the degree of devulcanisation achievable for two rubber compounds: ethylene-propylene-nonconjugated-diene monomer (EPDM) and neoprene. To determine product acceptance, samples of devulcanized EPDM and neoprene were prepared and used in factory trials for the production of automotive moldings (EPDM) and fiber-filled belting (neoprene). The factory trials indicated that the physical properties of the products were acceptable in both cases. The appearance of molded and calendared surface finishes was acceptable, while that of extruded finishes was unsatisfactory. The fiber-filled neoprene belting application offers the greatest economic potential. Process costs were estimated at $0.34/lb for neoprene waste rubber relative to a value of $0.57/lb. The results of the experimental program led to the decision to continue development of this technology is being planned, subject to the availability of about $3 million in financing from private-sector investors. The ability to recycle non-tire rubber scrap could conserve as much as 90,000 Btu/lb, thus yielding an estimated energy savings potential of about 0.25 quad/yr.« less

[Mortality study in a cohort of workers employed in the hot working processing of plastics and rubber].

PubMed

Gerosa, Alberto; Scarnato, Corrado; Marchesini, Bruno; Ietri, Evi; Pavone, Venere Leda Mara

2017-01-01

to study mortality rates among workers in companies manufacturing thermoplastic and rubber articles (excluding tyres). cohort study. the cohort includes 4,543 workers employed up to 2000 in 131 companies in the Province of Bologna (Emilia-Romagna Region, Northern Italy) exposed to emissions from hot processing of plastics (3,937) and rubber (606). general- and cause-specific Standardized Mortality Rates (SMR), with 95% confidence intervals; entire reference population resides in the Emilia-Romagna Region. excess mortality for all causes (116 Obs; SMR: 1.20; 95%CI 1.00-1.44) and for lung cancer (18 Obs; SMR: 1.67; 95%CI 1.05-2.65) in men of the rubber factories. Increased mortality rates for oesophageal cancers in women (3 Obs; SMR: 5.41; 95%CI 1.74-16.8) and in men (6 Obs; SMR: 2.16; 95%CI 0.97-4.81), for malignant tumours of pancreas (16 Obs; SMR: 1.65; 95%CI 1.01- 2.70), rectum (11 Obs; SMR: 2.17; 95%CI 1.20-3.92) and kidney (11 Obs; SMR: 1.98; 95%CI 1.10-3.58) in men occupied in plastic processing. in this study, we observed an excess of mortality rates for lung cancer in men of rubber factories and for malignant tumours of the digestive tract, pancreas, and kidney in workers employed in the production of plastic articles. Nevertheless, these results must be interpreted with caution, because exposures to non-occupational risk factors, like tobacco smoke or other occupational exposures outside the companies concerned, are not known. The results suggest to continue epidemiological surveillance.

Industrial Pollutants and Nasopharyngeal Cancer: An Open Question.

PubMed

Menicagli, Roberto; Bolla, Gianni; Menicagli, Laura; Esseiridou, Anastassia

2017-05-01

Nasopharyngeal Carcinoma represents 0.7% of the total cancer cases in the world with an ASR index of 1.7 and is widely associated with Epstein-Barr virus. It is not common in Italy (ASR index of 0.5) while in China (ASR 1.9), one third of the clinical cases are observed in Guangdong (ASR index 11.3). It is also quite common in Malaysia and Indonesia. The activation of the cancerogenesis process happens after the exposure to some environmental parameters that epidemiological studies have indicated with various dietary habits, mainly for salted fish consumption. The purpose of this work is to highlight such as exposure to compounds, such as formaldehyde, which is present in the different working conditions of these countries and may lead to the real cause to establish the carcinogenic process. The most recent publications regarding the impact of various external factors on Pub Med, Google, TOXLINE, Chem Abstract, were analyzed with the radiological data that were found in Milan hospitals database. The relationship between food consumption and nasopharyngeal cancer are not clear and statistically insignificant in Indonesia. In Malaysia, the preparation of natural rubber for the use of formaldehyde is a dangerous environmental factor. The same exposure is a risk factor in Guangdong, where many workers are employed in the wood panel industry. Incidence of cancer in these Chinese ethnic groups decreases when they migrate to other countries. In the last 5 years, few cases were recorded in Italy, without any apparent change in ethnic environmental factors or HBV infection Discussion: In the production of natural rubber, a lot of people are exposed to formaldehyde during the various steps of preparation and production such as stripping, drying and coagulation without observing proper environmental hygiene precautions. The same working conditions are present in industrial production of wood panels in Guangdong, China. The relationship between exposure to formaldehyde and nasopharyngeal cancer is demonstrated by the fact that epidemiological studies on the population of this Chinese district whose immigrant populations were not exposed to these pollutants, the appearance of these tumors decreases. Also an examination of our radiological data in Italy shows that in about one hundred sixty cases of nasopharyngeal cancer none of the patients were Indonesian or Chinese Conclusion: The preliminary results of our study suggest that EPST-BARR virus could be a risk factor if associated with exposure to compounds such as formaldehyde which is present in industrial productions of countries like Indonesia, Malaysia, and China.

Natural Rubber Nanocomposite with Human-Tissue-Like Mechanical Characteristic

NASA Astrophysics Data System (ADS)

Murniati, Riri; Novita, Nanda; Sutisna; Wibowo, Edy; Iskandar, Ferry; Abdullah, Mikrajuddin

2017-07-01

The blends of synthetic rubber and natural rubber with nanosilica were prepared using a blending technique in presence of different filler volume fraction. The effect of filler on morphological and mechanical characteristics was studied. Utilization of human cadaver in means of medical study has been commonly used primarily as tools of medical teaching and training such as surgery. Nonetheless, human cadaver brought inevitable problems. So it is necessary to find a substitute material that can be used to replace cadavers. In orthopaedics, the materials that resemble in mechanical properties to biological tissues are elastomers such as natural rubber (latex) and synthetic rubber (polyurethanes, silicones). This substitution material needs to consider the potential of Indonesia to help the development of the nation. Indonesia is the second largest country producer of natural rubber in the world. This paper aims to contribute to adjusting the mechanical properties of tissue-mimicking materials (TMMs) to the recommended range of biological tissue value and thus allow the development of phantoms with greater stability and similarity to human tissues. Repeatability for the phantom fabrication process was also explored. Characteristics were then compared to the control and mechanical characteristics of different human body part tissue. Nanosilica is the best filler to produce the best nanocomposite similarities with human tissue. We produced composites that approaching the properties of human internal tissues.

Rubber Trees Demonstrate a Clear Retranslocation Under Seasonal Drought and Cold Stresses

PubMed Central

Li, Yuwu; Lan, Guoyu; Xia, Yujie

2016-01-01

Having been introduced to the northern edge of Asian tropics, the rubber tree (Hevea brasiliensis) has become deciduous in this climate with seasonal drought and cold stresses. To determine its internal nutrient strategy during leaf senescence and deciduous periods, we investigated mature leaf and senescent leaf nutrients, water-soluble soil nutrients and characteristics of soil microbiota in nine different ages of monoculture rubber plantations. Rubber trees demonstrate complicated retranslocation of N, P, and K during foliar turnover. Approximately 50.26% of leaf nutrients and 21.47% of soil nutrients were redistributed to the rubber tree body during the leaf senescence and withering stages. However, no significant changes in the structure- or function-related properties of soil microbes were detected. These nutrient retranslocation strategy may be important stress responses. In the nutrient retranslocation process, soil plays a dual role as nutrient supplier and nutrient “bank.” Soil received the nutrients from abscised leaves, and also supplied nutrients to trees in the non-growth stage. Nutrient absorption and accumulation began before the leaves started to wither and fall. PMID:28066467

Potential of activated carbon from waste rubber tire for the adsorption of phenolics: effect of pre-treatment conditions.

PubMed

Gupta, Vinod Kumar; Nayak, Arunima; Agarwal, Shilpi; Tyagi, Inderjeet

2014-03-01

Rubber tire activated carbon modification (RTACMC) and rubber tire activated carbon (RTAC) were prepared from waste rubber tire by microwave assisted chemical treatment and physical heating respectively. A greater improvement in porosity and total pore volume was achieved in RTACMC as compared to that of RTAC. But both have a predominantly mesoporous structure. Under identical operating conditions, an irradiation time of 10 min, chemical impregnation ratio of 1.50 and a microwave power of 600 W resulted in maximizing the efficiency of RTACMC for p-cresol (250 mg/g) at a contact time of 90 min while RTAC showed a 71.43 mg/g adsorption capacity at 150 min. Phenol, due to its higher solubility was adsorbed to a lesser extent by both adsorbents. Physical nature of interactions, pore diffusion mechanism and exothermicity of the adsorption process was operative in both adsorbents. The outcomes support the feasibility of preparing high quality activated carbon from waste rubber tire by microwave assisted chemical activation. Copyright © 2013 Elsevier Inc. All rights reserved.

Using Action Research to prevent work-related illness among rubber farmers in Northeastern Thailand.

PubMed

Sena, Wijitra; Nilvarangkul, Kessarawan; Saranrittichai, Kesinee; Smith, John F; Phajan, Teerasak; Seetangkham, Sansanee

2018-06-10

This research aimed to enhance self-care among rubber farmers for preventing work-related illness. The project used Action Research's four phase iterative process: fact-finding to understand the problems, action planning, action plan implementation, and evaluation and reflection on action plan impacts. Sixty-six participants (46 rubber farmers and 20 community stakeholders) were purposively recruited from two villages in the top 10 rubber producing provinces in Northeastern Thailand. Demographic and work-related illness data were collected in face-to-face structured interviews, Focus group interviews and participant observations were used to collect data in each project phase. Night group meetings were held throughout the research phases. The intervention included training workshops and establishing a community health education team for ongoing farmer support. Results showed improved farmer self-care behaviors and establishment of a community health education team to encourage farmers to care for themselves properly. Community nurses, other health personnel, and the Thai government can build on initiatives like this to strengthen occupational health and safety practices and services policy for rubber farmers. © 2018 Wiley Periodicals, Inc.

Thermal and Mechanical Properties of Natural Rubber Composites Reinforced with Cellulose Nanocrystals from Southern Pine

Treesearch

Chunmei Zhang; Yi Dan; Jun Peng; Lih-Sheng Turng; Ronald Sabo; Craig Clemons

2014-01-01

There is currently a considerable interest in developing bio-based and green nanocomposites in industrial and technological areas owing to their biodegradability, biocompatibility, and environmental friendliness. In this study, a bio-based nanosized material, cellulose nanocrystals (CNC), extracted from southern pine pulp was employed as a reinforcing agent in a...

77 FR 3031 - The Goodyear Tire & Rubber Company, Grant of Petition for Decision of Inconsequential Noncompliance

Federal Register 2010, 2011, 2012, 2013, 2014

2012-01-20

... inconsequentiality to motor vehicle safety in this case is that there is no effect of the noncompliances on the... retread, repair and recycling industries must also be considered. Although tire construction affects the... labeling of the tire construction information will have an inconsequential effect on motor vehicle safety...

Liquid Loss From Advancing Aqueous Foams With Very Low Water Content

DTIC Science & Technology

2011-01-14

fractionation used by pharmaceutical and food industries for protein separation, and froth flotation used by the mining industry for mineral separation...SureShotsSprayer.com) onto a copper screen with a diameter of 6.4 cm and 30x30 mesh cells per inch (40.8% open area) held in place by a rubber gasket. The N2 pressure...distribution over the copper screen. Air flow rates of 8 L/min and 20 L/min, as determined by a mass-flow controller (Sierra Control Flo-Box Model

New dielectric elastomers with improved properties for energy harvesting and actuation

NASA Astrophysics Data System (ADS)

Stiubianu, George; Bele, Adrian; Tugui, Codrin; Musteata, Valentina

2015-02-01

New materials with large value for dielectric constant were obtained by using siloxane and chemically modified lignin. The modified lignin does not act as a stiffening filler material for the siloxane but acts as bulk filler, preserving the softness and low value of Young's modulus specific for silicones. The measured values for dielectric constant compare positively with the ones for previously tested dielectric elastomers based on siloxane rubber or acrylic rubber loaded with ceramic nanoparticles. The new materials use the well-known silicone chemistry and lignin which is available worldwide in large amounts as a by-product of pulp and paper industry, making its manufacturing affordable. The prepared dielectric elastomers were tested for possible applications for wave, wind and kinetic body motion energy harvesting. Siloxane, lignin, dielectric

Proposed Expansion of Acme Landfill Operations.

DTIC Science & Technology

1982-08-01

plastic beverage bottles, cardboard, wood, yardwastes, textiles , rubber, and leather. In addition to traditional activities, a central processing center...from food and garden wastes), a considerable portion of the leachate strength may be attributable to the textiles , rubber, leather, wood, paper, and...poisoning); mosquitos which may carry viral diseases such as encephalitis, malaria, and yellow fever; rodents which are carriers of enteric and other

Is Body Dysmorphic Disorder Associated with Abnormal Bodily Self-Awareness? A Study Using the Rubber Hand Illusion

PubMed Central

Kaplan, Ryan A.; Enticott, Peter G.; Hohwy, Jakob; Castle, David J.; Rossell, Susan L.

2014-01-01

Evidence from past research suggests that behaviours and characteristics related to body dissatisfaction may be associated with greater instability of perceptual body image, possibly due to problems in the integration of body-related multisensory information. We investigated whether people with body dysmorphic disorder (BDD), a condition characterised by body image disturbances, demonstrated enhanced susceptibility to the rubber hand illusion (RHI), which arises as a result of multisensory integration processes when a rubber hand and the participant's hidden real hand are stimulated in synchrony. Overall, differences in RHI experience between the BDD group and healthy and schizophrenia control groups (n = 17 in each) were not significant. RHI strength, however, was positively associated with body dissatisfaction and related tendencies. For the healthy control group, proprioceptive drift towards the rubber hand was observed following synchronous but not asynchronous stimulation, a typical pattern when inducing the RHI. Similar drifts in proprioceptive awareness occurred for the BDD group irrespective of whether stimulation was synchronous or not. These results are discussed in terms of possible abnormalities in visual processing and multisensory integration among people with BDD. PMID:24925079

Self-healing and thermoreversible rubber from supramolecular assembly.

PubMed

Cordier, Philippe; Tournilhac, François; Soulié-Ziakovic, Corinne; Leibler, Ludwik

2008-02-21

Rubbers exhibit enormous extensibility up to several hundred per cent, compared with a few per cent for ordinary solids, and have the ability to recover their original shape and dimensions on release of stress. Rubber elasticity is a property of macromolecules that are either covalently cross-linked or connected in a network by physical associations such as small glassy or crystalline domains, ionic aggregates or multiple hydrogen bonds. Covalent cross-links or strong physical associations prevent flow and creep. Here we design and synthesize molecules that associate together to form both chains and cross-links via hydrogen bonds. The system shows recoverable extensibility up to several hundred per cent and little creep under load. In striking contrast to conventional cross-linked or thermoreversible rubbers made of macromolecules, these systems, when broken or cut, can be simply repaired by bringing together fractured surfaces to self-heal at room temperature. Repaired samples recuperate their enormous extensibility. The process of breaking and healing can be repeated many times. These materials can be easily processed, re-used and recycled. Their unique self-repairing properties, the simplicity of their synthesis, their availability from renewable resources and the low cost of raw ingredients (fatty acids and urea) bode well for future applications.

Ionic Modification Turns Commercial Rubber into a Self-Healing Material.

PubMed

Das, Amit; Sallat, Aladdin; Böhme, Frank; Suckow, Marcus; Basu, Debdipta; Wiessner, Sven; Stöckelhuber, Klaus Werner; Voit, Brigitte; Heinrich, Gert

2015-09-23

Invented by Charles Goodyear, chemical cross-linking of rubbers by sulfur vulcanization is the only method by which modern automobile tires are manufactured. The formation of these cross-linked network structures leads to highly elastic properties, which substantially reduces the viscous properties of these materials. Here, we describe a simple approach to converting commercially available and widely used bromobutyl rubber (BIIR) into a highly elastic material with extraordinary self-healing properties without using conventional cross-linking or vulcanising agents. Transformation of the bromine functionalities of BIIR into ionic imidazolium bromide groups results in the formation of reversible ionic associates that exhibit physical cross-linking ability. The reversibility of the ionic association facilitates the healing processes by temperature- or stress-induced rearrangements, thereby enabling a fully cut sample to retain its original properties after application of the self-healing process. Other mechanical properties, such as the elastic modulus, tensile strength, ductility, and hysteresis loss, were found to be superior to those of conventionally sulfur-cured BIIR. This simple and easy approach to preparing a commercial rubber with self-healing properties offers unique development opportunities in the field of highly engineered materials, such as tires, for which safety, performance, and longer fatigue life are crucial factors.

Red rubber bulb, cheap and effective vacuum drainage.

PubMed

Vatanasapt, V; Areemit, S; Jeeravipoolvarn, P; Kuyyakanond, T; Kuptarnond, C

1989-04-01

Red rubber bulbs have been used for vacuum drainage in head, neck, breast and several other operations by the authors since 1975 quite effectively without any major problems. The vacuum pressure of the red rubber bulbs was found to be higher than the expensive commercially available vacuum wound drainage device. The question of remaining old blood and infective microorganisms inside the reservoir for the reused ones were tested by the manual cleaning process and the standard sterile technique using steam under increased pressure (autoclave). The result is quite satisfactory. We encourage the use of this cheap and effective (made in Thailand) vacuum wound drainage in Thai hospitals and Thai medical schools.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Azimi, H.R.

This study examines several mechanisms by which the fatigue crack propagation (FCP) resistance of shear-yielding thermoset polymers can be improved. Specifically, this research has four objectives as follows: first, to develop a mechanistic understanding of the FCP behavior of rubber-modified thermoset polymers; second, to understand the effect of strength and shape of the inorganic fillers on the FCP resistance and micromechanisms in filled epoxy polymers; third, to elucidate the nature of the interactions among the crack-tip shielding mechanisms in thermoset polymers subjected to cyclic loading and synergistically toughened with both rubber and inorganic particles (i.e., hybrid composites); fourth, to studymore » the role of interfaces on the synergistic interactions in FCP behavior of hybrid composites. The model - matrix material consists of a diglycidyl ether of bisphenol A (DGEBA) based type epoxy cured with piperidine. Parallel to the first objective, the epoxy matrix was modified with rubber while changing volume fraction, type, and size of the rubber particles. To accomplish the second goal, the epoxy polymers were modified by a total 10 volume percent of either one of the following three types of inorganic modifiers: hollow glass spheres (HGS); solid glass spheres (SGS); and short glass fibers (SGF). The third goal was met by processing three different systems of hybrid epoxy composites modified by (1) CTBN rubber and HGS, (2) CTBN rubber and SGS, and (3) CTBN rubber and SGF. The total volume fraction of the two modifiers in each hybrid system was kept constant at 10 percent while systematically changing their ratio. To meet the fourth objective, the surface properties of the SGS particles in the hybrid system were altered using adhesion promoter. A mechanistic understanding of the FCP behavior of rubber-modified epoxies was achieved by relating fractographs to observed FCP behavior.« less

Reactivity of sulfide-containing silane toward boehmite and in situ modified rubber/boehmite composites by the silane

NASA Astrophysics Data System (ADS)

Lin, Tengfei; Zhu, Lixin; Chen, Weiwei; Wu, Siwu; Guo, Baochun; Jia, Demin

2013-09-01

The silanization reaction between boehmite (BM) nanoplatelets and bis-[3-(triethoxysilyl)-propyl]-tetrasulfide (TESPT) was characterized in detail. Via such modification process, the grafted sulfide moieties on the BM endow reactivity toward rubber and substantially improved hydrophobicity for BM. Accordingly, TESPT was employed as in situ modifier for the nitrile rubber (NBR)/BM compounds to improve the mechanical properties of the reinforced vulcanizates. The effects of BM content and in situ modification on the mechanical properties, curing characteristics and morphology were investigated. BM was found to be effective in improving the mechanical performance of NBR vulcanizates. The NBR/BM composites could be further strengthened by the incorporation of TESPT. The interfacial adhesion of NBR/BM composites was obviously improved by the addition of TESPT. The substantially improved mechanical performance was correlated to the interfacial reaction and the improved dispersion of BM in rubber matrix.

Exploiting epoxidized natural rubber latex (ENRL) as a starting raw material for latex-based products

NASA Astrophysics Data System (ADS)

Siti Nor Qamarina, M.; Fatimah Rubaizah, M. R.; Nurul Suhaira, A.; Norhanifah, M. Y.

2017-12-01

Epoxidized natural rubber latex (ENRL) is a chemically modified natural rubber latex produced from epoxidation process that involves usage of organic peracids. Conversion of the ENRL into dry rubber products has been known to exhibit many beneficial properties, however limited published works were found on diversifiying the ENRL latex-based products applications. In this preliminary work, different source of raw materials and neutralization systems were investigated. The objective was to explore possibilities in producing distinctive ENRL. Findings have demonstrated that different source of raw materials and neutralization systems influenced the typical ENRL specifications, stability behavior and particle size distribution. Morphological observations performed on these ENRL systems appeared to agree with the ENRL characteristics achieved. Since experimenting these two main factors resulted in encouraging ENRL findings, detailed work shall be further scrutinized to search for an optimum condition in producing marketable ENRL specifically for latex-based products applications.

Historical limitations of determinant based exposure groupings in the rubber manufacturing industry

PubMed Central

Vermeulen, R; Kromhout, H

2005-01-01

Aims: To study the validity of using a cross-sectional industry-wide exposure survey to develop exposure groupings for epidemiological purposes that extend beyond the time period in which the exposure data were collected. Methods: Exposure determinants were used to group workers into high, medium, and low exposure groups. The contrast of this grouping and other commonly used grouping schemes based on plant and department within this exposure survey and a previously conducted survey within the same industry (and factories) were estimated and compared. Results: Grouping of inhalable and dermal exposure based on exposure determinants resulted in the highest, but still modest, contrast (ε ∼ 0.3). Classifying subjects based on a combination of plant and department resulted in a slightly lower contrast (ε ∼ 0.2). If the determinant based grouping derived from the 1997 exposure survey was used to classify workers in the 1988 survey the average contrast decreased significantly for both exposures (ε ∼ 0.1). On the contrary, the exposure classification based on plant and department increased in contrast (from ε ∼ 0.2 to ε ∼ 0.3) and retained its relative ranking overtime. Conclusions: Although determinant based groupings seem to result in more efficient groupings within a cross-sectional survey, they have to be used with caution as they might result in significant less contrast beyond the studied population or time period. It is concluded that a classification based on plant and department might be more desirable for retrospective studies in the rubber manufacturing industry, as they seem to have more historical relevance and are most likely more accurately recorded historically than information on exposure determinants in a particular industry. PMID:16234406

Cure-in-place process for seals

DOEpatents

Hirasuna, Alan R.

1981-01-01

A cure-in-place process which allows a rubber seal element to be deformed to its service configuration before it is cross-linked and, hence, is a plastic and does not build up internal stress as a result of the deformation. This provides maximum residual strength to resist the differential pressure. Furthermore, the process allows use of high modulus formulations of the rubber seal element which would otherwise crack if cured and then deformed to its service configuration, resulting in a seal which has better gap bridging capability. Basically, the process involves positioning an uncured seal element in place, deforming it to its service configuration, heating the seal element, curing it in place, and then fully seating the seal.

Soil Carbon Losses after Rainforest Conversion to Oil Palm and Rubber Plantations: Processes and Sensitivity of Soil Fertility Indicators Assessed by a New Approach

NASA Astrophysics Data System (ADS)

Guillaume, T.; Maranguit, D.; Murtilaksono, K.; Kuzyakov, Y.

2015-12-01

Tropical forest conversion to agricultural land leads to strong decrease of soil organic matter (SOM). Nonetheless, the magnitude of SOM losses and their impacts on soil fertility in oil palm and rubber plantations remain unclear, despite the large scale extension of such land-use types. We quantified SOM losses, and estimated soil erosion and changes in SOM turnover using SOM δ13C values in forest, oil palm plantations, extensive rubber plantations and rubber monocultures on Sumatra Island (Indonesia). Further, we assessed the response of biological (basal respiration, microbial biomass, acid phosphatase) and chemical fertility indicators (light fraction, DOC, total N, available P) to SOM losses. We used a new approach based on (non-)linear regressions between SOM losses and the indices standardized to natural ecosystem. Carbon contents in the Ah horizon under oil palm and rubber plantations were strongly reduced: up to 70% and 62%, respectively. The decrease was lower under extensive rubber (41%). The estimated erosion was the strongest in oil palm (35±8 cm) and rubber (33±10 cm) plantations. The SOM 13C enrichment used as a proxy of its turnover indicates a decrease of SOM turnover under oil palm after forest conversion. The negative impact of land-use changes on all measured indicators increased in the following sequence: forest > extensive rubber > rubber > oil palm. The basal respiration, microbial biomass and nutrients were comparatively resistant to SOM losses, whereas the light fraction was lost faster than the SOM. The resistance of the microbial activity to SOM losses is an indication that the microbial functions sustain SOM losses. However, responses of basal respiration and microbial biomass to SOM losses were non-linear. Below 2.7 % C content, the relationship was reversed. The basal respiration decreased faster than the SOM, resulting in a stronger drop of microbial activity under oil palm compared to rubber despite small difference in C content. We conclude that the new approach allows a quantitative assessment of the sensitivity and threshold of various soil functions to land-use changes and consequently, can be used to assess resilience of agroecosystem of gradual use intensity.

Pyrolytic conversion of plastic and rubber waste to hydrocarbons with basic salt catalysts

DOEpatents

Wingfield, Jr., Robert C.; Braslaw, Jacob; Gealer, Roy L.

1985-01-01

The invention relates to a process for improving the pyrolytic conversion of waste selected from rubber and plastic to low molecular weight olefinic materials by employing basis salt catalysts in the waste mixture. The salts comprise alkali or alkaline earth compounds, particularly sodium carbonate, in an amount of greater than about 1 weight percent based on the waste feed.

Hybrid joining of polyamide and hydrogenated acrylonitrile butadiene rubber through heat-resistant functional layer of silane coupling agent

NASA Astrophysics Data System (ADS)

Sang, Jing; Sato, Riku; Aisawa, Sumio; Hirahara, Hidetoshi; Mori, Kunio

2017-08-01

A simple, direct adhesion method was developed to join polyamide (PA6) to hydrogenated acrylonitrile butadiene rubber (HNBR) by grafting a functional layer of a silane coupling agent on plasma functionalized PA6 surfaces. The functional layer of the silane coupling agent was prepared using a self-assembly method, which greatly improved the heat resistance of PA6 from 153 °C up to 325 °C and the resulting PA6/HNBR joints showed excellent adhesion properties with cohesive failure between PA6 and HNBR. X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), and nanoscale infrared microscopy and chemical imaging (Nano-IR, AFM-IR) were employed to characterize the surfaces and interfaces. The Nano-IR analysis method was employed for the first time to analyze the chemical structures of the adhesion interfaces between different materials and to establish the interface formation mechanism. This study is of significant value for interface research and the study of adhesion between resins and rubbers. There is a promising future for heat-resistant functional layers on resin surfaces, with potential application in fuel hose composite materials for the automotive and aeronautical industries.

Higher Education As a Catalyst for the Local Economy: Project Care--Retraining the Unemployed.

ERIC Educational Resources Information Center

Groff, Warren H.

This three-part report describes the development and operation of Project Care III, an interagency effort involving area colleges, unions, and industry, and state agencies in the retraining of 500 tire builders laid off in August 1978, when the Mansfield Tire and Rubber Company (Mansfield, Ohio) was shut down. Part I outlines the historical…

West Europe Report.

DTIC Science & Technology

1987-02-18

linguistic disasters. They are devoid of meaning, grammar, concept, reason and fluency . However, the journal that we are reading now is far ahead of...1984 list but were included in the 1985 list: Meric Textile, Sivas Cement , Nigde Cement , Ege Metal, Istanbul Piston Ring Casings, Denizli Printed...Textile, Gimsan, Teknik Rubber, Ipsan Textile, Turk Cement , Bozuyuk Ceramic, Kampana Leather and Shoesoles Industry, Vestel, Turkish Shipbuilding

Performance testing of asphalt concrete containing crumb rubber modifier and warm mix additives

NASA Astrophysics Data System (ADS)

Ikpugha, Omo John

Utilisation of scrap tire has been achieved through the production of crumb rubber modified binders and rubberised asphalt concrete. Terminal and field blended asphalt rubbers have been developed through the wet process to incorporate crumb rubber into the asphalt binder. Warm mix asphalt technologies have been developed to curb the problem associated with the processing and production of such crumb rubber modified binders. Also the lowered production and compaction temperatures associated with warm mix additives suggests the possibility of moisture retention in the mix, which can lead to moisture damage. Conventional moisture sensitivity tests have not effectively discriminated good and poor mixes, due to the difficulty of simulating field moisture damage mechanisms. This study was carried out to investigate performance properties of crumb rubber modified asphalt concrete, using commercial warm mix asphalt technology. Commonly utilised asphalt mixtures in North America such as dense graded and stone mastic asphalt were used in this study. Uniaxial Cyclic Compression Testing (UCCT) was used to measure permanent deformation at high temperatures. Indirect Tensile Testing (IDT) was used to investigate low temperature performance. Moisture Induced Sensitivity Testing (MiST) was proposed to be an effective method for detecting the susceptibility of asphalt mixtures to moisture damage, as it incorporates major field stripping mechanisms. Sonnewarm(TM), Sasobit(TM) and Evotherm(TM) additives improved the resistance to permanent deformation of dense graded mixes at a loading rate of 0.5 percent by weight of the binder. Polymer modified mixtures showed superior resistance to permanent deformation compared to asphalt rubber in all mix types. Rediset(TM) WMX improves low temperature properties of dense graded mixes at 0.5 percent loading on the asphalt cement. Rediset LQ and Rediset WMX showed good anti stripping properties at 0.5 percent loading on the asphalt cement. The American Association of State Highway and Transportation Official's Mechanistic-Empirical Pavement Design Guide (AASHTO MEPDG) software was used to predict long term low temperature performance of the mixtures in various areas of Ontario. Sasobit, Rediset LQ and Rediset WMX gave good 15 years prediction with stone mastic asphalt mixtures but the performance of dense graded mixtures was less satisfactory.

Zinc Oxide—From Synthesis to Application: A Review

PubMed Central

Kołodziejczak-Radzimska, Agnieszka; Jesionowski, Teofil

2014-01-01

Zinc oxide can be called a multifunctional material thanks to its unique physical and chemical properties. The first part of this paper presents the most important methods of preparation of ZnO divided into metallurgical and chemical methods. The mechanochemical process, controlled precipitation, sol-gel method, solvothermal and hydrothermal method, method using emulsion and microemulsion enviroment and other methods of obtaining zinc oxide were classified as chemical methods. In the next part of this review, the modification methods of ZnO were characterized. The modification with organic (carboxylic acid, silanes) and inroganic (metal oxides) compounds, and polymer matrices were mainly described. Finally, we present possible applications in various branches of industry: rubber, pharmaceutical, cosmetics, textile, electronic and electrotechnology, photocatalysis were introduced. This review provides useful information for specialist dealings with zinc oxide. PMID:28788596

Reinforcement of SBR/waste rubber powder vulcanizate with in situ generated zinc dimethacrylate

NASA Astrophysics Data System (ADS)

Wang, X. P.; Cheng, B. K.; Zhang, X.; Jia, D. M.

2016-07-01

Methyl acrylic acid/zinc oxide (MAA/ZnO) was introduced to modify styrene- butadiene rubber/waste rubber powder (SBR/WRP) composites by blending. The enhanced mechanical properties and processing ability were presumably originated from improved compatibility and interfacial interaction between WRP and the SBR matrix by the in situ polymerization of zinc dimethacrylate (ZDMA). A refined interface of the modified SBR/WRP composite was observed by scanning electron microscopy. The formation of ZDMA significantly increased the ionic bond content in the vulcanizate, resulting in exceptional mechanical performance. The comprehensive mechanical properties including tensile strength, tear strength and dynamic heat-building performance reached optimum values with 16 phr MAA.

A review on the cords & plies reinforcement of elastomeric polymer matrix

NASA Astrophysics Data System (ADS)

Mahmood, S. S.; Husin, H.; Mat-Shayuti, M. S.; Hassan, Z.

2016-06-01

Steel, polyester, nylon and rayon are the main materials of cords & plies that have been reinforced in the natural rubber to produce quality tyres but there is few research reported on cord and plies reinforcement in silicone rubber. Taking the innovation of tyres as inspiration, this review's first objective is to compile the comprehensive studies about the cords & plies reinforcement in elastomeric polymer matrix. The second objective is to gather information about silicone rubber that has a high potential as a matrix phase for cords and plies reinforcement. All the tests and findings are gathered and compiled in sections namely processing preparation, curing, physical and mechanical properties, and adhesion between cords-polymer.

Effect of different concentrations of sodium dodecyl sulfate and additional anionic surfactant on properties of low protein natural rubber latex

NASA Astrophysics Data System (ADS)

Abdullah, Nurulhuda; Manaf, Siti Nor Qamarina; Hassan, Aziana Abu

2017-12-01

This paper describes the chemical deproteinization process of natural rubber latex (NRL) using chemical denaturants namely urea and sodium dodecyl sulfate (SDS). Commercial high ammoniated natural rubber latex (HANRL) was incubated with both denaturants - urea and SDS for selected period of time before centrifugation and characterization. The role of SDS in NRL deproteinization process was further elucidated by manipulating the concentration of SDS at 0.3 phr and 0.5 phr during the incubation process. It was found that the physical properties of NRL especially stability, were governed by the amount of SDS, whereby higher concentration of SDS used led to greater NRL stability. However, too much concentration of SDS in the system might cause detrimental effect on the properties of low protein NRL. The effects of additional anionic surfactant namely potassium laurate on the physical properties of low protein NRL and its stabilization were also scrutinized. Characterizations include nitrogen determination by Kjeldahl method, zeta potential, and morphological analysis by Field Emission Scanning Electron Microscopy (FESEM).

[Biological monitoring in the molding of plastics and rubbers].

PubMed

Fustinoni, S; Campo, L; Cirla, A M; Cirla, P E; Cutugno, V; Lionetti, C; Martinotti, I; Mossini, E; Foà, V

2007-01-01

This survey was carried out in the molding of plastics and rubbers, in the "Professional Cancer Prevention Project" sponsored by the Lombardy region with the objective of developing and implementing protocols for evaluating exposure to carcinogens through the biological monitoring. The realities of molding the thermoplastic polymer ABS, rubber, and thermosetting plastics containing formaldehyde were examined. The carcinogenic substances identified in these processes were: 1,3-butadiene, acrylonitrile and styrene in molding ABS, polycyclic aromatic hydrocarbons (PAH) in molding rubber, and formaldehyde in molding the thermosetting plastics. Only for some of these substances biological indicators are available. The limited exposure to airborne chemicals in molding ABS and the intrinsic characteristics of biological indicators available for 1-3 butadiene have determined the non applicability of biological monitoring to this situation. The absence of a biological indicator of exposure to formaldehyde has made this situation not investigable. Exposure in the rubber molding was studied in 19 subjects applying the determination not metabolized PAH in urine. The levels of these indicators were similar to those measured in other groups of subjects without occupational exposure to PAH, confirming a low airborne contamination in this workplace.

Electron tomography provides a direct link between the Payne effect and the inter-particle spacing of rubber composites

PubMed Central

Staniewicz, Lech; Vaudey, Thomas; Degrandcourt, Christophe; Couty, Marc; Gaboriaud, Fabien; Midgley, Paul

2014-01-01

Rubber-filler composites are a key component in the manufacture of tyres. The filler provides mechanical reinforcement and additional wear resistance to the rubber, but it in turn introduces non-linear mechanical behaviour to the material which most likely arises from interactions between the filler particles, mediated by the rubber matrix. While various studies have been made on the bulk mechanical properties and of the filler network structure (both imaging and by simulations), there presently does not exist any work directly linking filler particle spacing and mechanical properties. Here we show that using STEM tomography, aided by a machine learning image analysis procedure, to measure silica particle spacings provides a direct link between the inter-particle spacing and the reduction in shear modulus as a function of strain (the Payne effect), measured using dynamic mechanical analysis. Simulations of filler network formation using attractive, repulsive and non-interacting potentials were processed using the same method and compared with the experimental data, with the net result being that an attractive inter-particle potential is the most accurate way of modelling styrene-butadiene rubber-silica composite formation. PMID:25487130

Environmental impact of highway construction and repair materials on surface and ground waters. Case study: crumb rubber asphalt concrete.

PubMed

Azizian, Mohammad F; Nelson, Peter O; Thayumanavan, Pugazhendhi; Williamson, Kenneth J

2003-01-01

The practice of incorporating certain waste products into highway construction and repair materials (CRMs) has become more popular. These practices have prompted the National Academy of Science, National Cooperative Highway Research Program (NCHRP) to research the possible impacts of these CRMs on the quality of surface and ground waters. State department of transportations (DOTs) are currently experimenting with use of ground tire rubber ( crumb rubber) in bituminous construction and as a crack sealer. Crumb rubber asphalt concrete (CR-AC) leachates contain a mixture of organic and metallic contaminants. Benzothiazole and 2(3H)-benzothiazolone (organic compounds used in tire rubber manufacturing) and the metals mercury and aluminum were leached in potentially harmful concentrations (exceeding toxic concentrations for aquatic toxicity tests). CR-AC leachate exhibited moderate to high toxicity for algae ( Selenastrum capriconutum) and moderate toxicity for water fleas ( Daphnia magna). Benzothiazole was readily removed from CR-AC leachate by the environmental processes of soil sorption, volatilization, and biodegradation. Metals, which do not volatilize or photochemically or biologically degrade, were removed from the leachate by soil sorption. Contaminants from CR-AC leachates are thus degraded or retarded in their transport through nearby soils and ground waters.

Cellulose nanocrystals reinforced foamed nitrile rubber nanocomposites.

PubMed

Chen, Yukun; Zhang, Yuanbing; Xu, Chuanhui; Cao, Xiaodong

2015-10-05

Research on foamed nitrile rubber (NBR)/cellulose nanocrystals (CNs) nanocomposites is rarely found in the literatures. In this paper, CNs suspension and NBR latex was mixed to prepared the foamed NBR/CNs nanocomposites. We found that the CNs mainly located in the cell walls, effectively reinforcing the foamed NBR. The strong interaction between the CNs and NBR matrix restricted the mobility of NBR chains surrounding the CNs, hence increasing the crosslink density of the NBR matrix. CNs exhibited excellent reinforcement on the foamed NBR: a remarkable increase nearly 76% in the tensile strength of the foamed nanocomposites was achieved with a load of only 15 phr CNs. Enhanced mechanical properties make the foamed NBR/CNs nanocomposites a promising damping material for industrial applications with a potential to reduce the petroleum consumption. Copyright © 2015 Elsevier Ltd. All rights reserved.

NMR investigation of gaseous SF6 confinement into EPDM rubber.

PubMed

Neutzler, Sven; Terekhov, Maxim; Hoepfel, Dieter; Oellrich, Lothar Rainer

2005-02-01

The confinement process of gaseous sulphurhexafluoride (SF6) in ethylene-propylene-diene (EPDM) rubber was investigated by spectroscopic and spatially resolved NMR techniques. A strong elongation of T1 relaxation time of SF6 and a decrease of the diffusion coefficient were found. A possible explanation may be the strong restriction of molecular mobility due to interactions between SF6 and active centers of the EPDM.

The Pharmaceutical Capping Process-Correlation between Residual Seal Force, Torque Moment, and Flip-off Removal Force.

PubMed

Mathaes, Roman; Mahler, Hanns-Christian; Vorgrimler, Lothar; Steinberg, Henrik; Dreher, Sascha; Roggo, Yves; Nieto, Alejandra; Brown, Helen; Roehl, Holger; Adler, Michael; Luemkemann, Joerg; Huwyler, Joerg; Lam, Philippe; Stauch, Oliver; Mohl, Silke; Streubel, Alexander

2016-01-01

The majority of parenteral drug products are manufactured in glass vials with an elastomeric rubber stopper and a crimp cap. The vial sealing process is a critical process step during fill-and-finish operations, as it defines the seal quality of the final product. Different critical capping process parameters can affect rubber stopper defects, rubber stopper compression, container closure integrity, and also crimp cap quality. A sufficiently high force to remove the flip-off button prior to usage is required to ensure quality of the drug product unit by the flip-off button during storage, transportation, and until opening and use. Therefore, the final product is 100% visually inspected for lose or defective crimp caps, which is subjective as well as time- and labor-intensive. In this study, we sealed several container closure system configurations with different capping equipment settings (with corresponding residual seal force values) to investigate the torque moment required to turn the crimp cap. A correlation between torque moment and residual seal force has been established. The torque moment was found to be influenced by several parameters, including diameter of the vial head, type of rubber stopper (serum or lyophilized) and type of crimp cap (West(®) or Datwyler(®)). In addition, we measured the force required to remove the flip-off button of a sealed container closure system. The capping process had no influence on measured forces; however, it was possible to detect partially crimped vials. In conclusion, a controlled capping process with a defined target residual seal force range leads to a tight crimp cap on a sealed container closure system and can ensure product quality. The majority of parenteral drug products are manufactured in a glass vials with an elastomeric rubber stopper and a crimp cap. The vial sealing process is a critical process step during fill-and-finish operations, as it defines the seal quality of the final product. An adequate force to remove the flip-off button prior to usage is required to ensure product quality during storage and transportation until use. In addition, the complete crimp cap needs to be fixed in a tight position on the vial. In this study, we investigated the torque moment required to turn the crimp cap and the force required to remove the flip-off button of container closure system sealed with different capping equipment process parameters (having different residual seal force values). © PDA, Inc. 2016.

The private funding of public research. New directions in the administration of occupational and environmental health research.

PubMed

Cullen, M R; Upton, A; Buffler, P; Robins, T; Schenker, M; Fine, L; Wiencek, R; Widess, E; Chiazze, L

1994-12-01

Dr. Cullen: The experience with the new research models, starting with the prototypic experience of the rubber industry studies of the 1970s and expanding to diverse sectors of American industry in the 1980s, has yielded some important lessons for the future. In closing this symposium I shall try to summarize these briefly. Certain strengths of the evolving process seem common to each of the models. Alone and collectively, the new research arrangements have quite apparently served to increase substantially the pool of funds available to the academic sector for the study of occupational health and safety problems. As a consequence, a larger pool of investigators has participated in the research process, greatly strengthening the future academic capability and experience of our fragilely supported teaching centers. Combined with the involvement of the academic centers in the review process, there has been an undeniable broadening and deepening of the nation's research output and long-term capability in occupational health. On the side of the private sector, the new relationships have led to marked progress in the knowledge base about health and safety problems, with a heavily directed focus on those of greatest relevance to the industries involved. The credibility of the knowledge acquired has been enhanced, an important achievement in a society in which perception of truth is often as important as the truth itself! Because of the requirements of the process for broad involvement by the organizations which undertake these activities, health and safety have achieved far greater visibility and attention by corporate and union leaders who may have previously had no involvement in issues of health and safety.(ABSTRACT TRUNCATED AT 250 WORDS)

Wicking of light hydrophobic liquid phase from water by pulverized rubber: Theoretical and experimental analyses.

PubMed

Boglaienko, Daria; Tansel, Berrin

2017-03-05

Pulverized rubber (PR) can be utilized for capturing floating oils to prevent spreading and volatilization of hydrocarbons. Experiments were conducted using PR with four different particle sizes (ranging from 0.075 to 0.600mm) and South Louisiana crude oil. The oil capture performance of the PR particles was compared with that of powdered activated carbon (AC). Oil-particle interactions were analyzed using capillary theories for lateral aggregation and wicking processes, as well as sorption capacity in relation to particle size. The sorption capacity (as oil to sorbent ratio) for PR with particle size 0.115mm (4.41g/g) was comparable to that of AC with particle size 0.187mm (5.00g/g). Sorption efficiency (oil:powder ratio, g/g) of the PR increased with decreasing particle size. Sorption of oil by PR occurred rapidly (in less than 10min) which indicated strong capillary action. No additional sorption occurred after 30min. For the PR sample with larger particle size (0.600-0.400mm), lateral aggregation was clearly noticeable. The PR-oil aggregates could be easily removed from the water surface without breaking. The cost, availability and recycling potential of PR make it a feasible alternative material for oil spill response and industrial applications which require removal of floating oils. Copyright © 2016 Elsevier B.V. All rights reserved.

A novel technique for preventing skin pressure sores using a rubber tube during surgical treatment of mandibular condyle fractures.

PubMed

Kawase-Koga, Yoko; Mori, Yoshiyuki; Hoshi, Kazuhito; Takato, Tsuyoshi

2013-11-01

Craniofacial surgery occasionally results in sores and necrosis of the facial skin because of pressure from surgical instruments. During surgical treatment of mandibular condylar process fractures, the main mandibular fragment is routinely retracted downward using a wire to achieve a satisfactory anatomic reduction. This procedure may injure the facial skin. This potential complication is easily overlooked by medical staff, but it is easily preventable. We herein describe a method of using a rubber tube to avoid causing pressure sores of the facial skin during surgical treatment of mandibular condylar process fractures.

Prime Contract Awards by Service Category and Federal Supply Classification, Fiscal Years 1977, 1978, 1979, 1980.

DTIC Science & Technology

1980-01-01

MACHINES NA 19 284 14 3590 MISC SERVICE AND TRADE EQUIPMENT 318 1,412 981 771 TOTAL 4,759 5,835 8,057 8,338 36 SPECIAL INDUSTRY MACHINERY 3605 FOOD... MACHINES 144 79 26 55 3615 PULP AND PAPER INDUSTRIES MACHINERY 383 671 651 813 3620 RUBBER A PLASTIC WORKING MACHINERY 500 364 234 182 3625 TEXTILE... MACHINERY 76 18 36 29 3220 WOODWORK!NG MACHINES 1,769 1,902 1,389 635 3230 TOOLS - ATTACHMENTS FOR WOODWORKING MACH NA NA 61 858 TOTAL 1,845 1,920 1,486

Compression Molding of Composite of Recycled HDPE and Recycled Tire Particles

NASA Technical Reports Server (NTRS)

Liu, Ping; Waskom, Tommy L.; Chen, Zhengyu; Li, Yanze; Peng, Linda

1996-01-01

Plastic and rubber recycling is an effective means of reducing solid waste to the environment and preserving natural resources. A project aimed at developing a new composite material from recycled high density polyethylene (HDPE) and recycled rubber is currently being conducted at Eastern Illinois University. The recycled plastic pellets with recycled rubber particles are extruded into some HDPE/rubber composite strands. The strand can be further cut into pellets that can be used to fabricate other material forms or products. This experiment was inspired by the above-mentioned research activity. In order to measure Durometer hardness of the extruded composite, a specimen with relatively large dimensions was needed. Thus, compression molding was used to form a cylindrical specimen of 1 in. diameter and 1 in. thickness. The initial poor quality of the molded specimen prompted a need to optimize the processing parameters such as temperature, holding time, and pressure. Design of experiment (DOE) was used to obtain optimum combination of the parameters.

Investigations on the properties of NH4HCO3 filled natural rubber based magnetorheological elastomers (MREs)

NASA Astrophysics Data System (ADS)

Fan, Lili; Wang, Guoping; Wang, Wenju; Shi, Guanxin; Yang, Fufeng; Rui, Xiaoting

2018-04-01

Various anisotropic magnetorheological elastomers (MREs) were synthesized using the rubber mixing technique. Magnetic and temperature distributions of the experimental equipment and test instruments were analyzed by the ANSYS. NH4HCO3 was filled in the natural rubber matrix to modify properties of MREs. Microstructures and compositions of samples were studied by the scanning electron microscope (SEM), the energy dispersive x-ray spectroscopy (EDAX) analysis and x-ray powder diffraction (XRD). Via vibrating sample magnetometer (VSM) and density functional theory (DFT) method, the magnetic property of carbonyl iron (CI) was illuminated. The shear storage modulus and MR effect of MREs were investigated by the dynamic mechanical analyzer (DMA). It indicated that distributions of magnetic and temperature in the experimental and testing devices were uniform. Before vulcanization, CI particles were uniformly distributed in the matrix, while a CI chain structure was formed and embedded in the matrix after the vulcanization process. Moderate addition of NH4HCO3 accelerated the rubber vulcanization and enhanced the MR effect.

Biocompatibility of platinum-metallized silicone rubber: in vivo and in vitro evaluation.

PubMed

Vince, V; Thil, M A; Veraart, C; Colin, I M; Delbeke, J

2004-01-01

Silicone rubber is commonly used for biomedical applications, including implanted cuff electrodes for both recording and stimulation of peripheral nerves. This study was undertaken to evaluate the consequences of a new platinum metallization method on the biocompatibility of silicone rubber cuff electrodes. This method was introduced in order to allow the manufacture of spiral nerve cuff electrodes with a large number of contacts. The metallization process, implying silicone coating with poly(methyl methacrylate) (PMMA), its activation by an excimer laser and subsequent electroless metal deposition, led to a new surface microtexture. The neutral red cytotoxicity assay procedure was first applied in vitro on BALB/c 3T3 fibroblasts in order to analyze the cellular response elicited by the studied material. An in vivo assay was then performed to investigate the tissue reaction after chronic subcutaneous implantation of the metallized material. Results demonstrate that silicone rubber biocompatibility is not altered by the new platinum metallization method.

Influence of Rubber Size on Properties of Crumb Rubber Mortars

PubMed Central

Yu, Yong; Zhu, Han

2016-01-01

Studies on the properties and applications of rubber cement-based materials are well documented. The sizes of rubbers used in these materials varied. However, information about the effects of rubber size on the properties of rubber cement-based materials, especially pore structure, mechanical strengths, and drying shrinkage properties, remains limited. Three groups of rubber with major particle sizes of 2–4 mm, 1–3 mm, and 0–2 mm were selected in this study. This paper presents experimental studies on the effects of rubber size on the consistency, fresh density, pore structure, mechanical properties, and drying shrinkage properties of crumb rubber mortars (CRMs). Results demonstrated that the consistency and fresh density of CRMs decreased with the rubber size. As to the pore structure, the total pore volume increased with the decrease of the rubber size. By contrast, the influence of the rubber size on the mesopore (<50 nm) volume is not as significant as that of the rubber content. The mechanical properties of CRMs decreased with the rubber size. Low rubber stiffness and large pore volumes, especially those of small sized rubbers, contribute to the reduction of CRMs strength. The drying shrinkage of CRM increases as the rubber size decreases. The influences of rubber size on capillary tension are not significant. Thus, the shrinkage increases with the decrease of rubber size mainly because of its function in the deformation modulus reduction of CRMs. PMID:28773649

Down-Regulation of Small Rubber Particle Protein Expression Affects Integrity of Rubber Particles and Rubber Content in Taraxacum brevicorniculatum

PubMed Central

Hillebrand, Andrea; Post, Janina J.; Wurbs, David; Wahler, Daniela; Lenders, Malte; Krzyzanek, Vladislav; Prüfer, Dirk; Gronover, Christian Schulze

2012-01-01

The biosynthesis of rubber is thought to take place on the surface of rubber particles in laticifers, highly specialized cells that are present in more than 40 plant families. The small rubber particle protein (SRPP) has been supposed to be involved in rubber biosynthesis, and recently five SRPPs (TbSRPP1–5) were identified in the rubber-producing dandelion species Taraxacum brevicorniculatum. Here, we demonstrate by immunogold labeling that TbSRPPs are localized to rubber particles, and that rubber particles mainly consist of TbSRPP3, 4 and 5 as shown by high-resolution two-dimensional gel electrophoresis and mass spectrometric analysis. We also carried out an RNA-interference approach in transgenic plants to address the function of TbSRPPs in rubber biosynthesis as well as rubber particle morphology and stability. TbSRPP-RNAi transgenic T. brevicorniculatum plants showed a 40–50% reduction in the dry rubber content, but neither the rubber weight average molecular mass nor the polydispersity of the rubber were affected. Although no phenotypical differences to wild-type particles could be observed in vivo, rubber particles from the TbSRPP-RNAi transgenic lines were less stable and tend to rapidly aggregate in expelling latex after wounding of laticifers. Our results prove that TbSRPPs are very crucial for rubber production in T. brevicorniculatum, probably by contributing to a most favourable and stable rubber particle architecture for efficient rubber biosynthesis and eventually storage. PMID:22911861

Evaluation of rice husk ash as filler in tread compounds

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fernandes, M. R. S., E-mail: monica.fernandes@lanxess.com; Furtado, C. R. G., E-mail: russi@globo.com, E-mail: ana.furtado.sousa@gmail.com; Sousa, A. M. F. de, E-mail: russi@globo.com, E-mail: ana.furtado.sousa@gmail.com

Rice which is one of the largest agriculture crops produces around 22% of rice rusk during its milling process. This material is mainly used as fuel for energy generation, which results in an ash, which disposal represents an environmental issue. The rice husk ash (RHA) contains over than 70% of silica in an amorphous form and a lot of applications is being developed for it all over the world. The use of silica as a filler in the tire industry is growing since it contributes significantly to the reduction of fuel consumption of the automobiles, allowing at the same timemore » better traction (safety). This paper presents an evaluation of the use of RHA as filler in rubber tread compounds prepared in lab scale and compares its performance with compounds prepared with commercial silica and carbon black, the fillers normally used in tire industry. Mechanical and rheological properties are evaluated, with emphasis for tan delta as an indicator of tread performance related with rolling resistance (fuel consumption) and wet grip/traction (safety)« less

Application of laser processing for disassembly of nuclear power plants

NASA Astrophysics Data System (ADS)

Baranov, Gennady A.; Zinchenko, A. V.; Arutyunyan, R. B.

1998-12-01

Provision of safety and drop of ecological risk at salvaging of nuclear submarines (NSM) of Russia Navy Forces represents one of the most actual problems of nowadays. It is necessary to remove from services of Russian Navy Forces 170 - 180 nuclear submarines by 2000. At salvaging of Russian Navy Forces NSM it should be necessary to cut out reactor compartments with more than 150 thousand tons of gross weight and to fragment terminal carcasses of submarines with gross weight of 2 million tons. Taking into account overall dimensions of salvaging objects and Euro-standard requirement on the sizes of carcass fragments, for salvaging of one NSM it is necessary to execute more than 10 km of cuts. Using of conventional methods of gas and plasma cutting of ship constructions and equipment polluted with radioactive oxides and bedding of insulation and paint and varnish materials causes contamination of working zones and environment by a mix of radioactive substances and highly toxic combustion products, nomenclature of which includes up to 50 names. Calculations carried out in the Institute of industrial and Marine Medicine have shown that salvage of just one NSM with using of gas and plasma cutting are accompanied by discharge into an environment of up to 11.5 kg of chromium oxides, up to 22.5 kg of manganese oxides, up to 97 kg of carbon oxides and up to 650 kg of nitrogen oxides. Fragmentation of such equipment by a method of directional explosion or hydraulic jet is problematic because of complexity of treated constructions and necessity to create special protective facilities, which will accumulate a bulk of radioactive and toxic discharges, as a consequence of the explosion and spreaded by shock waves and water deluges. In a number of new technological processes the cutting with using of high-power industrial lasers radiation stands out. As compared with other technological processes, laser cutting has many advantages determined by such unique properties of laser radiation as large power, capability to concentrate power on the small area (up to 108 W/cm2), good spatial and temporal controllability. The laser cutting advantages are the following: (1) high efficiency; (2) capability to cut various materials (metals, alloys, plastics, rubber, ceramics) and their compositions (fiber glass plastics, rubber-plastics, cermets) by one installation; (3) minimum pollution in gas and condensed phases; (4) high degree of technological process automation; (5) remote character of cutting and personnel absence in a processing zone.

Biodegradation of cis-1,4-Polyisoprene Rubbers by Distinct Actinomycetes: Microbial Strategies and Detailed Surface Analysis

PubMed Central

Linos, Alexandros; Berekaa, Mahmoud M.; Reichelt, Rudolf; Keller, Ulrike; Schmitt, Jürgen; Flemming, Hans-Curt; Kroppenstedt, Reiner M.; Steinbüchel, Alexander

2000-01-01

Several actinomycetes isolated from nature were able to use both natural rubber (NR) and synthetic cis-1,4-polyisoprene rubber (IR) as a sole source of carbon. According to their degradation behavior, they were divided into two groups. Representatives of the first group grew only in direct contact to the rubber substrate and led to considerable disintegration of the material during cultivation. The second group consisted of weaker rubber decomposers that did not grow adhesively, as indicated by the formation of clear zones (translucent halos) around bacterial colonies after cultivation on NR dispersed in mineral agar. Taxonomic analysis of four selected strains based on 16S rRNA similarity examinations revealed two Gordonia sp. strains, VH2 and Kb2, and one Mycobacterium fortuitum strain, NF4, belonging to the first group as well as one Micromonospora aurantiaca strain, W2b, belonging to the second group. Schiff's reagent staining tests performed for each of the strains indicated colonization of the rubber surface, formation of a bacterial biofilm, and occurrence of compounds containing aldehyde groups during cultivation with NR latex gloves. Detailed analysis by means of scanning electron microscopy yielded further evidence for the two different microbial strategies and clarified the colonization efficiency. Thereby, strains VH2, Kb2, and NF4 directly adhered to and merged into the rubber material, while strain W2b produced mycelial corridors, especially on the surface of IR. Fourier transform infrared spectroscopy comprising the attenuated total reflectance technique was applied on NR latex gloves overgrown by cells of the Gordonia strains, which were the strongest rubber decomposers. Spectra demonstrated the decrease in number of cis-1,4 double bonds, the formation of carbonyl groups, and the change of the overall chemical environment, indicating that an oxidative attack at the double bond is the first metabolic step of the biodegradation process. PMID:10742254

A study of sound absorption by street canyon boundaries and asphalt rubber concrete pavement

NASA Astrophysics Data System (ADS)

Drysdale, Graeme Robert

A sound field model, based on a classical diffusion equation, is extended to account for sound absorption in a diffusion parameter used to model sound energy in a narrow street canyon. The model accounts for a single sound absorption coefficient, separate accommodation coefficients and a combination of separate absorption and accommodation coefficients from parallel canyon walls. The new expressions are compared to the original formula through numerical simulations to reveal the effect of absorption on sound diffusion. The newly established analytical formulae demonstrate satisfactory agreement with their predecessor under perfect reflection. As well, the influence of the extended diffusion parameter on normalized sound pressure levels in a narrow street canyon is in agreement with experimental data. The diffusion parameters are used to model sound energy density in a street canyon as a function of the sound absorption coefficient of the street canyon walls. The acoustic and material properties of conventional and asphalt rubber concrete (ARC) pavement are also studied to assess how the crumb rubber content influences sound absorption in street canyons. The porosity and absolute permeability of compacted specimens of asphalt rubber concrete are measured and compared to their normal and random incidence sound absorption coefficients as a function of crumb rubber content in the modified binder. Nonlinear trends are found between the sound absorption coefficients, porosity and absolute permeability of the compacted specimens and the percentage of crumb rubber in the modified binders. The cross-sectional areas of the air voids on the surfaces of the compacted specimens are measured using digital image processing techniques and a linear relationship is obtained between the average void area and crumb rubber content. The measured material properties are used to construct an empirical formula relating the average porosity, normal incidence noise reduction coefficients and percentage of crumb rubber in the modified binder of the compacted specimens.

Multi-objective optimization of process conditions in the manufacturing of banana (Musa paradisiaca L.) starch/natural rubber films.

PubMed

Ramírez-Hernández, A; Aparicio-Saguilán, A; Reynoso-Meza, G; Carrillo-Ahumada, J

2017-02-10

Multi-objective optimization was used to evaluate the effect of adding banana (Musa paradisiaca L.) starch and natural rubber (cis-1,4-poliisopreno) at different ratios (1-13w/w) to the manufacturing process of biodegradable films, specifically the effect on the biodegradability, crystallinity and moisture of the films. A structural characterization of the films was performed by X-ray diffraction, Fourier transform infrared spectroscopy and SEM, moisture and biodegradability properties were studied. The models obtained showed that degradability vs. moisture tend to be inversely proportional and crystallinity vs. degradability tend to be directly proportional. With respect to crystallinity vs. moisture behavior, it is observed that crystallinity remains constant when moisture values remain between 27 and 41%. Beyond this value there is an exponential increase in crystallinity. These results allow for predictions on the mechanical behavior that can occur in starch/rubber films. Copyright © 2016 Elsevier Ltd. All rights reserved.

Nanocelluloses from jute fibers and their nanocomposites with natural rubber: Preparation and characterization.

PubMed

Thomas, Martin George; Abraham, Eldho; Jyotishkumar, P; Maria, Hanna J; Pothen, Laly A; Thomas, Sabu

2015-11-01

Nanocellulose fibers having an average diameter of 50nm were isolated from raw jute fibers by steam explosion process. The isolation of nanocellulose from jute fibers by this extraction process is proved by SEM, XRD, FTIR, birefringence and TEM characterizations. This nanocellulose was used as the reinforcing agent in natural rubber (NR) latex along with crosslinking agents to prepare crosslinked nanocomposite films. The effects of nanocellulose loading on the morphology and mechanics of the nanocomposites have been carefully analyzed. Significant improvements in the Young's modulus and tensile strength of the nanocomposite were observed because of the reinforcing ability of the nanocellulose in the rubber matrix. A mechanism is suggested for the formation of the Zn-cellulose complex. The three-dimensional network of cellulose nanofibers (cellulose/cellulose network and Zn/cellulose network) in the NR matrix plays a major role in improving the properties of the crosslinked nanocomposites. Copyright © 2015 Elsevier B.V. All rights reserved.

Monitoring Network and Interfacial Healing Processes by Broadband Dielectric Spectroscopy: A Case Study on Natural Rubber.

PubMed

Hernández, M; Grande, A M; van der Zwaag, S; García, S J

2016-04-27

Broadband dielectric spectroscopy (BDS) is introduced as a new and powerful technique to monitor network and macroscale damage healing in an elastomer. For the proof of concept, a partially cured sulfur-cured natural rubber (NR) containing reversible disulfides as the healing moiety was employed. The forms of damage healed and monitored were an invisible damage in the rubber network due to multiple straining and an imposed macroscopic crack. The relaxation times of pristine, damaged, and healed samples were determined and fitted to the Havriliak-Negami equation to obtain the characteristic polymer parameters. It is shown that seemingly full mechanical healing occurred regardless the type of damage, while BDS demonstrates that the polymer architecture in the healed material differs from that in the original one. These results represent a step forward in the understanding of damage and healing processes in intrinsic self-healing polymer systems with prospective applications such as coatings, tires, seals, and gaskets.

The Environmental Assessment and Management (TEAM) Guide: Mississippi Supplement

DTIC Science & Technology

2010-03-01

4 The Environmental Assessment and Management (TEAM) Guide: Mississippi Supplement C on st ru ct io n E n gi...resins manufacturing 10. pulp and paper industry 11. rubber and miscellaneous paper products 12. stone, glass, clay, and concrete products 13...contaminant risk assessment of the material. 4 . The registrant of the by-product must have the certification of a professional engineer licensed in

Mechanisms to improve the mechanical performance of surgical gloves

NASA Astrophysics Data System (ADS)

Watkins, Michelle Hoyt

1997-11-01

The use of gloves as a barrier to cross infection in the medical industry has increased substantially due to the heightened awareness of viral transmission, especially the human immunodeficiency virus and the hepatitis B virus. The glove must allow for tactile sensation, comfort and long use times, while providing equally critical mechanical performance. The majority of surgical gloves are made of natural rubber latex which do not give a critical level of cut-resistance or puncture-resistance. Natural rubber latex gloves are also known to cause latex allergy with hypersensitivity reactions ranging from mild skin rashes to more severe bronchial asthma, anaphylactic reactions, and even death. It has been postulated natural rubber latex (NRL) proteins cause these allergic reactions. The research that has been conducted comprises two approaches that have been explored for improving the cut-resistance of surgical gloves. The first method involves an integral fiber-latex structure that possesses the combination of high reversible extensibility, barrier performance and retention of tactile sense. Improvement in mechanical properties in excess of 85% has been achieved as well as an improvement in cut-resistance. The second method involves the incorporation of a low concentration of ultra high molecular weight (UHMW) polyacrylamide. Although the initial premise for using a UHMW polymer was that it would bridge the latex compound particulates to improve strength, an entirely different mechanism for the enhancement of strength was explored through a parallel investigation of the release of proteins from cured natural rubber. However, no mechanism was conclusively identified. To address the allergy aspects of NRL, a thorough examination of the release of naturally-occurring latex proteins from cured natural rubber latex glove material was conducted in order to identify mechanisms for eliminating and/or reducing the potential allergens. The initial study examined the release of loaded proteins from cured NR and NR that contained PA in the initial latex compound and the results showed the likelihood of binding between proteins and PA.

Leaching of zinc compound from rubber stoppers into the contents of automatic atropine injectors.

PubMed

Ellin, R I; Kaminskis, A; Zvirblis, P; Sultan, W E; Shutz, M B; Matthews, R

1985-07-01

This report describes how a material within the cartridge of an automatic injector contaminated its contents. On prolonged storage, a formulation that contained atropine produced lethality in mice. The toxic material originated from zinc compounds that were present in the rubber stopper and plunger of the container and that subsequently leached into the formulation. The contents of cartridges that contained greater than or equal to 0.75 mg/mL of solubilized zinc were lethal to at least 20% of the mice tested; those that contained 0.42 mg/mL showed no lethality. The problem resulted from the physicochemical properties of the rubber, not the concentration of zinc used in the vulcanization process.

Implementation of sobel method to detect the seed rubber plant leaves

NASA Astrophysics Data System (ADS)

Suyanto; Munte, J.

2018-03-01

This research was conducted to develop a system that can identify and recognize the type of rubber tree based on the pattern of leaves of the plant. The steps research are started with the identification of the image data acquisition, image processing, image edge detection and identification method template matching. Edge detection is using Sobel edge detection. Pattern recognition would detect image as input and compared with other images in a database called templates. Experiments carried out in one phase, identification of the leaf edge, using a rubber plant leaf image 14 are superior and 5 for each type of test images (clones) of the plant. From the experimental results obtained by the recognition rate of 91.79%.

Rapid production of polymer microstructures

NASA Astrophysics Data System (ADS)

Nagarajan, Pratapkumar

The goal of this research is to develop an integrated polymer embossing module, with which difficult-to-emboss polymer microstructures and microparts can be fabricated in a cost-effective manner. In particular, the research addresses three major limitations of the hot embossing process, namely, long cycle time, difficulty in producing shell patterns, and difficulty in building up a high embossing pressure on thick substrates. To overcome these limitations, three new technical approaches - two-station embossing, rubber-assisted embossing, and through-thickness embossing - were developed and investigated. Fundamental understanding of these new embossing techniques were achieved through extensive experimental and theoretical studies involving parametric experiments, rheological characterization, surface investigation, mathematical modeling, and computer simulation. A two-station embossing process was developed to reduce the hot embossing cycle time, accomplished by decoupling the heating and cooling stations. For this purpose, the standard hot embossing mold was replaced by a shell type mold, and separate hot and cold stations were used to selectively heat and cool the shell mold during the process. With this method, microlens arrays and micro channels were fabricated onto ABS and HDPE substrates with a cycle time of approximately 10 s. Numerical simulations were performed to study the effect of different design parameters, including thermal contact resistance, shell material and shell thickness, on the thermal response at the mold surface. Furthermore, the polymer flow during the two-station embossing process for the microlens was numerically studied. The simulated filling behavior agreed with the experimental observation, and the predicted thermal and deformation history of the polymer offers a good explanation on the experimentally observed process characteristics. The second technique, rubber-assisted embossing, involving a rubber pad as a soft counter tool, was developed for precision embossing of shell structures. The rubber pad acted as a temporary negative during embossing and recovered to its original geometry after mold opening. With rubber-assisted embossing, a micro shell pattern with a characteristic size of 50 mum was successfully patterned on 25-mum thick polystyrene films. A focused study was undertaken on rubber-assisted isothermal embossing to establish the relationship between process parameters and pattern replication. It was found that the pattern replication and film uniformity were affected by the embossing temperature and the hardness of rubber. It was also found that adequate plasticity and higher stiffness of the deforming film were essential in achieving excellent pattern replication and uniformity in film thickness. The through-thickness embossing process was developed for embossing pressure buildup and fabrication of 3-D parts. The embossing tool includes a punching head and to-be-replicated features in the socket behind the punching head. The built-in punching head facilitates a through-thickness action and provides a close-die environment for embossing pressure buildup. The method was used to emboss multichannel millimeter waveguides which requires crispy edges and accurate dimensions. With a tool temperature of 140°C, an embossing time of 3 min and a total cycle time of 7 min, discrete 4-channel waveguides were successfully embossed from a room-temperature ABS substrate. A computer model was established to study the flow behavior during through-thickness embossing. It was found that nonisothermal embossing conditions helped to confine the polymer in the cavity and reduce the outflow into the surrounding region, thus achieving complete fill of the cavity.

Novel Elastomeric Closed Cell Foam - Nonwoven Fabric Composite Material (Phase III)

DTIC Science & Technology

2008-10-01

increasing the polymer content of the foam. From laboratory studies, processing was found to improve by using different types of NBR rubber . The AF07 B...Foam Optimization (Task 1) Prior development of fire retarded closed cell foam yielded attractive candidates for scale-up. Nitrile-butadiene rubber ... NBR ) and polyvinyl chloride (PVC) blends provided the most cost effective solutions. Two types of formulas were chosen for optimization. The first

Reusable Material for Drop Tower

DTIC Science & Technology

2011-08-01

R3 Buna-N Rubber ............................................................................................... 32 B-3. R5 EPDM Rubber ...Butyl Rubber . Figure B-2. R3 Buna-N Rubber . Figure B-3. R5 EPDM Rubber . Figure B-4. R6 Gel Rubber . UNCLASSIFIED 33...11 Current Drop Tower Material & Setup .......................................................... 11 Bowling Ball Rubber Material Sample Test

Interpersonal touch suppresses visual processing of aversive stimuli

PubMed Central

Kawamichi, Hiroaki; Kitada, Ryo; Yoshihara, Kazufumi; Takahashi, Haruka K.; Sadato, Norihiro

2015-01-01

Social contact is essential for survival in human society. A previous study demonstrated that interpersonal contact alleviates pain-related distress by suppressing the activity of its underlying neural network. One explanation for this is that attention is shifted from the cause of distress to interpersonal contact. To test this hypothesis, we conducted a functional MRI (fMRI) study wherein eight pairs of close female friends rated the aversiveness of aversive and non-aversive visual stimuli under two conditions: joining hands either with a rubber model (rubber-hand condition) or with a close friend (human-hand condition). Subsequently, participants rated the overall comfortableness of each condition. The rating result after fMRI indicated that participants experienced greater comfortableness during the human-hand compared to the rubber-hand condition, whereas aversiveness ratings during fMRI were comparable across conditions. The fMRI results showed that the two conditions commonly produced aversive-related activation in both sides of the visual cortex (including V1, V2, and V5). An interaction between aversiveness and hand type showed rubber-hand-specific activation for (aversive > non-aversive) in other visual areas (including V1, V2, V3, and V4v). The effect of interpersonal contact on the processing of aversive stimuli was negatively correlated with the increment of attentional focus to aversiveness measured by a pain-catastrophizing scale. These results suggest that interpersonal touch suppresses the processing of aversive visual stimuli in the occipital cortex. This effect covaried with aversiveness-insensitivity, such that aversive-insensitive individuals might require a lesser degree of attentional capture to aversive-stimulus processing. As joining hands did not influence the subjective ratings of aversiveness, interpersonal touch may operate by redirecting excessive attention away from aversive characteristics of the stimuli. PMID:25904856

Optimization of transesterification of rubber seed oil using heterogeneous catalyst calcium oxide

NASA Astrophysics Data System (ADS)

Inggrid, Maria; Kristanto, Aldi; Santoso, Herry

2015-12-01

Biodiesel is an alternative fuel manufactured with the help of alkali hydroxide catalyst through transesterification reaction of vegetable oil. This study aims to examine methods and the most suitable conditions for transesterification reaction producing biodiesel from crude rubber seed oil by varying process parameters such as the molar ratio of alcohol, CaO amount as the alkaline catalyst, and reaction time. The rubber seed oil has a high level of free fatty acid content, which means the use of homogenous alkaline catalyst gives some technological problems such as soap formation which leaded in difficulty in the separation and purification of the product. Calcium oxide (CaO) is one of the most favorable heterogeneous base catalysts because it's reusable, noncorrosive, and low cost. Pre-treatment was performed by acid esterification with H2SO4 as the catalyst to decrease the content of free fatty acid in the rubber seed oil, in this pretreatment process the 12% FFA of crude oil could be reduced to below 3% FFA. The product after esterification process was then transesterified by alkaline transesterification by varying process parameters to convert triglyceride into biodiesel. The study found that maximum curvature for biodiesel yield occurred at 9:1 molar ratio of alcohol, 5%w catalyst loading, and 3 hours reaction time. Design expert software is used to determine the optimum point from experimental data. The result showed that the optimum yield of methyl ester from transesterification was 73.5 % by mass with 0.69 degree of desirability. The yielded methyl ester was tested for its density, viscosity, acid number, and solubility to meet SNI requirement standards.

Stock, turnover and functions of carbon in heavily weathered soils under lowland rainforest transformation systems

NASA Astrophysics Data System (ADS)

Guillaume, Thomas; Kuzyakov, Yakov

2013-04-01

Tropical rainforest are experiencing worldwide a strong lost through deforestation and transformation into agricultural systems. Land use changes in such ecosystems leads to major modifications of soils properties and processes. One indication of it are the losses of organic carbon content (Corg); an important soil fertility parameter in heavily weathered soil. Between 1985 and 2007, Sumatra (Indonesia) has lost half of his remaining natural rainforest, which currently covers only 30% the island. The deforestation is still ongoing and the main drivers of deforestation are oil palm, rubber and timber industries. Our study aims to identify and quantify the impacts of lowland rainforest transformation systems (TS): oil palm, rubber and jungle rubber plantations on soil organic carbon (SOC) and nitrogen (SON) quality, turnover and stocks and so, on soil fertility and functions. We hypothesize that transformation of natural lowland rainforest changes not only C stock and budget throughout quantity and quality of C input, but also DOM production and water consumption by vegetation, leading to a relocation of C in the subsoil. This should be reflected in C and N content in soil profile horizons as well as their δ13C and δ15N isotopic signatures. We will evaluate also C stability through biological, thermal and chemical stability in bulk soil and aggregate fractions. The TS investigated, including lowland rainforest as reference sites, are located in Jambi Province (Sumatra). Soil has been described and sampled per horizon on 4 replicates of each TS in 2 different regions (32 sites) in Autumn 2012. As hypothesized, first results show strong effects of forest transformation on C and N content, as well as on isotopic signatures of soil. Those results will also be used further to select DOM sampling depths and adequate horizons to perform sorption and incubation experiments.

Electron beam curing of EPDM

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vroomen, G.L.M.; Visser, G.W.; Gehring, J.

1991-11-01

Normally EPDM rubbers are vulcanized by systems based on sulphur, resin or peroxide. The common feature of these systems is that they all require activator energy in the form of heat. The (extremely) high temperatures (approximately 180C) have the disadvantage that the final properties of the finished product may be affected in one way or another by a variety of uncontrolled side reactions which may occur. Radiation curing, on the other hand, is a process which differs from those mentioned above in that the final curing is carried out at about 20C under closely controlled conditions (such as radiation dose,more » penetration depth, etc.), and this form of curing ultimately results in a more well-defined end product. In the rubber industry, this technique is used by large rubber processors (for example, in roof sheeting and cable production). Its widespread use is, however, impeded by the high investment costs. One way of avoiding these high costs is to arrange for the products to be irradiated by contractors. The optimum radiation dose for EPDM is determined by the required pattern of properties. From this study it may be concluded that the network is primarily built up at a radiation dose of up to approximately 100 kGy. The degree to which it is built up depends partly on the coactivator used and the EPDM type used. In choosing the coactivator, allowance has to be made for its solubility in EPDM. The type of oil chosen and any stabilizer additions will affect the crosslinking efficiency. Contrary to studies published earlier, in this study it was found that when EDMA is used as a coactivator, no difference can be detected between a DCPD type (4%) and an ENB type (4%), provided both have an identical molecular weight distribution. Increasing the ENB content has less effect on the final crosslink density than using a type having a broader molecular weight distribution.« less

Properties and potential environmental applications of carbon adsorbents from waste tire rubber

USGS Publications Warehouse

Lehmann, C.M.B.; Rameriz, D.; Rood, M.J.; Rostam-Abadi, M.

2000-01-01

The properties of tire-derived carbon adsorbents (TDCA) produced from select tire chars were compared with those derived from an Illinois coal and pistachio nut shells. Chemical analyses of the TDCA indicated that these materials contain metallic elements not present in coal-and nut shell-derived carbons. These metals, introduced during the production of tire rubber, potentially catalyze steam gasification reactions of tire char. TDCA carbons contained larger meso-and macopore volumes than their counterparts derived from coal and nut shell (on the moisture-and ash-free-basis). Adsorptive properties of the tire-derived adsorbent carbons for air separation, gas storage, and gas clean up were also evaluated and compared with those of the coal-and nut shell derived carbons as well as a commercial activated carbon. The results revealed that TDCA carbons are suitable adsorbents for removing vapor-phase mercury from combustion flue gases and hazardous organic compounds from industrial gas streams.

Carlos Chagas in the "war of the rivers:" the passage of the Instituto Oswaldo Cruz commission up the Yaco river (Alto Purus, federal territory of Acre, 1913).

PubMed

Vital, André Vasques

2018-03-01

The writing of the Relatório sobre as condições médico-sanitárias do vale do Amazonas (Report on the medical and sanitary conditions in the Amazon Valley) is analyzed from the perspective of the macro- and micropolitical implications of the Instituto Oswaldo Cruz's expedition to the departments in the federal territory of Acre. The analysis focuses on the interactions between Carlos Chagas, Pacheco Leão, and João Pedroso and judges, doctors, and rubber barons from the Yaco and Caeté rivers at the town of Sena Madureira, capital of Alto Purus, in January 1913. The scientific report was also influenced by the contact the commission members had with the major players in the rubber industry and their resulting immersion in local and regional political conflicts.

Identification of a Taraxacum brevicorniculatum rubber elongation factor protein that is localized on rubber particles and promotes rubber biosynthesis.

PubMed

Laibach, Natalie; Hillebrand, Andrea; Twyman, Richard M; Prüfer, Dirk; Schulze Gronover, Christian

2015-05-01

Two protein families required for rubber biosynthesis in Taraxacum brevicorniculatum have recently been characterized, namely the cis-prenyltransferases (TbCPTs) and the small rubber particle proteins (TbSRPPs). The latter were shown to be the most abundant proteins on rubber particles, where rubber biosynthesis takes place. Here we identified a protein designated T. brevicorniculatum rubber elongation factor (TbREF) by using mass spectrometry to analyze rubber particle proteins. TbREF is homologous to the TbSRPPs but has a molecular mass that is atypical for the family. The promoter was shown to be active in laticifers, and the protein itself was localized on the rubber particle surface. In TbREF-silenced plants generated by RNA interference, the rubber content was significantly reduced, correlating with lower TbCPT protein levels and less TbCPT activity in the latex. However, the molecular mass of the rubber was not affected by TbREF silencing. The colloidal stability of rubber particles isolated from TbREF-silenced plants was also unchanged. This was not surprising because TbREF depletion did not affect the abundance of TbSRPPs, which are required for rubber particle stability. Our findings suggest that TbREF is an important component of the rubber biosynthesis machinery in T. brevicorniculatum, and may play a role in rubber particle biogenesis and influence rubber production. © 2015 The Authors The Plant Journal © 2015 John Wiley & Sons Ltd.

CFD Modeling of a Laser-Induced Ethane Pyrolysis in a Wall-less Reactor

NASA Astrophysics Data System (ADS)

Stadnichenko, Olga; Snytnikov, Valeriy; Yang, Junfeng; Matar, Omar

2014-11-01

Ethylene, as the most important feedstock, is widely used in chemical industry to produce various rubbers, plastics and synthetics. A recent study found the IR-laser irradiation induced ethane pyrolysis yields 25% higher ethylene production rates compared to the conventional steam cracking method. Laser induced pyrolysis is initiated by the generation of radicals upon heating of the ethane, then, followed by ethane/ethylene autocatalytic reaction in which ethane is converted into ethylene and other light hydrocarbons. This procedure is governed by micro-mixing of reactants and the feedstock residence time in reactor. Under mild turbulent conditions, the turbulence enhances the micro-mixing process and allows a high yield of ethylene. On the other hand, the high flow rate only allows a short residence time in the reactor which causes incomplete pyrolysis. This work attempts to investigate the interaction between turbulence and ethane pyrolysis process using large eddy simulation method. The modelling results could be applied to optimize the reactor design and operating conditions. Skolkovo Foundation through the UNIHEAT Project.

Use of Ultrasound in Reconditioning by Welding of Tools Used in the Process of Regenerating Rubber.

PubMed

Dobrotă, Dan; Petrescu, Valentin

2018-02-10

Addressing the problem of reconditioning large parts is of particular importance, due to their value and to the fact that the technologies for their reconditioning are very complex. The tools used to refine regenerated rubber which measure 660 mm in diameter and 2130 mm in length suffer from a rather fast dimensional wear. Within this research, the authors looked for a welding reconditioning procedure that would allow a very good adhesion between the deposited material layer and the base material. In this regard, the MAG (Metal Active Gas) welding process was used, but the ultrasonic activation of the welding process was also considered. Thus, the wire used for welding was activated considering a variation of the frequency of ultrasounds in the range f = 18-22 kHz respectively of the oscillation amplitude A = 30-60 μm. Under these conditions it was found that the presence of ultrasonic waves during the welding cladding process results in uniform deposition of hard carbons at the grain boundary and in the elimination of any existing oxides on the deposition surface, but at the same time increases the adhesion between the base material and the additional material, all of which positively influence the wear and corrosion resistance of the tools used to refine the regenerated rubber.

Natural plant chemicals: source of industrial and medicinal materials

DOE Office of Scientific and Technical Information (OSTI.GOV)

Balandrin, M.F.; Klocke, J.A.; Wurtele, E.S.

1985-01-01

Many higher plants produce economically important organic compounds such as oils, resins, tannins, natural rubber, gums, waxes, dyes, flavors and fragrances, pharmaceuticals, and pesticides. However, most species of higher plants have never been described, much less surveyed for chemical or biologically active constituents, and new sources of commercially valuable materials remain to be discovered. Advances in biotechnology, particularly methods for culturing plants cells and tissues, should provide new means for the commercial processing of even rare plants and the chemicals they produce. These new technologies will extend and enhance the usefulness of plants as renewable resources of valuable chemicals. Inmore » the future, biologically active plant-derived chemicals can be expected to play an increasingly significant role in the commercial development of new products for regulating plant growth and for insect and weed control. 65 references.« less

The Structure of Ethylbenzene, Styrene and Phenylacetylene Determined by Total Neutron Scattering

PubMed Central

Szala‐Bilnik, Joanna; Falkowska, Marta; Bowron, Daniel T.

2017-01-01

Abstract Organic solvents such as phenylacetylene, styrene and ethylbenzene are widely used in industrial processes, especially in the production of rubber or thermoplastics. Despite their important applications detailed knowledge about their structure is limited. In this paper the structures of these three aromatic solvents were investigated using neutron diffraction. The results show that many of their structural characteristics are similar, although the structure of phenylacetylene is more ordered and has a smaller solvation sphere than either ethylbenzene or styrene. Two regions within the first coordination sphere, in which the surrounding molecules show different preferable orientations with respect to the central molecule, were found for each liquid. Additionally, the localisation of the aliphatic chains reveals that they tend to favour closer interactions with each other than to the aromatic rings of the adjacent molecules. PMID:28672104

Job safety analysis and hazard identification for work accident prevention in para rubber wood sawmills in southern Thailand.

PubMed

Thepaksorn, Phayong; Thongjerm, Supawan; Incharoen, Salee; Siriwong, Wattasit; Harada, Kouji; Koizumi, Akio

2017-11-25

We utilized job safety analysis (JSA) and hazard identification for work accident prevention in Para rubber wood sawmills, which aimed to investigate occupational health risk exposures and assess the health hazards at sawmills in the Trang Province, located in southern Thailand. We conducted a cross-sectional study which included a walk-through survey, JSA, occupational risk assessment, and environmental samplings from March through September 2015 at four Para rubber wood sawmills. We identified potential occupational safety and health hazards associated with six main processes, including: 1) logging and cutting, 2) sawing the lumber into sheets, 3) planing and re-arranging, 4) vacuuming and wood preservation, 5) drying and planks re-arranging, and 6) grading, packing, and storing. Working in sawmills was associated with high risk of wood dust and noise exposure, occupational accidents injuring hands and feet, chemicals and fungicide exposure, and injury due to poor ergonomics or repetitive work. Several high-risk areas were identified from JSA and hazard identification of the working processes, especially high wood dust and noise exposure when sawing lumber into sheets and risk of occupational accidents of the hands and feet when struck by lumber. All workers were strongly recommended to use personal protective equipment in any working processes. Exposures should be controlled using local ventilation systems and reducing noise transmission. We recommend that the results from the risk assessment performed in this study be used to create an action plan for reducing occupational health hazards in Para rubber sawmills.

Job safety analysis and hazard identification for work accident prevention in para rubber wood sawmills in southern Thailand

PubMed Central

Thepaksorn, Phayong; Thongjerm, Supawan; Incharoen, Salee; Siriwong, Wattasit; Harada, Kouji; Koizumi, Akio

2017-01-01

Objective: We utilized job safety analysis (JSA) and hazard identification for work accident prevention in Para rubber wood sawmills, which aimed to investigate occupational health risk exposures and assess the health hazards at sawmills in the Trang Province, located in southern Thailand. Methods: We conducted a cross-sectional study which included a walk-through survey, JSA, occupational risk assessment, and environmental samplings from March through September 2015 at four Para rubber wood sawmills. Results: We identified potential occupational safety and health hazards associated with six main processes, including: 1) logging and cutting, 2) sawing the lumber into sheets, 3) planing and re-arranging, 4) vacuuming and wood preservation, 5) drying and planks re-arranging, and 6) grading, packing, and storing. Working in sawmills was associated with high risk of wood dust and noise exposure, occupational accidents injuring hands and feet, chemicals and fungicide exposure, and injury due to poor ergonomics or repetitive work. Discussion: Several high-risk areas were identified from JSA and hazard identification of the working processes, especially high wood dust and noise exposure when sawing lumber into sheets and risk of occupational accidents of the hands and feet when struck by lumber. All workers were strongly recommended to use personal protective equipment in any working processes. Exposures should be controlled using local ventilation systems and reducing noise transmission. We recommend that the results from the risk assessment performed in this study be used to create an action plan for reducing occupational health hazards in Para rubber sawmills. PMID:28993571

Tennessee plant species screened for renewable energy sources

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carr, M.E.; Bagby, M.O.

The USDA Northern Regional Research Center (NRRC) has previously studied chemical and botanical characteristics of about 1000 plant species in efforts to identify potential new plant sources for industrial raw materials. For this report, an additional 51 species were collected from Tennessee and studied. Above-ground plant samples were analyzed for yields of oils, polyphenols, hydrocarbons, protein, and ash. Oils were examined for the presence of seven classes of lipids and analyzed for yields of fatty acids and unsaponifiable matter. Hydrocarbons were examined for the presence of rubber, gutta, and waxes. Rubber and gutta were analyzed for average molecular weight (MW)more » and MW distribution. Chemical and botanical data are presented for eight of the 51 species. A checklist of the 43 other species is given; data on these are available from NRRC. Lapsana communis yielded the most oil (6.1%; dry, ash-free, plant sample basis). Ilex montana yielded the most polyphenol (21.5%) plus 4.5% oil. Agrimonia parviflora and Catalpa bignonioides gave substantial yields of polyphenol (20.0% and 17.9%, respectively), and Passiflora incarnata contained the most apparent protein (19.8%). Chrysopsis graminifolia, Solidago erecta, and Verbesina alternifolia were identified as rubber-producing species with 0.4-0.7% hydrocarbon.« less

Optimization of mechanical performance of oxidative nano-particle electrode nitrile butadiene rubber conducting polymer actuator.

PubMed

Kim, Baek-Chul; Park, S J; Cho, M S; Lee, Y; Nam, J D; Choi, H R; Koo, J C

2009-12-01

Present work delivers a systematical evaluation of actuation efficiency of a nano-particle electrode conducting polymer actuator fabricated based on Nitrile Butadiene Rubber (NBR). Attempts are made for maximizing mechanical functionality of the nano-particle electrode conducting polymer actuator that can be driven in the air. As the conducting polymer polypyrrole of the actuator is to be fabricated through a chemical oxidation polymerization process that may impose certain limitations on both electrical and mechanical functionality of the actuator, a coordinated study for optimization process of the actuator is necessary for maximizing its performance. In this article actuation behaviors of the nano-particle electrode polypyrrole conducting polymer is studied and an optimization process for the mechanical performance maximization is performed.

[Health and environment in the rubber-tree plantations in the Bolivian Acre (1870-1903): the role of exogenous factors and processes].

PubMed

de Almeida Neto, Domingos José; Heller, Léo

2014-10-01

A peculiar situation marks the conditions of human and environmental health in the first major cycle of rubber production in the Acre region of the Western Amazon, whereby the bulk of the boom (1870-1903) occurred in the territory that at that time still belonged to Bolivia. Based on this historical background, this work seeks to describe and comprehend how these factors and processes, which are exogenous to these two fields of analysis mediated the risks that originated in the environment, gave rise to sickness and death in the population of the "Brazilian" rubber-tree plantations established in Bolivian territory. In this manner, the inter-relations between health and environment linked to historically specific configurations of the physical-natural, socioeconomic, political, and cultural conditions, are examined. The work shows that these extrinsic factors and processes to the productive activities exerted an influence not only on its organizational but also functional aspects, while also resulting in the unhealthy conditions observed in the productive regions. It further highlights the fact that the extant infrastructure of the time was sufficient for extractive production and reproduction.

Treatment of natural rubber processing wastewater using a combination system of a two-stage up-flow anaerobic sludge blanket and down-flow hanging sponge system.

PubMed

Tanikawa, D; Syutsubo, K; Hatamoto, M; Fukuda, M; Takahashi, M; Choeisai, P K; Yamaguchi, T

2016-01-01

A pilot-scale experiment of natural rubber processing wastewater treatment was conducted using a combination system consisting of a two-stage up-flow anaerobic sludge blanket (UASB) and a down-flow hanging sponge (DHS) reactor for more than 10 months. The system achieved a chemical oxygen demand (COD) removal efficiency of 95.7% ± 1.3% at an organic loading rate of 0.8 kg COD/(m(3).d). Bacterial activity measurement of retained sludge from the UASB showed that sulfate-reducing bacteria (SRB), especially hydrogen-utilizing SRB, possessed high activity compared with methane-producing bacteria (MPB). Conversely, the acetate-utilizing activity of MPB was superior to SRB in the second stage of the reactor. The two-stage UASB-DHS system can reduce power consumption by 95% and excess sludge by 98%. In addition, it is possible to prevent emissions of greenhouse gases (GHG), such as methane, using this system. Furthermore, recovered methane from the two-stage UASB can completely cover the electricity needs for the operation of the two-stage UASB-DHS system, accounting for approximately 15% of the electricity used in the natural rubber manufacturing process.

Elastomer toughened polyimide adhesives

NASA Technical Reports Server (NTRS)

St.clair, A. K.; St.clair, T. L. (Inventor)

1983-01-01

A rubber-toughened addition-type polyimide composition is disclosed which has excellent high temperature bonding characteristics in the fully cured state, and improved peel strength and adhesive fracture resistance physical property characteristics. The process for making the improved adhesive involves preparing the rubber containing amic acid prepolymer by chemically reacting an amine-terminated elastomer and an aromatic diamine with an aromatic dianhydride with which a reactive chain stopper anhydride was mixed, and utilizing solvent or mixture of solvents for the reaction.

Studies on Stress-Strain Relationships of Polymeric Materials Used in Space Applications

NASA Technical Reports Server (NTRS)

Jana, Sadhan C.; Freed, Alan

2002-01-01

A two-year research plan was undertaken in association with Polymers Branch, NASA Glenn Research Center, to carry out experimental and modeling work relating stress and strain behavior of polymeric materials, especially elastomers and vulcanized rubber. An experimental system based on MTS (Mechanical Testing and Simulation) A/T-4 test facility environment has been developed for a broader range of polymeric materials in addition to a design of laser compatible temperature control chamber for online measurements of various strains. Necessary material processing has been accomplished including rubber compounding and thermoplastic elastomer processing via injection molding. A broad suite of testing methodologies has been identified to reveal the complex non-linear mechanical behaviors of rubbery materials when subjected to complex modes of deformation. This suite of tests required the conceptualization, design and development of new specimen geometries, test fixtures, and test systems including development of a new laser based technique to measure large multi-axial deformations. Test data has been generated for some of these new fixtures and has revealed some complex coupling effects generated during multi-axial deformations. In addition, fundamental research has been conducted concerning the foundation principles of rubber thermodynamics and resulting theories of rubber elasticity. Studies have been completed on morphological properties of several thermoplastic elastomers. Finally, a series of steps have been identified to further advance the goals of NASA's ongoing effort.

Identification of natural rubber and characterization of rubber biosynthetic activity in fig tree.

PubMed

Kang, H; Kang, M Y; Han, K H

2000-07-01

Natural rubber was extracted from the fig tree (Ficus carica) cultivated in Korea as part of a survey of rubber producing plants. Fourier transform infrared and (13)C nuclear magnetic resonance analysis of samples prepared by successive extraction with acetone and benzene confirmed that the benzene-soluble residues are natural rubber, cis-1,4-polyisoprene. The rubber content in the latex of fig tree was about 4%, whereas the rubber content in the bark, leaf, and fruit was 0.3%, 0.1%, and 0.1%, respectively. Gel-permeation chromatography revealed that the molecular size of the natural rubber from fig tree is about 190 kD. Similar to rubber tree (Hevea brasiliensis) and guayule (Parthenium argentatum Gray), rubber biosynthesis in fig tree is tightly associated with rubber particles. The rubber transferase in rubber particles exhibited a higher affinity for farnesyl pyrophosphate than for isopentenyl pyrophosphate, with apparent K(m) values of 2.8 and 228 microM, respectively. Examination of latex serum from fig tree by sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed major proteins of 25 and 48 kD in size, and several proteins with molecular mass below 20 and above 100 kD. Partial N-terminal amino acid sequencing and immunochemical analyses revealed that the 25- and 48-kD proteins were novel and not related to any other suggested rubber transferases. The effect of EDTA and Mg(2+) ion on in vitro rubber biosynthesis in fig tree and rubber tree suggested that divalent metal ion present in the latex serum is an important factor in determining the different rubber biosynthetic activities in fig tree and rubber tree.

Identification of Natural Rubber and Characterization of Rubber Biosynthetic Activity in Fig Tree1

PubMed Central

Kang, Hunseung; Kang, Min Young; Han, Kyung-Hwan

2000-01-01

Natural rubber was extracted from the fig tree (Ficus carica) cultivated in Korea as part of a survey of rubber producing plants. Fourier transform infrared and 13C nuclear magnetic resonance analysis of samples prepared by successive extraction with acetone and benzene confirmed that the benzene-soluble residues are natural rubber, cis-1,4-polyisoprene. The rubber content in the latex of fig tree was about 4%, whereas the rubber content in the bark, leaf, and fruit was 0.3%, 0.1%, and 0.1%, respectively. Gel-permeation chromatography revealed that the molecular size of the natural rubber from fig tree is about 190 kD. Similar to rubber tree (Hevea brasiliensis) and guayule (Parthenium argentatum Gray), rubber biosynthesis in fig tree is tightly associated with rubber particles. The rubber transferase in rubber particles exhibited a higher affinity for farnesyl pyrophosphate than for isopentenyl pyrophosphate, with apparent Km values of 2.8 and 228 μm, respectively. Examination of latex serum from fig tree by sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed major proteins of 25 and 48 kD in size, and several proteins with molecular mass below 20 and above 100 kD. Partial N-terminal amino acid sequencing and immunochemical analyses revealed that the 25- and 48-kD proteins were novel and not related to any other suggested rubber transferases. The effect of EDTA and Mg2+ ion on in vitro rubber biosynthesis in fig tree and rubber tree suggested that divalent metal ion present in the latex serum is an important factor in determining the different rubber biosynthetic activities in fig tree and rubber tree. PMID:10889262

Organic materials for ceramic molding processes

NASA Technical Reports Server (NTRS)

Saito, K.

1984-01-01

Ceramic molding processes are examined. Binders, wetting agents, lubricants, plasticizers, surface active agents, dispersants, etc., for pressing, rubber pressing, sip casting, injection casting, taping, extrusion, etc., are described, together with forming machines.

A Systematic Approach to In Situ Bioremediation in Groundwater Including Decision Trees on In Situ Bioremediation for Nitrates, Carbon Tetrachloride, and Perchlorate

DTIC Science & Technology

2002-08-01

and Disease Registry (ATSDR). When conducting risk assessments , primary and secondary contaminants must be incorporated into the exposure...industry; acid production; textile bleaching; petroleum refining; refrigeration; production of pulp , paper , and rubber; as a catalytic agent in...memorandum from Michael Honeycutt, Ph.D., Toxicology and Risk Assessment Section, Office of Permitting, Remediation and Registration, Texas Natural Resource

Standard Samples and Reference Standards Issued by the National Bureau of Standards

DTIC Science & Technology

1954-08-31

precision and accuracy of control testing in the melting - point , density, index of refraction, heat rubber industry. of combustion, color, and gloss...pH (approx.) 1.7 65 2.50 Melting - Point Standards 44d Aluminum ---------------------------- 659.70 C...calculating the best frequencies for communication between any two points in the world at any time during the given month. The data are important to all

Protective Clothing Part 4. Industrial Environments (A Bibliography with Abstracts)

DTIC Science & Technology

1976-04-01

Synthetic rubber, Textiles, Sprays, Gas detectors, Damage control , Propellants IDENTIFIERS: Chlorine trifluoride AD-661 333...and Petroleum (107) Apr 75 Excludes flue gas and other post-combustion sulfur con- trol NTIS/PS-75/381/4GSB Coal Gasification and Liquefaction... desulfurization NTIS/PS-75/455/6GSB Sulfur Dioxide Control . Vol 1. 1964-1972 (159) May 75 NTIS/PS-75/456/4GSB Activated Carbon (221) May

40 CFR 60.542 - Standards for volatile organic compounds.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Rubber Tire Manufacturing Industry § 60.542 Standards for volatile organic compounds. (a) On and after... duration of the compliance period: (A) 3,870 kg (8,531 lb) of VOC per 28 days, (B) 4,010 kg (8,846 lb) of VOC per 29 days, (C) 4,150 kg (9,149 lb) of VOC per 30 days, (D) 4,280 kg (9,436 lb) of VOC per 31...

Comparative studies on the mechanical properties of natural rubber and natural rubber filled with multi-walled carbon nanotubes

NASA Astrophysics Data System (ADS)

Ismail, R.; Ibrahim, A.; Rusop, M.; Adnan, A.

2018-05-01

The present article compares the mechanical properties of natural rubber (NR) and carbon nanotubes (CNTs) filled natural rubber composites. Four types of nanocomposite specimens are fabricated with different MWCNT loadings: 0 wt% (pure natural rubber), 1 wt%, 3 wt%, and 5 wt%. The specimens are tested for their mechanical properties. It is observed that the tensile strength, hardness and elongation break of CNTs filled rubber composites are remarkably higher than that of raw rubber indicating the inherent reinforcing potential of CNTs. Percentage of the elongation at break of rubber CNTs composites is lower than that of raw rubber.

Mechanical Performance Test of Rubber-Powder Modified Concrete

NASA Astrophysics Data System (ADS)

Zhang, Yan Cong; Gao, Ling Ling

2018-06-01

A number of rubber cement concrete specimens that rubber powder dosage different were obtained using same cement, water and fine aggregates, by adjusting the dosage of rubber powder. Then it was used to research the influence of rubber powder dosage on performance of cement concrete by measuring its liquidity, strength and toughness. The results show that: when water-cement ratio was equal and rubber powder replacing the same volume sand, the fluidity of cement concrete almost linear increased with rubber powder dosage increasing. With dosage of rubber powder increasing, compressive strength and flexural strength reduced, but toughness linear growth trend when dosage of rubber powder less 30%.

Simple green approach to reinforce natural rubber with bacterial cellulose nanofibers.

PubMed

Trovatti, Eliane; Carvalho, Antonio J F; Ribeiro, Sidney J L; Gandini, Alessandro

2013-08-12

Natural rubber (NR) is a renewable polymer with a wide range of applications, which is constantly tailored, further increasing its utilizations. The tensile strength is one of its most important properties susceptible of being enhanced by the simple incorporation of nanofibers. The preparation and characterization of natural-rubber based nanocomposites reinforced with bacterial cellulose (BC) and bacterial cellulose coated with polystyrene (BCPS), yielded high performance materials. The nanocomposites were prepared by a simple and green process, and characterized by tensile tests, dynamical mechanical analysis (DMA), scanning electron microscopy (SEM), and swelling experiments. The effect of the nanofiber content on morphology, static, and dynamic mechanical properties was also investigated. The results showed an increase in the mechanical properties, such as Young's modulus and tensile strength, even with modest nanofiber loadings.

Evidence for existence in human tissues of monomers for plastics and rubber manufacture.

PubMed Central

Wolff, M S

1976-01-01

Although exposure to many industrially important monomers is controlled by law, few of these reactive chemicals have been determined in human tissues. Analogy with other fat-soluble organic substances strongly implies that these monomers may be retained in tissue, subject to the usual physiological constraints of metabolism, solubility and volatility. The storage of DDT and PCBs is discussed, as well as tetrachloro-ethylene (PCE) and trichloroethylene (TCE), which are chemically similar to many industrially used monomers. Styrene in blood and breath and its metabolites in urine have been studied in humans. Styrene and vinyl chloride have been measured in fat tissue of polymerization workers. PMID:829070

Workplace risk factors for cancer in the German rubber industry: Part 2. Mortality from non-respiratory cancers

PubMed Central

Straif, K.; Weiland, S. K.; Werner, B.; Chambless, L.; Mundt, K. A.; Keil, U.

1998-01-01

OBJECTIVES: To determine the mortality from non-respiratory cancers by work area among active and retired male workers of the German rubber industry. METHODS: A cohort of 11,633 male German workers was followed up for mortality from 1 January 1981 to 31 December 1991. Cohort members were active (n = 7536) or retired (n = 4127) on 1 January 1981 and had been employed for at least one year in one of five study plants producing tyres or technical rubber goods. Work histories were reconstructed from routinely documented "cost centre codes" and classified into six categories: I preparation of materials; II production of technical rubber goods; III production of tyres; IV storage and dispatch; V general service; VI others. Standardised mortality ratios (SMRs) and 95% confidence intervals (95% CIs), controlling for age and calendar year and stratified by work area (employment in respective work area for at least one year) and time related variables (year of hire, lagged years of employment in work area) were calculated from national mortality rates as the reference. RESULTS: Significant increases in mortality were found for pharyngeal cancer in work area IV (three deaths, SMR 486, 95% CI 101 to 1419), oesophageal cancer in work area III (11 deaths, SMR 227, 95% CI 114 to 407), and leukaemia in work areas I (11 deaths, SMR 216; 95% CI 108 to 387) and II (14 deaths, SMR 187; 95% CI 102 to 213). Furthermore, increased SMRs were found for stomach cancer in work area I (22 deaths, SMR 134; 95% CI 84 to 203), colon cancer in work area II (27 deaths, SMR 131, 95% CI 86 to 191), prostatic cancer in work area V (27 deaths, SMR 152, 95% CI 99 to 221), and bladder cancer in work areas IV (six deaths, SMR 253; 95% CI 93 to 551) and V (12 deaths, SMR 159, 95% CI 82 to 279). Mortality from cancer of the liver or gall bladder, pancreas and kidney, and from lymphomas was not substantially increased in any of the work areas. CONCLUSIONS: Mortality from cancer of several sites was associated with specific work areas. Some of these associations have been reported previously. Future analyses of our study will have to determine the role of specific exposures in the aetiology of these cancers.   PMID:9764110

40 CFR 428.20 - Applicability; description of the emulsion crumb rubber subcategory.

Code of Federal Regulations, 2013 CFR

2013-07-01

... emulsion crumb rubber subcategory. 428.20 Section 428.20 Protection of Environment ENVIRONMENTAL PROTECTION... CATEGORY Emulsion Crumb Rubber Subcategory § 428.20 Applicability; description of the emulsion crumb rubber... manufacture of emulsion crumb rubber, other than acrylonitrilebutadiene rubber. [40 FR 18173, Apr. 25, 1975] ...

40 CFR 428.20 - Applicability; description of the emulsion crumb rubber subcategory.

Code of Federal Regulations, 2012 CFR

2012-07-01

... emulsion crumb rubber subcategory. 428.20 Section 428.20 Protection of Environment ENVIRONMENTAL PROTECTION... CATEGORY Emulsion Crumb Rubber Subcategory § 428.20 Applicability; description of the emulsion crumb rubber... manufacture of emulsion crumb rubber, other than acrylonitrilebutadiene rubber. [40 FR 18173, Apr. 25, 1975] ...

40 CFR 428.20 - Applicability; description of the emulsion crumb rubber subcategory.

Code of Federal Regulations, 2014 CFR

2014-07-01

... emulsion crumb rubber subcategory. 428.20 Section 428.20 Protection of Environment ENVIRONMENTAL PROTECTION... CATEGORY Emulsion Crumb Rubber Subcategory § 428.20 Applicability; description of the emulsion crumb rubber... manufacture of emulsion crumb rubber, other than acrylonitrilebutadiene rubber. [40 FR 18173, Apr. 25, 1975] ...

Strength and microstructure characteristics of the recycled rubber tire-sand mixtures as lightweight backfill.

PubMed

Zhang, Tao; Cai, Guojun; Duan, Weihong

2018-02-01

The disposal of scrap rubber tires has induced critical environmental issue worldwide due to the rapid increase in the number of vehicles. Recycled scrap tires as a construction material in civil engineering have significant environmental benefits from a waste management perspective. A systematic study that deals with strength and microstructure characteristics of the rubber-sand mixtures is initiated, and mechanical response of the mixtures is discussed in this investigation. Experiments were conducted to evaluate the effects of rubber fraction on the basic properties including mass density (ρ), stress-strain characteristics, shear strength, and unconfined compression strength (q u ) of the rubber-sand mixtures. Additionally, scanning electron microscopy (SEM) was carried out to reveal the microstructure characteristics of the mixtures with various rubber fractions. A discussion on the micromechanics of the mixtures also was conducted. This study demonstrates that the ρ, friction angle, and q u decrease linearly with an increase in rubber fraction, whereas shear strain at peak increases. The stress-strain characteristics of the rubber-sand mixtures shift from brittle to ductile as the rubber fraction increase. These changes are attributed to remarkably lower stiffness and higher compressibility of the rubber particle compared with those of the conventional mineral aggregates. With an increase in the rubber fraction, the mechanical response of rubber-sand mixtures exhibits two types: sand-like material and rubber-like material. Rubber particle possesses the capacity to prevent the contacted sand particles from sliding at lower rubber fraction, whereas it transmits the applied loadings as the rubber fraction increased. This outcome reinforces the practicability of using recycled rubber tire-sand mixtures as a lightweight backfill in subbase/base applications.

Experimental Investigation of the Mechanical and Durability Properties of Crumb Rubber Concrete.

PubMed

Liu, Hanbing; Wang, Xianqiang; Jiao, Yubo; Sha, Tao

2016-03-07

Recycling waste tire rubber by incorporating it into concrete has become the preferred solution to dispose of waste tires. In this study, the effect of the volume content of crumb rubber and pretreatment methods on the performances of concrete was evaluated. Firstly, the fine aggregate and mixture were partly replaced by crumb rubber to produce crumb rubber concrete. Secondly, the mechanical and durability properties of crumb rubber concrete with different replacement forms and volume contents had been investigated. Finally, the crumb rubber after pretreatment by six modifiers was introduced into the concrete mixture. Corresponding tests were conducted to verify the effectiveness of pretreatment methods as compared to the concrete containing untreated crumb rubber. It was observed that the mechanical strength of crumb rubber concrete was reduced, while durability was improved with the increasing of crumb rubber content. 20% replacement of fine aggregate and 5% replacement of the total mixture exhibited acceptable properties for practical applications. In addition, the results indicated that the modifiers had a positive impact on the mechanical and durability properties of crumb rubber concrete. It avoided the disadvantage of crumb rubber concrete having lower strength and provides a reference for the production of modified crumb rubber concrete.

Experimental Investigation of the Mechanical and Durability Properties of Crumb Rubber Concrete

PubMed Central

Liu, Hanbing; Wang, Xianqiang; Jiao, Yubo; Sha, Tao

2016-01-01

Recycling waste tire rubber by incorporating it into concrete has become the preferred solution to dispose of waste tires. In this study, the effect of the volume content of crumb rubber and pretreatment methods on the performances of concrete was evaluated. Firstly, the fine aggregate and mixture were partly replaced by crumb rubber to produce crumb rubber concrete. Secondly, the mechanical and durability properties of crumb rubber concrete with different replacement forms and volume contents had been investigated. Finally, the crumb rubber after pretreatment by six modifiers was introduced into the concrete mixture. Corresponding tests were conducted to verify the effectiveness of pretreatment methods as compared to the concrete containing untreated crumb rubber. It was observed that the mechanical strength of crumb rubber concrete was reduced, while durability was improved with the increasing of crumb rubber content. 20% replacement of fine aggregate and 5% replacement of the total mixture exhibited acceptable properties for practical applications. In addition, the results indicated that the modifiers had a positive impact on the mechanical and durability properties of crumb rubber concrete. It avoided the disadvantage of crumb rubber concrete having lower strength and provides a reference for the production of modified crumb rubber concrete. PMID:28773298