Strain and Temperature Sensing Properties of Multiwalled Carbon Nanotube Yarn Composites

NASA Technical Reports Server (NTRS)

Kahng, Seun K.; Gates, Thomas S.; Jefferson, Gail D.

2008-01-01

Strain and temperature response of Multiwalled Carbon Nanotube (MWCNT/CNT) yarns on a stainless steel test beam has been studied. The carbon nanotube yarns are spun from a multiwalled carbon nanotube forest grown on a silicon substrate to a 4-ply yarn with a diameter of about 15-20 microns. Four of the 4-ply CNT yarns are arranged in a Wheatstone bridge configuration on the stainless steel test beam using a thin layer of polyurethane resin that insulates and protects the yarns from the test beam. Strain sensitivities of the CNT yarn sensors range from 1.39 to 1.75 mV/V/1000 microstrain at room temperature, and temperature sensitivity of the CNT yarn bridge is 91 microA/degC. Resistance of the yarns range from 215 to 270 ohms for CNT yarn length of approximately 5 mm. Processes used in attaching the CNT yarns on the test beam and experimental procedures used for the measurements are described. Conventional metallic foil strain gages are attached to the test beam to compare with the CNT sensors. The study demonstrates multifunctional capability of the sensor for strain and temperature measurements and shows its applicability where engineering strain is less than 3%.

Design and Fabrication of Smart Diapers with Antibacterial Yarn

PubMed Central

Lin, Jia-Horng; Shiu, Bing-Chiuan; Lou, Ching-Wen

2017-01-01

In this study, intelligent eco-diapers are made by combining antibacterial yarns coated with quaternary ammonium salts with conductive yarns to improve caretaking for urinary incontinence. The combination of conductive yarns and sensors can detect the moisture content in eco-diapers, and an alarm is sent when moisture is significant. A wireless module is used to send detected signals to a smartphone or tablet PC via the Internet. This concept is used for a scenario in which nurses do not randomly check on patients in a long-term care institution. When used offline, eco-diapers can send caregivers an alarm for the need to change diapers via cell phones. The diameters of the copper and silver-plated copper fibers are 0.08 and 0.10 mm, respectively. Cotton yarns are twisted with copper and silver-plated copper fibers to form the conductive yarns, which are 0.12 mm in diameter. Moreover, 30-count cotton and 150 D nylon yarns are coated with quaternary ammonium salt via dyeing and finishing processes to form antibacterial yarns. In the current study, intelligent eco-diapers are tested for their electrical and antibacterial properties as specified by AATC and JISL test standards. PMID:29065646

Scratch-resistant, highly conductive, and high-strength carbon nanotube-based composite yarns.

PubMed

Liu, Kai; Sun, Yinghui; Lin, Xiaoyang; Zhou, Ruifeng; Wang, Jiaping; Fan, Shoushan; Jiang, Kaili

2010-10-26

High-strength and conductive carbon nanotube (CNT) yarns are very attractive in many potential applications. However, there is a difficulty when simultaneously enhancing the strength and conductivity of CNT yarns. Adding some polymers into CNT yarns to enhance their strength will decrease their conductivity, while treating them in acid or coating them with metal nanoparticles to enhance their conductivity will reduce their strength. To overcome this difficulty, here we report a method to make high-strength and highly conductive CNT-based composite yarns by using a continuous superaligned CNT (SACNT) yarn as a conductive framework and then inserting polyvinyl alcohol (PVA) into the intertube spaces of the framework through PVA/dimethyl sulphoxide solution to enhance the strength of yarns. The as-produced CNT/PVA composite yarns possess very high tensile strengths up to 2.0 GPa and Young's moduli more than 120 GPa, much higher than those of the CNT/PVA yarns reported. The electric conductivity of as-produced composite yarns is as high as 9.2 × 10(4) S/m, comparable to HNO(3)-treated or Au nanoparticle-coated CNT yarns. These composite yarns are flexible, lightweight, scratch-resistant, very stable in the lab environment, and resistant to extremely humid ambient and as a result can be woven into high-strength and heatable fabrics, showing potential applications in flexible heaters, bullet-proof vests, radiation protection suits, and spacesuits.

Method and apparatus for sizing and separating warp yarns using acoustical energy

DOEpatents

Sheen, Shuh-Haw; Chien, Hual-Te; Raptis, Apostolos C.; Kupperman, David S.

1998-01-01

A slashing process for preparing warp yarns for weaving operations including the steps of sizing and/or desizing the yarns in an acoustic resonance box and separating the yarns with a leasing apparatus comprised of a set of acoustically agitated lease rods. The sizing step includes immersing the yarns in a size solution contained in an acoustic resonance box. Acoustic transducers are positioned against the exterior of the box for generating an acoustic pressure field within the size solution. Ultrasonic waves that result from the acoustic pressure field continuously agitate the size solution to effect greater mixing and more uniform application and penetration of the size onto the yarns. The sized yarns are then separated by passing the warp yarns over and under lease rods. Electroacoustic transducers generate acoustic waves along the longitudinal axis of the lease rods, creating a shearing motion on the surface of the rods for splitting the yarns.

Method and apparatus for sizing and separating warp yarns using acoustical energy

DOEpatents

Sheen, S.H.; Chien, H.T.; Raptis, A.C.; Kupperman, D.S.

1998-05-19

A slashing process is disclosed for preparing warp yarns for weaving operations including the steps of sizing and/or desizing the yarns in an acoustic resonance box and separating the yarns with a leasing apparatus comprised of a set of acoustically agitated lease rods. The sizing step includes immersing the yarns in a size solution contained in an acoustic resonance box. Acoustic transducers are positioned against the exterior of the box for generating an acoustic pressure field within the size solution. Ultrasonic waves that result from the acoustic pressure field continuously agitate the size solution to effect greater mixing and more uniform application and penetration of the size onto the yarns. The sized yarns are then separated by passing the warp yarns over and under lease rods. Electroacoustic transducers generate acoustic waves along the longitudinal axis of the lease rods, creating a shearing motion on the surface of the rods for splitting the yarns. 2 figs.

Antifungal activity of fabrics knitted by metalized Silver/Polyester composite yarn

NASA Astrophysics Data System (ADS)

Özkan, İ.; Duru Baykal, P.

2017-10-01

In this study, antifungal properties of fabric knitted from metalized silver/polyester composite yarn were investigated. Intermingling is an alternative technique for yarn blending process. Yarns having different features can be combined by feeding the same intermingling jet. This process is defined as commingling. In the study, intermingling process was used to produce metalized silver/polyester composite yarn. Commingled yarns were knitted to single jersey fabrics by IPM brand sample type circular knitting machine. Antifungal activity test was applied to samples against Aspergillus Niger according to AATCC 30 test procedure. It has been identified that the application provides antifungal activity to fabric.

An all-solid-state yarn supercapacitor using cotton yarn electrodes coated with polypyrrole nanotubes.

PubMed

Wei, Chengzhuo; Xu, Qi; Chen, Zeqi; Rao, Weida; Fan, Lingling; Yuan, Ye; Bai, Zikui; Xu, Jie

2017-08-01

A novel all-solid-state yarn supercapacitor (YSC) has been fabricated by using the cotton yarns coated with polypyrrole (PPy) nanotubes. The interconnected network structure of PPy can increase the surface area as well as the electrode/electrolyte interface area, thus resulting in improved electrochemical performance. For the proposed YSC, a high areal-specific capacitance of 74.0mFcm -2 and a desirable energy density of 7.5μWhcm -2 are achieved. The flexibility of the YSC demonstrates that it is suitable for the integration as flexible power sources in wearable electronic textiles. Copyright © 2017 Elsevier Ltd. All rights reserved.

Asymmetric carbon nanotube-MnO₂ two-ply yarn supercapacitors for wearable electronics.

PubMed

Su, Fenghua; Miao, Menghe

2014-04-04

Strong and flexible two-ply carbon nanotube yarn supercapacitors are electrical double layer capacitors that possess relatively low energy storage capacity. Pseudocapacitance metal oxides such as MnO₂ are well known for their high electrochemical performance and can be coated on carbon nanotube yarns to significantly improve the performance of two-ply carbon nanotube yarn supercapacitors. We produced a high performance asymmetric two-ply yarn supercapacitor from as-spun CNT yarn and CNT@Mn₂2 composite yarn in aqueous electrolyte. The as-spun CNT yarn serves as negative electrode and the CNT@MnO₂ composite yarn as positive electrode. This asymmetric architecture allows the operating potential window to be extended from 1.0 to 2.0 V and results in much higher energy and power densities than the reference symmetric two-ply yarn supercapacitors, reaching 42.0 Wh kg(-1) at a lower power density of 483.7 W kg(-1), and 28.02 Wh kg(-1) at a higher power density of 19,250 W kg(-1). The asymmetric supercapacitor can sustain cyclic charge-discharge and repeated folding/unfolding actions without suffering significant deterioration of specific capacitance. The combination of high strength, flexibility and electrochemical performance makes the asymmetric two-ply yarn supercapacitor a suitable power source for flexible electronic devices for applications that require high durability and wearer comfort.

Physical and Thermal Comfort Properties of Viscose Fabrics made from Vortex and Ring Spun Yarns

NASA Astrophysics Data System (ADS)

Thilagavathi, G.; Muthukumar, N.; Kumar, V. Kiran; Sadasivam, Sanjay; Sidharth, P. Mithun; Nikhil Jain, G.

2017-06-01

Viscose fiber is frequently preferred for various types of inner and outer knitwear products for its comfort and visual characteristics. In this study, the physical and thermal comfort properties of viscose fabrics made from ring and vortex yarns have been studied to explore the impact of spinning process on fabric properties. 100% viscose fibers were spun into yarns by ring and vortex spinning and the developed yarns were converted to single jersey fabrics. The results indicated that fabrics made from vortex spun yarns had better pilling resistance over that of those from ring spun yarns. There was no significant difference between bursting strength values of vortex and ring spun yarn fabrics. Fabrics made from ring yarn had better dimensional stability compared to fabrics made from vortex yarn. The air permeability and water vapour permeability of vortex yarn fabrics were higher than ring spun yarn fabrics. The vortex yarn fabrics had better thermal comfort properties compared to ring yarn fabrics.

Thread-like supercapacitors based on one-step spun nanocomposite yarns.

PubMed

Meng, Qinghai; Wang, Kai; Guo, Wei; Fang, Jin; Wei, Zhixiang; She, Xilin

2014-08-13

Thread-like electronic devices have attracted great interest because of their potential applications in wearable electronics. To produce high-performance, thread-like supercapacitors, a mixture of stable dispersions of single-walled carbon nanotubes and conducting polyaniline nanowires are prepared. Then, the mixture is spun into flexible yarns with a polyvinyl alcohol outer sheath by a one-step spinning process. The composite yarns show excellent mechanical properties and high electrical conductivities after sufficient washing to remove surfactants. After applying a further coating layer of gel electrolyte, two flexible yarns are twisted together to form a thread-like supercapacitor. The supercapacitor based on these two yarns (SWCNTs and PAniNWs) possesses a much higher specific capacitance than that based only on pure SWCNTs yarns, making it an ideal energy-storage device for wearable electronics. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Potentiometric sensors using cotton yarns, carbon nanotubes and polymeric membranes.

PubMed

Guinovart, Tomàs; Parrilla, Marc; Crespo, Gastón A; Rius, F Xavier; Andrade, Francisco J

2013-09-21

A simple and generalized approach to build electrochemical sensors for wearable devices is presented. Commercial cotton yarns are first turned into electrical conductors through a simple dyeing process using a carbon nanotube ink. These conductive yarns are then partially coated with a suitable polymeric membrane to build ion-selective electrodes. Potentiometric measurements using these yarn-potentiometric sensors are demonstrated. Examples of yarns that can sense pH, K(+) and NH4(+) are presented. In all cases, these sensing yarns show limits of detection and linear ranges that are similar to those obtained with lab-made solid-state ion-selective electrodes. Through the immobilization of these sensors in a band-aid, it is shown that this approach could be easily implemented in a wearable device. Factors affecting the performance of the sensors and future potential applications are discussed.

Study on Single-yarn Pullout Test of Ballistic Resistant Fabric under Different Preloads

NASA Astrophysics Data System (ADS)

Fang, Q. C.; Lei, Z. K.; Y Qin, F.; Li, W. K.; Bai, R. X.

2017-12-01

During bullet penetrating fabric, the pull-out force of yarn in fabric is related to the impact resistance of fabric when the yarn is pulled out from the fabric. The complex uncrimping and friction slip behavior occur during the yarn pullout process, which is critical to learn the impact resistance of fabric. Based on digital image correlation technique, the deformation behavior of Kevlar 49 fabric subjected to preload during the single-yarn pullout process was studied in this paper. The pullout force and displacement curve shows a straight rise and an oscillated decrease. In the linear rise stage, the yarn uncrimping causes a static friction effect. The maximum of the pullout force is not linearly increased with the preload. In the oscillating descending stage, the local descent of the pullout force indicates that the yarn end is gradually withdrawn from the fabric, and the local rise indicates that the yarn end moves to the next weft/warp interaction until the yarn is completely pulled out. The shear deformation of fabric corresponds to the single-yarn pullout process.

Multifunctional Yarns and Fabrics for Energy Applications (NBIT Phase 2)

DTIC Science & Technology

2013-05-29

project focus on developing biscrolled carbon nanotube yarns and textiles for supercapacitor /battery and fuel cell electrode applications was chosen...redox supercapacitors resulted from program work. While project focus was on fuel cell and energy storage electrodes based on biscrolled yarns...project focus on developing biscrolled carbon nanotube yarns and textiles for supercapacitor /battery and fuel cell electrode applications was chosen

Development of yarn breakage detection software system based on machine vision

NASA Astrophysics Data System (ADS)

Wang, Wenyuan; Zhou, Ping; Lin, Xiangyu

2017-10-01

For questions spinning mills and yarn breakage cannot be detected in a timely manner, and save the cost of textile enterprises. This paper presents a software system based on computer vision for real-time detection of yarn breakage. The system and Windows8.1 system Tablet PC, cloud server to complete the yarn breakage detection and management. Running on the Tablet PC software system is designed to collect yarn and location information for analysis and processing. And will be processed after the information through the Wi-Fi and http protocol sent to the cloud server to store in the Microsoft SQL2008 database. In order to follow up on the yarn break information query and management. Finally sent to the local display on time display, and remind the operator to deal with broken yarn. The experimental results show that the system of missed test rate not more than 5%o, and no error detection.

The arrangement of the fibers in the yarn and effect on its strength

NASA Astrophysics Data System (ADS)

Bobajonov, H. T.; Yuldashev, J. K.; Gafurov, J. K.; Gofurov, K.

2017-10-01

This article presents the results of research on the deformation changes in the initial moments of loading and unloading of conversional ring and compact yarns samples with a special strain gauge device. It was revealed that compact yarn in the initial load moment is deformed slowly doubled (4 seconds) compared to the conversional ring yarn. At the moment of unloading, on the contrary, the deformation of the compact yarn occurs rapidly (2 seconds), and the compact yarn in which a fiber foredeck regularly deformed quickly (1 second). A comparative study of resistance to stretching of the conversional ring and compact yarn based on Kelvin model was done. As a result, it has been found that the instant and long elastic module of compact yarn are slightly higher than conversional ring yarn with similar module, and the viscosity parameter which characterizes the decrease of the modulus of elasticity is lower compare with it..

Lightweight electrically-powered flexible thermal laminate. [made of metal and nonconductive yarns

NASA Technical Reports Server (NTRS)

Dawn, F. S.; Sauers, D. G. (Inventor)

1978-01-01

Cross-layered woven or unwoven yarns are used to provide an active thermal control mechanism for spacecraft use. One set of yarns is composed of flexible electrically conductive metal fibers which are capable of being resistance heated by the application of voltage. Another set of yarns, nonconductive and flexible, provides mechanical strength and precludes the passage of electrical current between the metal yarns by virtue of the spacing between them. A lightweight, electrically nonconductive film is bonded to the cross-layered yarns to protect the metal yarns from the elements (minimize electrical shorts from moisture such as rain), to provide additional strength to the fabric, and to prevent conductive loss of heat in nonvacuum applications. The nonconductive film is metalized on its obverse side to provide a more uniform heat load distribution.

Asymmetric carbon nanotube-MnO2 two-ply yarn supercapacitors for wearable electronics

NASA Astrophysics Data System (ADS)

Su, Fenghua; Miao, Menghe

2014-04-01

Strong and flexible two-ply carbon nanotube yarn supercapacitors are electrical double layer capacitors that possess relatively low energy storage capacity. Pseudocapacitance metal oxides such as MnO2 are well known for their high electrochemical performance and can be coated on carbon nanotube yarns to significantly improve the performance of two-ply carbon nanotube yarn supercapacitors. We produced a high performance asymmetric two-ply yarn supercapacitor from as-spun CNT yarn and CNT@MnO2 composite yarn in aqueous electrolyte. The as-spun CNT yarn serves as negative electrode and the CNT@MnO2 composite yarn as positive electrode. This asymmetric architecture allows the operating potential window to be extended from 1.0 to 2.0 V and results in much higher energy and power densities than the reference symmetric two-ply yarn supercapacitors, reaching 42.0 Wh kg-1 at a lower power density of 483.7 W kg-1, and 28.02 Wh kg-1 at a higher power density of 19 250 W kg-1. The asymmetric supercapacitor can sustain cyclic charge-discharge and repeated folding/unfolding actions without suffering significant deterioration of specific capacitance. The combination of high strength, flexibility and electrochemical performance makes the asymmetric two-ply yarn supercapacitor a suitable power source for flexible electronic devices for applications that require high durability and wearer comfort.

Buckling Structured Stretchable Pseudocapacitor Yarn.

PubMed

Lee, Duck Weon; Lee, Jung Han; Min, Nam Ki; Jin, Joon-Hyung

2017-09-20

Cable-type stretchable electrochemical pseudocapacitors based on multi-walled carbon nanotube (MWCNT) sheets and two different metal oxide nanopowders (NP), i.e., MnO 2 and RuO 2 are developed using a newly-devised dry painting method to mechanically fix the NP to the elastic rubber-based MWCNT electrode substrate, resulting in a porous buckling structured pseudocapacitor yarn. Highly stretchable stylene-ethylene/butylene-stylene (SEBS) is used as the supporting elastomeric core for wrapping with the MWCNT sheets and the electroactive NP. The dry painting can successfully deposit NP on the soft SEBS surface, which is normally an unfavorable substrate for coating alien materials. The resulting yarn-type pseudocapacitor, composed of eight-layered MWCNT sheets, three-layered RuO 2 , and two-layered MnO 2 , showing a diameter of approximately 400 μm with a porous buckling structure, records a specific capacitance of 25 F g -1 . After being stretched by 200% in strain with no sacrifice of the porous buckling structure, the cable-type stretchable electrochemical pseudocapacitor yarn retains its electrical capacity, and is potentially applicable to energy storage devices for wearable electronics.

Investigation of electrically conducting yarns for use in textile actuators

NASA Astrophysics Data System (ADS)

Martinez, Jose G.; Richter, Klaus; Persson, Nils-Krister; Jager, Edwin W. H.

2018-07-01

Textile actuators are an emerging technology to develop biomimetic actuators with synergetic actuation. They are composed of a passive fabric coated with an electroactive polymer providing with mechanical motion. Here we used different conducting yarns (polyamide + carbon, silicon + carbon, polyamide + silver coated, cellulose + carbon, polyester + 2 × INOX 50 μm, polyester + 2 × Cu/Sn and polyester + gold coated) to develop such textile actuators. It was possible to coat them through direct electrochemical methods, which should provide with an easier and more cost-effective fabrication process. The conductivity and the electrochemical properties of the yarns were sufficient to allow the electropolymerization of the conducting polymer polypyrrole on the yarns. The electropolymerization was carried out and both the linear and angular the actuation of the yarns was investigated. These yarns may be incorporated into textile actuators for assistive prosthetic devices easier and cheaper to get and at the same time with good mechanical performance are envisaged.

Flexible helical yarn swimmers.

PubMed

Zakharov, A P; Leshansky, A M; Pismen, L M

2016-09-01

We investigate the motion of a flexible Stokesian flagellar swimmer realised as a yarn made of two intertwined elastomer fibres, one active, that can reversibly change its length in response to a local excitation causing transition to the nematic state or swelling, and the other one, a passive isotropic elastomer with identical mechanical properties. A propagating chemical wave may provide an excitation mechanism ensuring a constant length of the excited region. Generally, the swimmer moves along a helical trajectory, and the propagation and rotation velocity are very sensitive to the ratio of the excited region to the pitch of the yarn, as well as to the size of a carried load. External excitation by a moving actuating beam is less effective, unless the direction of the beam is adjusted to rotation of the swimmer.

Fatigue behaviour of core-spun yarns containing filament by means of cyclic dynamic loading

NASA Astrophysics Data System (ADS)

Esin, S.; Osman, B.

2017-10-01

The behaviour of yarns under dynamic loading is important that leads to understand the growth characteristics which is exposed to repetitive loadings during usage of fabric made from these yarns. Fabric growth is undesirable property that originated from low resilience characteristics of fabric. In this study, the effects of the filament fineness and yarn linear density on fatigue behaviour of rigid-core spun yarns were determined. Cotton covered yarns containing different filament fineness of polyester (PET) draw textured yarns (DTY) (100d/36f, 100d/96f, 100d/144f, 100d/192f and 100d/333f) and yarn linear densities (37 tex, 30 tex, 25 tex and 21 tex) were manufactured by using a modified ring spinning system at the same spinning parameters. Repetitive loads were applied for 25 cycles at levels between 0.1 and 3 N. Dynamic modulus and dynamic strain of yarn samples were analyzed statistically. Results showed that filament fineness and yarn linear density have significance effect on dynamic modulus and dynamic strain after cyclic loading.

Biscrolling nanotube sheets and functional guests into yarns

NASA Astrophysics Data System (ADS)

Baughman, Ray

2011-03-01

Multifunctional applications of textiles have been limited by the inability to spin important materials into yarns. Generically applicable methods are demonstrated for producing weavable yarns comprising up to 95 wt % of otherwise unspinnable particulate or nanofiber powders that remain highly functional. Scrolled 50 nm thick carbon nanotube sheets confine these powders in the galleries of irregular scroll sacks, whose observed complex structures are related to twist-dependent extension of Archimedean spirals, Fermat spirals, or spiral pairs into scrolls. The strength and electronic connectivity of a small weight fraction of scrolled carbon nanotube sheet enables yarn weaving, sewing, knotting, braiding, and charge collection. This technology is used to make yarns of superconductors, Li-ion battery materials, graphene ribbons, catalytic nanofibers for fuel cells, and Ti O2 for photocatalysis. Work done in collaboration with Shaoli Fang, Xavier Lepro-Chavez, Chihye Lewis, Raquel Ovalle-Robles, Javier Carratero-Gonzalez, Elisabet Castillo-Martinez, Mikhail Kozlov, Jiyoung Oh, Neema Rawat, Carter Haines, Mohammed Haque, Vaishnavi Aare, Stephanie Stoughton, Anvar Zakhidov, and Ray Baughman, The University of Texas at Dallas / Alan G. MacDiarmid NanoTech Institute.

Effect of twist on transverse impact response of ballistic fiber yarns

DOE PAGES

Song, Bo; Lu, Wei -Yang

2015-06-15

A Hopkinson bar was employed to conduct transverse impact testing of twisted Kevlar KM2 fiber yarns at the same impact speed. The speed of Euler transverse wave generated by the impact was measured utilizing a high speed digital camera. The study included fiber yarns twisted by different amounts. The Euler transverse wave speed was observed to increase with increasing amount of twist of the fiber yarn, within the range of this investigation. As a result, the higher transverse wave speeds in the more twisted fiber yarns indicate better ballistic performance in soft body armors for personal protection.

Superaligned carbon nanotube arrays, films, and yarns: a road to applications.

PubMed

Jiang, Kaili; Wang, Jiaping; Li, Qunqing; Liu, Liang; Li, Changhong; Fan, Shoushan

2011-03-04

A superaligned carbon nanotube (CNT) array is a special kind of vertically aligned CNT array with the capability of being converted into continuous fi lms and yarns. The as-produced CNT fi lms are transparent and highly conductive, with aligned CNTs parallel to the direction of drawing. After passing through volatile solutions or being twisted, CNT fi lms can be further condensed into shrunk yarns. These shrunk yarns possess high tensile strengths and Young’s moduli, and are good conductors. Many applications of CNT fi lms and shrunk yarns have been demonstrated, such as TEM grids, loudspeakers, touch screens, etc.

Characterization of Multifunctional Carbon Nanotube Yarns: In-situ Strain Sensing and Composite Reinforcement

NASA Astrophysics Data System (ADS)

Page, Christian David

A large body of scientific research and development worldwide has focused on the unprecedented structural/functional properties of carbon nanotubes (CNT), yet translation of these unique properties of CNTs to macroscopic materials has been slow to develop. CNT yarns are an appealing application for CNTs; their lightweight and small diameter can allow for them to be embedded into composite materials. Since the individual nanotubes have shown to have incredibly high strength, stiffness, and strain sensitivity, CNT yarns have the potential to be highly effective for in-situ structural health monitoring of advanced materials and structures. This work identifies the sources for losses in strength and electromechanical sensitivity. This is done by first understanding the physics involved with a CNT yarn under axial strain. Since this material is not a Newtonian solid, the stress-strain relationships are dissimilar to conventional materials, exhibiting a three zone behavior. This is present in both the stress-strain and resistance-strain relationships. A tensile test performed in-situ within a scanning electron microscope showed that the diameter of the yarn reduced greatly during tension, which indicates that the volume is not constant; therefore, the intratube/intrabundle load transfer efficiency and electrical conductivity change significantly under strain. Observation of this phenomenon helps elucidate the source for loss in the translation from nanoscopic CNTs to the macroscopic CNT yarns. Following the observation that the CNT yarn is not a solid body mechanics system, investigation into the long-standing field of textile engineering helped to identify that the CNT yarn structural hierarchy should be re-evaluated. Literary review reveals that the predominant base morphology of CNT yarns is bundles of CNTs as opposed to individual CNTs. Furthermore, in conventional textiles, it is well known that the base morphology (in textiles this is the "fiber") will bundle

Effect of jute yarn on the mechanical behavior of concrete composites.

PubMed

Zakaria, Mohammad; Ahmed, Mashud; Hoque, Md Mozammel; Hannan, Abdul

2015-01-01

The objective of the study is to investigate the effect of introducing jute yarn on the mechanical properties of concrete. Jute fibre is produced abundantly in Bangladesh and hence, very cheap. The investigation on the enhancement of mechanical properties of concrete with jute yarn as reinforcement, if enhanced, will not only explore a way to improve the properties of concrete, it will also explore the use of jute and restrict the utilization of polymer which is environmentally detrimental. To accomplish the objective, an experimental investigation of the compressive, flexural and tensile strengths of Jute Yarn Reinforced Concrete composites (JYRCC) has been conducted. Cylinders, prisms and cubes of standard dimensions have been made to introducing jute yarn varying the mix ratio of the ingredients in concrete, water cement ratio, length and volume of yarn to know the effect of parameters as mentioned. Compressive, flexural and tensile strength tests had been conducted on the prepared samples by appropriate testing apparatus following Standards of tests. Mechanical properties of JYRCC were observed to be enhanced for a particular range of lengths of cut (10, 15, 20 and 25 mm) and volume content of jute yarn (0.1, 0.25, 0.5 and 0.75 %). The maximum increment of compressive, flexural and tensile strengths observed in the investigation are 33, 23 and 38 %, respectively with respect to concrete without jute yarn.

Regenerative braking systems with torsional springs made of carbon nanotube yarn

NASA Astrophysics Data System (ADS)

Liu, S.; Martin, C.; Lashmore, D.; Schauer, M.; Livermore, C.

2014-11-01

The demonstration of large stroke, high energy density and high power density torsional springs based on carbon nanotube (CNT) yarns is reported, as well as their application as an energy-storing actuator for regenerative braking systems. Originally untwisted CNT yarn is cyclically loaded and unloaded in torsion, with the maximum rotation angle increasing until failure. The maximum extractable energy density is measured to be as high as 6.13 kJ/kg. The tests also reveal structural reorganization and hysteresis in the torsional loading curves. A regenerative braking system is built to capture the kinetic energy of a wheel and store it as elastic energy in twisted CNT yarns. When the yam's twist is released, the stored energy reaccelerates the wheel. The measured energy and mean power densities of the CNT yarns in the simple regenerative braking system are up to 4.69 kJ/kg and 1.21 kW/kg, respectively. A slightly lower energy density of up to 1.23 kJ/kg and a 0.29 kW/kg mean power density are measured for the CNT yarns in a more complex system that mimics a unidirectional rotating regenerative braking mechanism. The lower energy densities for CNT yarns in the regenerative braking systems as compared with the yarns themselves reflect the frictional losses of the regenerative systems.

A theoretical analysis of deformation behavior of auxetic plied yarn structure

NASA Astrophysics Data System (ADS)

Zeng, Jifang; Hu, Hong

2018-07-01

This paper presents a theoretical analysis of the auxetic plied yarn (APY) structure formed with two types of single yarns having different diameter and modulus. A model which can be used to predict its deformation behavior under axial extension is developed based on the theoretical analysis. The developed model is first compared with the experimental data obtained in the previous study, and then used to predict the effects of different structural and material parameters on the auxetic behavior of the APY. The calculation results show that the developed model can correctly predict the variation trend of the auxetic behavior of the APY, which first increases and then decrease with the increase of the axial strain. The calculation results also indicate that the auxetic behavior of the APY simultaneously depends on the diameter ratio of the soft yarn and stiff yarn as well as the ratio between the pitch length and stiff yarn diameter. The study provides a way to design and fabricate APYs with the same auxetic behavior by using different soft and stiff yarns as long as these two ratios are kept unchanged.

Analyzing the Effect of Spinning Process Variables on Draw Frame Blended Cotton Mélange Yarn Quality

NASA Astrophysics Data System (ADS)

Ray, Suchibrata; Ghosh, Anindya; Banerjee, Debamalya

2018-06-01

An investigation has been made to study the effect of important spinning process variables namely shade depth, ring frame spindle speed and yarn twist multiplier (TM) on various yarn quality parameters like unevenness, strength, imperfection, elongation at break and hairiness index of draw frame blended cotton mélange yarn. Three factors Box and Behnken design of experiment has been used to conduct the study. The quadratic regression model is used to device the statistical inferences about sensitivity of the yarn quality parameters to the different process variables. The response surfaces are constructed for depicting the geometric representation of yarn quality parameters plotted as a function of process variables. Analysis of the results show that yarn strength of draw frame blended cotton mélange yarn is significantly affected by shade depth and TM. Yarn unevenness is affected by shade depth and ring frame spindle speed. Yarn imperfection level is mainly influenced by the shade depth and spindle speed. The shade depth and yarn TM have shown significant impact on yarn hairiness index.

Analyzing the Effect of Spinning Process Variables on Draw Frame Blended Cotton Mélange Yarn Quality

NASA Astrophysics Data System (ADS)

Ray, Suchibrata; Ghosh, Anindya; Banerjee, Debamalya

2017-12-01

An investigation has been made to study the effect of important spinning process variables namely shade depth, ring frame spindle speed and yarn twist multiplier (TM) on various yarn quality parameters like unevenness, strength, imperfection, elongation at break and hairiness index of draw frame blended cotton mélange yarn. Three factors Box and Behnken design of experiment has been used to conduct the study. The quadratic regression model is used to device the statistical inferences about sensitivity of the yarn quality parameters to the different process variables. The response surfaces are constructed for depicting the geometric representation of yarn quality parameters plotted as a function of process variables. Analysis of the results show that yarn strength of draw frame blended cotton mélange yarn is significantly affected by shade depth and TM. Yarn unevenness is affected by shade depth and ring frame spindle speed. Yarn imperfection level is mainly influenced by the shade depth and spindle speed. The shade depth and yarn TM have shown significant impact on yarn hairiness index.

Ultrafast charge and discharge biscrolled yarn supercapacitors for textiles and microdevices

NASA Astrophysics Data System (ADS)

Lee, Jae Ah; Shin, Min Kyoon; Kim, Shi Hyeong; Cho, Hyun U.; Spinks, Geoffrey M.; Wallace, Gordon G.; Lima, Márcio D.; Lepró, Xavier; Kozlov, Mikhail E.; Baughman, Ray H.; Kim, Seon Jeong

2013-06-01

Flexible, wearable, implantable and easily reconfigurable supercapacitors delivering high energy and power densities are needed for electronic devices. Here we demonstrate weavable, sewable, knottable and braidable yarns that function as high performance electrodes of redox supercapacitors. A novel technology, gradient biscrolling, provides fast-ion-transport yarn in which hundreds of layers of conducting-polymer-infiltrated carbon nanotube sheet are scrolled into ~20 μm diameter yarn. Plying the biscrolled yarn with a metal wire current collector increases power generation capabilities. The volumetric capacitance is high (up to ~179 F cm-3) and the discharge current of the plied yarn supercapacitor linearly increases with voltage scan rate up to ~80 V s-1 and ~20 V s-1 for liquid and solid electrolytes, respectively. The exceptionally high energy and power densities for the complete supercapacitor, and high cycle life that little depends on winding or sewing (92%, 99% after 10,000 cycles, respectively) are important for the applications in electronic textiles.

Structure and yarn sensor for fabric

DOEpatents

Mee, David K.; Allgood, Glenn O.; Mooney, Larry R.; Duncan, Michael G.; Turner, John C.; Treece, Dale A.

1998-01-01

A structure and yarn sensor for fabric directly determines pick density in a fabric thereby allowing fabric length and velocity to be calculated from a count of the picks made by the sensor over known time intervals. The structure and yarn sensor is also capable of detecting full length woven defects and fabric. As a result, an inexpensive on-line pick (or course) density measurement can be performed which allows a loom or knitting machine to be adjusted by either manual or automatic means to maintain closer fiber density tolerances. Such a sensor apparatus dramatically reduces fabric production costs and significantly improves fabric consistency and quality for woven or knitted fabric.

Machine-Washable PEDOT:PSS Dyed Silk Yarns for Electronic Textiles.

PubMed

Ryan, Jason D; Mengistie, Desalegn Alemu; Gabrielsson, Roger; Lund, Anja; Müller, Christian

2017-03-15

Durable, electrically conducting yarns are a critical component of electronic textiles (e-textiles). Here, such yarns with exceptional wear and wash resistance are realized through dyeing silk from the silkworm Bombyx mori with the conjugated polymer:polyelectrolyte complex PEDOT:PSS. A high Young's modulus of approximately 2 GPa combined with a robust and scalable dyeing process results in up to 40 m long yarns that maintain their bulk electrical conductivity of approximately 14 S cm -1 when experiencing repeated bending stress as well as mechanical wear during sewing. Moreover, a high degree of ambient stability is paired with the ability to withstand both machine washing and dry cleaning. For the potential use for e-textile applications to be illustrated, an in-plane thermoelectric module that comprises 26 p-type legs is demonstrated by embroidery of dyed silk yarns onto a piece of felted wool fabric.

Machine-Washable PEDOT:PSS Dyed Silk Yarns for Electronic Textiles

PubMed Central

2017-01-01

Durable, electrically conducting yarns are a critical component of electronic textiles (e-textiles). Here, such yarns with exceptional wear and wash resistance are realized through dyeing silk from the silkworm Bombyx mori with the conjugated polymer:polyelectrolyte complex PEDOT:PSS. A high Young’s modulus of approximately 2 GPa combined with a robust and scalable dyeing process results in up to 40 m long yarns that maintain their bulk electrical conductivity of approximately 14 S cm–1 when experiencing repeated bending stress as well as mechanical wear during sewing. Moreover, a high degree of ambient stability is paired with the ability to withstand both machine washing and dry cleaning. For the potential use for e-textile applications to be illustrated, an in-plane thermoelectric module that comprises 26 p-type legs is demonstrated by embroidery of dyed silk yarns onto a piece of felted wool fabric. PMID:28245105

Thermoplastic-carbon fiber hybrid yarn

NASA Technical Reports Server (NTRS)

Ketterer, M. E.

1984-01-01

Efforts were directed to develop processing methods to make carbon fiber/thermoplastic fiber preforms that are easy to handle and drapeable, and to consolidate them into low void content laminates. The objectives were attained with the development of the hybrid yarn concept; whereby, thermoplastic fiber can be intimately intermixed with carbon fiber into a hybrid yarn. This was demonstrated with the intermixing of Celion 3000 with a Celanese liquid crystal polymer fiber, polybutylene terepthalate fiber, or polyetheretherketone fiber. The intermixing of the thermoplastic matrix fiber and the reinforcing carbon fiber gives a preform that can be easily fabricated into laminates with low void content. Mechanical properties of the laminates were not optimized; however, initial results indicated properties typical of a thermoplastic/carbon fiber composites prepared by more conventional methods.

Multi Objective Optimization of Yarn Quality and Fibre Quality Using Evolutionary Algorithm

NASA Astrophysics Data System (ADS)

Ghosh, Anindya; Das, Subhasis; Banerjee, Debamalya

2013-03-01

The quality and cost of resulting yarn play a significant role to determine its end application. The challenging task of any spinner lies in producing a good quality yarn with added cost benefit. The present work does a multi-objective optimization on two objectives, viz. maximization of cotton yarn strength and minimization of raw material quality. The first objective function has been formulated based on the artificial neural network input-output relation between cotton fibre properties and yarn strength. The second objective function is formulated with the well known regression equation of spinning consistency index. It is obvious that these two objectives are conflicting in nature i.e. not a single combination of cotton fibre parameters does exist which produce maximum yarn strength and minimum cotton fibre quality simultaneously. Therefore, it has several optimal solutions from which a trade-off is needed depending upon the requirement of user. In this work, the optimal solutions are obtained with an elitist multi-objective evolutionary algorithm based on Non-dominated Sorting Genetic Algorithm II (NSGA-II). These optimum solutions may lead to the efficient exploitation of raw materials to produce better quality yarns at low costs.

Full-field fabric stress mapping by micro Raman spectroscopy in a yarn push-out test.

PubMed

Lei, Z K; Qin, F Y; Fang, Q C; Bai, R X; Qiu, W; Chen, X

2018-02-01

The full-field stress distribution of a two-dimensional plain fabric was mapped using micro Raman spectroscopy (MRS) through a novel yarn push-out test, simulating a quasi-static projectile impact on the fabric. The stress-strain relationship for a single yarn was established using a digital image correlation method in a single-yarn tensile test. The relationship between Raman peak shift and aramid Kevlar 49 yarn stress was established using MRS in a single-yarn tensile test. An out-of-plane loading test was conducted on an aramid Kevlar 49 plain fabric, and the yarn stress was measured using MRS. From the full-field fabric stress distribution, it can be observed that there is a cross-shaped distribution of high yarn stress; this result would be helpful in further studies on load transfer on a fabric during a projectile impact.

High-performance two-ply yarn supercapacitors based on carbon nanotubes and polyaniline nanowire arrays.

PubMed

Wang, Kai; Meng, Qinghai; Zhang, Yajie; Wei, Zhixiang; Miao, Menghe

2013-03-13

Fine count two-ply yarn supercapacitors are constructed from carbon nanotube yarns and polyaniline nanowires. The thread-like supercapacitor possess excellent electrochemical capacity and are very strong and flexible. When being woven or knitted into wearable electronic devices, alone or in combination with conventional textile yarns, the two-ply yarn supercapacitors can be flexed and stretched repeatedly without significant loss of capacitance. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Single-step process to improve the mechanical properties of carbon nanotube yarn.

PubMed

Evora, Maria Cecilia; Lu, Xinyi; Hiremath, Nitilaksha; Kang, Nam-Goo; Hong, Kunlun; Uribe, Roberto; Bhat, Gajanan; Mays, Jimmy

2018-01-01

Carbon nanotube (CNT) yarns exhibit low tensile strength compared to conventional high-performance carbon fibers due to the facile sliding of CNTs past one another. Electron beam (e-beam) irradiation was employed for in a single-step surface modification of CNTs to improve the mechanical properties of this material. To this end, CNT yarns were simultaneously functionalized and crosslinked using acrylic acid (AA) and acrylonitrile (AN) in an e-beam irradiation process. The chemical modification of CNT yarns was confirmed by X-ray photoelectron spectroscopy (XPS), Raman spectroscopy and scanning electron microscopy (SEM). The best improvement in mechanical properties was achieved on a sample treated with an aqueous solution of AA and subsequent irradiation. CNT yarn treatment with AA enhanced the strength (444.5 ± 68.4 MPa) by more than 75% and the modulus (21.5 ± 0.6 GPa) by more than 144% as compared to untreated CNT yarn (strength 251 ± 26.5 MPa and modulus 8.8 ± 1.2 GPa).

Single-step process to improve the mechanical properties of carbon nanotube yarn

PubMed Central

Lu, Xinyi; Hiremath, Nitilaksha; Kang, Nam-Goo; Hong, Kunlun; Uribe, Roberto; Bhat, Gajanan; Mays, Jimmy

2018-01-01

Carbon nanotube (CNT) yarns exhibit low tensile strength compared to conventional high-performance carbon fibers due to the facile sliding of CNTs past one another. Electron beam (e-beam) irradiation was employed for in a single-step surface modification of CNTs to improve the mechanical properties of this material. To this end, CNT yarns were simultaneously functionalized and crosslinked using acrylic acid (AA) and acrylonitrile (AN) in an e-beam irradiation process. The chemical modification of CNT yarns was confirmed by X-ray photoelectron spectroscopy (XPS), Raman spectroscopy and scanning electron microscopy (SEM). The best improvement in mechanical properties was achieved on a sample treated with an aqueous solution of AA and subsequent irradiation. CNT yarn treatment with AA enhanced the strength (444.5 ± 68.4 MPa) by more than 75% and the modulus (21.5 ± 0.6 GPa) by more than 144% as compared to untreated CNT yarn (strength 251 ± 26.5 MPa and modulus 8.8 ± 1.2 GPa). PMID:29527431

Structure and yarn sensor for fabric

DOEpatents

Mee, D.K.; Allgood, G.O.; Mooney, L.R.; Duncan, M.G.; Turner, J.C.; Treece, D.A.

1998-10-20

A structure and yarn sensor for fabric directly determines pick density in a fabric thereby allowing fabric length and velocity to be calculated from a count of the picks made by the sensor over known time intervals. The structure and yarn sensor is also capable of detecting full length woven defects and fabric. As a result, an inexpensive on-line pick (or course) density measurement can be performed which allows a loom or knitting machine to be adjusted by either manual or automatic means to maintain closer fiber density tolerances. Such a sensor apparatus dramatically reduces fabric production costs and significantly improves fabric consistency and quality for woven or knitted fabric. 13 figs.

Dwindling the resistance value of PEDOT:PSS – coated on fabric yarns

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

Amba Sankar, K.N., E-mail: amb@psgias.ac.in; Kallol, Mohanta

2016-05-23

Herein we describe by dip coating method to transform typical fabric yarn to conductive fiber. Different types of yarns have been used to coat from a known conductive polymer, Poly (3,4ethylenedioxythiophene) Poly (styrene sulfonic acid). We have optimized the method to have lesser resistance of the conductive yarns. The minimum resistance achieved has a value of 77 Ω/cm. This value is not high as metals but could be comparable to that of metal oxides or semiconducting materials. However, flexibility of yarns and feeling of fabric combining with the conductivity developed in this process is suitable for wearable electronics and alsomore » as gas sensors, electromagnetic shielding.« less

Investigation on the Yarn Squeezing Effect of Three Dimensional Full Five Directional Braided Composites

NASA Astrophysics Data System (ADS)

Hu, Long; Tao, Guoquan; Liu, Zhenguo; Wang, Yibo; Ya, Jixuan

2018-04-01

The influence of yarn squeezing effect on the geometric morphology and mechanical property of the three dimensional full five directional (3DF5D) braided composites is explored. Spatial path and cross-section shape of the yarns in the braided structure are characterized based on the micro computed tomography (micro CT) scanning images. The yarn distortion due to the squeezing effect is discussed and mathematical morphology of the yarn geometry is established. A new repeated unit cell (RUC) model of 3DF5D braided composites considering yarn squeezing effect is developed. Based on this model, mechanical properties of 3DF5D braided composites are analyzed. Good agreement is obtained between the predicted and experiment results. Moreover, the stress distribution of the new RUC model are compared with original RUC model, showing that the squeezing effect significantly increases the stress concentration level of the axial yarns.

Sensor yarns for real-time in situ detection of damage behavior for the purpose of structural health monitoring of textile-reinforced thermoset composites: development of a continuous wet-chemical silvering process for high-performance filament yarn

NASA Astrophysics Data System (ADS)

Onggar, T.; Häntzsche, E.; Nocke, A.; Hund, R. D.; Cherif, Ch

2017-04-01

High-performance textile yarns such as glass filament (GF) yarn will be used as the base material for the development of sensor yarns because glass filament yarns offer both high tensile strengths and moduli of elasticity, as well as high melting temperatures and elongation. A new continuous wet-chemical metallization process has been developed for GF yarns on a laboratory scale to achieve special properties such as electrical conductivity. The aim of the work is to develop a continuous wet-chemical silver plating process for the GF-filament yarn in order to achieve electrical conductivity on the GF-surface. The process was carried out continuously in order to metallize the GF, which is sensitive to the shear force. A homogeneous, completely covered and adhered silver layer on the GF yarn surfaces was obtained by the application of this technology. The surface morphology was been determined by light and scanning electron microscopy to assess the silver layer properties such as structure, homogeneity, and cracking. The chemical structure of the surfaces was analyzed by means of energy dispersive x-ray spectroscopy. For structural analysis, GF yarns were investigated using a Fourier transform infrared spectrometer. The dispersive and polar component of the surface energy of the sized and silvered GF yarn was measured by using a single fiber Tensiometer K100. The silver layer thickness and the silver content were determined after the metallization. Textile physical tests of the tensile strength, elasticity modulus, elongation at break, and yarn fineness of the single GF yarns as well as GF bundle were carried out.

Mesoscale mechanics of twisting carbon nanotube yarns.

PubMed

Mirzaeifar, Reza; Qin, Zhao; Buehler, Markus J

2015-03-12

Fabricating continuous macroscopic carbon nanotube (CNT) yarns with mechanical properties close to individual CNTs remains a major challenge. Spinning CNT fibers and ribbons for enhancing the weak interactions between the nanotubes is a simple and efficient method for fabricating high-strength and tough continuous yarns. Here we investigate the mesoscale mechanics of twisting CNT yarns using full atomistic and coarse grained molecular dynamics simulations, considering concurrent mechanisms at multiple length-scales. To investigate the mechanical response of such a complex structure without losing insights into the molecular mechanism, we applied a multiscale strategy. The full atomistic results are used for training a coarse grained model for studying larger systems consisting of several CNTs. The mesoscopic model parameters are updated as a function of the twist angle, based on the full atomistic results, in order to incorporate the atomistic scale deformation mechanisms in larger scale simulations. By bridging across two length scales, our model is capable of accurately predicting the mechanical behavior of twisted yarns while the atomistic level deformations in individual nanotubes are integrated into the model by updating the parameters. Our results focused on studying a bundle of close packed nanotubes provide novel mechanistic insights into the spinning of CNTs. Our simulations reveal how twisting a bundle of CNTs improves the shear interaction between the nanotubes up to a certain level due to increasing the interaction surface. Furthermore, twisting the bundle weakens the intertube interactions due to excessive deformation in the cross sections of individual CNTs in the bundle.

Modifying friction between ultra-high molecular weight polyethylene (UHMWPE) yarns with plasma enhanced chemical vapour deposition (PCVD)

NASA Astrophysics Data System (ADS)

Chu, Yanyan; Chen, Xiaogang; Tian, Lipeng

2017-06-01

Ultra-high molecular weight polyethylene (UHMWPE) yarns are widely used in military applications for protection owing to its high modulus and high strength; however, the friction between UHMWPE yarns is too small, which is a weakness for ballistic applications. The purpose of current research is to increase the friction between UHMWPE yarns by plasma enhanced chemical vapour deposition (PCVD). The changes of morphology and chemical structure were characterised by SEM and FTIR individually. The coefficients of friction between yarns were tested by means of Capstan method. Results from tests showed that the yarn-yarn coefficient of static friction (CSF) has been improved from 0.12 to 0.23 and that of kinetic friction (CSF) increased from 0.11 to 0.19, as the samples exposure from 21 s to 4 min. The more inter-yarn friction can be attributed to more and more particles and more polar groups deposited on the surfaces of yarns, including carboxyl, carbonyl, hydroxyl and amine groups and compounds containing silicon. The tensile strength and modulus of yarns, which are essential to ballistic performance, keep stable and are not affected by the treatments, indicating that PCVD treatment is an effective way to improve the inter-yarn friction without mechanical property degradation.

Coaxial wet-spun yarn supercapacitors for high-energy density and safe wearable electronics

NASA Astrophysics Data System (ADS)

Kou, Liang; Huang, Tieqi; Zheng, Bingna; Han, Yi; Zhao, Xiaoli; Gopalsamy, Karthikeyan; Sun, Haiyan; Gao, Chao

2014-05-01

Yarn supercapacitors have great potential in future portable and wearable electronics because of their tiny volume, flexibility and weavability. However, low-energy density limits their development in the area of wearable high-energy density devices. How to enhance their energy densities while retaining their high-power densities is a critical challenge for yarn supercapacitor development. Here we propose a coaxial wet-spinning assembly approach to continuously spin polyelectrolyte-wrapped graphene/carbon nanotube core-sheath fibres, which are used directly as safe electrodes to assembly two-ply yarn supercapacitors. The yarn supercapacitors using liquid and solid electrolytes show ultra-high capacitances of 269 and 177 mF cm-2 and energy densities of 5.91 and 3.84 μWh cm-2, respectively. A cloth supercapacitor superior to commercial capacitor is further interwoven from two individual 40-cm-long coaxial fibres. The combination of scalable coaxial wet-spinning technology and excellent performance of yarn supercapacitors paves the way to wearable and safe electronics.

Coaxial wet-spun yarn supercapacitors for high-energy density and safe wearable electronics

PubMed Central

Kou, Liang; Huang, Tieqi; Zheng, Bingna; Han, Yi; Zhao, Xiaoli; Gopalsamy, Karthikeyan; Sun, Haiyan; Gao, Chao

2014-01-01

Yarn supercapacitors have great potential in future portable and wearable electronics because of their tiny volume, flexibility and weavability. However, low-energy density limits their development in the area of wearable high-energy density devices. How to enhance their energy densities while retaining their high-power densities is a critical challenge for yarn supercapacitor development. Here we propose a coaxial wet-spinning assembly approach to continuously spin polyelectrolyte-wrapped graphene/carbon nanotube core-sheath fibres, which are used directly as safe electrodes to assembly two-ply yarn supercapacitors. The yarn supercapacitors using liquid and solid electrolytes show ultra-high capacitances of 269 and 177 mF cm−2 and energy densities of 5.91 and 3.84 μWh cm−2, respectively. A cloth supercapacitor superior to commercial capacitor is further interwoven from two individual 40-cm-long coaxial fibres. The combination of scalable coaxial wet-spinning technology and excellent performance of yarn supercapacitors paves the way to wearable and safe electronics. PMID:24786366

Investigation of the electrical characteristics of electrically conducting yarns and fabrics

NASA Astrophysics Data System (ADS)

Akbarov, R. D.; Baymuratov, B. H.; Akbarov, D. N.; Ilhamova, M.

2017-11-01

Electro-conductive textile materials and products are used presently giving solutions to the problems, related to static electricity, electromagnetic shielding and electromagnetic radiation. Thus a study of their electro-physical characteristics, character of conductivity, possibility of forecasting of electric parameters etc has a substantial value. This work shows the possibility of production electro-conducting textile materials with stable anti-static properties by introduction of electro-conducting yarn into the structure of fabrics. The results of the research, directed to the study of the electro-physical characteristics of electroconducting yarn and fabrics, are influenced by the frequent washing of polyester fabrics containing the different amounts of electro-conducting filaments in the composition. This article reviews the results of the related research, of the electrical characteristics of the yarn and fabric, of the effect of multiple water treatments on the electrical properties of polyester fabrics, containing in their composition different amounts of electrically conductive yarns.

Fabrication and processing of high-strength densely packed carbon nanotube yarns without solution processes.

PubMed

Liu, Kai; Zhu, Feng; Liu, Liang; Sun, Yinghui; Fan, Shoushan; Jiang, Kaili

2012-06-07

Defects of carbon nanotubes, weak tube-tube interactions, and weak carbon nanotube joints are bottlenecks for obtaining high-strength carbon nanotube yarns. Some solution processes are usually required to overcome these drawbacks. Here we fabricate ultra-long and densely packed pure carbon nanotube yarns by a two-rotator twisting setup with the aid of some tensioning rods. The densely packed structure enhances the tube-tube interactions, thus making high tensile strengths of carbon nanotube yarns up to 1.6 GPa. We further use a sweeping laser to thermally treat as-produced yarns for recovering defects of carbon nanotubes and possibly welding carbon nanotube joints, which improves their Young's modulus by up to ∼70%. The spinning and laser sweeping processes are solution-free and capable of being assembled together to produce high-strength yarns continuously as desired.

Developing an Acoustic Sensing Yarn for Health Surveillance in a Military Setting.

PubMed

Hughes-Riley, Theodore; Dias, Tilak

2018-05-17

Overexposure to high levels of noise can cause permanent hearing disorders, which have a significant adverse effect on the quality of life of those affected. Injury due to noise can affect people in a variety of careers including construction workers, factory workers, and members of the armed forces. By monitoring the noise exposure of workers, overexposure can be avoided and suitable protective equipment can be provided. This work focused on the creation of a noise dosimeter suitable for use by members of the armed forces, where a discrete dosimeter was integrated into a textile helmet cover. In this way the sensing elements could be incorporated very close to the ears, providing a highly representative indication of the sound level entering the body, and also creating a device that would not interfere with military activities. This was achieved by utilising commercial microelectromechanical system microphones integrated within the fibres of yarn to create an acoustic sensing yarn. The acoustic sensing yarns were fully characterised over a range of relevant sound levels and frequencies at each stage in the yarn production process. The yarns were ultimately integrated into a knitted helmet cover to create a functional acoustic sensing helmet cover prototype.

Effect of solvent/polymer infiltration and irradiation on microstructure and tensile properties of carbon nanotube yarns

DOE PAGES

Hiremath, Nitilaksha; Lu, Xinyi; Evora, Maria Cecilia; ...

2016-07-29

Recently carbon nanotube (CNT) yarns have been gaining importance as an approach to harvest the excellent properties of the CNTs. However, the properties of CNT yarns at this stage are well below the expected value. Investigation of the structure of CNT yarns and possible approaches to enhance the strength and modulus are reported. Scanning electron microscopy and focused ion beam imaging reveal the inherently porous structure and poor orientation, emphasizing the need to enhance packing of CNT bundles in the yarns for increased strength and modulus. Densification of CNT yarn by toluene or polystyrene increases the strength by 140 ormore » 172 % and modulus by 79 or 218 %, respectively, as compared to that of the pristine yarn. E-beam irradiation was investigated as a means to introduce crosslinking and enhanced internanotubes bonding to increase strength and modulus. However, the irradiation resulted in generation of defects and damages to the yarn contributing to reduction in strength and modulus. Raman spectroscopy studies on the irradiated samples reveal the change in bonding characteristics resulting in poor mechanical properties. As a result, denser packing of nanotubes and increased interaction without any damage is the key to improve the properties of CNT yarns.« less

Effect of solvent/polymer infiltration and irradiation on microstructure and tensile properties of carbon nanotube yarns

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

Hiremath, Nitilaksha; Lu, Xinyi; Evora, Maria Cecilia

Recently carbon nanotube (CNT) yarns have been gaining importance as an approach to harvest the excellent properties of the CNTs. However, the properties of CNT yarns at this stage are well below the expected value. Investigation of the structure of CNT yarns and possible approaches to enhance the strength and modulus are reported. Scanning electron microscopy and focused ion beam imaging reveal the inherently porous structure and poor orientation, emphasizing the need to enhance packing of CNT bundles in the yarns for increased strength and modulus. Densification of CNT yarn by toluene or polystyrene increases the strength by 140 ormore » 172 % and modulus by 79 or 218 %, respectively, as compared to that of the pristine yarn. E-beam irradiation was investigated as a means to introduce crosslinking and enhanced internanotubes bonding to increase strength and modulus. However, the irradiation resulted in generation of defects and damages to the yarn contributing to reduction in strength and modulus. Raman spectroscopy studies on the irradiated samples reveal the change in bonding characteristics resulting in poor mechanical properties. As a result, denser packing of nanotubes and increased interaction without any damage is the key to improve the properties of CNT yarns.« less

Electro-spun PLA-PEG-yarns for tissue engineering applications.

PubMed

Kruse, Magnus; Greuel, Marc; Kreimendahl, Franziska; Schneiders, Thomas; Bauer, Benedict; Gries, Thomas; Jockenhoevel, Stefan

2018-06-27

Electro-spinning is widely used in tissue-engineered applications mostly in form of non-woven structures. The development of e-spun yarn opens the door for textile fabrics which combine the micro to nanoscale dimension of electro-spun filaments with three-dimensional (3D) drapable textile fabrics. Therefore, the aim of the study was the implementation of a process for electro-spun yarns. Polylactic acid (PLA) and polyethylene glycol (PEG) were spun from chloroform solutions with varying PLA/PEG ratios (100:0, 90:10, 75:25 and 50:50). The yarn samples produced were analyzed regarding their morphology, tensile strength, water uptake and cytocompatibility. It was found that the yarn diameter decreased when the funnel collector rotation was increasd, however, the fiber diameter was not influenced. The tensile strength was also found to be dependent on the PEG content. While samples composed of 100% PLA showed a tensile strength of 2.5±0.7 cN/tex, the tensile strength increased with a decreasing PLA content (PLA 75%/PEG 25%) to 6.2±0.5 cN/tex. The variation of the PEG content also influenced the viscosity of the spinning solutions. The investigation of the cytocompatibility with endothelial cells was conducted for PLA/PEG 90:10 and 75:25 and indicated that the samples are cytocompatible.

Nanofiber-structured hydrogel yarns with pH-response capacity and cardiomyocyte-drivability for bio-microactuator application.

PubMed

Wu, Shaohua; Duan, Bin; Qin, Xiaohong; Butcher, Jonathan T

2017-09-15

Polymeric hydrogels have great potential in soft biological micro-actuator applications. However, inappropriate micro-architecture, non-anisotropy, weak biomechanics, and inferior response behaviors limit their development. In this study, we designed and manufactured novel polyacrylonitrile (PAN)-based hydrogel yarns composed with uniaxially aligned nanofibers. The nanofibrous hydrogel yarns possessed anisotropic architecture and robust mechanical properties with flexibility, and could be assembled into defined scaffold structures by subsequent processes. The as-prepared hydrogel yarns showed excellent pH response behaviors, with around 100% maximum length and 900% maximum diameter changes, and the pH response was completed within several seconds. Moreover, the hydrogel yarns displayed unique cell-responsive abilities to promote the cell adhesion, proliferation, and smooth muscle differentiation of human adipose derived mesenchymal stem cells (HADMSC). Chicken cardiomyocytes were further seeded onto our nanofibrous hydrogel yarns to engineer living cell-based microactuators. Our results demonstrated that the uniaxially aligned nanofibrous networks within the hydrogel yarns were the key characteristics leading to the anisotropic organization of cardiac cells, and improved sarcomere organization, mimicking the cardiomyocyte bundles in the native myocardium. The construct is capable of sustaining spontaneous cardiomyocyte pumping behaviors for 7days. Our PAN-based nanofibrous hydrogel yarns are attractive for creating linear microactuators with pH-response capacity and biological microactuators with cardiomyocyte-drivability. A mechanically robust polyacrylonitrile-based nanofibrous hydrogel yarn is fabricated by using a modified electrospinning setup in combination with chemical modification processes. The as-prepared hydrogel yarn possesses a uniaxially aligned nanofiber microarchitecture and supports a rapid, pH-dependent expansion/contraction response within a few

Nanofibrous Smart Fabrics from Twisted Yarns of Electrospun Piezopolymer.

PubMed

Yang, Enlong; Xu, Zhe; Chur, Lucas K; Behroozfar, Ali; Baniasadi, Mahmoud; Moreno, Salvador; Huang, Jiacheng; Gilligan, Jules; Minary-Jolandan, Majid

2017-07-19

Smart textiles are envisioned to make a paradigm shift in wearable technologies to directly impart functionality into the fibers rather than integrating sensors and electronics onto conformal substrates or skin in wearable devices. Among smart materials, piezoelectric fabrics have not been widely reported, yet. Piezoelectric smart fabrics can be used for mechanical energy harvesting, for thermal energy harvesting through the pyroelectric effect, for ferroelectric applications, as pressure and force sensors, for motion detection, and for ultrasonic sensing. We report on mechanical and material properties of the plied nanofibrous piezoelectric yarns as a function of postprocessing conditions including thermal annealing and drawing (stretching). In addition, we used a continuous electrospinning setup to directly produce P(VDF-TrFE) nanofibers and convert them into twisted plied yarns, and demonstrated application of these plied yarns in woven piezoelectric fabrics. The results of this work can be an early step toward realization of piezoelectric smart fabrics.

Developing an Acoustic Sensing Yarn for Health Surveillance in a Military Setting

PubMed Central

Dias, Tilak

2018-01-01

Overexposure to high levels of noise can cause permanent hearing disorders, which have a significant adverse effect on the quality of life of those affected. Injury due to noise can affect people in a variety of careers including construction workers, factory workers, and members of the armed forces. By monitoring the noise exposure of workers, overexposure can be avoided and suitable protective equipment can be provided. This work focused on the creation of a noise dosimeter suitable for use by members of the armed forces, where a discrete dosimeter was integrated into a textile helmet cover. In this way the sensing elements could be incorporated very close to the ears, providing a highly representative indication of the sound level entering the body, and also creating a device that would not interfere with military activities. This was achieved by utilising commercial microelectromechanical system microphones integrated within the fibres of yarn to create an acoustic sensing yarn. The acoustic sensing yarns were fully characterised over a range of relevant sound levels and frequencies at each stage in the yarn production process. The yarns were ultimately integrated into a knitted helmet cover to create a functional acoustic sensing helmet cover prototype. PMID:29772756

Recent researches concerning the obtaining of functional textiles based on conductive yarns

NASA Astrophysics Data System (ADS)

Leon, A. L.; Manea, L. R.; Hristian, L.

2016-08-01

Modem textile industry is influenced both by consumers' lifestyle and by novel materials. Functional textiles can be included into the group of technical textiles. The functional activity can be shortly interpreted as "sense - react - adapt" to the environment while traditional materials meet only passive protective role, a barrier between body and environment. Functional materials cross the conventional limits because they are designed for specific performances, being part of domains as: telemedicine, medicine, aeronautics, biotechnology, nanotechnology, protective clothes, sportswear, etc. This paper highlights the most recent developments in the field of using conductive yarns for obtaining functional textiles. Conductive fabrics can be done by incorporating into the textile structure the conductive fibers / yarns. The technologies differ from embroidering, sewing, weaving, knitting to braiding and obtaining nonwovens. The conductive fabrics production has a quickly growth because it is a high demand for these textiles used for data transfer in clothing, monitoring vital signs, germ-free garments, brain-computer interface, etc. Nowadays it is of high interest surface treatments of fibers/yarns which can be considered as a novel kind of textile finishing. There are presented some researches related to obtaining conductive yarns by coating PET and PP yarns with PANi conductive polymer.

Moisture Management Behaviour of Knitted Fabric from Structurally Modified Ring and Vortex Spun Yarn

NASA Astrophysics Data System (ADS)

Sharma, Navendu; Kumar, Pawan; Bhatia, Dinesh; Sinha, Sujit Kumar

2016-10-01

The acceptability of a new product is decided by its performance, level of improvement in quality and economy of production. The basic aim of generating micro pores in a textile structure is to provide better thermo-physiological comfort by enhancing the breathability and hence improving moisture management behaviour. In the present study, an attempt has been made to create a relatively more open structure through removal of a component. A comparative assessment with a homogeneous and parent yarn was also made. Yarns of two linear densities, each from ring and vortex spinning systems were produced using 100 % polyester and 80:20 polyester/cotton blend. The modified yarn was produced by removing a component, viz; cotton, by treatment with sulphuric acid from the blended yarn. The knitted fabric from modified yarn was found to show significant improvement in air permeability, water vapour permeability and total absorbency while the wicking characteristic was found to decline.

Properties of CF/PA6 friction spun hybrid yarns for textile reinforced thermoplastic composites

NASA Astrophysics Data System (ADS)

Hasan, MMB; Nitsche, S.; Abdkader, A.; Cherif, Ch

2017-10-01

Due to their excellent strength, rigidity and damping properties as well as low weight, carbon fibre reinforced composites (CFRC) are widely being used for load bearing structures. On the other hand, with an increased demand und usage of CFRCs, effective methods to re-use waste carbon fibre (CF) materials, which are recoverable either from the process scraps or from the end-of-life components are attracting increased attention. In this paper, hybrid yarns consisting of staple CF and polyamide 6 (PA 6) are manufactured on a DREF-3000 friction spinning machine with various machine parameters such as spinning drum speed and suction air pressure. The relationship between different textile physical properties of the hybrid yarns, such as tensile strength and elongation with different spinning parameters and CF content of hybrid yarn is investigated. Furthermore, the tensile properties of uni-directional (UD) composites manufactured from the developed hybrid yarn shows 80% of the UD composite strength made from CF filament yarn.

A Fast Response Ammonia Sensor Based on Coaxial PPy-PAN Nanofiber Yarn.

PubMed

Liu, Penghong; Wu, Shaohua; Zhang, Yue; Zhang, Hongnan; Qin, Xiaohong

2016-06-23

Highly orientated polypyrrole (PPy)-coated polyacrylonitrile (PAN) (PPy-PAN) nanofiber yarn was prepared with an electrospinning technique and in-situ chemical polymerization. The morphology and chemical structure of PPy-PAN nanofiber yarn was characterized by scanning electron microscopy (SEM), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), and fourier transform infrared spectroscopy (FTIR), which indicated that the PPy as the shell layer was homogeneously and uniformly polymerized on the surface of PAN nanofiber. The effects of different concentration of doping acid on the responses of PPy-PAN nanofiber yarn sensor were investigated. The electrical responses of the gas sensor based on the PPy-PAN nanofiber yarn to ammonia were investigated at room temperature. The nanoyarn sensor composed of uniaxially aligned PPy-PAN nanofibers with a one-dimensional structure exhibited a transient response, and the response time was less than 1 s. The excellent sensing properties mentioned above give rise to good potential application prospects in the field of ammonia sensor.

A Complex Shaped Reinforced Thermoplastic Composite Part Made of Commingled Yarns With Integrated Sensor

NASA Astrophysics Data System (ADS)

Risicato, Jean-Vincent; Kelly, Fern; Soulat, Damien; Legrand, Xavier; Trümper, Wolfgang; Cochrane, Cedric; Koncar, Vladan

2015-02-01

This paper focuses on the design and one shot manufacturing process of complex shaped composite parts based on the overbraiding of commingled yarns. The commingled yarns contain thermoplastic fibres used as the matrix and glass fibres as the reinforcement material. This technology reduces the flow path length for the melted thermoplastic and aims to improve the impregnation of materials with high viscosity. The tensile strength behaviour of the material was firstly investigated in order to evaluate the influence of the manufacturing parameters on flat structured braids that have been consolidated on a heating press. A good compatibility between the required geometry and the braiding process was observed. Additionally, piezo-resistive sensor yarns, based on glass yarns coated with PEDOT: PSS, have been successfully integrated within the composite structure. The sensor yarns have been inserted into the braided fabric, before consolidation. The inserted sensors provide the ability to monitor the structural health of the composite part in a real time. The design and manufacture of the complete complex shaped part has then been successfully achieved.

Stiffness and Poisson ratio in longitudinal compression of fiber yarns in meso-FE modelling of composite reinforcement forming

NASA Astrophysics Data System (ADS)

Wang, D.; Naouar, N.; Vidal-Salle, E.; Boisse, P.

2018-05-01

In meso-scale finite element modeling, the yarns of the reinforcement are considered to be solids made of a continuous material in contact with their neighbors. The present paper consider the mechanical behavior of these yarns that can happen for some loadings of the reinforcement. The yarns present a specific mechanical behavior when under longitudinal compression because they are made up of a large number of fibers, Local buckling of the fibers causes the compressive stiffness of the continuous material representing the yarn to be much weaker than when under tension. In addition, longitudinal compression causes an important transverse expansion. It is shown that the transverse expansion can be depicted by a Poisson ratio that remained roughly constant when the yarn length and the compression strain varied. Buckling of the fibers significantly increases the transverse dimensions of the yarn which leads to a large Poisson ratio (up to 12 for a yarn analyzed in the present study). Meso-scale finite element simulations of reinforcements with binder yarns submitted to longitudinal compression showed that these improvements led to results in good agreement with micro-CT analyses.

A display module implemented by the fast high-temperatue response of carbon nanotube thin yarns.

PubMed

Wei, Yang; Liu, Peng; Jiang, Kaili; Fan, Shoushan

2012-05-09

Suspending superaligned multiwalled carbon nanotube (MWCNT) films were processed into CNT thin yarns, about 1 μm in diameter, by laser cutting and an ethanol atomization bath treatment. The fast high-temperature response under a vacuum was revealed by monitoring the incandescent light with a photo diode. The thin yarns can be electrically heated up to 2170 K in 0.79 mS, and the succeeding cool-down time is 0.36 mS. The fast response is attributed to the ultrasmall mass of the independent single yarn, large radiation coefficient, and improved thermal conductance through the two cool ends. The millisecond response time makes it possible to use the visible hot thin yarns as light-emitting elements of an incandescent display. A fully sealed display with 16 × 16 matrix was successfully fabricated using screen-printed thick electrodes and CNT thin yarns. It can display rolling characters with a low power consumption. More applications can be further developed based on the addressable CNT thermal arrays.

Nonlinear Deformation Behavior of New Braided Composites with Six-axis Yarn Orientations

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

Ahn, H.-C.; Yu, W.-R.; Guo, Z.

The braiding technology is one of fabrication methods that can produce three-dimensional fiber preforms. Braided composites have many advantages over other two-dimensional composites such as no delamination, high impact and fatigue properties, near-net shape preform, etc. Due to the undulated yarns in the braided preforms, however, their axial stiffness is lower than that of uni-directional or woven composites. To improve the axial stiffness, the longitudinal axial yarns were already introduced along with the braiding axis (five-axis braiding technology). In this study, we developed a new braided structure using six-axis braiding technology. In addition to braiding and longitudinal axial yarns, transversemore » axial yarn was introduced. New braided composites, so called six-axis braiding composites, were manufactured using ultra high molecular weight polyethylene and epoxy resin and their mechanical properties were characterized. To investigate the mechanical performance of these braided composites according to their manufacturing conditions, a numerical analysis was performed using their unit-cell modeling and finite element analysis. In the analysis the nonlinear deformation behavior will be included.« less

Piezoresistive effect of the carbon nanotube yarn embedded axially into the 3D braided composite

NASA Astrophysics Data System (ADS)

Ma, Xin; Cao, Xiaona

2018-06-01

A new method for monitoring 3D braided composite structure health in real time by embedding the carbon nanotube yarn, based on its piezoresistivity, in the composite axially has been designed. The experimental system for piezoresistive effect detection of the carbon nanotube yarn in the 3D braided composite was built, and the sensing characteristics has been analyzed for further research. Compared with other structural health monitoring methods, the monitoring technique with carbon nanotubes yarns is more suitable for internal damage detection immediately, in addition the strength of the composite can be increased by embedding carbon nanotubes yarns. This method can also be used for strain sensing, the development of intelligent materials and structure systems.

Study on the Filament Yarns Spreading Techniques and Assessment Methods of the Electronic Fiberglass Fabric

NASA Astrophysics Data System (ADS)

Wang, Xi; Chen, Shouhui; Zheng, Tianyong; Ning, Xiangchun; Dai, Yifei

2018-03-01

The filament yarns spreading techniques of electronic fiberglass fabric were developed in the past few years in order to meet the requirements of the development of electronic industry. Copper clad laminate (CCL) requires that the warp and weft yarns of the fabric could be spread out of apart and formed flat. The penetration performance of resin could be improved due to the filament yarns spreading techniques of electronic fiberglass fabric, the same as peeling strength of CCL and drilling performance of printed circuit board (PCB). This paper shows the filament yarns spreading techniques of electronic fiberglass fabric from several aspects, such as methods and functions, also with the assessment methods of their effects.

Study the relation between the yarn pulling force and the bursting strength of single jersey knitted fabric

NASA Astrophysics Data System (ADS)

El-Tarfawy, S. Y.

2017-10-01

There are various methods to evaluate knitted fabric’s properties; the yarn pulling force is a suitable experimental method to investigate the properties of single jersey knitted fabric.In this study, a frame is attached to the electronic tensile strength tester to fix different single jersey knitted fabrics with different dimensional properties. A hook is connected to the upper load cell in the tensile tester to ravel the first upper course then records the values of the yarn pulling force. In addition to that, the effect of the loop length, yarn count, and raw material on yarn pulling force and specific fabric bursting strength are studied. It is concluded that yarn pulling force has a significant relation with specific fabric bursting strength.

From industrially weavable and knittable highly conductive yarns to large wearable energy storage textiles.

PubMed

Huang, Yan; Hu, Hong; Huang, Yang; Zhu, Minshen; Meng, Wenjun; Liu, Chang; Pei, Zengxia; Hao, Chonglei; Wang, Zuankai; Zhi, Chunyi

2015-05-26

Wearable electronic textiles that store capacitive energy are a next frontier in personalized electronics. However, the lack of industrially weavable and knittable conductive yarns in conjunction with high capacitance, limits the wide-scale application of such textiles. Here pristine soft conductive yarns are continuously produced by a scalable method with the use of twist-bundle-drawing technique, and are mechanically robust enough to be knitted to a cloth by a commercial cloth knitting machine. Subsequently, the reduced-graphene-oxide-modified conductive yarns covered with a hierarchical structure of MnO2 nanosheets and a polypyrrole thin film were used to fabricate weavable, knittable and wearable yarn supercapacitors. The resultant modified yarns exhibit specific capacitances as high as 36.6 mF cm(-1) and 486 mF cm(-2) in aqueous electrolyte (three-electrode cell) or 31 mF cm(-1) and 411 mF cm(-2) in all solid-state two-electrode cell. The symmetric solid-state supercapacitor has high energy densities of 0.0092 mWh cm(-2) and 1.1 mWh cm(-3) (both normalized to the whole device) with a long cycle life. Large energy storage textiles are fabricated by weaving our flexible all-solid-state supercapacitor yarns to a 15 cm × 10 cm cloth on a loom and knitting in a woollen wrist band to form a pattern, enabling dual functionalities of energy storage capability and wearability.

A comparative study on cotton fiber length parameters’ effects on modeling yarn property

USDA-ARS?s Scientific Manuscript database

Fiber length is one of the key properties of cotton and has important influences on yarn production and yarn quality. Various parameters have been developed to characterize cotton fiber length in the past decades. This study was carried out to investigate the effects of these parameters and their ...

Deformation and Failure of a Multi-Wall Carbon Nanotube Yarn Composite

NASA Technical Reports Server (NTRS)

Gates, Thomas S.; Jefferson, Gail D.; Frankland, Sarah-Jane V.

2008-01-01

Forests of multi-walled carbon nanotubes can be twisted and manipulated into continuous fibers or yarns that exhibit many of the characteristics of traditional textiles. Macro-scale analysis and test may provide strength and stiffness predictions for a composite composed of a polymer matrix and low-volume fraction yarns. However, due to the nano-scale of the carbon nanotubes, it is desirable to use atomistic calculations to consider tube-tube interactions and the influence of simulated twist on the effective friction coefficient. This paper reports laboratory test data on the mechanical response of a multi-walled, carbon nanotube yarn/polymer composite from both dynamic and quasi-static tensile tests. Macroscale and nano-scale analysis methods are explored and used to define some of the key structure-property relationships. The measured influence of hot-wet aging on the tensile properties is also reported.

Magnetoreresistance of carbon nanotube-polypyrrole composite yarns

NASA Astrophysics Data System (ADS)

Ghanbari, R.; Ghorbani, S. R.; Arabi, H.; Foroughi, J.

2018-05-01

Three types of samples, carbon nanotube yarn and carbon nanotube-polypyrrole composite yarns had been investigated by measurement of the electrical conductivity as a function of temperature and magnetic field. The conductivity was well explained by 3D Mott variable range hopping (VRH) law at T < 100 K. Both positive and negative magnetoresistance (MR) were observed by increasing magnetic field. The MR data were analyzed based a theoretical model. A quadratic positive and negative MR was observed for three samples. It was found that the localization length decreases with applied magnetic field while the density of states increases. The increasing of the density of states induces increasing the number of available energy states for hopping. Thus the electron hopping probability increases in between sites with the shorter distance that results to small the average hopping length.

Micro-Scale Mechanical Testing of Non-Woven Carbon Nanotube Sheets and Yarns

NASA Technical Reports Server (NTRS)

Magargee, J.; Morestin, F.; Cao, J.; Jones, J. S.

2013-01-01

Non-woven carbon nanotube (CNT) sheets and yarns were tested using a novel micro-scale mechanical testing system. CNT sheets were observed to delaminate during uniaxial testing using an adbesive gripping method, resulting from a higher proportion of load bearing in the outer sheets versus internal sheets and an apparently low interlaminar shear strength. In response to this, a new spool-grip method was used to alleviate non-uniform through-thickness stresses, circumvent premature delamination, and allow the sheet material to sustain a 72% increase in measured tensile strength. Furthermore, tension tests of CNT yarns showed that the yarn-structure was approximaiely 7 times stronger than the sheet structure, owing to a higher degree of CNT alignment in the test direction.

Cost-Benefit and Performance of Handmade Carpets Produced with Wool, Untreated and Chemical Treated Jute Pile Yarns

NASA Astrophysics Data System (ADS)

Gupta, Shravan Kumar; Goswami, Kamal Kanti

2018-03-01

Jute is a natural fibre which is used to make different type of products due to low cost, easy availability and eco-friendliness. However, the stiffness and harshness of jute fibre affect the use of jute in many products like pile yarns in hand knotted carpets. In this research, a study has been done on the application of jute pile yarns in Persian hand knotted carpet. Three types of commercial yarns (wool, untreated jute and woollenized jute) as well as three types of chemical treated jute yarns (hydrogen peroxide bleached, softened bleached and woollenized yarns) have been applied as pile yarns in Persian hand knotted carpets. Cost-benefit analysis of hand knotted carpets shows that manufacturing cost of wool carpet is lower than others. The contribution of manpower charges is higher than material cost during carpet manufacturing. Hand knotted carpet shows the lowest pile abrasion loss and highest compression recovery when wool is used as pile. Wool hand knotted carpet shows higher compression than untreated and treated jute carpets.

Cost-Benefit and Performance of Handmade Carpets Produced with Wool, Untreated and Chemical Treated Jute Pile Yarns

NASA Astrophysics Data System (ADS)

Gupta, Shravan Kumar; Goswami, Kamal Kanti

2018-06-01

Jute is a natural fibre which is used to make different type of products due to low cost, easy availability and eco-friendliness. However, the stiffness and harshness of jute fibre affect the use of jute in many products like pile yarns in hand knotted carpets. In this research, a study has been done on the application of jute pile yarns in Persian hand knotted carpet. Three types of commercial yarns (wool, untreated jute and woollenized jute) as well as three types of chemical treated jute yarns (hydrogen peroxide bleached, softened bleached and woollenized yarns) have been applied as pile yarns in Persian hand knotted carpets. Cost-benefit analysis of hand knotted carpets shows that manufacturing cost of wool carpet is lower than others. The contribution of manpower charges is higher than material cost during carpet manufacturing. Hand knotted carpet shows the lowest pile abrasion loss and highest compression recovery when wool is used as pile. Wool hand knotted carpet shows higher compression than untreated and treated jute carpets.

Wearable energy-dense and power-dense supercapacitor yarns enabled by scalable graphene–metallic textile composite electrodes

PubMed Central

Liu, Libin; Yu, You; Yan, Casey; Li, Kan; Zheng, Zijian

2015-01-01

One-dimensional flexible supercapacitor yarns are of considerable interest for future wearable electronics. The bottleneck in this field is how to develop devices of high energy and power density, by using economically viable materials and scalable fabrication technologies. Here we report a hierarchical graphene–metallic textile composite electrode concept to address this challenge. The hierarchical composite electrodes consist of low-cost graphene sheets immobilized on the surface of Ni-coated cotton yarns, which are fabricated by highly scalable electroless deposition of Ni and electrochemical deposition of graphene on commercial cotton yarns. Remarkably, the volumetric energy density and power density of the all solid-state supercapacitor yarn made of one pair of these composite electrodes are 6.1 mWh cm−3 and 1,400 mW cm−3, respectively. In addition, this SC yarn is lightweight, highly flexible, strong, durable in life cycle and bending fatigue tests, and integratable into various wearable electronic devices. PMID:26068809

Wearable energy-dense and power-dense supercapacitor yarns enabled by scalable graphene-metallic textile composite electrodes.

PubMed

Liu, Libin; Yu, You; Yan, Casey; Li, Kan; Zheng, Zijian

2015-06-11

One-dimensional flexible supercapacitor yarns are of considerable interest for future wearable electronics. The bottleneck in this field is how to develop devices of high energy and power density, by using economically viable materials and scalable fabrication technologies. Here we report a hierarchical graphene-metallic textile composite electrode concept to address this challenge. The hierarchical composite electrodes consist of low-cost graphene sheets immobilized on the surface of Ni-coated cotton yarns, which are fabricated by highly scalable electroless deposition of Ni and electrochemical deposition of graphene on commercial cotton yarns. Remarkably, the volumetric energy density and power density of the all solid-state supercapacitor yarn made of one pair of these composite electrodes are 6.1 mWh cm(-3) and 1,400 mW cm(-3), respectively. In addition, this SC yarn is lightweight, highly flexible, strong, durable in life cycle and bending fatigue tests, and integratable into various wearable electronic devices.

Elastic Response and Failure Studies of Multi-Wall Carbon Nanotube Twisted Yarns

NASA Technical Reports Server (NTRS)

Gates, Thomas S.; Jefferson, Gail D.; Frankland, Sarah-Jane V.

2007-01-01

Experimental data on the stress-strain behavior of a polymer multiwall carbon nanotube (MWCNT) yarn composite are used to motivate an initial study in multi-scale modeling of strength and stiffness. Atomistic and continuum length scale modeling methods are outlined to illustrate the range of parameters required to accurately model behavior. The carbon nanotubes yarns are four-ply, twisted, and combined with an elastomer to form a single-layer, unidirectional composite. Due to this textile structure, the yarn is a complicated system of unique geometric relationships subjected to combined loads. Experimental data illustrate the local failure modes induced by static, tensile tests. Key structure-property relationships are highlighted at each length scale indicating opportunities for parametric studies to assist the selection of advantageous material development and manufacturing methods.

Shear and friction between carbon nanotubes in bundles and yarns.

PubMed

Paci, Jeffrey T; Furmanchuk, Al'ona; Espinosa, Horacio D; Schatz, George C

2014-11-12

We perform a detailed density functional theory assessment of the factors that determine shear interactions between carbon nanotubes (CNTs) within bundles and in related CNT and graphene structures including yarns, providing an explanation for the shear force measured in recent experiments (Filleter, T. etal. Nano Lett. 2012, 12, 73). The potential energy barriers separating AB stacked structures are found to be irrelevant to the shear analysis for bundles and yarns due to turbostratic stacking, and as a result, the tube-tube shear strength for pristine CNTs is estimated to be <0.24 MPa, that is, extremely small. Instead, it is pinning due to the presence of defects and functional groups at the tube ends that primarily cause resistance to shear when bundles are fractured in weak vacuum (∼10(-5) Torr). Such defects and groups are estimated to involve 0.55 eV interaction energies on average, which is much larger than single-atom vacancy defects (approximately 0.039 eV). Furthermore, because graphitic materials are stiff they have large coherence lengths, and this means that push-pull effects result in force cancellation for vacancy and other defects that are internal to the CNTs. Another important factor is the softness of cantilever structures relative to the stiff CNTs in the experiments, as this contributes to elastic instability transitions that account for significant dissipation during shear that has been observed. The application of these results to the mechanical behavior of yarns is discussed, providing general guidelines for the manufacture of strong yarns composed of CNTs.

Development of novel textile and yarn actuators using plasticized PVC gel

NASA Astrophysics Data System (ADS)

Furuse, A.; Hashimoto, M.

2017-04-01

Soft actuators based on polymers are expected to be used for power sources to drive wearable robots which required in a wide range of fields such as medical, care and welfare, because they are light weight, flexible and quiet. Plasticized PVC gel which has a large deformation by applying a voltage and high driving stability in the atmosphere is considered as a suitable candidate material for development of soft actuator. Then, we proposed two kinds of novel flexible actuators constructed like yarn and textile by using plasticized PVC gel to develop soft actuator to realize a higher flexibility and low-voltage driving. In this study, we prepared prototypes of these actuators and clarify their characteristic. In addition, we considered the deformation model from its characteristics and geometric calculation. When a voltage was applied to their actuators, textile type actuator was contracted, while the twisted yarn type actuator was expanded. The deformation behavior of the proposed actuators could be found at a low voltage of 200V, the contraction strain of the textile actuator was about 27 %, and the expanding ratio of the yarn actuator was 0.4 %. Maximum contraction strain of textile actuator and expansion ratio of yarn actuator was 53% and 1.4% at 600 V, respectively. The calculation results from the proposed model were in roughly agreement with the experimental values. It indicated that deformation behavior of these actuators could estimate from models.

Multifunctional smart composites with integrated carbon nanotube yarn and sheet

NASA Astrophysics Data System (ADS)

Chauhan, Devika; Hou, Guangfeng; Ng, Vianessa; Chaudhary, Sumeet; Paine, Michael; Moinuddin, Khwaja; Rabiee, Massoud; Cahay, Marc; Lalley, Nicholas; Shanov, Vesselin; Mast, David; Liu, Yijun; Yin, Zhangzhang; Song, Yi; Schulz, Mark

2017-04-01

Multifunctional smart composites (MSCs) are materials that combine the good electrical and thermal conductivity, high tensile and shear strength, good impact toughness, and high stiffness properties of metals; the light weight and corrosion resistance properties of composites; and the sensing or actuation properties of smart materials. The basic concept for MSCs was first conceived by Daniel Inman and others about 25 years ago. Current laminated carbon and glass fiber polymeric composite materials have high tensile strength and are light in weight, but they still lack good electrical and thermal conductivity, and they are sensitive to delamination. Carbon nanotube yarn and sheets are lightweight, electrically and thermally conductive materials that can be integrated into laminated composite materials to form MSCs. This paper describes the manufacturing of high quality carbon nanotube yarn and sheet used to form MSCs, and integrating the nanotube yarn and sheet into composites at low volume fractions. Various up and coming technical applications of MSCs are discussed including composite toughening for impact and delamination resistance; structural health monitoring; and structural power conduction. The global carbon nanotube overall market size is estimated to grow from 2 Billion in 2015 to 5 Billion by 2020 at a CAGR of 20%. Nanotube yarn and sheet products are predicted to be used in aircraft, wind machines, automobiles, electric machines, textiles, acoustic attenuators, light absorption, electrical wire, sporting equipment, tires, athletic apparel, thermoelectric devices, biomedical devices, lightweight transformers, and electromagnets. In the future, due to the high maximum current density of nanotube conductors, nanotube electromagnetic devices may also become competitive with traditional smart materials in terms of power density.

Yarn-dyed fabric defect classification based on convolutional neural network

NASA Astrophysics Data System (ADS)

Jing, Junfeng; Dong, Amei; Li, Pengfei; Zhang, Kaibing

2017-09-01

Considering that manual inspection of the yarn-dyed fabric can be time consuming and inefficient, we propose a yarn-dyed fabric defect classification method by using a convolutional neural network (CNN) based on a modified AlexNet. CNN shows powerful ability in performing feature extraction and fusion by simulating the learning mechanism of human brain. The local response normalization layers in AlexNet are replaced by the batch normalization layers, which can enhance both the computational efficiency and classification accuracy. In the training process of the network, the characteristics of the defect are extracted step by step and the essential features of the image can be obtained from the fusion of the edge details with several convolution operations. Then the max-pooling layers, the dropout layers, and the fully connected layers are employed in the classification model to reduce the computation cost and extract more precise features of the defective fabric. Finally, the results of the defect classification are predicted by the softmax function. The experimental results show promising performance with an acceptable average classification rate and strong robustness on yarn-dyed fabric defect classification.

Multi-layered sensor yarns for in situ monitoring of textile reinforced composites

NASA Astrophysics Data System (ADS)

Haentzsche, E.; Onggar, T.; Nocke, A.; Hund, R. D.; Cherif, Ch

2017-10-01

In this contribution, the characteristic of yarns that have intrinsically conductivity as well as such with coaxial conductive coatings acting as in situ strain sensors are described. The objective of the based research projects is the real-time in situ sensing of both global stresses acting on fibre reinforced plastic (FRP) components and the detection of resulted local microscopic damages due to creep, delamination and micro-cracks in the fibre-matrix interphase of glass fibre (GFRP) and carbon fibre (CFRP) composites. Sensor materials similar to the particular FRP and its mechanical behaviour have been chosen. In the first approach, GF- and aramid-based sensor yarns have been developed with multiple tailored silver layer coating system capable to distinguish multiple scaled damage mechanism due to these effects globally and locally. The second approach bases on the piezoresistive effect of CF rovings for their usage as in situ strain sensors. In the next step, suitable fibre and polymer film-based cleading have been tested and evaluated, granting sufficient electrical isolation to avoid shortcircuits between the conductive sensor layers itself or between the sensor and intrinsically conductive CFRP respectively. Initially, the sensor performance of global strain measurement, means the accumulated strain along the integration length of the sensor yarn, has been evaluated during tensile stressing of FRP with integrated suchlike functionalised sensor yarns.

Electron Beam Irradiated Intercalated CNT Yarns For Aerospace Applications

NASA Technical Reports Server (NTRS)

Waters, Deborah L.; Gaier, James R.; Williams, Tiffany S.; Lopez Calero, Johnny E.; Ramirez, Christopher; Meador, Michael A.

2015-01-01

Multi-walled CNT yarns have been experimentally and commercially created to yield lightweight, high conductivity fibers with good tensile properties for application as electrical wiring and multifunctional tendons. Multifunctional tendons are needed as the cable structures in tensegrity robots for use in planetary exploration. These lightweight robust tendons can provide mechanical strength for movement of the robot in addition to power distribution and data transmission. In aerospace vehicles, such as Orion, electrical wiring and harnessing mass can approach half of the avionics mass. Use of CNT yarns as electrical power and data cables could reduce mass of the wiring by thirty to seventy percent. These fibers have been intercalated with mixed halogens to increase their specific electrical conductivity to that near copper. This conductivity, combined with the superior strength and fatigue resistance makes it an attractive alternative to copper for wiring and multifunctional tendon applications. Electron beam irradiation has been shown to increase mechanical strength in pristine CNT fibers through increased cross-linking. Both pristine and intercalated CNT yarns have been irradiated using a 5-megavolt electron beam for various durations and the conductivities and tensile properties will be discussed. Structural information obtained using a field emission scanning electron microscope, energy dispersive X-ray spectroscopy (EDS), and Raman spectroscopy will correlate microstructural details with bulk properties.

Multiscale modeling of interwoven Kevlar fibers based on random walk to predict yarn structural response

NASA Astrophysics Data System (ADS)

Recchia, Stephen

Kevlar is the most common high-end plastic filament yarn used in body armor, tire reinforcement, and wear resistant applications. Kevlar is a trade name for an aramid fiber. These are fibers in which the chain molecules are highly oriented along the fiber axis, so the strength of the chemical bond can be exploited. The bulk material is extruded into filaments that are bound together into yarn, which may be chorded with other materials as in car tires, woven into a fabric, or layered in an epoxy to make composite panels. The high tensile strength to low weight ratio makes this material ideal for designs that decrease weight and inertia, such as automobile tires, body panels, and body armor. For designs that use Kevlar, increasing the strength, or tenacity, to weight ratio would improve performance or reduce cost of all products that are based on this material. This thesis computationally and experimentally investigates the tenacity and stiffness of Kevlar yarns with varying twist ratios. The test boundary conditions were replicated with a geometrically accurate finite element model, resulting in a customized code that can reproduce tortuous filaments in a yarn was developed. The solid model geometry capturing filament tortuosity was implemented through a random walk method of axial geometry creation. A finite element analysis successfully recreated the yarn strength and stiffness dependency observed during the tests. The physics applied in the finite element model was reproduced in an analytical equation that was able to predict the failure strength and strain dependency of twist ratio. The analytical solution can be employed to optimize yarn design for high strength applications.

Thermoacoustic chips with carbon nanotube thin yarn arrays.

PubMed

Wei, Yang; Lin, Xiaoyang; Jiang, Kaili; Liu, Peng; Li, Qunqing; Fan, Shoushan

2013-10-09

Aligned carbon nanotube (CNT) films drawn from CNT arrays have shown the potential as thermoacoustic loudspeakers. CNT thermoacoustic chips with robust structures are proposed to promote the applications. The silicon-based chips can play sound and fascinating rhythms by feeding alternating currents and audio signal to the suspending CNT thin yarn arrays across grooves in them. In additional to the thin yarns, experiments further revealed more essential elements of the chips, the groove depth and the interdigital electrodes. The sound pressure depends on the depth of the grooves, and the thermal wavelength can be introduced to define the influence-free depth. The interdigital fingers can effectively reduce the driving voltage, making the chips safe and easy to use. The chips were successfully assembled into earphones and have been working stably for about one year. The thermoacoustic chips can find many applications in consumer electronics and possibly improve the audiovisual experience.

Tensile strength of ramie yarn (spinning by machine)/HDPE thermoplastic matrix composites

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

Banowati, Lies, E-mail: liesbano@gmail.com; Hadi, Bambang K., E-mail: bkhadi@ae.itb.ac.id; Suratman, Rochim, E-mail: rochim@material.itb.ac.id

2016-03-29

Technological developments should be trooped to prevent a gap between technology and environmental sustainability, then it needs to be developed “Green technology”. In this research is making of green composites which use natural fiber ramie as reinforcement. Whereas the matrix used was HDPE (High Density Polyethylene) thermoplastic polymer which could be recycled and had a good formability and flexibility. The ramie yarns and fibers for unidirectional (0°) direction respectively were mixed with HDPE powder and processed using hot compression molding. The surface morphology was observed by SEM (Scanning Electrone Microscopy). Results showed that both tensile strength of the ramie fiber/HDPEmore » composites increased in comparison with the ramie yarn (spinning by machine)/HDPE composites. However, the ramie yarn (spinning by machine)/HDPE composites have a good producibility for wider application. Analysis of the test results using the Weibull distribution as approaches to modeling the reliability of the specimens.« less

Increased Tensile Strength of Carbon Nanotube Yarns and Sheets through Chemical Modification and Electron Beam Irradiation

NASA Technical Reports Server (NTRS)

Miller, Sandi G.; Williams, Tiffany S.; Baker, James S.; Sola, Francisco; Lebron-Colon, Marisabel; McCorkle, Linda S.; Wilmoth, Nathan G.; Gaier, James; Chen, Michelle; Meador, Michael A.

2014-01-01

The inherent strength of individual carbon nanotubes offers considerable opportunity for the development of advanced, lightweight composite structures. Recent work in the fabrication and application of carbon nanotube (CNT) forms such as yarns and sheets has addressed early nanocomposite limitations with respect to nanotube dispersion and loading; and has pushed the technology toward structural composite applications. However, the high tensile strength of an individual CNT has not directly translated to macro-scale CNT forms where bulk material strength is limited by inter-tube electrostatic attraction and slippage. The focus of this work was to assess post processing of CNT sheet and yarn to improve the macro-scale strength of these material forms. Both small molecule functionalization and e-beam irradiation was evaluated as a means to enhance tensile strength and Youngs modulus of the bulk CNT material. Mechanical testing results revealed a tensile strength increase in CNT sheets by 57 when functionalized, while an additional 48 increase in tensile strength was observed when functionalized sheets were irradiated; compared to unfunctionalized sheets. Similarly, small molecule functionalization increased yarn tensile strength up to 25, whereas irradiation of the functionalized yarns pushed the tensile strength to 88 beyond that of the baseline yarn.

Pyrolytic boron nitride coatings on ceramic yarns and fabrication of insulations

NASA Technical Reports Server (NTRS)

Moore, Arthur W.

1992-01-01

Pyrolytic boron nitride (PBN) was deposited on Nicalon NL 202 silicon carbide yarns at 1000 to 1200 C with the goal of improving the resistance of the Nicalon to deterioration in an aerodynamic environment at temperatures up to 1000 C. For continuous coating, the yarns were fed through the deposition chamber of a pilot plant sized CVD furnace at a rate of about 2 feet per minute. PBN coatings were obtained by reacting boron trichloride and ammonia gases inside the deposition chamber. Most of the PBN coatings were made at around 1080 C to minimize thermal degradation of the Nicalon. Pressures were typically below 0.1 Torr. The coated yarns were characterized by weight per unit length, tensile strength and modulus, scanning electron microscopy, and scanning Auger microscopy. The PBN coated Nicalon was woven into cloth, but was not entirely satisfactory as a high temperature sizing. Several 13 in. square pieces of Nicalon cloth were coated with PBN in a batch process in a factory sized deposition furnace. Samples of cloth made from the PBN coated Nicalon were sewn into thermal insulation panels, whose performance is being compared with that of panels made using uncoated Nicalon.

New-type planar field emission display with superaligned carbon nanotube yarn emitter.

PubMed

Liu, Peng; Wei, Yang; Liu, Kai; Liu, Liang; Jiang, Kaili; Fan, Shoushan

2012-05-09

With the superaligned carbon nanotube yarn as emitter, we have fabricated a 16 × 16 pixel field emission display prototype by adopting screen printing and laser cutting technologies. A planar diode field emission structure has been adopted. A very sharp carbon nanotube yarn tip emitter can be formed by laser cutting. Low voltage phosphor was coated on the anode electrodes also by screen printing. With a specially designed circuit, we have demonstrated the dynamic character display with the field emission display prototype. The emitter material and fabrication technologies in this paper are both easy to scale up to large areas.

INITIAL ASSESSMENT OF EMISSIONS FROM HEAT SETTING CARPET YARN

EPA Science Inventory

The report gives initial results of a project to determine the nature of emissions resulting from the heat setting of carpet yarn and to identify possible control options. o collect the necessary technical information, two manufacturing facilities were visited: World Carpets in D...

INITIAL ASSESSMENT OF EMISSIONS FROM HEAT SETTING CARPET YARN

EPA Science Inventory

The report gives initial results of a project to determine the nature of emissions resulting from the heat setting of carpet yarn and to identify possible control options. To collect the necessary technical information, two manufacturing facilities were visited: World Carpets in ...

Electrically, chemically, and photonically powered torsional and tensile actuation of hybrid carbon nanotube yarn muscles.

PubMed

Lima, Márcio D; Li, Na; Jung de Andrade, Mônica; Fang, Shaoli; Oh, Jiyoung; Spinks, Geoffrey M; Kozlov, Mikhail E; Haines, Carter S; Suh, Dongseok; Foroughi, Javad; Kim, Seon Jeong; Chen, Yongsheng; Ware, Taylor; Shin, Min Kyoon; Machado, Leonardo D; Fonseca, Alexandre F; Madden, John D W; Voit, Walter E; Galvão, Douglas S; Baughman, Ray H

2012-11-16

Artificial muscles are of practical interest, but few types have been commercially exploited. Typical problems include slow response, low strain and force generation, short cycle life, use of electrolytes, and low energy efficiency. We have designed guest-filled, twist-spun carbon nanotube yarns as electrolyte-free muscles that provide fast, high-force, large-stroke torsional and tensile actuation. More than a million torsional and tensile actuation cycles are demonstrated, wherein a muscle spins a rotor at an average 11,500 revolutions/minute or delivers 3% tensile contraction at 1200 cycles/minute. Electrical, chemical, or photonic excitation of hybrid yarns changes guest dimensions and generates torsional rotation and contraction of the yarn host. Demonstrations include torsional motors, contractile muscles, and sensors that capture the energy of the sensing process to mechanically actuate.

Electrically, Chemically, and Photonically Powered Torsional and Tensile Actuation of Hybrid Carbon Nanotube Yarn Muscles

NASA Astrophysics Data System (ADS)

Lima, Márcio D.; Li, Na; Jung de Andrade, Mônica; Fang, Shaoli; Oh, Jiyoung; Spinks, Geoffrey M.; Kozlov, Mikhail E.; Haines, Carter S.; Suh, Dongseok; Foroughi, Javad; Kim, Seon Jeong; Chen, Yongsheng; Ware, Taylor; Shin, Min Kyoon; Machado, Leonardo D.; Fonseca, Alexandre F.; Madden, John D. W.; Voit, Walter E.; Galvão, Douglas S.; Baughman, Ray H.

2012-11-01

Artificial muscles are of practical interest, but few types have been commercially exploited. Typical problems include slow response, low strain and force generation, short cycle life, use of electrolytes, and low energy efficiency. We have designed guest-filled, twist-spun carbon nanotube yarns as electrolyte-free muscles that provide fast, high-force, large-stroke torsional and tensile actuation. More than a million torsional and tensile actuation cycles are demonstrated, wherein a muscle spins a rotor at an average 11,500 revolutions/minute or delivers 3% tensile contraction at 1200 cycles/minute. Electrical, chemical, or photonic excitation of hybrid yarns changes guest dimensions and generates torsional rotation and contraction of the yarn host. Demonstrations include torsional motors, contractile muscles, and sensors that capture the energy of the sensing process to mechanically actuate.

75 FR 11559 - Certain Combed Cotton Yarns: Effect of Modification of U.S.-Bahrain FTA Rules of Origin

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-11

... INTERNATIONAL TRADE COMMISSION [Investigation No. Bahrain-FTA-103-025] Certain Combed Cotton Yarns.... 3805 note), the Commission instituted investigation No. Bahrain FTA-103-025, Certain Combed Cotton... rules of origin to the FTA for certain combed cotton yarns used in the production of certain home...

Thermal annealing effects on multi-walled carbon nanotube yarns probed by Raman spectroscopy.

PubMed

Pierlot, Anthony P; Woodhead, Andrea L; Church, Jeffrey S

2014-01-03

The realized mechanical properties of CNT macrostructures such as webs and yarns remain significantly lower than those of the individual CNTs. Structural changes induced by thermal annealing under inert atmosphere were assessed using Raman spectroscopy. Annealing above 1000 °C resulted in a marked decrease in the D/G ratio which can be attributed to an increase in the crystallite size or the distance between defects. The band component parameters obtained by spectral deconvolution reveal that the D band peak maximum shifts to slightly higher energy with increased annealing temperature. In contrast, the energy of the G band did not change. The full widths at half height (FWHH) of the D and G bands are seen to decrease with increasing annealing temperature. The tensile properties of the yarns have been investigated and it was found that the yarn tenacity did not improve with these structural changes. The effect of impurities in the annealing system such as oxygen, adsorbed water or organic surface contamination was also investigated. Crown Copyright © 2013. Published by Elsevier B.V. All rights reserved.

Fiber and fabric solar cells by directly weaving carbon nanotube yarns with CdSe nanowire-based electrodes

NASA Astrophysics Data System (ADS)

Zhang, Luhui; Shi, Enzheng; Ji, Chunyan; Li, Zhen; Li, Peixu; Shang, Yuanyuan; Li, Yibin; Wei, Jinquan; Wang, Kunlin; Zhu, Hongwei; Wu, Dehai; Cao, Anyuan

2012-07-01

Electrode materials are key components for fiber solar cells, and when combined with active layers (for light absorption and charge generation) in appropriate ways, they enable design and fabrication of efficient and innovative device structures. Here, we apply carbon nanotube yarns as counter electrodes in combination with CdSe nanowire-grafted primary electrodes (Ti wire) for making fiber and fabric-shaped photoelectrochemical cells with power conversion efficiencies in the range 1% to 2.9%. The spun-twist long nanotube yarns possess both good electrical conductivity and mechanical flexibility compared to conventional metal wires or carbon fibers, which facilitate fabrication of solar cells with versatile configurations. A unique feature of our process is that instead of making individual fiber cells, we directly weave single or multiple nanotube yarns with primary electrodes into a functional fabric. Our results demonstrate promising applications of semiconducting nanowires and carbon nanotubes in woven photovoltaics.Electrode materials are key components for fiber solar cells, and when combined with active layers (for light absorption and charge generation) in appropriate ways, they enable design and fabrication of efficient and innovative device structures. Here, we apply carbon nanotube yarns as counter electrodes in combination with CdSe nanowire-grafted primary electrodes (Ti wire) for making fiber and fabric-shaped photoelectrochemical cells with power conversion efficiencies in the range 1% to 2.9%. The spun-twist long nanotube yarns possess both good electrical conductivity and mechanical flexibility compared to conventional metal wires or carbon fibers, which facilitate fabrication of solar cells with versatile configurations. A unique feature of our process is that instead of making individual fiber cells, we directly weave single or multiple nanotube yarns with primary electrodes into a functional fabric. Our results demonstrate promising applications

Development of Flame Resistant Combat Uniform Fabrics Made from Long Staple Wool and Aramid Blend Yarn

DTIC Science & Technology

2013-04-15

Kentwool recombed the wool top ( wool is first combed during the production of wool top); a second combing process is an optional step sometimes used in...RESISTANT COMBAT UNIFORM FABRICS MADE FROM LONG STAPLE WOOL AND ARAMID BLEND YARN by Parvez Mehta* Mitchell Driggers* and Carole...SUBTITLE DEVELOPMENT OF FLAME RESISTANT COMBAT UNIFORM FABRICS MADE FROM LONG STAPLE WOOL AND ARAMID BLEND YARN 5a. CONTRACT NUMBER W911QY-11

The Development of an IMU Integrated Clothes for Postural Monitoring Using Conductive Yarn and Interconnecting Technology.

PubMed

Kang, Sung-Won; Choi, Hyeob; Park, Hyung-Il; Choi, Byoung-Gun; Im, Hyobin; Shin, Dongjun; Jung, Young-Giu; Lee, Jun-Young; Park, Hong-Won; Park, Sukyung; Roh, Jung-Sim

2017-11-07

Spinal disease is a common yet important condition that occurs because of inappropriate posture. Prevention could be achieved by continuous posture monitoring, but most measurement systems cannot be used in daily life due to factors such as burdensome wires and large sensing modules. To improve upon these weaknesses, we developed comfortable "smart wear" for posture measurement using conductive yarn for circuit patterning and a flexible printed circuit board (FPCB) for interconnections. The conductive yarn was made by twisting polyester yarn and metal filaments, and the resistance per unit length was about 0.05 Ω/cm. An embroidered circuit was made using the conductive yarn, which showed increased yield strength and uniform electrical resistance per unit length. Circuit networks of sensors and FPCBs for interconnection were integrated into clothes using a computer numerical control (CNC) embroidery process. The system was calibrated and verified by comparing the values measured by the smart wear with those measured by a motion capture camera system. Six subjects performed fixed movements and free computer work, and, with this system, we were able to measure the anterior/posterior direction tilt angle with an error of less than 4°. The smart wear does not have excessive wires, and its structure will be optimized for better posture estimation in a later study.

Yarning/Aboriginal storytelling: towards an understanding of an Indigenous perspective and its implications for research practice.

PubMed

Geia, Lynore K; Hayes, Barbara; Usher, Kim

2013-12-01

There is increasing recognition of Indigenous perspectives from various parts of the world in relation to storytelling, research and its effects on practice. The recent emergence of storytelling or yarning as a research method in Australian Aboriginal and Torres Strait Island studies and other Indigenous peoples of the world is gaining momentum. Narratives, stories, storytelling and yarning are emerging methods in research and has wide ranging potential to shape conventional research discourse making research more meaningful and accessible for researchers. In this paper we argue for the importance of Indigenous research methods and Indigenous method(ology), within collaborative respectful partnerships with non-Indigenous researchers. It is imperative to take these challenging steps together towards better outcomes for Indigenous people and their communities. In the Australian context we as researchers cannot afford to allow the gap between Aboriginal and Torres Strait Islanders and mainstream Australia health outcomes to grow even wider. One such pathway is the inclusion of Aboriginal storytelling or yarning from an Aboriginal and Torres Strait perspective within Indigenous and non-Indigenous research paradigms. Utilising Aboriginal storytelling or yarning will provide deeper understanding; complementing a two-way research paradigm for collaborative research. Furthermore, it has significant social implications for research and clinical practice amongst Indigenous populations; thus complementing the biomedical medical paradigm.

Weavable, Conductive Yarn-Based NiCo//Zn Textile Battery with High Energy Density and Rate Capability.

PubMed

Huang, Yan; Ip, Wing Shan; Lau, Yuen Ying; Sun, Jinfeng; Zeng, Jie; Yeung, Nga Sze Sea; Ng, Wing Sum; Li, Hongfei; Pei, Zengxia; Xue, Qi; Wang, Yukun; Yu, Jie; Hu, Hong; Zhi, Chunyi

2017-09-26

With intrinsic safety and much higher energy densities than supercapacitors, rechargeable nickel/cobalt-zinc-based textile batteries are promising power sources for next generation personalized wearable electronics. However, high-performance wearable nickel/cobalt-zinc-based batteries are rarely reported because there is a lack of industrially weavable and knittable highly conductive yarns. Here, we use scalably produced highly conductive yarns uniformly covered with zinc (as anode) and nickel cobalt hydroxide nanosheets (as cathode) to fabricate rechargeable yarn batteries. They possess a battery level capacity and energy density, as well as a supercapacitor level power density. They deliver high specific capacity of 5 mAh cm -3 and energy densities of 0.12 mWh cm -2 and 8 mWh cm -3 (based on the whole solid battery). They exhibit ultrahigh rate capabilities of 232 C (liquid electrolyte) and 116 C (solid electrolyte), which endows the batteries excellent power densities of 32.8 mW cm -2 and 2.2 W cm -3 (based on the whole solid battery). These are among the highest values reported so far. A wrist band battery is further constructed by using a large conductive cloth woven from the conductive yarns by a commercial weaving machine. It powers various electronic devices successfully, enabling dual functions of wearability and energy storage.

Structural CNT Composites Part II: Assessment of CNT Yarns as Reinforcement for Composite Overwrapped Pressure Vessels

NASA Technical Reports Server (NTRS)

Kim, Jae-Woo; Sauti, Godfrey; Cano, Roberto J.; Wincheski, Russell A.; Ratcliffe, James G.; Czabaj, Michael; Siochi, Emilie J.

2015-01-01

Carbon nanotubes (CNTs) are one-dimensional nanomaterials with outstanding electrical and thermal conductivities and mechanical properties. This combination of properties offers routes to enable lightweight structural aerospace components. Recent advances in the manufacturing of CNTs have made bulk forms such as yarns, tapes and sheets available in commercial quantities to permit the evaluation of these materials for aerospace use, where the superior tensile properties of CNT composites can be exploited in tension dominated applications such as composite overwrapped pressure vessels (COPVs). To investigate their utility in this application, aluminum rings were overwrapped with thermoset/CNT yarn composite and their mechanical properties measured. CNT composite overwrap characteristics such as processing method, CNT/resin ratio, and applied tension during CNT yarn winding were varied to determine their effects on the mechanical performance of the CNT composite overwrapped Al rings (CCOARs). Mechanical properties of the CCOARs were measured under static and cyclic loads at room, elevated, and cryogenic temperatures to evaluate their mechanical performance relative to bare Al rings. At room temperature, the breaking load of CCOARs with a 10.8% additional weight due to the CNT yarn/thermoset overwrap increased by over 200% compared to the bare Al ring. The quality of the wound CNT composites was also investigated using x-ray computed tomography.

Bio-inspired, Moisture-Powered Hybrid Carbon Nanotube Yarn Muscles

PubMed Central

Kim, Shi Hyeong; Kwon, Cheong Hoon; Park, Karam; Mun, Tae Jin; Lepró, Xavier; Baughman, Ray H.; Spinks, Geoffrey M.; Kim, Seon Jeong

2016-01-01

Hygromorph artificial muscles are attractive as self-powered actuators driven by moisture from the ambient environment. Previously reported hygromorph muscles have been largely limited to bending or torsional motions or as tensile actuators with low work and energy densities. Herein, we developed a hybrid yarn artificial muscle with a unique coiled and wrinkled structure, which can be actuated by either changing relative humidity or contact with water. The muscle provides a large tensile stroke (up to 78%) and a high maximum gravimetric work capacity during contraction (2.17 kJ kg−1), which is over 50 times that of the same weight human muscle and 5.5 times higher than for the same weight spider silk, which is the previous record holder for a moisture driven muscle. We demonstrate an automatic ventilation system that is operated by the tensile actuation of the hybrid muscles caused by dew condensing on the hybrid yarn. This self-powered humidity-controlled ventilation system could be adapted to automatically control the desired relative humidity of an enclosed space. PMID:26973137

An investigation of density measurement method for yarn-dyed woven fabrics based on dual-side fusion technique

NASA Astrophysics Data System (ADS)

Zhang, Rui; Xin, Binjie

2016-08-01

Yarn density is always considered as the fundamental structural parameter used for the quality evaluation of woven fabrics. The conventional yarn density measurement method is based on one-side analysis. In this paper, a novel density measurement method is developed for yarn-dyed woven fabrics based on a dual-side fusion technique. Firstly, a lab-used dual-side imaging system is established to acquire both face-side and back-side images of woven fabric and the affine transform is used for the alignment and fusion of the dual-side images. Then, the color images of the woven fabrics are transferred from the RGB to the CIE-Lab color space, and the intensity information of the image extracted from the L component is used for texture fusion and analysis. Subsequently, three image fusion methods are developed and utilized to merge the dual-side images: the weighted average method, wavelet transform method and Laplacian pyramid blending method. The fusion efficacy of each method is evaluated by three evaluation indicators and the best of them is selected to do the reconstruction of the complete fabric texture. Finally, the yarn density of the fused image is measured based on the fast Fourier transform, and the yarn alignment image could be reconstructed using the inverse fast Fourier transform. Our experimental results show that the accuracy of density measurement by using the proposed method is close to 99.44% compared with the traditional method and the robustness of this new proposed method is better than that of conventional analysis methods.

Foil Strain Gauges Using Piezoresistive Carbon Nanotube Yarn: Fabrication and Calibration

PubMed Central

Góngora-Rubio, Mário R.; Kiyono, César Y.; Mello, Luis A. M.; Cardoso, Valtemar F.; Rosa, Reinaldo L. S.; Kuebler, Derek A.; Brodeur, Grace E.; Alotaibi, Amani H.; Coene, Marisa P.; Coene, Lauren M.; Jean, Elizabeth; Santiago, Rafael C.; Oliveira, Francisco H. A.; Rangel, Ricardo; Thomas, Gilles P.; Belay, Kalayu; da Silva, Luciana W.; Moura, Rafael T.; Seabra, Antonio C.; Silva, Emílio C. N.

2018-01-01

Carbon nanotube yarns are micron-scale fibers comprised by tens of thousands of carbon nanotubes in their cross section and exhibiting piezoresistive characteristics that can be tapped to sense strain. This paper presents the details of novel foil strain gauge sensor configurations comprising carbon nanotube yarn as the piezoresistive sensing element. The foil strain gauge sensors are designed using the results of parametric studies that maximize the sensitivity of the sensors to mechanical loading. The fabrication details of the strain gauge sensors that exhibit the highest sensitivity, based on the modeling results, are described including the materials and procedures used in the first prototypes. Details of the calibration of the foil strain gauge sensors are also provided and discussed in the context of their electromechanical characterization when bonded to metallic specimens. This characterization included studying their response under monotonic and cyclic mechanical loading. It was shown that these foil strain gauge sensors comprising carbon nanotube yarn are sensitive enough to capture strain and can replicate the loading and unloading cycles. It was also observed that the loading rate affects their piezoresistive response and that the gauge factors were all above one order of magnitude higher than those of typical metallic foil strain gauges. Based on these calibration results on the initial sensor configurations, new foil strain gauge configurations will be designed and fabricated, to increase the strain gauge factors even more. PMID:29401745

Sucrose Treated Carbon Nanotube and Graphene Yarns and Sheets

NASA Technical Reports Server (NTRS)

Sauti, Godfrey (Inventor); Kim, Jae-Woo (Inventor); Siochi, Emilie J. (Inventor); Wise, Kristopher E. (Inventor)

2017-01-01

Consolidated carbon nanotube or graphene yarns and woven sheets are consolidated through the formation of a carbon binder formed from the dehydration of sucrose. The resulting materials, on a macro-scale are lightweight and of a high specific modulus and/or strength. Sucrose is relatively inexpensive and readily available, and the process is therefore cost-effective.

The Development of an IMU Integrated Clothes for Postural Monitoring Using Conductive Yarn and Interconnecting Technology

PubMed Central

Kang, Sung-Won; Park, Hyung-Il; Choi, Byoung-Gun; Shin, Dongjun; Jung, Young-Giu; Lee, Jun-Young; Park, Hong-Won; Park, Sukyung

2017-01-01

Spinal disease is a common yet important condition that occurs because of inappropriate posture. Prevention could be achieved by continuous posture monitoring, but most measurement systems cannot be used in daily life due to factors such as burdensome wires and large sensing modules. To improve upon these weaknesses, we developed comfortable “smart wear” for posture measurement using conductive yarn for circuit patterning and a flexible printed circuit board (FPCB) for interconnections. The conductive yarn was made by twisting polyester yarn and metal filaments, and the resistance per unit length was about 0.05 Ω/cm. An embroidered circuit was made using the conductive yarn, which showed increased yield strength and uniform electrical resistance per unit length. Circuit networks of sensors and FPCBs for interconnection were integrated into clothes using a computer numerical control (CNC) embroidery process. The system was calibrated and verified by comparing the values measured by the smart wear with those measured by a motion capture camera system. Six subjects performed fixed movements and free computer work, and, with this system, we were able to measure the anterior/posterior direction tilt angle with an error of less than 4°. The smart wear does not have excessive wires, and its structure will be optimized for better posture estimation in a later study. PMID:29112125

Hollow Polypropylene Yarns as a Biomimetic Brain Phantom for the Validation of High-Definition Fiber Tractography Imaging.

PubMed

Guise, Catarina; Fernandes, Margarida M; Nóbrega, João M; Pathak, Sudhir; Schneider, Walter; Fangueiro, Raul

2016-11-09

Current brain imaging methods largely fail to provide detailed information about the location and severity of axonal injuries and do not anticipate recovery of the patients with traumatic brain injury. High-definition fiber tractography appears as a novel imaging modality based on water motion in the brain that allows for direct visualization and quantification of the degree of axons damage, thus predicting the functional deficits due to traumatic axonal injury and loss of cortical projections. This neuroimaging modality still faces major challenges because it lacks a "gold standard" for the technique validation and respective quality control. The present work aims to study the potential of hollow polypropylene yarns to mimic human white matter axons and construct a brain phantom for the calibration and validation of brain diffusion techniques based on magnetic resonance imaging, including high-definition fiber tractography imaging. Hollow multifilament polypropylene yarns were produced by melt-spinning process and characterized in terms of their physicochemical properties. Scanning electronic microscopy images of the filaments cross section has shown an inner diameter of approximately 12 μm, confirming their appropriateness to mimic the brain axons. The chemical purity of polypropylene yarns as well as the interaction between the water and the filament surface, important properties for predicting water behavior and diffusion inside the yarns, were also evaluated. Restricted and hindered water diffusion was confirmed by fluorescence microscopy. Finally, the yarns were magnetic resonance imaging scanned and analyzed using high-definition fiber tractography, revealing an excellent choice of these hollow polypropylene structures for simulation of the white matter brain axons and their suitability for constructing an accurate brain phantom.

Comparison of polyester, film-yarn composite, balloon materials subjected to shear and biaxial loading

NASA Technical Reports Server (NTRS)

Niccum, R. J.

1972-01-01

A series of candidate materials for use in large balloons was tested and their tensile and shear strength capabilities were compared. The tests were done in a cold box at -68 C (-90 F). Some of these materials were fabricated on a special machine called the flying thread loom. This machine laminates various patterns of polyester yarn to a thin polyester film. The results show that the shear strength of materials changes with the angle selected for the transverse yarns, and substantial increases in biaxial load carrying capabilities, compared to materials formerly used, are possible. The loom capabilities and the test methods are discussed.

Wearable Self-Charging Power Textile Based on Flexible Yarn Supercapacitors and Fabric Nanogenerators.

PubMed

Pu, Xiong; Li, Linxuan; Liu, Mengmeng; Jiang, Chunyan; Du, Chunhua; Zhao, Zhenfu; Hu, Weiguo; Wang, Zhong Lin

2016-01-06

A novel and scalable self-charging power textile is realized by combining yarn supercapacitors and fabric triboelectric nanogenerators as energy-harvesting devices. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The study about the improvement of the quality for the fabrics made of chenille yarn

NASA Astrophysics Data System (ADS)

Hristian, L.; Ostafe, M. M.; Manea, L. R.; Leon, A. L.

2016-08-01

The work is a study about the decrease of the serious defects from the fabrics such as: the deviations from quality or the high costs, discovered and seized by customers. The analyzed fabrics have in their structures three types of different chenille yarns, such as: the Article A1 (viscose fiber with cotton, Nm 3500 dyed coil), the Article A2 (textured polyester, Nm 8000 dyed coil), the Article A3 (Trevira CS polyester, Nm 3000 the pre-dyed raw materials). The technology of chenille yarn, regardless of composition and properties is the same and is performed on the twisting machines. This study has found that the most of the flaws in the fabric, noticed by customers, are caused by the production technology of the chenille yarns. In any organization which makes goods, there are concerns about the improvement of the quality through the elimination of the nonquality. It is extremely difficult to get to “zero defects” but the first step is a systematic action plan to reduce drastically the nonconformities and the defects. The continuous improvement of the effectiveness of the integrated quality and environmental management is achieved by applying the PDCA methodology: planning, development, control, action.

Vision-based in-line fabric defect detection using yarn-specific shape features

NASA Astrophysics Data System (ADS)

Schneider, Dorian; Aach, Til

2012-01-01

We develop a methodology for automatic in-line flaw detection in industrial woven fabrics. Where state of the art detection algorithms apply texture analysis methods to operate on low-resolved ({200 ppi) image data, we describe here a process flow to segment single yarns in high-resolved ({1000 ppi) textile images. Four yarn shape features are extracted, allowing a precise detection and measurement of defects. The degree of precision reached allows a classification of detected defects according to their nature, providing an innovation in the field of automatic fabric flaw detection. The design has been carried out to meet real time requirements and face adverse conditions caused by loom vibrations and dirt. The entire process flow is discussed followed by an evaluation using a database with real-life industrial fabric images. This work pertains to the construction of an on-loom defect detection system to be used in manufacturing practice.

Comparative relationship of fiber strength and yarn tenacity in four cotton cultivars

USDA-ARS?s Scientific Manuscript database

High volume instrumentation (HVITM) measurement is a primary and routine tool of providing fiber properties to cotton researchers. There have been considerable studies designed to derive yarn quality from acquired fiber quality data by various means, including HVI. There is also of desired informati...

Yarn-dyed fabric defect classification based on convolutional neural network

NASA Astrophysics Data System (ADS)

Jing, Junfeng; Dong, Amei; Li, Pengfei

2017-07-01

Considering that the manual inspection of the yarn-dyed fabric can be time consuming and less efficient, a convolutional neural network (CNN) solution based on the modified AlexNet structure for the classification of the yarn-dyed fabric defect is proposed. CNN has powerful ability of feature extraction and feature fusion which can simulate the learning mechanism of the human brain. In order to enhance computational efficiency and detection accuracy, the local response normalization (LRN) layers in AlexNet are replaced by the batch normalization (BN) layers. In the process of the network training, through several convolution operations, the characteristics of the image are extracted step by step, and the essential features of the image can be obtained from the edge features. And the max pooling layers, the dropout layers, the fully connected layers are also employed in the classification model to reduce the computation cost and acquire more precise features of fabric defect. Finally, the results of the defect classification are predicted by the softmax function. The experimental results show the capability of defect classification via the modified Alexnet model and indicate its robustness.

Relationship of Fiber Properties to Vortex Yarn Quality via Partial Least Squares

USDA-ARS?s Scientific Manuscript database

The Cotton Quality Research Station (CQRS) of the USDA-ARS, recently completed a comprehensive study of the relationship of cotton fiber properties to the quality of spun yarn. The five year study, began in 2001, utilized commercial variety cotton grown, harvested and ginned in each of three major ...

Effect of Electron Beam Irradiation on the Tensile Properties of Carbon Nanotubes Sheets and Yarns

NASA Technical Reports Server (NTRS)

Williams, Tiffany S.; Miller, Sandi G.; Baker, James S.; McCorkle, Linda S.; Meador, Michael A.

2013-01-01

Carbon nanotube sheets and yarns were irradiated using electron beam (e-beam) energy to determine the effect of irradiation dose on the tensile properties. Results showed that a slight change in tensile strength occurred after irradiating as-received CNT sheets for 20 minutes, and a slight decrease in tensile strength as the irradiation time approached 90 minutes. On the other hand, the addition of small molecules to the CNT sheet surface had a greater effect on the tensile properties of e-beam irradiated CNT sheets. Some functionalized CNT sheets displayed up to a 57% increase in tensile strength following 90 minutes of e-beam exposure. In addition, as-received CNT yarns showed a significant increase in tensile strength as the irradiation time increased.

Production of Banana Fiber Yarns for Technical Textile Reinforced Composites

PubMed Central

Ortega, Zaida; Morón, Moisés; Monzón, Mario D.; Badalló, Pere; Paz, Rubén

2016-01-01

Natural fibers have been used as an alternative to synthetic ones for their greener character; banana fibers have the advantage of coming from an agricultural residue. Fibers have been extracted by mechanical means from banana tree pseudostems, as a strategy to valorize banana crops residues. To increase the mechanical properties of the composite, technical textiles can be used as reinforcement, instead of short fibers. To do so, fibers must be spun and woven. The aim of this paper is to show the viability of using banana fibers to obtain a yarn suitable to be woven, after an enzymatic treatment, which is more environmentally friendly. Extracted long fibers are cut to 50 mm length and then immersed into an enzymatic bath for their refining. Conditions of enzymatic treatment have been optimized to produce a textile grade of banana fibers, which have then been characterized. The optimum treating conditions were found with the use of Biopectinase K (100% related to fiber weight) at 45 °C, pH 4.5 for 6 h, with bath renewal after three hours. The first spinning trials show that these fibers are suitable to be used for the production of yarns. The next step is the weaving process to obtain a technical fabric for composites production. PMID:28773490

Effect of ecological surface treatment method on friction strength properties of nettle (urtica dioica) fibre yarns

NASA Astrophysics Data System (ADS)

Şansal, S.; Mıstık, S. I.; Fettahov, R.; Ovalı, S.; Duman, M.

2017-10-01

Over the last few decades, more attention is given to lignocellulose based fibres as reinforcement material in the polymer composites owing to the environmental pollution caused by the extensive usage of synthetic and inorganic fibres. Developing new natural fibre reinforced composites is the focus of many researches nowadays. They are made from renewable resources and they have less environmental effect in comparison to inorganic fibre reinforced composites. The interest of consumers in eco-friendly natural fibres and textiles has increased in recent years. Unlike inorganic fibres, natural fibres present light weight, high strength/density ratio and are readily available, environmentally friendly and biodegradable. Many different types of natural fibres are exploited for the production of biodegradable polymer composites. The nettle (Urtica dioica L.) is a well-known plant growing on rural sites of Europe, Asia, and North America. Nettle plant contains fibre similar to hemp and flax. However, similar to other natural fibres, nettle fibres are poorly compatible with the thermoplastic matrix of composites, due to their hydrophilic character which reduces mechanical properties of nettle fibre reinforced thermoplastics. In order to improve the fibrematrix adhesion of the natural fibre reinforced composites, surface treatment processes are applied to the lignocellulose fibres. In this study nettle (urtica dioica) fibre yarns were treated with NaOH by using conventional, ultrasonic and microwave energy methods. After treatment processes tensile strength, elongation, friction strength and SEM observations of the nettle fibre yarns were investigated. All treatment processes were improved the tensile strength, elongation and friction strength properties of the nettle fibre yarns. Also higher tensile strength, elongation and friction strength properties were obtained from treated nettle fibre yarns which treated by using microwave energy method.

Hybrid nanomembranes for high power and high energy density supercapacitors and their yarn application.

PubMed

Lee, Jae Ah; Shin, Min Kyoon; Kim, Shi Hyeong; Kim, Seon Jeong; Spinks, Geoffrey M; Wallace, Gordon G; Ovalle-Robles, Raquel; Lima, Márcio D; Kozlov, Mikhail E; Baughman, Ray H

2012-01-24

We report mechanically robust, electrically conductive, free-standing, and transparent hybrid nanomembranes made of densified carbon nanotube sheets that were coated with poly(3,4-ethylenedioxythiophene) using vapor phase polymerization and their performance as supercapacitors. The hybrid nanomembranes with thickness of ~66 nm and low areal density of ~15 μg/cm(2)exhibited high mechanical strength and modulus of 135 MPa and 12.6 GPa, respectively. They also had remarkable shape recovery ability in liquid and at the liquid/air interface unlike previous carbon nanotube sheets. The hybrid nanomembrane attached on a current collector had volumetric capacitance of ~40 F/cm(3) at 100 V s(-1) (~40 and ~80 times larger than that of onion-like carbon measured at 100 V s(-1) and activated carbon measured at 20 V s(-1), respectively), and it showed rectangular shapes of cyclic voltammograms up to ~5 V s(-1). High mechanical strength and flexibility of the hybrid nanomembrane enabled twisting it into microsupercapacitor yarns with diameters of ~30 μm. The yarn supercapacitor showed stable cycling performance without a metal current collector, and its capacitance decrease was only ~6% after 5000 cycles. Volumetric energy and power density of the hybrid nanomembrane was ~70 mWh cm(-3) and ~7910 W cm(-3), and the yarn possessed the energy and power density of ~47 mWh cm(-3) and ~538 W cm(-3). © 2011 American Chemical Society

MXene: a potential candidate for yarn supercapacitors.

PubMed

Zhang, Jizhen; Seyedin, Shayan; Gu, Zhoujie; Yang, Wenrong; Wang, Xungai; Razal, Joselito M

2017-12-07

The increasing developments in wearable electronics demand compatible power sources such as yarn supercapacitors (YSCs) that can effectively perform in a limited footprint. MXene nanosheets, which have been recently shown in the literature to possess ultra-high volumetric capacitance, were used in this study for the fabrication of YSCs in order to identify their potential merit and performance in YSCs. With the aid of a conductive binder (PEDOT-PSS), YSCs with high mass loading of MXene are demonstrated. These MXene-based YSCs exhibit excellent device performance and stability even under bending and twisting. This study demonstrates that MXene is a promising candidate for YSCs and its further development can lead to flexible power sources with sufficient performance for powering miniaturized and/or wearable electronics.

Relationships of cotton fiber properties to ring-spun yarn quality on selected High Plains cottons

USDA-ARS?s Scientific Manuscript database

The objective of this research was to evaluate the adequacy of High Volume Instruement (HVI) and Advanced Fiber Information System (AFIS) fiber quality parameters for predicting quality parameters of ring-spun yarns considering differences in harvest method. Fiber properties measured using the HVI (...

Effect on the partial least-squares prediction of yarn properties combining raman and infrared measurements and applying wavelength selection.

PubMed

de Groot, P J; Swierenga, H; Postma, G J; Melssen, W J; Buydens, L M C

2003-06-01

The combination of Raman and infrared spectroscopy on the one hand and wavelength selection on the other hand is used to improve the partial least-squares (PLS) prediction of seven selected yarn properties. These properties are important for on-line quality control during production. From 71 yarn samples, the Raman and infrared spectra are measured and reference methods are used to determine the selected properties. Making separate PLS models for all yarn properties using the Raman and infrared spectra, prior to wavelength selection, reveals that Raman spectroscopy outperforms infrared spectroscopy. If wavelength selection is applied, the PLS prediction error decreases and the correlation coefficient increases for all properties. However, a substantial wavelength selection effect is present for the infrared spectra compared to the Raman spectra. For the infrared spectra, wavelength selection results in PLS prediction errors comparable with the prediction performance of the Raman spectra prior to wavelength selection. Concatenating the Raman and infrared spectra does not enhance the PLS prediction performance, not even after wavelength selection. It is concluded that an infrared spectrometer, combined with a wavelength selection procedure, can be used if no (suitable) Raman instrument is available.

The Effect of Plain-Weaving on the Mechanical Properties of Warp and Weft P-Phenylene Terephthalamide (PPTA) Fibers/Yarns

DTIC Science & Technology

2014-08-15

made of hybrid polypropylene /glass yarns, at different testing strain rates. The results obtained relatively little damage (and, hence, strength...l 1.1 1.2 1.3 1.4 1.5 1.6 1.7 -20 0 20 40 60 80 (a) Two-Bond-Angle, rad B o n d -A n g le E n er g y, k J/ m o l 2.8 3 3.2 3.4 0 100 200 300 400 500...Experimental characterization of the tensile behavior of a polypropylene /glass 3D-fabric: from the yarn to the fabric. In: 4th world conference on 3D fabrics

Yarning about fall prevention: community consultation to discuss falls and appropriate approaches to fall prevention with older Aboriginal and Torres Strait Islander people.

PubMed

Lukaszyk, Caroline; Coombes, Julieann; Turner, Norma Jean; Hillmann, Elizabeth; Keay, Lisa; Tiedemann, Anne; Sherrington, Cathie; Ivers, Rebecca

2017-08-01

Fall related injury is an emerging issue for older Indigenous people worldwide, yet few targeted fall prevention programs are currently available for Indigenous populations. In order to inform the development of a new Aboriginal-specific fall prevention program in Australia, we conducted community consultation with older Aboriginal people to identify perceptions and beliefs about falls, and to identify desired program elements. Yarning Circles were held with Aboriginal and Torres Strait Islander people aged 45 years and over. Each Yarning Circle was facilitated by an Aboriginal researcher who incorporated six indicative questions into each discussion. Questions explored the impact of falls on Yarning Circle participants, their current use of fall prevention services and investigated Yarning Circle participant's preferences regarding the design and mode of delivery of a fall prevention program. A total of 76 older Aboriginal people participated in ten Yarning Circles across six sites in the state of New South Wales. Participants associated falls with physical disability, a loss of emotional well-being and loss of connection to family and community. Many participants did not use existing fall prevention services due to a lack of availability in their area, having no referral provided by their GP and/or being unaware of fall prevention programs in general. Program elements identified as important by participants were that it be Aboriginal-specific, group-based, and on-going, with the flexibility to be tailored to specific communities, with free transport provided to and from the program. Older Aboriginal people reported falls to be a priority health issue, with a significant impact on their health and well-being. Few older Aboriginal people accessed prevention programs, suggesting there is an important need for targeted Aboriginal-specific programs. A number of important program elements were identified which if incorporated into prevention programs, may help to

Development of sugar palm yarn/glass fibre reinforced unsaturated polyester hybrid composites

NASA Astrophysics Data System (ADS)

Nurazzi, N. Mohd; Khalina, A.; Sapuan, S. Mohd; Rahmah, M.

2018-04-01

This study investigates the effect of fibre hybridization for sugar palm yarn fibre with glass fibre reinforced with unsaturated polyester composites. In this work, unsaturated polyester resin are reinforced with fibre at a ratio of 70:30 wt% and 60:40 wt%. The hybrid composites were characterized in terms of physical (density and water absorption), mechanical (tensile, flexural and compression) and thermal properties through thermal gravimetry analysis (TGA). Density determination showed that density increased with higher wt% of glass fibre. The inherently higher density of glass fibre increased the density of hybrid composite. Resistance to water absorption is improved upon the incorporation of glass fibre and the hybrid composites were found to reach equilibrium absorption at days 4 and 5. As for mechanical performance, the highest tensile strength, tensile modulus, flexural strength, flexural modulus and compression strength were obtained from 40 wt% of fibres reinforcement with ratio of 50:50 wt% of sugar palm yarn fibre and glass fibre reinforced unsaturated polyester composites. The increase of glass fibre loading had a synergistic effect on the mechanical properties to the composites structure due to its superior strength and modulus. The thermal stability of hybrid composites was improved by the increase of onset temperature and the reduction of residues upon increase in temperature.

Fabrication and preliminary study of a biomimetic tri-layer tubular graft based on fibers and fiber yarns for vascular tissue engineering.

PubMed

Wu, Tong; Zhang, Jialing; Wang, Yuanfei; Li, Dandan; Sun, Binbin; El-Hamshary, Hany; Yin, Meng; Mo, Xiumei

2018-01-01

Designing a biomimetic and functional tissue-engineered vascular graft has been urgently needed for repairing and regenerating defected vascular tissues. Utilizing a multi-layered vascular scaffold is commonly considered an effective way, because multi-layered scaffolds can easily simulate the structure and function of natural blood vessels. Herein, we developed a novel tri-layer tubular graft consisted of Poly(L-lactide-co-caprolactone)/collagen (PLCL/COL) fibers and Poly(lactide-co-glycolide)/silk fibroin (PLGA/SF) yarns via a three-step electrospinning method. The tri-layer vascular graft consisted of PLCL/COL aligned fibers in inner layer, PLGA/SF yarns in middle layer, and PLCL/COL random fibers in outer layer. Each layer possessed tensile mechanical strength and elongation, and the entire tubular structure provided tensile and compressive supports. Furthermore, the human umbilical vein endothelial cells (HUVECs) and smooth muscle cells (SMCs) proliferated well on the materials. Fluorescence staining images demonstrated that the axially aligned PLCL/COL fibers prearranged endothelium morphology in lumen and the circumferential oriented PLGA/SF yarns regulated SMCs organization along the single yarns. The outside PLCL/COL random fibers performed as the fixed layer to hold the entire tubular structure. The in vivo results showed that the tri-layer vascular graft supported cell infiltration, scaffold biodegradation and abundant collagen production after subcutaneous implantation for 10weeks, revealing the optimal biocompatibility and tissue regenerative capability of the tri-layer graft. Therefore, the specially designed tri-layer vascular graft will be beneficial to vascular reconstruction. Copyright © 2017. Published by Elsevier B.V.

Molding Helmet Liners from Nylon Cloth Made from 1050 Denier Type 700 Nylon Yarns

DTIC Science & Technology

Helmet liners were satisfactorily molded from 14 ounce, 2 x 2 basket- weave nylon fabric made of 1050 denier, 168 filaments, 3 to 4 Z turns per inch...type 700 nylon yarn. These helmets liners satisfied the autoclave and the ballistics resistant requirements of Military Specification MIL-L-41800, Liner , Soldier’s Steel Helmet, 1 May 1961.

Nano-yarn carbon nanotube fiber based enzymatic glucose biosensor

NASA Astrophysics Data System (ADS)

Zhu, Zhigang; Song, Wenhui; Burugapalli, Krishna; Moussy, Francis; Li, Ya-Li; Zhong, Xiao-Hua

2010-04-01

A novel brush-like electrode based on carbon nanotube (CNT) nano-yarn fiber has been designed for electrochemical biosensor applications and its efficacy as an enzymatic glucose biosensor demonstrated. The CNT nano-yarn fiber was spun directly from a chemical-vapor-deposition (CVD) gas flow reaction using a mixture of ethanol and acetone as the carbon source and an iron nano-catalyst. The fiber, 28 µm in diameter, was made of bundles of double walled CNTs (DWNTs) concentrically compacted into multiple layers forming a nano-porous network structure. Cyclic voltammetry study revealed a superior electrocatalytic activity for CNT fiber compared to the traditional Pt-Ir coil electrode. The electrode end tip of the CNT fiber was freeze-fractured to obtain a unique brush-like nano-structure resembling a scale-down electrical 'flex', where glucose oxidase (GOx) enzyme was immobilized using glutaraldehyde crosslinking in the presence of bovine serum albumin (BSA). An outer epoxy-polyurethane (EPU) layer was used as semi-permeable membrane. The sensor function was tested against a standard reference electrode. The sensitivities, linear detection range and linearity for detecting glucose for the miniature CNT fiber electrode were better than that reported for a Pt-Ir coil electrode. Thermal annealing of the CNT fiber at 250 °C for 30 min prior to fabrication of the sensor resulted in a 7.5 fold increase in glucose sensitivity. The as-spun CNT fiber based glucose biosensor was shown to be stable for up to 70 days. In addition, gold coating of the electrode connecting end of the CNT fiber resulted in extending the glucose detection limit to 25 µM. To conclude, superior efficiency of CNT fiber for glucose biosensing was demonstrated compared to a traditional Pt-Ir sensor.

Carbon nanotube yarns for deep brain stimulation electrode.

PubMed

Jiang, Changqing; Li, Luming; Hao, Hongwei

2011-12-01

A new form of deep brain stimulation (DBS) electrode was proposed that was made of carbon nanotube yarns (CNTYs). Electrode interface properties were examined using cyclic voltammetry (CV) and electrochemical impedance spectrum (EIS). The CNTY electrode interface exhibited large charge storage capacity (CSC) of 12.3 mC/cm(2) which increased to 98.6 mC/cm(2) after acid treatment, compared with 5.0 mC/cm(2) of Pt-Ir. Impedance spectrum of both untreated and treated CNTY electrodes showed that finite diffusion process occurred at the interface due to their porous structure and charge was delivered through capacitive mechanism. To evaluate stability electrical stimulus was exerted for up to 72 h and CV and EIS results of CNTY electrodes revealed little alteration. Therefore CNTY could make a good electrode material for DBS.

High-performance multifunctional graphene yarns: toward wearable all-carbon energy storage textiles.

PubMed

Aboutalebi, Seyed Hamed; Jalili, Rouhollah; Esrafilzadeh, Dorna; Salari, Maryam; Gholamvand, Zahra; Aminorroaya Yamini, Sima; Konstantinov, Konstantin; Shepherd, Roderick L; Chen, Jun; Moulton, Simon E; Innis, Peter Charles; Minett, Andrew I; Razal, Joselito M; Wallace, Gordon G

2014-03-25

The successful commercialization of smart wearable garments is hindered by the lack of fully integrated carbon-based energy storage devices into smart wearables. Since electrodes are the active components that determine the performance of energy storage systems, it is important to rationally design and engineer hierarchical architectures atboth the nano- and macroscale that can enjoy all of the necessary requirements for a perfect electrode. Here we demonstrate a large-scale flexible fabrication of highly porous high-performance multifunctional graphene oxide (GO) and rGO fibers and yarns by taking advantage of the intrinsic soft self-assembly behavior of ultralarge graphene oxide liquid crystalline dispersions. The produced yarns, which are the only practical form of these architectures for real-life device applications, were found to be mechanically robust (Young's modulus in excess of 29 GPa) and exhibited high native electrical conductivity (2508 ± 632 S m(-1)) and exceptionally high specific surface area (2605 m(2) g(-1) before reduction and 2210 m(2) g(-1) after reduction). Furthermore, the highly porous nature of these architectures enabled us to translate the superior electrochemical properties of individual graphene sheets into practical everyday use devices with complex geometrical architectures. The as-prepared final architectures exhibited an open network structure with a continuous ion transport network, resulting in unrivaled charge storage capacity (409 F g(-1) at 1 A g(-1)) and rate capability (56 F g(-1) at 100 A g(-1)) while maintaining their strong flexible nature.

19 CFR 10.543 - Certain apparel goods made from fabric or yarn not available in commercial quantities.

Code of Federal Regulations, 2010 CFR

2010-04-01

... RATE, ETC. United States-Singapore Free Trade Agreement Rules of Origin § 10.543 Certain apparel goods... both of the Parties from fabric or yarn, regardless of origin, designated by the Committee for the... FR 17412), May 28, 2002 (67 FR 36858), and September 5, 2002 (67 FR 56806). Origin Verifications and...

Design of Novel Wearable, Stretchable, and Waterproof Cable-Type Supercapacitors Based on High-Performance Nickel Cobalt Sulfide-Coated Etching-Annealed Yarn Electrodes.

PubMed

Chen, Yuejiao; Xu, Bingang; Wen, Jianfeng; Gong, Jianliang; Hua, Tao; Kan, Chi-Wai; Deng, Jiwei

2018-04-19

Rapid advances in functional electronics bring tremendous demands on innovation toward effective designs of device structures. Yarn supercapacitors (SCs) show advantages of flexibility, knittability, and small size, and can be integrated into various electronic devices with low cost and high efficiency for energy storage. In this work, functionalized stainless steel yarns are developed to support active materials of positive and negative electrodes, which not only enhance capacitance of both electrodes but can also be designed into stretchable configurations. The as-made asymmetric yarn SCs show a high energy density of 0.0487 mWh cm -2 (10.19 mWh cm -3 ) at a power density of 0.553 mW cm -2 (129.1 mW cm -3 ) and a specific capacitance of 127.2 mF cm -2 under an operating voltage window of 1.7 V. The fabricated SC is then made into a stretchable configuration by a prestraining-then-releasing approach using polydimethylsiloxane (PDMS) tube, and its electrochemical performance can be well maintained when stretching up to a high strain of 100%. Moreover, the stretchable cable-type SCs are stably workable under water-immersed condition. The method opens up new ways for fabricating flexible, stretchable, and waterproof devices. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Why Clothes Don't Fall Apart: Tension Transmission in Staple Yarns

NASA Astrophysics Data System (ADS)

Warren, Patrick B.; Ball, Robin C.; Goldstein, Raymond E.

2018-04-01

The problem of how staple yarns transmit tension is addressed within abstract models in which the Amontons-Coulomb friction laws yield a linear programing (LP) problem for the tensions in the fiber elements. We find there is a percolation transition such that above the percolation threshold the transmitted tension is in principle unbounded. We determine that the mean slack in the LP constraints is a suitable order parameter to characterize this supercritical state. We argue the mechanism is generic, and in practical terms, it corresponds to a switch from a ductile to a brittle failure mode accompanied by a significant increase in mechanical strength.

Living nanofiber yarn-based woven biotextiles for tendon tissue engineering using cell tri-culture and mechanical stimulation.

PubMed

Wu, Shaohua; Wang, Ying; Streubel, Philipp N; Duan, Bin

2017-10-15

Non-woven nanofibrous scaffolds have been developed for tendon graft application by using electrospinning strategies. However, electrospun nanofibrous scaffolds face some obstacles and limitations, including suboptimal scaffold structure, weak tensile and suture-retention strengths, and compact structure for cell infiltration. In this work, a novel nanofibrous, woven biotextile, fabricated based on electrospun nanofiber yarns, was implemented as a tissue engineered tendon scaffold. Based on our modified electrospinning setup, polycaprolactone (PCL) nanofiber yarns were fabricated with reproducible quality, and were further processed into plain-weaving fabrics interlaced with polylactic acid (PLA) multifilaments. Nonwoven nanofibrous PCL meshes with random or aligned fiber structures were generated using typical electrospinning as comparative counterparts. The woven fabrics contained 3D aligned microstructures with significantly larger pore size and obviously enhanced tensile mechanical properties than their nonwoven counterparts. The biological results revealed that cell proliferation and infiltration, along with the expression of tendon-specific genes by human adipose derived mesenchymal stem cells (HADMSC) and human tenocytes (HT), were significantly enhanced on the woven fabrics compared with those on randomly-oriented or aligned nanofiber meshes. Co-cultures of HADMSC with HT or human umbilical vein endothelial cells (HUVEC) on woven fabrics significantly upregulated the functional expression of most tenogenic markers. HADMSC/HT/HUVEC tri-culture on woven fabrics showed the highest upregulation of most tendon-associated markers than all the other mono- and co-culture groups. Furthermore, we conditioned the tri-cultured constructs with dynamic conditioning and demonstrated that dynamic stretch promoted total collagen secretion and tenogenic differentiation. Our nanofiber yarn-based biotextiles have significant potential to be used as engineered scaffolds to

Effects of (Oxy-)Fluorination on Various High-Performance Yarns.

PubMed

Kruppke, Iris; Bartusch, Matthias; Hickmann, Rico; Hund, Rolf-Dieter; Cherif, Chokri

2016-08-26

In this work, typical high-performance yarns are oxy-fluorinated, such as carbon fibers, ultra-high-molecular-weight polyethylene, poly(p-phenylene sulfide) and poly(p-phenylene terephthalamide). The focus is on the property changes of the fiber surface, especially the wetting behavior, structure and chemical composition. Therefore, contact angle, XPS and tensile strength measurements are performed on treated and untreated fibers, while SEM is utilized to evaluate the surface structure. Different results for the fiber materials are observed. While polyethylene exhibits a relevant impact on both surface and bulk properties, polyphenylene terephthalamide and polyphenylene sulfide are only affected slightly by (oxy-)fluorination. The wetting of carbon fiber needs higher treatment intensities, but in contrast to the organic fibers, even its textile-physical properties are enhanced by the treatment. Based on these findings, the capability of (oxy-)fluorination to improve the adhesion of textiles in fiber-reinforced composite materials can be derived.

Multifilament cellulose/chitin blend yarn spun from ionic liquids.

PubMed

Mundsinger, Kai; Müller, Alexander; Beyer, Ronald; Hermanutz, Frank; Buchmeiser, Michael R

2015-10-20

Cellulose and chitin, both biopolymers, decompose before reaching their melting points. Therefore, processing these unmodified biopolymers into multifilament yarns is limited to solution chemistry. Especially the processing of chitin into fibers is rather limited to distinctive, often toxic or badly removable solvents often accompanied by chemical de-functionalization to chitosan (degree of acetylation, DA, <50%). This work proposes a novel method for the preparation of cellulose/chitin blend fibers using ionic liquids (ILs) as gentle, removable, recyclable and non-deacetylating solvents. Chitin and cellulose are dissolved in ethylmethylimidazolium propionate ([C2mim](+)[OPr](-)) and the obtained one-pot spinning dope is used to produce multifilament fibers by a continuous wet-spinning process. Both the rheology of the corresponding spinning dopes and the structural and physical properties of the obtained fibers have been determined for different biopolymer ratios. With respect to medical or hygienic application, the cellulose/chitin blend fiber show enhanced water retention capacity compared to pure cellulose fibers. Copyright © 2015 Elsevier Ltd. All rights reserved.

POF-yarn weaves: controlling the light out-coupling of wearable phototherapy devices

PubMed Central

Quandt, Brit M.; Pfister, Marisa S.; Lübben, Jörn F.; Spano, Fabrizio; Rossi, René M.; Bona, Gian-Luca; Boesel, Luciano F.

2017-01-01

Neonatal jaundice (hyperbilirubinaemia) is common in neonates and, often, intensive blue-light phototherapy is required to prevent long-term effects. A photonic textile can overcome three major incubator-related concerns: Insulation of the neonate, human contact, and usage restraints. This paper describes the development of a homogeneous luminous textile from polymer optical fibres to use as a wearable, long-term phototherapy device. The bend out-coupling of light from the POFs was related to the weave production, e.g. weave pattern and yarn densities. Comfort, determined by friction against a skin model and breathability, was investigated additionally. Our textile is the first example of phototherapeutic clothing that is produced sans post-processing allowing for faster commercial production. PMID:29082067

An eco-friendly dyeing of woolen yarn by Terminalia chebula extract with evaluations of kinetic and adsorption characteristics

PubMed Central

Shabbir, Mohd; Rather, Luqman Jameel; Shahid-ul-Islam; Bukhari, Mohd Nadeem; Shahid, Mohd; Ali Khan, Mohd; Mohammad, Faqeer

2016-01-01

In the present study Terminalia chebula was used as an eco-friendly natural colorant for sustainable textile coloration of woolen yarn with primary emphasis on thermodynamic and kinetic adsorption aspects of dyeing processes. Polyphenols and ellagitannins are the main coloring components of the dye extract. Assessment of the effect of pH on dye adsorption showed an increase in adsorption capacity with decreasing pH. Effect of temperature on dye adsorption showed 80 °C as optimum temperature for wool dyeing with T. chebula dye extract. Two kinetic equations, namely pseudo first-order and pseudo second-order equations, were employed to investigate the adsorption rates. Pseudo second-order model provided the best fit (R2 = 0.9908) to the experimental data. The equilibrium adsorption data were fitted by Freundlich and Langmuir isotherm models. The adsorption behavior accorded well (R2 = 0.9937) with Langmuir isotherm model. Variety of eco-friendly and sustainable shades were developed in combination with small amount of metallic mordants and assessed in terms of colorimetric (CIEL∗a∗b∗ and K/S) properties measured using spectrophotometer under D65 illuminant (10° standard observer). The fastness properties of dyed woolen yarn against light, washing, dry and wet rubbing were also evaluated. PMID:27222752

An eco-friendly dyeing of woolen yarn by Terminalia chebula extract with evaluations of kinetic and adsorption characteristics.

PubMed

Shabbir, Mohd; Rather, Luqman Jameel; Shahid-Ul-Islam; Bukhari, Mohd Nadeem; Shahid, Mohd; Ali Khan, Mohd; Mohammad, Faqeer

2016-05-01

In the present study Terminalia chebula was used as an eco-friendly natural colorant for sustainable textile coloration of woolen yarn with primary emphasis on thermodynamic and kinetic adsorption aspects of dyeing processes. Polyphenols and ellagitannins are the main coloring components of the dye extract. Assessment of the effect of pH on dye adsorption showed an increase in adsorption capacity with decreasing pH. Effect of temperature on dye adsorption showed 80 °C as optimum temperature for wool dyeing with T. chebula dye extract. Two kinetic equations, namely pseudo first-order and pseudo second-order equations, were employed to investigate the adsorption rates. Pseudo second-order model provided the best fit (R (2) = 0.9908) to the experimental data. The equilibrium adsorption data were fitted by Freundlich and Langmuir isotherm models. The adsorption behavior accorded well (R (2) = 0.9937) with Langmuir isotherm model. Variety of eco-friendly and sustainable shades were developed in combination with small amount of metallic mordants and assessed in terms of colorimetric (CIEL(∗) a (∗) b (∗) and K/S) properties measured using spectrophotometer under D65 illuminant (10° standard observer). The fastness properties of dyed woolen yarn against light, washing, dry and wet rubbing were also evaluated.

Art Teaching Guides: Using Cloth and Trimmings, Yarns and Fibers, Grades 2-6. Curriculum Bulletin No. 8d, 1968-69 Series.

ERIC Educational Resources Information Center

New York City Board of Education, Brooklyn, NY. Bureau of Curriculum Development.

Creating with fabrics, yarns, and fibers--from early basic explorations in handling an assortment of cloths and trimmings, through experiments with stitching and weaving, to the designing and making of bags, hats, and costumes that children can use--is the focus of this curriculum guide. For each grade (2-6), guidelines are provided on (1)…

A Highly Stretchable and Washable All-Yarn-Based Self-Charging Knitting Power Textile Composed of Fiber Triboelectric Nanogenerators and Supercapacitors.

PubMed

Dong, Kai; Wang, Yi-Cheng; Deng, Jianan; Dai, Yejing; Zhang, Steven L; Zou, Haiyang; Gu, Bohong; Sun, Baozhong; Wang, Zhong Lin

2017-09-26

Rapid advancements in stretchable and multifunctional wearable electronics impose a challenge on corresponding power devices that they should have comparable portability and stretchability. Here, we report a highly stretchable and washable all-yarn-based self-charging knitting power textile that enables both biomechanical energy harvesting and simultaneously energy storing by hybridizing triboelectrical nanogenerator (TENG) and supercapacitor (SC) into one fabric. With the weft-knitting technique, the power textile is qualified with high elasticity, flexibility, and stretchability, which can adapt to complex mechanical deformations. The knitting TENG fabric is able to generate electric energy with a maximum instantaneous peak power density of ∼85 mW·m -2 and light up at least 124 light-emitting diodes. The all-solid-state symmetrical yarn SC exhibits lightweight, good capacitance, high flexibility, and excellent mechanical and long-term stability, which is suitable for wearable energy storage devices. The assembled knitting power textile is capable of sustainably driving wearable electronics (for example, a calculator or temperature-humidity meter) with energy converted from human motions. Our work provides more opportunities for stretchable multifunctional power sources and potential applications in wearable electronics.

Having a yarn about smoking: using action research to develop a 'no smoking' policy within an Aboriginal Health Organisation.

PubMed

Fletcher, Gillian; Fredericks, Bronwyn; Adams, Karen; Finlay, Summer; Andy, Simone; Briggs, Lyn; Hall, Robert

2011-11-01

This article reports on a culturally appropriate process of development of a smoke-free workplace policy within the peak Aboriginal Controlled Community Health Organisation in Victoria, Australia. Smoking is acknowledged as being responsible for at least 20% of all deaths in Aboriginal communities in Australia, and many Aboriginal health workers smoke. The smoke-free workplace policy was developed using the iterative, discursive and experience-based methodology of Participatory Action Research, combined with the culturally embedded concept of 'having a yarn'. Staff members initially identified smoking as a topic to be avoided within workplace discussions. This was due, in part, to grief (everyone had suffered a smoking-related bereavement). Further, there was anxiety that discussing smoking would result in culturally difficult conflict. The use of yarning opened up a safe space for discussion and debate, enabling development of a policy that was accepted across the organisation. Within Aboriginal organisations, it is not sufficient to focus on the outcomes of policy development. Rather, due attention must be paid to the process employed in development of policy, particularly when that policy is directly related to an emotionally and communally weighted topic such as smoking. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Core-Shell-Yarn-Based Triboelectric Nanogenerator Textiles as Power Cloths.

PubMed

Yu, Aifang; Pu, Xiong; Wen, Rongmei; Liu, Mengmeng; Zhou, Tao; Zhang, Ke; Zhang, Yang; Zhai, Junyi; Hu, Weiguo; Wang, Zhong Lin

2017-12-26

Although textile-based triboelectric nanogenerators (TENGs) are highly promising because they scavenge energy from their working environment to sustainably power wearable/mobile electronics, the challenge of simultaneously possessing the qualities of cloth remains. In this work, we propose a strategy for TENG textiles as power cloths in which core-shell yarns with core conductive fibers as the electrode and artificial polymer fibers or natural fibrous materials tightly twined around core conductive fibers are applied as the building blocks. The resulting TENG textiles are comfortable, flexible, and fashionable, and their production processes are compatible with industrial, large-scale textile manufacturing. More importantly, the comfortable TENG textiles demonstrate excellent washability and tailorability and can be fully applied in further garment processing. TENG textiles worn under the arm or foot have also been demonstrated to scavenge various types of energy from human motion, such as patting, walking, and running. All of these merits of proposed TENG textiles for clothing uses suggest their great potentials for viable applications in wearable electronics or smart textiles in the near future.

Highly water-absorbing silk yarn with interpenetrating network via in situ polymerization.

PubMed

Lee, Ka I; Wang, Xiaowen; Guo, Xia; Yung, Ka-Fu; Fei, Bin

2017-02-01

Silk was modified via in situ polymerization of two monomers acrylamide and sodium acrylate by swelling in an effective LiBr dissolution system. Swelling of natural silks in LiBr solutions of low concentration was clearly observed under optical microscope, and their conformational changes were revealed by X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. Dissolution tests and FTIR spectra of these modified silks suggested the presence of interpenetrating network of polyacrylamide and poly(sodium acrylate) in the silk yarns. These modified silks exhibited superior water absorption to that of raw silk and greatly improved mechanical properties in both dry and wet states. These novel modified silks also showed low cytotoxicity towards skin keratinocytes, having potential applications in biomedical textiles. This modification method by in situ polymerization after swelling in LiBr provides a new route to highly enhance the properties and performance of silk for various applications. Copyright © 2016 Elsevier B.V. All rights reserved.

O2 Plasma Etching and Antistatic Gun Surface Modifications for CNT Yarn Microelectrode Improve Sensitivity and Antifouling Properties.

PubMed

Yang, Cheng; Wang, Ying; Jacobs, Christopher B; Ivanov, Ilia N; Venton, B Jill

2017-05-16

Carbon nanotube (CNT) based microelectrodes exhibit rapid and selective detection of neurotransmitters. While different fabrication strategies and geometries of CNT microelectrodes have been characterized, relatively little research has investigated ways to selectively enhance their electrochemical properties. In this work, we introduce two simple, reproducible, low-cost, and efficient surface modification methods for carbon nanotube yarn microelectrodes (CNTYMEs): O 2 plasma etching and antistatic gun treatment. O 2 plasma etching was performed by a microwave plasma system with oxygen gas flow and the optimized time for treatment was 1 min. The antistatic gun treatment flows ions by the electrode surface; two triggers of the antistatic gun was the optimized number on the CNTYME surface. Current for dopamine at CNTYMEs increased 3-fold after O 2 plasma etching and 4-fold after antistatic gun treatment. When the two treatments were combined, the current increased 12-fold, showing the two effects are due to independent mechanisms that tune the surface properties. O 2 plasma etching increased the sensitivity due to increased surface oxygen content but did not affect surface roughness while the antistatic gun treatment increased surface roughness but not oxygen content. The effect of tissue fouling on CNT yarns was studied for the first time, and the relatively hydrophilic surface after O 2 plasma etching provided better resistance to fouling than unmodified or antistatic gun treated CNTYMEs. Overall, O 2 plasma etching and antistatic gun treatment improve the sensitivity of CNTYMEs by different mechanisms, providing the possibility to tune the CNTYME surface and enhance sensitivity.

Application of a hybrid Electrocoagulation-Fenton process in yarn dye wastewater: Kinetic study

NASA Astrophysics Data System (ADS)

Riadi, L.; Sapei, L.; Lidiawati, T.; Agustin, Y. E.

2016-11-01

Reactive dyes contain a significant portion of colorants used in yarn dying process and also in textile industry. Since the COD content is usually high in such wastewater,we conducted a hybrid electrocoagulation-fenton method to treat the wastewater. This work describes the application of the hybrid system to the removal of chemical oxygen demand and color from the wastewater in a batch reactor. Having worked with initial pH of 3,0; temperature at 30°C, molar ratio of Fe2+/H2O2 =1/10 and the mol ratio H2O2/COD = 4, we got 88.3% COD conversion and 88.5% color removal. The COD degradation process can be explained in two phases, the first phase is instantaneous reaction and the second phase is first order reaction. The kinetic constant was 0.0053 minute-1 and the rate of COD degradation was 0.0053[COD] mg/L minute.

Additive Manufacturing of Multifunctional Components Using High Density Carbon Nanotube Yarn Filaments

NASA Technical Reports Server (NTRS)

Gardner, John M.; Sauti, Godfrey; Kim, Jae-Woo; Cano, Roberto J.; Wincheski, Russell A.; Stelter, Christopher J.; Grimsley, Brian W.; Working, Dennis C.; Siochi, Emilie J.

2016-01-01

Additive manufacturing allows for design freedom and part complexity not currently attainable using traditional manufacturing technologies. Fused Filament Fabrication (FFF), for example, can yield novel component geometries and functionalities because the method provides a high level of control over material placement and processing conditions. This is achievable by extrusion of a preprocessed filament feedstock material along a predetermined path. However if fabrication of a multifunctional part relies only on conventional filament materials, it will require a different material for each unique functionality printed into the part. Carbon nanotubes (CNTs) are an attractive material for many applications due to their high specific strength as well as good electrical and thermal conductivity. The presence of this set of properties in a single material presents an opportunity to use one material to achieve multifunctionality in an additively manufactured part. This paper describes a recently developed method for processing continuous CNT yarn filaments into three-dimensional articles, and summarizes the mechanical, electrical, and sensing performance of the components fabricated in this way.

A new model for impregnation mechanisms in different GF/PP commingled yarns

NASA Astrophysics Data System (ADS)

Klinkmüller, V.; Um, M.-K.; Steffens, M.; Friedrich, K.; Kim, B.-S.

1994-09-01

Impregnation mechanisms of different kinds of GF/PP commingled yarns have been studied. As the reinforcing fibres were always the same, a global description has been worked out. Two different mathematical approaches for fibre bed permeability (Kozeny-Carman and Gutowski) were compared. The constants of the applied mathematical models have to stay the same if the fibre reeinforcement and the fibre arrangement is the same. Neither the kind of matrix, nor the fibre volume content may change these constants. Differences in the degree of impregnation after the same process conditions can be only due to different sizes of fibre agglomerations, thus the initial distribution of reinforcing fibres and matrix. For an exact determination of impregnation times and conditions the exact distribution of fibres in the intermediate material and after processing has to be known. This distribution is determined by SEM microscopy and data given from the material supplier. The importance of different process parameters, such as temperature, pressure, processing time is weighted by determining the density and mechanical properties of the specimens.

Poly(D,L-Lactide-Co-Glycolide) Tubes With Multifilament Chitosan Yarn or Chitosan Sponge Core in Nerve Regeneration.

PubMed

Wlaszczuk, Adam; Marcol, Wiesław; Kucharska, Magdalena; Wawro, Dariusz; Palen, Piotr; Lewin-Kowalik, Joanna

2016-11-01

The influence of different kinds of nerve guidance conduits on regeneration of totally transected rat sciatic nerves through a 7-mm gap was examined. Five different types of conduits made of chitosan and poly(D,L-lactide-co-glycolide) (PLGA) were constructed and tested in vivo. We divided 50 animals into equal groups of 10, with a different type of conduit implanted in each group: chitosan sponge core with an average molecular mass of polymer (Mv) of 287 kDa with 7 channels in a PLGA sleeve, chitosan sponge core with an Mv of 423 kDa with 7 channels in a PLGA sleeve, chitosan sponge core (Mv, 423 kDa) with 13 channels in a PLGA sleeve, chitosan multifilament yarn in a PLGA sleeve, and a PLGA sleeve only. Seven weeks after the operation, we examined the distance covered by regenerating nerve fibers, growing of nerves into the conduit's core, and intensity and type of inflammatory reaction in the conduit, as well as autotomy behavior (reflecting neuropathic pain intensity) in the animals. Two types of conduits were allowing nerve outgrowth through the gap with minor autotomy and minor inflammatory reactions. These were the conduits with chitosan multifilament yarn in a PLGA sleeve and the conduits with 13-channel microcrystalline chitosan sponge in a PLGA sleeve. The type of chitosan used to build the nerve guidance conduit influences the intensity and character of inflammatory reaction present during nerve regeneration, which in turn affects the distance crossed by regenerating nerve fibers, growing of the nerve fibers into the conduit's core, and the intensity of autotomy in the animals. Copyright © 2016 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

Thermo-Mechanical Behavior of Textile Heating Fabric Based on Silver Coated Polymeric Yarn

PubMed Central

Hamdani, Syed Talha Ali; Potluri, Prasad; Fernando, Anura

2013-01-01

This paper presents a study conducted on the thermo-mechanical properties of knitted structures, the methods of manufacture, effect of contact pressure at the structural binding points, on the degree of heating. The test results also present the level of heating produced as a function of the separation between the supply terminals. The study further investigates the rate of heating and cooling of the knitted structures. The work also presents the decay of heating properties of the yarn due to overheating. Thermal images were taken to study the heat distribution over the surface of the knitted fabric. A tensile tester having constant rate of extension was used to stretch the fabric. The behavior of temperature profile of stretched fabric was observed. A comparison of heat generation by plain, rib and interlock structures was studied. It was observed from the series of experiments that there is a minimum threshold force of contact at binding points of a knitted structure is required to pass the electricity. Once this force is achieved, stretching the fabric does not affect the amount of heat produced. PMID:28809358

Smart electronic yarns and wearable fabrics for human biomonitoring made by carbon nanotube coating with polyelectrolytes.

PubMed

Shim, Bong Sup; Chen, Wei; Doty, Chris; Xu, Chuanlai; Kotov, Nicholas A

2008-12-01

The idea of electronic yarns and textiles has appeared for quite some time, but their properties often do not meet practical expectations. In addition to chemicallmechanical durability and high electrical conductivity, important materials qualifications include weavablity, wearability, light weight, and "smart" functionalities. Here we demonstrate a simple process of transforming general commodity cotton threads into intelligent e-textiles using a polyelectrolyte-based coating with carbon nanotubes (CNTs). Efficient charge transport through the network of nanotubes (20 omega/cm) and the possibility to engineer tunneling junctions make them promising materials for many high-knowledge-content garments. Along with integrated humidity sensing, we demonstrate that CNT-cotton threads can be used to detect albumin, the key protein of blood, with high sensitivity and selectivity. Notwithstanding future challenges, these proof-of-concept demonstrations provide a direct pathway for the application of these materials as wearable biomonitoring and telemedicine sensors, which are simple, sensitive, selective, and versatile.

High Performance Carbon Nanotube Yarn Supercapacitors with a Surface-Oxidized Copper Current Collector.

PubMed

Zhang, Daohong; Wu, Yunlong; Li, Ting; Huang, Yin; Zhang, Aiqing; Miao, Menghe

2015-11-25

Threadlike linear supercapacitors have demonstrated high potential for constructing fabrics to power electronic textiles (eTextiles). To improve the cyclic electrochemical performance and to produce power fabrics large enough for practical applications, a current collector has been introduced into the linear supercapcitors to transport charges produced by active materials along the length of the supercapacitor with high efficiency. Here, we first screened six candidate metal filaments (Pt, Au, Ag, AuAg, PtCu, and Cu) as current collectors for carbon nanotube (CNT) yarn-based linear supercapacitors. Although all of the metal filaments significantly improved the electrochemical performance of the linear supercapacitor, two supercapacitors constructed from Cu and PtCu filaments, respectively, demonstrate far better electrochemical performance than the other four supercapacitors. Further investigation shows that the surfaces of the two Cu-containing filaments are oxidized by the surrounding polymer electrolyte in the electrode. While the unoxidized core of the Cu-containing filaments remains highly conductive and functions as a current collector, the resulting CuO on the surface is an electrochemically active material. The linear supercapacitor architecture incorporating dual active materials CNT + Cu extends the potential window from 1.0 to 1.4 V, leading to significant improvement to the energy density and power density.

Yarn supplier selection using analytical hierarchy process (AHP) and standardized unitless rating (SUR) method on textile industry

NASA Astrophysics Data System (ADS)

Erfaisalsyah, M. H.; Mansur, A.; Khasanah, A. U.

2017-11-01

For a company which engaged in the textile field, specify the supplier of raw materials for production is one important part of supply chain management which can affect the company's business processes. This study aims to identify the best suppliers of raw material suppliers of yarn for PC. PKBI based on several criteria. In this study, the integration between the Analytical Hierarchy Process (AHP) and the Standardized Unitless Rating (SUR) are used to assess the performance of the suppliers. By using AHP, it can be known the value of the relative weighting of each criterion. While SUR shows the sequence performance value of the supplier. The result of supplier ranking calculation can be used to know the strengths and weaknesses of each supplier based on its performance criteria. From the final result, it can be known which suppliers should improve their performance in order to create long term cooperation with the company.

The electro-structural behaviour of yarn-like carbon nanotube fibres immersed in organic liquids

NASA Astrophysics Data System (ADS)

Terrones, Jeronimo; Windle, Alan H.; Elliott, James A.

2014-10-01

Yarn-like carbon nanotube (CNT) fibres are a hierarchically-structured material with a variety of promising applications such as high performance composites, sensors and actuators, smart textiles, and energy storage and transmission. However, in order to fully realize these possibilities, a more detailed understanding of their interactions with the environment is required. In this work, we describe a simplified representation of the hierarchical structure of the fibres from which several mathematical models are constructed to explain electro-structural interactions of fibres with organic liquids. A balance between the elastic and surface energies of the CNT bundle network in different media allows the determination of the maximum lengths that open junctions can sustain before collapsing to minimize the surface energy. This characteristic length correlates well with the increase of fibre resistance upon immersion in organic liquids. We also study the effect of charge accumulation in open interbundle junctions and derive expressions to describe experimental data on the non-ohmic electrical behaviour of fibres immersed in polar liquids. Our analyses suggest that the non-ohmic behaviour is caused by progressively shorter junctions collapsing as the voltage is increased. Since our models are not based on any property unique to carbon nanotubes, they should also be useful to describe other hierarchical structures.

Interwoven Aligned Conductive Nanofiber Yarn/Hydrogel Composite Scaffolds for Engineered 3D Cardiac Anisotropy.

PubMed

Wu, Yaobin; Wang, Ling; Guo, Baolin; Ma, Peter X

2017-06-27

Mimicking the anisotropic cardiac structure and guiding 3D cellular orientation play a critical role in designing scaffolds for cardiac tissue regeneration. Significant advances have been achieved to control cellular alignment and elongation, but it remains an ongoing challenge for engineering 3D cardiac anisotropy using these approaches. Here, we present a 3D hybrid scaffold based on aligned conductive nanofiber yarns network (NFYs-NET, composition: polycaprolactone, silk fibroin, and carbon nanotubes) within a hydrogel shell for mimicking the native cardiac tissue structure, and further demonstrate their great potential for engineering 3D cardiac anisotropy for cardiac tissue engineering. The NFYs-NET structures are shown to control cellular orientation and enhance cardiomyocytes (CMs) maturation. 3D hybrid scaffolds were then fabricated by encapsulating NFYs-NET layers within hydrogel shell, and these 3D scaffolds performed the ability to promote aligned and elongated CMs maturation on each layer and individually control cellular orientation on different layers in a 3D environment. Furthermore, endothelialized myocardium was constructed by using this hybrid strategy via the coculture of CMs on NFYs-NET layer and endothelial cells within hydrogel shell. Therefore, these 3D hybrid scaffolds, containing NFYs-NET layer inducing cellular orientation, maturation, and anisotropy and hydrogel shell providing a suitable 3D environment for endothelialization, has great potential in engineering 3D cardiac anisotropy.

Flexible and Robust Thermoelectric Generators Based on All-Carbon Nanotube Yarn without Metal Electrodes.

PubMed

Choi, Jaeyoo; Jung, Yeonsu; Yang, Seung Jae; Oh, Jun Young; Oh, Jinwoo; Jo, Kiyoung; Son, Jeong Gon; Moon, Seung Eon; Park, Chong Rae; Kim, Heesuk

2017-08-22

As practical interest in flexible/or wearable power-conversion devices increases, the demand for high-performance alternatives to thermoelectric (TE) generators based on brittle inorganic materials is growing. Herein, we propose a flexible and ultralight TE generator (TEG) based on carbon nanotube yarn (CNTY) with excellent TE performance. The as-prepared CNTY shows a superior electrical conductivity of 3147 S/cm due to increased longitudinal carrier mobility derived from a highly aligned structure. Our TEG is innovative in that the CNTY acts as multifunctions in the same device. The CNTY is alternatively doped into n- and p-types using polyethylenimine and FeCl 3 , respectively. The highly conductive CNTY between the doped regions is used as electrodes to minimize the circuit resistance, thereby forming an all-carbon TEG without additional metal deposition. A flexible TEG based on 60 pairs of n- and p-doped CNTY shows the maximum power density of 10.85 and 697 μW/g at temperature differences of 5 and 40 K, respectively, which are the highest values among reported TEGs based on flexible materials. We believe that the strategy proposed here to improve the power density of flexible TEG by introducing highly aligned CNTY and designing a device without metal electrodes shows great potential for the flexible/or wearable power-conversion devices.

Flexible pile thermal barrier insulator

NASA Technical Reports Server (NTRS)

Anderson, G. E.; Fell, D. M.; Tesinsky, J. S. (Inventor)

1978-01-01

A flexible pile thermal barrier insulator included a plurality of upstanding pile yarns. A generally planar backing section supported the upstanding pile yarns. The backing section included a plurality of filler yarns forming a mesh in a first direction. A plurality of warp yarns were looped around said filler yarns and pile yarns in the backing section and formed a mesh in a second direction. A binder prevented separation of the yarns in the backing section.

75 FR 65526 - AGY Holding Corporation, Huntingdon, PA; Notice of Revised Determination on Reconsideration

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-25

... are engaged in employment related to the production of fine yarns and specialty glass yarns. The... proportion of production of articles like or directly competitive with the fine yarns and/or specialty glass..., Pennsylvania, who are engaged in employment related to the production of fine yarns and specialty glass yarns...

Electrospinning of single wall carbon nanotube reinforced aligned fibrils and yarns

NASA Astrophysics Data System (ADS)

Lam, Hoa Le

Commercial carbon fibers produced from a polyacrylonitrile (PAN) precursor have reached their performance limit. The approach in this study involves the use of single carbon nanotubes (SWNT) with an ultra-high elastic modulus of approximately ˜1 TPa and tensile strength of ˜37 GPa at a breaking strain of ˜6% to reinforce PAN. In order to translate these extraordinary properties to a higher order structure, the need for a media to carry and assemble the SWNT into continuous fibers or yarns is necessary. Effective translation of properties can only be achieved through uniform distribution of SWNT and their alignment in the fiber axis. This has been one of the major challenges since SWNTs tend to agglomerate due to high van der Waals attraction between tubes. It is the goal of this study to develop dispersion technique(s) for the SWNT and process them into aligned fibers utilizing the electrospinning process. The electrospun nanofibers were then characterized by various techniques such as ESEM, Raman microspectroscopy, HRTEM, and tensile testing. Composite nanofibers containing various contents of SWNT up to 10 wt. % with diameter ranging from 40--300 nm were successfully electrospun through varying the polymer concentration and spinning parameters. The inclusion of SWNTs and their alignment in the fiber axis were confirmed by Raman microspectroscopy, polarized Raman and HRETEM. The failure mechanism of the nanofibers was investigated by HRTEM through fiber surface fracture. A two stage rupture mechanism was observed where crazing initiates at a surface defect followed by SWNTs pulling out of the PAN matrix. Such mechanisms consume energy therefore strengthening and toughening the fibers. Mechanical drawing of the fiber prior to heat treatment induced molecular orientation resulting in oriented graphite layers in the carbonized fibers. This study has established a processing base and characterization techniques to support the design and development of SWNT

Micro-CT Characterization on the Meso-Structure of Three-Dimensional Full Five-Directional Braided Composite

NASA Astrophysics Data System (ADS)

Ya, Jixuan; Liu, Zhenguo; Wang, Yuanhang

2017-06-01

The meso-structure is important in predicting mechanical properties of the three-dimensional (3D) braided composite. In this paper, the internal structure and porosity of three-dimensional full five-directional (3DF5D) braided composite is characterized at mesoscopic scale (the scale of the yarns) using micro-computed tomography (micro-CT) non-destructively. Glass fiber yarns as tracer are added into the sample made of carbon fiber to enhance the contrast in the sectional images. The model of tracer yarns is established with 3D reconstruction method to analyze the cross-section and path of yarns. The porosities are reconstructed and characterized in the end. The results demonstrate that the cross sections of braiding yarns and axial yarns change with the regions and the heights in one pitch of 3DF5D braided composites. The path of braiding yarns are various in the different regions while the axial yarns are always straight. Helical indentations appear on the surfaces of the axial yarns because of the squeeze from braiding yarns. Moreover, the porosities in different shapes and sizes are almost located in the matrix and between the yarns.

75 FR 38126 - AGY Holding Corporation, Huntingdon, PA; Notice of Affirmative Determination Regarding...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-01

... employment related to the production of fine yarns and specialty glass yarns. The negative determination was based on the Department's findings that increased imports of fine yarns and specialty glass yarns did...

TEXCAD: Textile Composite Analysis for Design. Version 1.0: User's manual

NASA Technical Reports Server (NTRS)

Naik, Rajiv A.

1994-01-01

The Textile Composite Analysis for Design (TEXCAD) code provides the materials/design engineer with a user-friendly desktop computer (IBM PC compatible or Apple Macintosh) tool for the analysis of a wide variety of fabric reinforced woven and braided composites. It can be used to calculate overall thermal and mechanical properties along with engineering estimates of damage progression and strength. TEXCAD also calculates laminate properties for stacked, oriented fabric constructions. It discretely models the yarn centerline paths within the textile repeating unit cell (RUC) by assuming sinusoidal undulations at yarn cross-over points and uses a yarn discretization scheme (which subdivides each yarn not smaller, piecewise straight yarn slices) together with a 3-D stress averaging procedure to compute overall stiffness properties. In the calculations for strength, it uses a curved beam-on-elastic foundation model for yarn undulating regions together with an incremental approach in which stiffness properties for the failed yarn slices are reduced based on the predicted yarn slice failure mode. Nonlinear shear effects and nonlinear geometric effects can be simulated. Input to TEXCAD consists of: (1) materials parameters like impregnated yarn and resin properties such moduli, Poisson's ratios, coefficients of thermal expansion, nonlinear parameters, axial failure strains and in-plane failure stresses; and (2) fabric parameters like yarn sizes, braid angle, yarn packing density, filament diameter and overall fiber volume fraction. Output consists of overall thermoelastic constants, yarn slice strains/stresses, yarn slice failure history, in-plane stress-strain response and ultimate failure strength. Strength can be computed under the combined action of thermal and mechanical loading (tension, compression and shear).

76 FR 52640 - Determination Under the Textile and Apparel Commercial Availability Provision of the Dominican...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-23

... (``CITA'') has determined that an acceptable substitute for certain compacted, plied, ring spun cotton... to remove or restrict (``Request'') certain compacted, plied, ring spun cotton yarns, currently on... Spun Cotton Yarns Compacted, plied, ring spun cotton yarns, with yarn counts in the range from 42 to...

Wicking Performance of Profiled Fibre Part B: Assessment of Fabric

NASA Astrophysics Data System (ADS)

Datta Roy, M.; Chattopadhyay, R.; Sinha, S. K.

2018-06-01

For moisture regulation, careful selection of fibre, fibre packing in yarns and fabric structure are necessary. Introducing selective porosity in yarn can significantly influence moisture transport properties in fabrics made out of profiled fibre yarn. The arrangement of fibres in the yarn and that of yarn in fabric provide wide variability in the size and shape of the passage of liquid to flow. A change in the cross sectional diameter of the capillary leads to a change in interfacial speed for liquid. The mechanism of liquid transmission in fabric is expected to be different from that in yarn in isolated state. Generally, openness in fabric offers least resistance to flow. However, at each cross over points of threads the pressure exerted by one set of yarn on another can influence the capillary geometry affecting flow of liquid. The present work reports on the investigation made to study the wicking performance of five sets of fabrics made out of five homogeneous profiled fibre yarns as weft and respective double yarns as warp. It was observed that the wicking time and height in the weft direction were different than that in the corresponding yarns. Interestingly, wicking height attained in warp direction and individual yarn in isolation does not show any significant difference. It was observed that the points of interlacements between warps and wefts were constantly splitting the fluid flow both in horizontal and vertical directions.

High sensitivity knitted fabric strain sensors

NASA Astrophysics Data System (ADS)

Xie, Juan; Long, Hairu; Miao, Menghe

2016-10-01

Wearable sensors are increasingly used in smart garments for detecting and transferring vital signals and body posture, movement and respiration. Existing fabric strain sensors made from metallized yarns have low sensitivity, poor comfort and low durability to washing. Here we report a knitted fabric strain sensor made from a cotton/stainless steel (SS) fibre blended yarn which shows much higher sensitivity than sensors knitted from metallized yarns. The fabric feels softer than pure cotton textiles owing to the ultrafine stainless steel fibres and does not lose its electrical property after washing. The reason for the high sensitivity of the cotton/SS knitted fabric sensor was explored by comparing its sensing mechanism with the knitted fabric sensor made from metallized yarns. The results show that the cotton/SS yarn-to-yarn contact resistance is highly sensitive to strain applied to hooked yarn loops.

Mercerization of Cotton for Strength with Special Reference to Aircraft Cloth

NASA Technical Reports Server (NTRS)

Wilkie, J B

1933-01-01

The object of the present investigation was to determine the conditions for mercerizing cotton yarn to obtain the maximum strength for a given weight. Apparatus for controlling the variables was built and yarns were mercerized with it under systematically varied conditions of tension, time, temperature, and concentration of caustic soda. The strongest conclusion to be drawn from this work is that the strongest mercerized yarn of a given count from a given quality of cotton is obtained under the following conditions: 1. use of low-twist yarn obtained with twist multipliers from 2.2 to 3; 2. thorough pretreatment of the yarn to remove all extraneous materials; 3. mercerization at a temperature of 0 C or lower; 4. use of sufficient tension during mercerization to prevent the yarn from contracting more than 3 percent. 5. Use of caustic solution having a concentration of 10 percent or higher; 6. the time of mercerization to be 5 minutes. The resulting yarn should be 40 to 100 percent stronger than the original yarn of the same weight.

Investigation of Woven Characteristics on Electromagnetic Shielding Behaviour

NASA Astrophysics Data System (ADS)

Javadi Toghchi, M.; Loghin, C.; Cristian, I.; Campagne, C.; Bruniaux, P.; Cayla, A.

2018-06-01

Textiles have been highly applied for electromagnetic shielding purposes due to the increasing concern about health issues caused by human exposure to radiation. Properties of conductive yarn, fabric structure, and garment design have extreme effects on the electromagnetic behaviour and comfort of the final product. Lots of electromagnetic shielding textiles are made of metallic yarns regarding their high electrical conductivity. Therefore, some researchers have worked on electromagnetic shielding textiles made of metals. For example; the shielding effectiveness of woven fabrics made of hybrid yarns containing stainless steel wire was investigated. As discussed earlier, the fabric structure has significant effects on electromagnetic protection. Consequently, woven samples were produced using two different commercial electroconductive yarns (PA12 coated with Ag and Inox) to investigate the effects of the fabric structure. The main purpose was to define the best pattern among three basic woven patterns leads to the highest electromagnetic shielding. Moreover, the different weft yarn densities were applied to examine the effects of yarn density on the level of electromagnetic shielding. The electromagnetic shielding effectiveness of all the 2-layer samples was evaluated in the frequency range from 0.8 to10 GHz in an anechoic chamber. The woven sample with higher yarn density of PA12 coated with Ag yarns shows higher protection against radiation. To conclude, the results show that the yarn properties play the main role in shielding as well as yarn density and fabric pattern.

Compressibility and resiliency properties of wilton type woven carpets produced with different fiber blend ratio

NASA Astrophysics Data System (ADS)

Osman, B.; Esin, S.; Sıdıka Ziba, O.

2017-10-01

Carpet is a textile structure that composed of three components: warp (stuffer and chain warp), weft and pile yarns. These textile products are used for areas which will stand up to the use of home, hotel, work place etc. Furthermore, the capable of carpets are related to it’s especially pile performance during use in various areas. During usage, carpets made from various type of raw materials of pile yarn also acts differently that these differentiate determines carpet performance, as well.This study was focused on the compression and resilience behaviour of carpet composed of 100% viscose and 100% acrylic pile yarns and blended pile yarns of blend ratios, 80%/20%, 50%/50% and 20%/80% viscose/acrylic. During the yarn production process, all spinning conditions were kept constant in order to eliminate the yarn production parameters. Five different types of wilton face to face carpet samples were produced from these yarns at the same pile height and pile density on Van de Wiele carpet weaving machine at 110 picks/min machine speed and 1/1 V carpet construction. Compressibility properties of carpets were examined whether blend ratio was statistically significant on carpet resilience or not. The behaviour of pile yarns under pressure is important that leads to understand the growth characteristic which is exposed to decrease and increase loadings during usage of carpet made from these yarns. Results indicated that blend ratio of pile yarns have significance effect on compression behaviour of carpet samples.

Weaving and bonding method to prevent warp and fill distortion

NASA Technical Reports Server (NTRS)

Farley, Gary L. (Inventor)

1997-01-01

A method to prevent fiber distortion in textile materials employed in a modified weaving process. In a first embodiment, a tacifier in powder form is applied to the yarn and melted while on the fabric. Cool air is then supplied after the tacifier has melted to expedite the solidification of the tacifier. In a second embodiment, a solution form of a tacifier is used by dissolving the tacifier into a solvent that has a high evaporation rate. The solution is then sprayed onto the fabric or fill yarn as each fill yarn is inserted into a shed of the fabric. A third embodiment applies the tacifier in a liquid form that has not been dissolved in a solvent. That is, the tacifier is melted and is sprayed as a liquid onto the fabric or fill yarn as it is being extracted from a fill yarn spool prior to the fill yarn being inserted into the shed of the fabric. A fourth embodiment employs adhesive yarns contained as an integral part of the warp or fill yarn. Additional tacifier material is not required because a matrix is used as the tacifier. The matrix is then locally melted using heating elements on clamping bars or take-up rollers, is cooled, if necessary, and solidified.

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

Gesta, E.; Intelligent Insect Control, 118 Chemin des Alouettes, Castelnau-le-Lez, 34170; Skovmand, O., E-mail: osk@insectcontrol.net

The purpose of this study is to understand the influence of the yarn processing on the migration of additives molecules, especially insecticide, within polyethylene (PE) yarns. Yarns were manufactured in the laboratory focusing on three key-steps (spinning, post-stretching and heat-setting). Influence of each step on yarn properties was investigated using tensile tests, differential scanning calorimetry and wide-angle X-ray diffraction. The post-stretching step was proved to be critical in defining yarn mechanical and structural properties. Although a first orientation of polyethylene crystals was induced during spinning, the optimal orientation was only reached by post-stretching. The results also showed that the heat-settingmore » did not significantly change these properties. The presence of additives crystals at the yarn surface was evidenced by scanning-electron microscopy. These studies performed at each yarn production step allowed a detailed analysis of the additives’ ability to migrate. It is concluded that while post-stretching decreased the migration rate, heat-setting seems to boost this migration.« less

Weavability of dry polymer powder towpreg

NASA Technical Reports Server (NTRS)

Hugh, Maylene K.; Marchello, Joseph M.; Maiden, Janice R.; Johnston, Norman J.

1993-01-01

Carbon fiber yarns (3k, 6k, 12k) were impregnated with LARC (tm) thermoplastic polyimide dry powder. Parameters for weaving these yarns were established. Eight-harness satin fabrics were successfully woven from each of the three classes of yarns and consolidated into test specimens to determine mechanical properties. It was observed that for optimum results warp yarns should have flexural rigidities between 10,000 and 100,000 mg-cm. Tow handling minimization, low tensioning, and tow bundle twisting were used to reduce fiber breakage, the separation of filaments, and tow-to-tow abrasion. No apparent effect of tow size or twist was observed on either tension or compression modulus. However, fiber damage and processing costs favor the use of 12k yarn bundles versus 3k or 6k yarn bundles in the weaving of powder-coated towpreg.

Investigation of nanoyarn preparation by modified electrospinning setup.

PubMed

Levitt, Ariana S; Knittel, Chelsea E; Vallett, Richard; Koerner, Michael; Dion, Genevieve; Schauer, Caroline L

2017-05-15

Higher ordered structures of nanofibers, including nanofiber-based yarns and cables, have a variety of potential applications, including wearable health monitoring systems, artificial tendons, and medical sutures. In this study, twisted assemblies of polyacrylonitrile (PAN), polyvinylidene fluoride trifluoroethylene (PVDF-TrFE), and polycaprolactone (PCL) nanofibers were fabricated via a modified electrospinning setup, consisting of a rotating cone-shaped copper collector, two syringe pumps, and two high voltage power supplies. The fiber diameters and twist angles varied as a function of the rotary speed of the collector. Mechanical testing of the yarns revealed that PVDF-TrFe and PCL yarns have a higher strain-to-failure than PAN yarns, reaching 307% for PCL nanoyarns. For the first time, the porosity of nanofiber yarns was studied as a function of twist angle, showing that PAN nanoyarns are more porous than PCL yarns.

Meso-macro simulation of the woven fabric local deformation in draping

NASA Astrophysics Data System (ADS)

Iwata, Akira; Inoue, Takuya; Naouar, Naim; Boisse, Philippe; Lomov, Stepan V.

2018-05-01

The paper reports results of such combined meso-macro modelling for a plain weave carbon fabric with spread yarns. The boundary conditions for a local meso-model are taken from the macro draping simulation. The fabric geometry is modelled with WiseTex and transferred to the finite element package. A hyperelastic constitutive model for the yarns (Charmetant - Boisse) is used in the meso-modelling; the model parameters are identified and validated in independent tension, shear, compaction and bending tests of the yarn and the fabric. The simulation reproduces local yarn slippage and buckling, for example, the yarn distortion on the 3D mould corner (see the figure). The simulations are compared with the local fabric distortions observed during draping experiments.

Micro-tomography based Geometry Modeling of Three-Dimensional Braided Composites

NASA Astrophysics Data System (ADS)

Fang, Guodong; Chen, Chenghua; Yuan, Shenggang; Meng, Songhe; Liang, Jun

2018-06-01

A tracking and recognizing algorithm is proposed to automatically generate irregular cross-sections and central path of braid yarn within the 3D braided composites by using sets of high resolution tomography images. Only the initial cross-sections of braid yarns in a tomography image after treatment are required to be calibrated manually as searching cross-section template. The virtual geometry of 3D braided composites including some detailed geometry information, such as the braid yarn squeezing deformation, braid yarn distortion and braid yarn path deviation etc., can be reconstructed. The reconstructed geometry model can reflect the change of braid configurations during solidification process. The geometry configurations and mechanical properties of the braided composites are analyzed by using the reconstructed geometry model.

More About The Farley Three-Dimensional Braider

NASA Technical Reports Server (NTRS)

Farley, Gary L.

1993-01-01

Farley three-dimensional braider, undergoing development, is machine for automatic fabrication of three-dimensional braided structures. Incorporates yarns into structure at arbitrary braid angles to produce complicated shape. Braiding surface includes movable braiding segments containing pivot points, along which yarn carriers travel during braiding process. Yarn carrier travels along sequence of pivot points as braiding segments move. Combined motions position yarns for braiding onto preform. Intended for use in making fiber preforms for fiber/matrix composite parts, such as multiblade propellers. Machine also described in "Farley Three-Dimensional Braiding Machine" (LAR-13911).

Studies on Thermal Behaviour of Cotton and Eri/Cotton Blended Fabrics Using Response Surface Methodology

NASA Astrophysics Data System (ADS)

Choudhuri, Prabir Kumar

2018-06-01

Eri silk fibre, the lone domesticated non-mulberry variety of silk is reported to possess excellent thermal insulation property and the fabrics made of eri silk yarn is popularly used as warmth giving apparels by the people of north-eastern states of India in particular. On the other side, cotton fibre which is comparatively cheaper than eri silk has wide application in making apparel fabrics. This paper deals with the manufacturing of plain woven fabrics made of eri/cotton blended yarn as weft over cotton warp yarn and to conduct an in-depth study on the effect of blend composition and yarn parameters like count (Ne) and amount of twist on its thermal behaviour. The Box and Behnken model of Design of Experiment for three variables and three levels, a popular statistical tool, has been used to study the influence of chosen factors. The fitted regression equation has been found to be linear in nature confirming the presence of independent effect of yarn fineness, twist and eri content in the blended yarn over thermal insulation value of the fabric with strong degree of association. The effects of yarn count, twist and proportion of eri in blends have been well explained using response surface methodology.

Studies on Thermal Behaviour of Cotton and Eri/Cotton Blended Fabrics Using Response Surface Methodology

NASA Astrophysics Data System (ADS)

Choudhuri, Prabir Kumar

2018-04-01

Eri silk fibre, the lone domesticated non-mulberry variety of silk is reported to possess excellent thermal insulation property and the fabrics made of eri silk yarn is popularly used as warmth giving apparels by the people of north-eastern states of India in particular. On the other side, cotton fibre which is comparatively cheaper than eri silk has wide application in making apparel fabrics. This paper deals with the manufacturing of plain woven fabrics made of eri/cotton blended yarn as weft over cotton warp yarn and to conduct an in-depth study on the effect of blend composition and yarn parameters like count (Ne) and amount of twist on its thermal behaviour. The Box and Behnken model of Design of Experiment for three variables and three levels, a popular statistical tool, has been used to study the influence of chosen factors. The fitted regression equation has been found to be linear in nature confirming the presence of independent effect of yarn fineness, twist and eri content in the blended yarn over thermal insulation value of the fabric with strong degree of association. The effects of yarn count, twist and proportion of eri in blends have been well explained using response surface methodology.

In-Vitro Analysis of the Effect of Constructional Parameters and Dye Class on the UV Protection Property of Cotton Knitted Fabrics.

PubMed

Kan, Chi-Wai; Au, Chui-Ha

2015-01-01

Cotton knitted fabrics were manufactured with different yarn types (conventional ring spun yarn and torque-free ring spun yarn) with different fibre types (combed cotton and combed Supima cotton) and yarn fineness (Ne30 and Ne40). These fabrics were then dyed with three types of dye (reactive, direct and sulphur dye) with three dye concentrations (0.1%, 1.0% and 5.0% on-weight of fabric (owf)) in three colours (red, yellow and blue). This study examined the impact of constructional parameters and dyeing on ultraviolet (UV) protection properties of cotton knitted fabric. In-vitro test with spectrophotometer was used for evaluating the UV protection property of dyed cotton knitted fabrics. Among the six parameters investigated, fineness of yarn and dye concentration were the most significant factors affecting UPF while the color effect is the least significant. Experimental results revealed that the UPF value of dyed fabrics made from combed cotton is generally higher than the combed Supima cotton since combed cotton is composed of shorter fibres which facilitate the blocking or absorption of UV radiation. Second, fabrics made with twist yarn (i.e. ring spun yarn) have higher UPF value than the corresponding ESTex one (i.e. torque-free yarn) in general since fabrics made with ring spun yarn tend to shrink during wet processing and so it is more compact. Third, the UPF value of fabrics made with 30Ne yarn was higher than the 40Ne one since it is thicker and has lower fabric porosity. Fourth, fabrics dyed with lower concentration of dye gave the lowest UPF. Fifth, the sulphur dyed samples performed worse than the reactive and direct dyed samples in terms of UV protection property. Sixth, there is no significant difference in UPF for red, yellow and blue coloured fabrics. Seventh, this study also demonstrated that lightness of fabric is negatively related to UV protection property.

In-Vitro Analysis of the Effect of Constructional Parameters and Dye Class on the UV Protection Property of Cotton Knitted Fabrics

PubMed Central

2015-01-01

Cotton knitted fabrics were manufactured with different yarn types (conventional ring spun yarn and torque-free ring spun yarn) with different fibre types (combed cotton and combed Supima cotton) and yarn fineness (Ne30 and Ne40). These fabrics were then dyed with three types of dye (reactive, direct and sulphur dye) with three dye concentrations (0.1%, 1.0% and 5.0% on-weight of fabric (owf)) in three colours (red, yellow and blue). This study examined the impact of constructional parameters and dyeing on ultraviolet (UV) protection properties of cotton knitted fabric. In-vitro test with spectrophotometer was used for evaluating the UV protection property of dyed cotton knitted fabrics. Among the six parameters investigated, fineness of yarn and dye concentration were the most significant factors affecting UPF while the color effect is the least significant. Experimental results revealed that the UPF value of dyed fabrics made from combed cotton is generally higher than the combed Supima cotton since combed cotton is composed of shorter fibres which facilitate the blocking or absorption of UV radiation. Second, fabrics made with twist yarn (i.e. ring spun yarn) have higher UPF value than the corresponding ESTex one (i.e. torque-free yarn) in general since fabrics made with ring spun yarn tend to shrink during wet processing and so it is more compact. Third, the UPF value of fabrics made with 30Ne yarn was higher than the 40Ne one since it is thicker and has lower fabric porosity. Fourth, fabrics dyed with lower concentration of dye gave the lowest UPF. Fifth, the sulphur dyed samples performed worse than the reactive and direct dyed samples in terms of UV protection property. Sixth, there is no significant difference in UPF for red, yellow and blue coloured fabrics. Seventh, this study also demonstrated that lightness of fabric is negatively related to UV protection property. PMID:26222792

Effect of Stretching on Ultraviolet Protection of Cotton and Cotton/Coolmax Blended Weft Knitted Fabric in a Wet State

PubMed Central

Kan, Chi-wai; Yam, Lim-yung; Ng, Sun-pui

2014-01-01

In this paper, the ultraviolet protection factor (UPF) of plain knitted fabrics made from 20Ne cotton yarns, Coolmax yarn and their combinations in wet, relaxed and stretched states were studied. According to the fiber composition, fabric samples are divided into three groups including Group I (single cotton yarn), Group II (cotton/cotton combination) and Group III (Coolmax/cotton combination) for discussion. In order to study the effect of wet condition on the UPF of different plain knitted fabrics, five wetting solutions, namely: (i) chlorinated pool water; (ii) sea water, (iii) acidic perspiration; (iv) alkaline perspiration and (v) deionized water (DI water) were prepared and the fabrics were wetted with different percentages of 50%, 75% and 100%. The UPF of the plain knitted fabrics in wet, relaxed and stretched states was measured and the results were discussed. In addition, yarn and fabric properties such as yarn tenacity, yarn strength, fiber combination and water vapor transmission, which affect the corresponding UPF values, were used for generating a prediction model in order to determine UPF. Verification of the prediction model was also conducted. PMID:28788440

The Effect of Stretching on Ultraviolet Protection of Cotton and Cotton/Coolmax-Blended Weft Knitted Fabric in a Dry State

PubMed Central

Kan, Chi-wai; Yam, Lim-yung; Ng, Sun-pui

2013-01-01

In this paper, the ultraviolet protection factor (UPF) of weft knitted fabrics made from 20Ne cotton yarn, Coolmax yarn and their blends in dry, relaxed and stretched states were studied. According to the fibre composition, samples were divided into three groups: Group I (single cotton yarn); Group II (cotton/cotton combination); and Group III (Coolmax/cotton combination) for discussion. In addition, yarn and fabric properties such as yarn tenacity, yarn strength, fibre combination and water vapour transmission that affect the corresponding UPF values are used for formulating a prediction model in order to determine UPF. Generally speaking, when samples are measured under stretched conditions in a dry state, they exhibit a remarkable reduction in ultraviolet protective power, as pores are opened up and UV radiation can easily penetrate through these pores. In addition, greater stretch percentage came along with greater reduction in UPF. This can be explained by the fact that the amount and the size of pores increase when samples are subjected to greater tension. PMID:28788371

Changing the color of textiles with realistic visual rendering

NASA Astrophysics Data System (ADS)

Hébert, Mathieu; Henckens, Lambert; Barbier, Justine; Leboulleux, Lucie; Page, Marine; Roujas, Lucie; Cazier, Anthony

2015-03-01

Fast and easy preview of a fabric without having to produce samples would be very profitable for textile designers, but remains a technological challenge. As a first step towards this objective, we study the possibility of making images of a real sample, and changing virtually the colors of its yarns while preserving the shine and shadow texture. We consider two types of fabrics: Jacquard weave fabrics made of polyester warp and weft yarns of different colors, and satin ribbons made of polyester and metallic yarns. For the Jacquard fabric, we make a color picture with a scanner on a sample in which the yarns have contrasted colors, threshold this image in order to distinguish the pixels corresponding to each yarn, and accordingly modify their hue and chroma values. This method is simple to operate but do not enable to simulate the angle-dependent shine. A second method, tested on the satin ribbon made of black polyester and achromatic metallic yarns, is based on polarized imaging. We analyze the polarization state of the reflected light which is different for dielectric and metallic materials illuminated by polarized light. We then add a fixed color value to the pixels representing the polyester yarns and modify the hue and chroma of the pixels representing the metallic yarns. This was performed for many incident angles of light, in order to render the twinkling effect displayed by these ribbons. We could verify through a few samples that the simulated previews reproduce real pictures with visually acceptable accuracy.

The construction phase’s influence to the moving ability of cross-sections of woven structure

NASA Astrophysics Data System (ADS)

Inogamdjanov, D.; Daminov, A.; Kasimov, O.

2017-10-01

The purpose of this study is to work out bases to predict properties for single layer flat woven fabrics depending on changes of construction phases. A structural model of cross-section of single layered fabric is described based on the Pierce’s model. Form transformation of the yarn like straight, semi-arch and arch yarn is considered according to the alteration of yarn tension under the theory of Novikov. The value contributions to movement index of warp and weft yarn and their total moving ability in cross-sections at all structure phases of fabric are summarized.

Innovative monitoring of 3D warp interlock fabric during forming process

NASA Astrophysics Data System (ADS)

Dufour, C.; Jerkovic, I.; Wang, P.; Boussu, F.; Koncar, V.; Soulat, D.; Grancaric, A. M.; Pineau, P.

2017-10-01

The final geometry of 3D warp interlock fabric needs to be check during the 3D forming step to ensure the right locations of warp and weft yarns inside the final structure. Thus, a new monitoring approach has been proposed based on sensor yarns located in the fabric thickness. To ensure the accuracy of measurements, the observation of the surface deformation of the 3D warp interlock fabric has been joined to the sensor yarns measurements. At the end, it has been revealed a good correlation between strain measurement done globally by camera and locally performed by sensor yarns.

19 CFR 141.89 - Additional information for certain classes of merchandise.

Code of Federal Regulations, 2010 CFR

2010-04-01

..., composed of yarns of different color, or dyed; if composed of cotton and other materials, state the... the yarns are combed or carded; (12) Number of colors or kinds (different yarn sizes or materials) in..., C, J, K, M, N, P and T. VIII. If 3(d) is larger than any other percent in 3 and if 4(d) is larger...

19 CFR 141.89 - Additional information for certain classes of merchandise.

Code of Federal Regulations, 2011 CFR

2011-04-01

..., composed of yarns of different color, or dyed; if composed of cotton and other materials, state the... the yarns are combed or carded; (12) Number of colors or kinds (different yarn sizes or materials) in..., C, J, K, M, N, P and T. VIII. If 3(d) is larger than any other percent in 3 and if 4(d) is larger...

Laminar composite structures for high power actuators

NASA Astrophysics Data System (ADS)

Hobosyan, M. A.; Martinez, P. M.; Zakhidov, A. A.; Haines, C. S.; Baughman, R. H.; Martirosyan, K. S.

2017-05-01

Twisted laminar composite structures for high power and large-stroke actuators based on coiled Multi Wall Carbon Nanotube (MWNT) composite yarns were crafted by integrating high-density Nanoenergetic Gas Generators (NGGs) into carbon nanotube sheets. The linear actuation force, resulting from the pneumatic force caused by expanding gases confined within the pores of laminar structures and twisted carbon nanotube yarns, can be further amplified by increasing NGG loading and yarns twist density, as well as selecting NGG compositions with high energy density and large-volume gas generation. Moreover, the actuation force and power can be tuned by the surrounding environment, such as to increase the actuation by combustion in ambient air. A single 300-μm-diameter integrated MWNT/NGG coiled yarn produced 0.7 MPa stress and a contractile specific work power of up to 4.7 kW/kg, while combustion front propagated along the yarn at a velocity up to 10 m/s. Such powerful yarn actuators can also be operated in a vacuum, enabling their potential use for deploying heavy loads in outer space, such as to unfold solar panels and solar sails.

Origin of tensile strength of a woven sample cut in bias directions

PubMed Central

Pan, Ning; Kovar, Radko; Dolatabadi, Mehdi Kamali; Wang, Ping; Zhang, Diantang; Sun, Ying; Chen, Li

2015-01-01

Textile fabrics are highly anisotropic, so that their mechanical properties including strengths are a function of direction. An extreme case is when a woven fabric sample is cut in such a way where the bias angle and hence the tension loading direction is around 45° relative to the principal directions. Then, once loaded, no yarn in the sample is held at both ends, so the yarns have to build up their internal tension entirely via yarn–yarn friction at the interlacing points. The overall fabric strength in such a sample is a result of contributions from the yarns being pulled out and those broken during the process, and thus becomes a function of the bias direction angle θ, sample width W and length L, along with other factors known to affect fabric strength tested in principal directions. Furthermore, in such a bias sample when the major parameters, e.g. the sample width W, change, not only the resultant strengths differ, but also the strength generating mechanisms (or failure types) vary. This is an interesting problem and is analysed in this study. More specifically, the issues examined in this paper include the exact mechanisms and details of how each interlacing point imparts the frictional constraint for a yarn to acquire tension to the level of its strength when both yarn ends were not actively held by the testing grips; the theoretical expression of the critical yarn length for a yarn to be able to break rather than be pulled out, as a function of the related factors; and the general relations between the tensile strength of such a bias sample and its structural properties. At the end, theoretical predictions are compared with our experimental data. PMID:26064655

'Fab-chips': a versatile, fabric-based platform for low-cost, rapid and multiplexed diagnostics.

PubMed

Bhandari, Paridhi; Narahari, Tanya; Dendukuri, Dhananjaya

2011-08-07

Low cost and scalable manufacture of lab-on-chip devices for applications such as point-of-care testing is an urgent need. Weaving is presented as a unified, scalable and low-cost platform for the manufacture of fabric chips that can be used to perform such testing. Silk yarns with different properties are first selected, treated with the appropriate reagent solutions, dried and handloom-woven in one step into an integrated fabric chip. This platform has the unique advantage of scaling up production using existing and low cost physical infrastructure. We have demonstrated the ability to create pre-defined flow paths in fabric by using wetting and non-wetting silk yarns and a Jacquard attachment in the loom. Further, we show that yarn parameters such as the yarn twist frequency and weaving coverage area may be conveniently used to tune both the wicking rate and the absorptive capacity of the fabric. Yarns optimized for their final function were used to create an integrated fabric chip containing reagent-coated yarns. Strips of this fabric were then used to perform a proof-of-concept immunoassay with sample flow taking place by capillary action and detection being performed by a visual readout. This journal is © The Royal Society of Chemistry 2011

Weaving multi-layer fabrics for reinforcement of engineering components

NASA Technical Reports Server (NTRS)

Hill, B. J.; Mcilhagger, R.; Mclaughlin, P.

1993-01-01

The performance of interlinked, multi-layer fabrics and near net shape preforms for engineering applications, woven on a 48 shaft dobby loom using glass, aramid, and carbon continuous filament yarns is assessed. The interlinking was formed using the warp yarns. Two basic types of structure were used. The first used a single warp beam and hence each of the warp yarns followed a similar path to form four layer interlinked reinforcements and preforms. In the second two warp beams were used, one for the interlinking yarns which pass from the top to the bottom layer through-the-thickness of the fabric and vice versa, and the other to provide 'straight' yarns in the body of the structure to carry the axial loading. Fabrics up to 15mm in thickness were constructed with varying amounts of through-the-thickness reinforcement. Tapered T and I sections were also woven, with the shaping produced by progressive removal of ends during construction. These fabrics and preforms were impregnated with resin and cured to form composite samples for testing. Using these two basic types of construction, the influence of reinforcement construction and the proportion and type of interlinking yarn on the performance of the composite was assessed.

3-Dimensional Nano-Scale Reinforcement Architecture for Advanced Composite Structures

DTIC Science & Technology

2008-10-01

textile structures on 3TEX equipment. Conduct experimental studies of the spinnability of Multi-Wall Carbon Nanotube ( MWCNT ) forests and...adjacent inner wall when MWNT length is one centimeter (Fig. 1.8). Complete stress transfer to all walls by going to longer nanotube lengths could...between regular IK T300 carbon yarn and 25-ply carbon nanotube yarn. Fig. 5.8 shows the nanotube yarns going through the heddles during weaving with

Carbon nanotube torsional springs for regenerative braking systems

NASA Astrophysics Data System (ADS)

Liu, Sanwei; Martin, Corbin; Lashmore, David; Schauer, Mark; Livermore, Carol

2015-10-01

The modeling and demonstration of large stroke, high energy density and high power density torsional springs based on carbon nanotube (CNT) yarns is reported, as well as their application as energy-storing actuators for regenerative braking systems. An originally untwisted CNT yarn is cyclically loaded and unloaded in torsion, with the maximum rotation angle increasing incrementally until failure. The measured average extractable energy density values are 2.9 kJ kg-1  ±  1.2 kJ kg-1 and 3.4 kJ kg-1  ±  0.4 kJ kg-1 for 1-ply CNT yarns and 2-ply CNT yarns, respectively. Additionally, a regenerative braking system is demonstrated to capture the kinetic energy of a wheel and store it as elastic energy in twisted CNT yarns. When the yarn’s twist is released, the stored energy reaccelerates the wheel. The measured energy and mean power densities of the CNT yarns in the simple regenerative braking setup are on average 3.3 kJ kg-1 and 0.67 kW kg-1, respectively, with maximum measured values of up to 4.7 kJ kg-1 and 1.2 kW kg-1, respectively. A slightly lower energy density of up to 1.2 kJ kg-1 and a 0.29 kW kg-1 mean power density are measured for CNT yarns in a more complex setup that mimics a unidirectional rotating regenerative braking mechanism.

The elastic properties of woven polymeric fabric

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

Warren, W.E.

1989-01-01

The in-plane linear elastic constants of woven fabric are determined in terms of the specific fabric microstructure. The fabric is assumed to be a spatially periodic interlaced network of orthogonal yarns and the individual yarns are modeled as extensible elastica. These results indicate that a significant coupling of bending and stretching effects occurs during deformation. Results of this theoretical analysis compare favorable with measured in-plane elastic constants for Vincel yarn fabrics. 17 refs., 2 figs., 1 tab.

Crimp-Imbalanced Protective (CRIMP) Fabrics: An Analytical Investigation into the Relationship Between Crimp Contents, Energy Absorption, and Fabric Ballistic Performance

DTIC Science & Technology

2010-09-15

migration and yarn stretching. These mechanisms relate to the force required to pull a yarn out from the fabric. If the fabric is made of low...the following assumptions were made : The fabric architecture is plain-woven. The yarns have a circular cross section with diameter D equal to 1.0... Bulletproof Aramid Fabric," Journal of Materials Science, vol. 32, pp. 4167-4173, 1997. 16. D. A. Shockey, D. C. Erlich, and J. W. Simons, "Improved

Tension Strength, Failure Prediction and Damage Mechanisms in 2D Triaxial Braided Composites with Notch

NASA Technical Reports Server (NTRS)

Norman, Timothy L.; Anglin, Colin

1995-01-01

The unnotched and notched (open hole) tensile strength and failure mechanisms of two-dimensional (2D) triaxial braided composites were examined. The effect of notch size and notch position were investigated. Damage initiation and propagation in notched and unnotched coupons were also examined. Theory developed to predict the normal stress distribution near an open hole and failure for tape laminated composites was evaluated for its applicability to 2D triaxial braided textile composite materials. Four different fiber architectures were considered; braid angle, yarn and braider size, percentage of longitudinal yarns and braider angle varied. Tape laminates equivalent to textile composites were also constructed for comparison. Unnotched tape equivalents were stronger than braided textiles but exhibited greater notch sensitivity. Notched textiles and tape equivalents have roughly the same strength at large notch sizes. Two common damage mechanisms were found: braider yarn cracking and near notch longitudinal yarn splitting. Cracking was found to initiate in braider yarns in unnotched and notched coupons, and propagate in the direction of the braider yarns until failure. Damage initiation stress decreased with increasing braid angle. No significant differences in prediction of near notch strain between textile and tape equivalents could be detected for small braid angle, but the correlations were weak for textiles with large braid angle. Notch strength could not be predicted using existing anisotropic theory for braided textiles due to their insensitivity to notch.

Structural mechanics of 3-D braided preforms for composites. IV - The 4-step tubular braiding

NASA Technical Reports Server (NTRS)

Hammad, M.; El-Messery, M.; El-Shiekh, A.

1991-01-01

This paper presents the fundamentals of the 4-step 3D tubular braiding process and the structure of the preforms produced. Based on an idealized structural model, geometric relations between the structural parameters of the preform are analytically established. The effects of machine arrangement and operating conditions are discussed. Yarn retraction, yarn surface angle, outside diameter, and yarn volume fraction of the preform in terms of the pitch length, the inner diameter, and the machine arrangement are theoretically predicted and experimentally verified.

Failure analysis of woven and braided fabric reinforced composites

NASA Technical Reports Server (NTRS)

Naik, Rajiv A.

1994-01-01

A general purpose micromechanics analysis that discretely models the yarn architecture within the textile repeating unit cell was developed to predict overall, three dimensional, thermal and mechanical properties, damage initiation and progression, and strength. This analytical technique was implemented in a user-friendly, personal computer-based, menu-driven code called Textile Composite Analysis for Design (TEXCAD). TEXCAD was used to analyze plain weave and 2x2, 2-D triaxial braided composites. The calculated tension, compression, and shear strengths correlated well with available test data for both woven and braided composites. Parametric studies were performed on both woven and braided architectures to investigate the effects of parameters such as yarn size, yarn spacing, yarn crimp, braid angle, and overall fiber volume fraction on the strength properties of the textile composite.

Quantification of micro-CT images of textile reinforcements

NASA Astrophysics Data System (ADS)

Straumit, Ilya; Lomov, Stepan V.; Wevers, Martine

2017-10-01

VoxTex software (KU Leuven) employs 3D image processing, which use the local directionality information, retrieved using analysis of local structure tensor. The processing results in a voxel 3D array, with each voxel carrying information on (1) material type (matrix; yarn/ply, with identification of the yarn/ply in the reinforcement architecture; void) and (2) fibre direction for fibrous yarns/plies. The knowledge of the material phase volume and known characterisation of the textile structure allows assigning to the voxels (3) fibre volume fraction. This basic voxel model can be further used for different type of the material analysis: Internal geometry and characterisation of defects; permeability; micromechanics; mesoFE voxel models. Apart from the voxel based analysis, approaches to reconstruction of the yarn paths are presented.

Thermal control structure and garment

DOEpatents

Klett, James W [Knoxville, TN; Cameron, Christopher Stan [Sanford, NC

2012-03-13

A flexible thermally conductive structure. The structure generally includes a plurality of thermally conductive yarns, at least some of which are at least partially disposed adjacent to an elastomeric material. Typically, at least a portion of the plurality of thermally conductive yarns is configured as a sheet. The yarns may be constructed from graphite, metal, or similar materials. The elastomeric material may be formed from urethane or silicone foam that is at least partially collapsed, or from a similar material. A thermal management garment is provided, the garment incorporating a flexible thermally conductive structure.

Method and apparatus for the application of textile treatment compositions to textile materials

DOEpatents

Argyle, Mark D.; Propp, William Alan

1998-01-01

A system for applying textile treatment compositions to textile materials. A conduit member is provided which includes a passageway having a first end, a second end, and a medial portion with a constricted (narrowed) region. The passageway may include at least one baffle having an opening therethrough. A yarn strand is then moved through the passageway. A textile treatment composition (a sizing agent or dye) dissolved in a carrier medium (a supercritical fluid or liquified gas) is thereafter introduced into the constricted region, preferably at an acute angle relative to the passageway. The carrier medium expands inside the passageway which causes delivery of the treatment composition to the yarn. The treated yarn then passes through the baffle (if used) which facilitates drying of the yarn. During this process, a carrier gas can be introduced into the passageway to ensure the production of a smooth, dry product.

Method and apparatus for the application of textile treatment compositions to textile materials

DOEpatents

Argyle, M.D.; Propp, W.A.

1998-01-20

A system is described for applying textile treatment compositions to textile materials. A conduit member is provided which includes a passageway having a first end, a second end, and a medial portion with a constricted (narrowed) region. The passageway may include at least one baffle having an opening there through. A yarn strand is then moved through the passageway. A textile treatment composition (a sizing agent or dye) dissolved in a carrier medium (a supercritical fluid or liquefied gas) is thereafter introduced into the constricted region, preferably at an acute angle relative to the passageway. The carrier medium expands inside the passageway which causes delivery of the treatment composition to the yarn. The treated yarn then passes through the baffle (if used) which facilitates drying of the yarn. During this process, a carrier gas can be introduced into the passageway to ensure the production of a smooth, dry product. 1 fig.

Formability of tufted 3-dimensional composite reinforcement

NASA Astrophysics Data System (ADS)

Liu, Ling Shan; Wang, Peng; Legrand, Xavier; Soulat, Damien

2016-10-01

In the aerospace industry, more and more complex preform for composite parts are needed. Traditionally, laminated reinforcement is largely used as the method. The development of tufting technology has now advanced to a stage whereby it can be employed to produce the 3D textile composite reinforcements. Because the tufting technology is user-friendly, in this study, the tufting parameters (tufting density, tufting length, tufting yarn orientations…) are varied, in order to improve the understanding of formability of the tufted 3D fabric during manufacturing, in particular the influence of the tufting yarns, the present work is performed to analyse the preforming behaviours of tufted 3D reinforcement in the hemispherical stamping process. The preforming behaviours are also compared with the ones of the multilayered forming. Interply sliding and winkling phenomenon during forming are fully influenced by tufting yarns on the material draw-in, by the orientations of tufting yarn, …

Multiscale mechanics of the lateral pressure effect on enhancing the load transfer between polymer coated CNTs.

PubMed

Yazdandoost, Fatemeh; Mirzaeifar, Reza; Qin, Zhao; Buehler, Markus J

2017-05-04

While individual carbon nanotubes (CNTs) are known as one of the strongest fibers ever known, even the strongest fabricated macroscale CNT yarns and fibers are still significantly weaker than individual nanotubes. The loss in mechanical properties is mainly because the deformation mechanism of CNT fibers is highly governed by the weak shear strength corresponding to sliding of nanotubes on each other. Adding polymer coating to the bundles, and twisting the CNT yarns to enhance the intertube interactions are both efficient methods to improve the mechanical properties of macroscale yarns. Here, we perform molecular dynamics (MD) simulations to unravel the unknown deformation mechanism in the intertube polymer chains and also local deformations of the CNTs at the atomistic scale. Our results show that the lateral pressure can have both beneficial and adverse effects on shear strength of polymer coated CNTs, depending on the local deformations at the atomistic scale. In this paper we also introduce a bottom-up bridging strategy between a full atomistic model and a coarse-grained (CG) model. Our trained CG model is capable of incorporating the atomistic scale local deformations of each CNT to the larger scale collect behavior of bundles, which enables the model to accurately predict the effect of lateral pressure on larger CNT bundles and yarns. The developed multiscale CG model is implemented to study the effect of lateral pressure on the shear strength of straight polymer coated CNT yarns, and also the effect of twisting on the pull-out force of bundles in spun CNT yarns.

A COMPARATIVE STUDY ON PARAMETERS USED FOR CHARACTERIZING COTTON SHORT FIBERS

USDA-ARS?s Scientific Manuscript database

The quantity of short cotton fibers in a cotton sample is an important cotton quality parameter which impacts yarn production performance and yarn quality. Researchers have proposed different parameters for characterizing the amount of short fibers in a cotton sample. A comprehensive study was car...

On the inter-stitch interaction in biaxial non-crimp fabrics

NASA Astrophysics Data System (ADS)

Colin, David; Bel, Sylvain; Hans, Thorsten; Hartmann, Mathias

2018-05-01

Simulation models of fiber reinforcements at the scale of fibers possibly reproduce important deformation mechanisms and can offer predictive capabilities on the macroscopic mechanical behavior. Although potential deformation mechanisms are already listed in the literature, these phenomena should be experimentally investigated to evaluate their relevance in simulation at the scale of fibers. This study focuses on the inter-stitch interaction of Non-Crimp Fabric (NCF) and aims at quantifying the relative motion of the stitching yarns. To this end, controlled shear deformation was introduced on +/-45° biaxial tricot stitched NCF. The stitching yarns have been colored on the backside of the sample while the front face remained uncolored. Therefore, an inter-stitch relative motion can be observed if an uncolored portion of the stitching yarn appears on the back face of the sample. The samples were observed during the experiments with a digital microscope in order to measure the uncolored portion of the yarns on the back face. Thus, the stitching yarn movement can be quantified for various shear angles. A significant relative motion was observed compared to the original stitching length. Based on this study, the authors argue that the inter-stitch sliding is a relevant deformation mechanism for biaxial tricot stitched NCF at the scale of fibers.

Studies on Tasar Cocoon Cooking Using Permeation Method

NASA Astrophysics Data System (ADS)

Javali, Uday C.; Malali, Kiran B.; Ramya, H. G.; Naik, Subhas V.; Padaki, Naveen V.

2018-02-01

Cocoon cooking is an important process before reeling of tasar silk yarn. Cooking ensures loosening of the filaments in the tasar cocoons thereby easing the process of yarn withdrawal during reeling process. Tasar cocoons have very hard shell and hence these cocoons need chemical cooking process to loosen the silk filaments. Attempt has been made in this article to study the effect of using vacuum permeation chamber for tasar cocoon cooking in order to reduce the cooking time and improve the quality of tasar silk yarn. Vacuum assisted permeation cooking method has been studied in this article on tasar daba cocoons for cooking efficiency, deflossing and reelability. Its efficiency has been evaluated with respect to different cooking methods viz, traditional and open pan cooking methods. The tasar silk produced after reeling process has been tested for fineness, strength and cohesion properties. Results indicate that permeation method of tasar cooking ensures uniform cooking with higher efficiency along with better reeling performance and improved yarn properties.

Geometrical modelling of textile reinforcements

NASA Technical Reports Server (NTRS)

Pastore, Christopher M.; Birger, Alexander B.; Clyburn, Eugene

1995-01-01

The mechanical properties of textile composites are dictated by the arrangement of yarns contained with the material. Thus to develop a comprehensive understanding of the performance of these materials, it is necessary to develop a geometrical model of the fabric structure. This task is quite complex, as the fabric is made form highly flexible yarn systems which experience a certain degree of compressability. Furthermore there are tremendous forces acting on the fabric during densification typically resulting in yarn displacement and misorientation. The objective of this work is to develop a methodology for characterizing the geometry of yarns within a fabric structure including experimental techniques for evaluating these models. Furthermore, some applications of these geometric results to mechanical prediction models are demonstrated. Although more costly than its predecessors, the present analysis is based on the detailed architecture developed by one of the authors and his colleagues and accounts for many of the geometric complexities that other analyses ignore.

Multi Length Scale Finite Element Design Framework for Advanced Woven Fabrics

NASA Astrophysics Data System (ADS)

Erol, Galip Ozan

Woven fabrics are integral parts of many engineering applications spanning from personal protective garments to surgical scaffolds. They provide a wide range of opportunities in designing advanced structures because of their high tenacity, flexibility, high strength-to-weight ratios and versatility. These advantages result from their inherent multi scale nature where the filaments are bundled together to create yarns while the yarns are arranged into different weave architectures. Their highly versatile nature opens up potential for a wide range of mechanical properties which can be adjusted based on the application. While woven fabrics are viable options for design of various engineering systems, being able to understand the underlying mechanisms of the deformation and associated highly nonlinear mechanical response is important and necessary. However, the multiscale nature and relationships between these scales make the design process involving woven fabrics a challenging task. The objective of this work is to develop a multiscale numerical design framework using experimentally validated mesoscopic and macroscopic length scale approaches by identifying important deformation mechanisms and recognizing the nonlinear mechanical response of woven fabrics. This framework is exercised by developing mesoscopic length scale constitutive models to investigate plain weave fabric response under a wide range of loading conditions. A hyperelastic transversely isotropic yarn material model with transverse material nonlinearity is developed for woven yarns (commonly used in personal protection garments). The material properties/parameters are determined through an inverse method where unit cell finite element simulations are coupled with experiments. The developed yarn material model is validated by simulating full scale uniaxial tensile, bias extension and indentation experiments, and comparing to experimentally observed mechanical response and deformation mechanisms. Moreover

19 CFR 208.3 - Petitions.

Code of Federal Regulations, 2011 CFR

2011-04-01

... or likely time of the receipt by an apparel producer in all countries where the fabric or yarn has... sale, including lesser developed beneficiary sub-Saharan African countries, by country, for the most... yarn, by firm, that will be available in lesser developed beneficiary sub-Saharan African countries in...

PEDOT:PSS-Based Piezo-Resistive Sensors Applied to Reinforcement Glass Fibres for in Situ Measurement during the Composite Material Weaving Process

PubMed Central

Trifigny, Nicolas; Kelly, Fern M.; Cochrane, Cédric; Boussu, François; Koncar, Vladan; Soulat, Damien

2013-01-01

The quality of fibrous reinforcements used in composite materials can be monitored during the weaving process. Fibrous sensors previously developed in our laboratory, based on PEDOT:PSS, have been adapted so as to directly measure the mechanical stress on fabrics under static or dynamic conditions. The objective of our research has been to develop new sensor yarns, with the ability to locally detect mechanical stresses all along the warp or weft yarn. This local detection is undertaken inside the weaving loom in real time during the weaving process. Suitable electronic devices have been designed in order to record in situ measurements delivered by this new fibrous sensor yarn. PMID:23959238

19 CFR 10.843 - Articles eligible for duty-free treatment.

Code of Federal Regulations, 2010 CFR

2010-04-01

... paragraphs (a) through (j) of this section that are imported directly from Haiti or the Dominican Republic...-shape, and yarns, subject to the applicable quantitative limits set forth in U.S. Note 6(g), Subchapter...-shape, and yarns, without regard to the source of the fabric, fabric components, components knit-to...

19 CFR 10.843 - Articles eligible for duty-free treatment.

Code of Federal Regulations, 2011 CFR

2011-04-01

... paragraphs (a) through (j) of this section that are imported directly from Haiti or the Dominican Republic...-shape, and yarns, subject to the applicable quantitative limits set forth in U.S. Note 6(g), Subchapter...-shape, and yarns, without regard to the source of the fabric, fabric components, components knit-to...

40 CFR 63.4281 - Am I subject to this subpart?

Code of Federal Regulations, 2013 CFR

2013-07-01

... fabric, rainwear, sheets, tents, threads and V-belts. The coating and printing subcategory includes any... slashing process, sizing compounds are applied to warp yarn to bind the fiber together and stiffen the yarn..., sheets, towels, and threads. (b) You are subject to this subpart if you own or operate a new...

40 CFR 63.4281 - Am I subject to this subpart?

Code of Federal Regulations, 2014 CFR

2014-07-01

... fabric, rainwear, sheets, tents, threads and V-belts. The coating and printing subcategory includes any... slashing process, sizing compounds are applied to warp yarn to bind the fiber together and stiffen the yarn..., sheets, towels, and threads. (b) You are subject to this subpart if you own or operate a new...

40 CFR 63.4281 - Am I subject to this subpart?

Code of Federal Regulations, 2012 CFR

2012-07-01

... fabric, rainwear, sheets, tents, threads and V-belts. The coating and printing subcategory includes any... slashing process, sizing compounds are applied to warp yarn to bind the fiber together and stiffen the yarn..., sheets, towels, and threads. (b) You are subject to this subpart if you own or operate a new...

Spinning Wool with a Hand Spindle.

ERIC Educational Resources Information Center

Kren, Margo

1982-01-01

Describes an eight-week program in which 8- to 14-year-olds learned to spin raw wool into yarn. Students observed wool shearing at a sheep farm, learned to prepare wool for spinning, and spun their own yarn. Detail directions for carding and use of hand spindles are included. (AM)

75 FR 48931 - Determination Under the Textile and Apparel Commercial Availability Provision of the Dominican...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-12

... Agreements (``CITA'') has determined that certain woven yarn-dyed fabrics of lyocell and cotton, as specified...'') for BWA, Inc. (``BWA'') Corporation for certain woven yarn-dyed fabrics of lyocell and cotton. On July... Fabrics of Lyocell and Cotton HTS Subheading: 5516.13.0000, 5516.43.00 Fiber Content: 55-85% standard...

19 CFR 10.244 - Certificate of Origin.

Code of Federal Regulations, 2011 CFR

2011-04-01

... assembled from U.S. formed, dyed, printed and finished fabrics or fabric components, or U.S. formed knit-to... llama, alpaca or vicuña fabrics, fabric components, or knit-to-shape components, from Andean yarns 10... more yarns, fabrics, fabric components, or knit-to-shape components described in preference groups A...

19 CFR 10.244 - Certificate of Origin.

Code of Federal Regulations, 2010 CFR

2010-04-01

... assembled from U.S. formed, dyed, printed and finished fabrics or fabric components, or U.S. formed knit-to... llama, alpaca or vicuña fabrics, fabric components, or knit-to-shape components, from Andean yarns 10... more yarns, fabrics, fabric components, or knit-to-shape components described in preference groups A...

Analysis of woven and braided fabric reinforced composites

NASA Technical Reports Server (NTRS)

Naik, Rajiv A.

1994-01-01

A general purpose micromechanics analysis that discretely models the yarn architecture within the textile repeating unit cell, was developed to predict overall, three dimensional, thermal and mechanical properties. This analytical technique was implemented in a user-friendly, personal computer-based, windows compatible code called Textile Composite Analysis for Design (TEXCAD). TEXCAD was used to analyze plain, 5-harness satin, and 8-harness satin weave composites along with 2-D braided and 2x2, 2-D triaxial braided composites. The calculated overall stiffnesses correlated well with available 3-D finite element results and test data for both the woven and the braided composites. Parametric studies were performed to investigate the effects of yarn size on the yarn crimp and the overall thermal and mechanical constants for plain weave composites. The effects of braid angle were investigated for the 2-D braided composites. Finally, the effects of fiber volume fraction on the yarn undulations and the thermal and mechanical properties of 2x2, 2-D triaxial braided composites were also investigated.

A finite element analysis of a 3D auxetic textile structure for composite reinforcement

NASA Astrophysics Data System (ADS)

Ge, Zhaoyang; Hu, Hong; Liu, Yanping

2013-08-01

This paper reports the finite element analysis of an innovative 3D auxetic textile structure consisting of three yarn systems (weft, warp and stitch yarns). Different from conventional 3D textile structures, the proposed structure exhibits an auxetic behaviour under compression and can be used as a reinforcement to manufacture auxetic composites. The geometry of the structure is first described. Then a 3D finite element model is established using ANSYS software and validated by the experimental results. The deformation process of the structure at different compression strains is demonstrated, and the validated finite element model is finally used to simulate the auxetic behaviour of the structure with different structural parameters and yarn properties. The results show that the auxetic behaviour of the proposed structure increases with increasing compression strain, and all the structural parameters and yarn properties have significant effects on the auxetic behaviour of the structure. It is expected that the study could provide a better understanding of 3D auxetic textile structures and could promote their application in auxetic composites.

The properties of weft knitted fabric medical and preventive treatment action using eco-raw materials

NASA Astrophysics Data System (ADS)

Halavska, L.; Batrak, O.

2016-07-01

A new trend in the world is the clothing production using the new types of ecological raw materials application - milk, pineapple, coconut, hemp, banana, eucalyptus, clams, corn, bamboo, soya, nettle yarn. This makes it possible to create textile materials of new generation with unique antibacterial and antiseptic properties. Such materials have a positive preventive and sometimes therapeutic effect on people, and their health. Eco-raw materials clothing is able to protect the human body from the environment harmful effects: cold, heat, rain, dust, opportunely remove from underclothing layer the steam and gases, sweat; maintain in underclothing layer the necessary microclimate for normal organism functioning. Study of knitwear consumer properties, produced with eco-materials, is an urgent task of the world vector, directed on ecological environmental protection. This paper presents the research results of hygroscopicity and capillarity weft knitted fabrics, what knitted from different types of eco-raw materials: bamboo yarn, yarn containing soybean and nettle yarn. Character of influence of the liquid raising level changes depending on the experiment time and the knitting structure is revealed.

A carbon nanotube based ammonia sensor on cotton textile

NASA Astrophysics Data System (ADS)

Han, Jin-Woo; Kim, Beomseok; Li, Jing; Meyyappan, M.

2013-05-01

A single-wall carbon nanotube (CNT) based ammonia (NH3) sensor was implemented on a cotton yarn. Two types of sensors were fabricated: Au/sensing CNT/Au and conducting/sensing/conducting all CNT structures. Two perpendicular Au wires were designed to contact CNT-cotton yarn for metal-CNT sensor, whereas nanotubes were used for the electrode as well as sensing material for the all CNT sensor. The resistance shift of the CNT network upon NH3 was monitored in a chemiresistor approach. The CNT-cotton yarn sensors exhibited uniformity and repeatability. Furthermore, the sensors displayed good mechanical robustness against bending. The present approach can be utilized for low-cost smart textile applications.

Torsional Carbon Nanotube Artificial Muscles

NASA Astrophysics Data System (ADS)

Foroughi, Javad; Spinks, Geoffrey M.; Wallace, Gordon G.; Oh, Jiyoung; Kozlov, Mikhail E.; Fang, Shaoli; Mirfakhrai, Tissaphern; Madden, John D. W.; Shin, Min Kyoon; Kim, Seon Jeong; Baughman, Ray H.

2011-10-01

Rotary motors of conventional design can be rather complex and are therefore difficult to miniaturize; previous carbon nanotube artificial muscles provide contraction and bending, but not rotation. We show that an electrolyte-filled twist-spun carbon nanotube yarn, much thinner than a human hair, functions as a torsional artificial muscle in a simple three-electrode electrochemical system, providing a reversible 15,000° rotation and 590 revolutions per minute. A hydrostatic actuation mechanism, as seen in muscular hydrostats in nature, explains the simultaneous occurrence of lengthwise contraction and torsional rotation during the yarn volume increase caused by electrochemical double-layer charge injection. The use of a torsional yarn muscle as a mixer for a fluidic chip is demonstrated.

Analysis, design, fabrication, and performance of three-dimensional braided composites

NASA Astrophysics Data System (ADS)

Kostar, Timothy D.

1998-11-01

Cartesian 3-D (track and column) braiding as a method of composite preforming has been investigated. A complete analysis of the process was conducted to understand the limitations and potentials of the process. Knowledge of the process was enhanced through development of a computer simulation, and it was discovered that individual control of each track and column and multiple-step braid cycles greatly increases possible braid architectures. Derived geometric constraints coupled with the fundamental principles of Cartesian braiding resulted in an algorithm to optimize preform geometry in relation to processing parameters. The design of complex and unusual 3-D braids was investigated in three parts: grouping of yarns to form hybrid composites via an iterative simulation; design of composite cross-sectional shape through implementation of the Universal Method; and a computer algorithm developed to determine the braid plan based on specified cross-sectional shape. Several 3-D braids, which are the result of variations or extensions to Cartesian braiding, are presented. An automated four-step braiding machine with axial yarn insertion has been constructed and used to fabricate two-step, double two-step, four-step, and four-step with axial and transverse yarn insertion braids. A working prototype of a multi-step braiding machine was used to fabricate four-step braids with surrogate material insertion, unique hybrid structures from multiple track and column displacement and multi-step cycles, and complex-shaped structures with constant or varying cross-sections. Braid materials include colored polyester yarn to study the yarn grouping phenomena, Kevlar, glass, and graphite for structural reinforcement, and polystyrene, silicone rubber, and fasteners for surrogate material insertion. A verification study for predicted yarn orientation and volume fraction was conducted, and a topological model of 3-D braids was developed. The solid model utilizes architectural parameters

Finger materials for air cushion vehicles. Volume 2: Base fabrics for finger materials

NASA Astrophysics Data System (ADS)

Schoppee, M. M.; Skelton, J.; Toney, M. M.; Klemens, W.

1984-12-01

Since the short lifetimes of seal/skirt systems on surface effect vehicles (SEV's) severely limit the long-term serviceability on such craft, a systematic study was undertaken to evaluate the effects of fabric structure on the performance of rubber/fabric skirt materials under conditions of high speed, high-curvature flexing. A series of nylon fabrics was designed and manufactured in which the fiber denier, yarn denier, yarn twist, yarn crimp, weave pattern and float length were varied, but in which the tensile strength was kept constant throughout. Each one of the fabrics was rubber-coated using the same natural rubber/polybutadiene blend and the same coating technique. A flex-testing apparatus was designed and built for flexing the rubber/fabric composite materials in air at an average radius of curvature of 0.28 in. at a cycling frequency of 15 Hz. The lifetimes in flex of the experimental series of fabrics, as indicated by the appearance of flex cracks in the rubber layer, ranged from a low of 140,000 cycles to a high of 21.7 million cycles, a range of over two orders of magnitude. Factorial analysis of the test results showed that lower yarn denier, lower yarn crimp, and shorter float length (plain weave) in the fabric substrate offer significant advantages in the ability of the fabric to withstand flexing. Design of three broad fabrics for full-scale skirt trials on the SRN4 craft is described.

Effect of open hole on tensile failure properties of 2D triaxial braided textile composites and tape equivalents

NASA Technical Reports Server (NTRS)

Norman, Timothy L.; Anglin, Colin; Gaskin, David; Patrick, Mike

1995-01-01

The unnotched and notched (open hole) tensile strength and failure mechanisms of two-dimensional (2D) triaxial braided composites were examined. The effect of notch size and notch position were investigated. Damage initiation and propagation in notched and unnotched coupons were also examined. Theory developed to predict the normal stress distribution near an open hole and failure for tape laminated composites was evaluated for its applicability to triaxial braided textile composite materials. Four fiber architectures were considered with different combinations of braid angle, longitudinal and braider yam size, and percentage of longitudinal yarns. Tape laminates equivalent to textile composites were also constructed for comparison. Unnotched tape equivalents were stronger than braided textiles but exhibited greater notch sensitivity. Notched textiles and tape equivalents have roughly the same strength at large notch sizes. Two common damage mechanisms were found: braider yams cracking and near notch longitudinal yarn splitting. Cracking was found to initiate in braider yarns in unnotched and notched coupons, and propagate in the direction of the braider yarns until failure. Longitudinal yarn splitting occurred in three of four architectures that were longitudinally fiber dominated. Damage initiation stress decreased with increasing braid angle. No significant differences in prediction of near notch stress between measured and predicted stress were weak for textiles with large braid angle. Notch strength could not be predicted using existing anisotropic theory for braided textiles due to their insensitivity to notch.

Structural mass irregularities and fiber volume influence on morphology and mechanical properties of unsaturated polyester resin in matrix composites

PubMed Central

Ahmed, Khalil; Nasir, Muhammad; Fatima, Nasreen; Khan, Khalid M.; Zahra, Durey N.

2014-01-01

This paper presents the comparative results of a current study on unsaturated polyester resin (UPR) matrix composites processed by filament winding method, with cotton spun yarn of different mass irregularities and two different volume fractions. Physical and mechanical properties were measured, namely ultimate stress, stiffness, elongation%. The mechanical properties of the composites increased significantly with the increase in the fiber volume fraction in agreement with the Counto model. Mass irregularities in the yarn structure were quantitatively measured and visualized by scanning electron microscopy (SEM). Mass irregularities cause marked decrease in relative strength about 25% and 33% which increases with fiber volume fraction. Ultimate stress and stiffness increases with fiber volume fraction and is always higher for yarn with less mass irregularities. PMID:26644920

Electrically controllable twisted-coiled artificial muscle actuators using surface-modified polyester fibers

NASA Astrophysics Data System (ADS)

Park, Jungwoo; Yoo, Ji Wang; Seo, Hee Won; Lee, Youngkwan; Suhr, Jonghwan; Moon, Hyungpil; Koo, Ja Choon; Ryeol Choi, Hyouk; Hunt, Robert; Kim, Kwang Jin; Kim, Soo Hyun; Nam, Jae-Do

2017-03-01

As a new class of thermally activated actuators based on polymeric fibers, we investigated polyethylene terephthalate (PET) yarns for the development of a twisted-coiled polymer fiber actuator (TCA). The PET yarn TCA exhibited the maximum linear actuation up to 8.9% by external heating at above the glass transition temperature, 160 °C-180 °C. The payload of the actuator was successfully correlated with the preload and training-load conditions by an empirical equation. Furthermore, the PET-based TCA was electrically driven by Joule heating after the PET surface was metallization with silver. For the fast and precise control of PET yarn TCA, electroless silver plating was conducted to form electrical conductive layers on the PET fiber surface. The silver plated PET-based TCA was tested by Joule heating and the tensile actuation was increased up to 12.1% (6 V) due to the enhanced surface hardness and slippage of PET fibers. Overall, silver plating of the polymeric yarn provided a fast actuation speed and enhanced actuation performance of the TCA actuator by Joule heating, providing a great potential for being used in artificial muscle for biomimetic machines including robots, industrial actuators and powered exoskeletons.

Consideration of Conductive Motor Winding Materials at Room and Elevated Temperatures

NASA Technical Reports Server (NTRS)

de Groh, Henry C., III

2015-01-01

A brief history of conductive motor winding materials is presented, comparing various metal motor winding materials and their properties in terms of conductivity, density and cost. The proposed use of carbon nanotubes (CNTs) and composites incorporating CNTs is explored as a potential way to improve motor winding conductivity, density, and reduce motor size which are important to electric aircraft technology. The conductivity of pure Cu, a CNT yarn, and a dilute Cu-CNT composite was measured at room temperature and at several temperatures up to 340 C. The conductivity of the Cu-CNT composite was about 3 percent lower than pure copper's at all temperatures measured. The conductivity of the CNT yarn was about 200 times lower than copper's, however, the yarn's conductivity dropped less with increasing temperature compared to Cu. It is believed that the low conductivity of the yarn is due primarily to high interfacial resistances and the presence of CNTs with low, semiconductor like electrical properties (s-CNT). It is believed the conductivity of the CNT-Cu composite could be improved by not using s-CNT, and instead using only CNTs with high, metallic like electrical properties (m-CNT); and by increasing the vol% m-CNTs.

Thermo-mechanical behavior of stainless steel knitted structures

NASA Astrophysics Data System (ADS)

Hamdani, Syed Talha Ali; Fernando, Anura; Maqsood, Muhammad

2016-09-01

Heating fabric is an advanced textile material that is extensively researched by the industrialists and the scientists alike. Ability to create highly flexible and drapeable heating fabrics has many applications in everyday life. This paper presents a study conducted on the comparison of heatability of knitted fabric made of stainless steel yarn. The purpose of the study is to find a suitable material for protective clothing against cold environments. In the current research the ampacity of stainless steel yarn is observed in order to prevent the overheating of the heating fabrics. The behavior of the knitted structure is studied for different levels of supply voltage. Infrared temperature sensing is used to measure the heat generated from the fabrics in order to measure the temperature of the fabrics without physical contact. It is concluded that interlock structure is one of the most suited structures for knitted heating fabrics. As learnt through this research, fabrics made of stainless steel yarn are capable of producing a higher level of heating compared to that of knitted fabric made using silver coated polymeric yarn at the same supply voltage.

New Types of Artificial Muscles for Large Stroke and High Force Applications

DTIC Science & Technology

2012-10-10

University of Texas at Dallas and include Aerogel Muscles, Torsional and Tensile Yarn Muscles, Artificial Muscles Based on Polypyrrole Laminates and...Stroke, Superelastic Carbon Nanotube Aerogel Muscles 3. Torsional and Tensile Carbon Nanotube Yarn Muscles 4. Artificial Muscles Based on...in numerous press releases and TV programs. As we reported in Science 2009, carbon nanotube aerogel sheets are the sole component of new artificial

Aspects of the dimensional changes of jersey structures after knitting process

NASA Astrophysics Data System (ADS)

Szabo, M.; Barbu, I.; Jiaru, L.

2017-08-01

The study proposes a statistical analysis by applying a mathematical model for the study of the dimensional changes of jersey structures made of 100% cotton yarn, with 58/1 metric count of yarn. The Structures are presented as tubular knitted metrage and are designed for underwear and/or outer garments. By analysing the jersey structures, from dimensional stability point of view, there can be observed that values in the limits are within the ±2% interval, values which are considered appropriate. Following the experimental researches, there are proposed solutions for the reduction of dimensional changes on both directions of the knit, on the stich course direction and also on the stich courses in vertical direction, being analyzed the behaviour of the knitted fabrics during relaxation after knitting process. The problem of the dimensional stability of the knitted fabrics is extensive researched. The knitted structures are elastic structures, this being a reason for which dimensional stability will always be a topical theme. The jersey structures, due to the distribution of the platinum loop in the knit plane, due to the relative small number of yarn-yarn contact points that causes the threads to slide into the structure, due to the spiral of the tubular metrage structure, are among those whose dimensional stability is difficult to control. The technical characteristics of the yarns, the technical characteristics of the knitting machines and the technological parameters of the knitting machine are the elements which will be correlated in order to obtain structures with minimum dimensional changes. In order to obtain knitted structures with adequate dimensional stability, this means within ±2%, it is necessary that the dimensional changes during the relaxation periods after knitting and chemical finishing being minimum. For this, all the processes to be applied will be conducted with appropriate and uniform tensions throughout the technological flow. The relaxation

U.S. Trade and Investment Relationship with Sub-Saharan Africa: The African Growth and Opportunity Act and Beyond

DTIC Science & Technology

2008-10-28

initiative, which granted LDCs tariff-free access to all goods, except for sugar , rice, and bananas , for which products a tariff- rate quota system...for AGOA beneficiaries; and strengthening the link between poverty reduction and trade in Africa. This product will be updated periodically. Contents ...fabric and yarns. The legislation also increased the maximum allowable content of non-regional or non-U.S. fibers or yarns in AGOA eligible apparel

Carded Tow Real-Time Color Assessment: A Spectral Camera-Based System.

PubMed

Furferi, Rocco; Governi, Lapo; Volpe, Yary; Carfagni, Monica

2016-08-31

One of the most important parameters to be controlled during the production of textile yarns obtained by mixing pre-colored fibers, is the color correspondence between the manufactured yarn and a given reference, usually provided by a designer or a customer. Obtaining yarns from raw pre-colored fibers is a complex manufacturing process entailing a number of steps such as laboratory sampling, color recipe corrections, blowing, carding and spinning. Carding process is the one devoted to transform a "fuzzy mass" of tufted fibers into a regular mass of untwisted fibers, named "tow". During this process, unfortunately, the correspondence between the color of the tow and the target one cannot be assured, thus leading to yarns whose color differs from the one used for reference. To solve this issue, the main aim of this work is to provide a system able to perform a spectral camera-based real-time measurement of a carded tow, to assess its color correspondence with a reference carded fabric and, at the same time, to monitor the overall quality of the tow during the carding process. Tested against a number of differently colored carded fabrics, the proposed system proved its effectiveness in reliably assessing color correspondence in real-time.

Non-destructive X-ray examination of weft knitted wire structures

NASA Astrophysics Data System (ADS)

Obermann, M.; Ellouz, M.; Aumann, S.; Martens, Y.; Bartelt, P.; Klöcker, M.; Kordisch, T.; Ehrmann, A.; Weber, M. O.

2016-07-01

Conductive yarns or wires are often integrated in smart textiles to enable data or energy transmission. In woven fabrics, these conductive parts are fixed at defined positions and thus protected from external loads. Knitted fabrics, however, have relatively loose structures, resulting in higher impacts of possible mechanical forces on the individual yarns. Hence, metallic wires with smaller diameters in particular are prone to break when integrated in knitted fabrics. In a recent project, wires of various materials including copper, silver and nickel with diameters varying between 0.05 mm and 0.23 mm were knitted in combination with textile yarns. Hand flat knitting machines of appropriate gauges were used to produce different structures. On these samples, non-destructive examinations, using an industrial X-ray system Seifert x|cube (225 kV) equipped with a minifocus X-ray tube, were carried out, directly after knitting as well as after different mechanical treatments (tensile, burst, and washing tests). In this way, structural changes of the stitch geometry could be visualized before failure. In this paper, the loop geometries in the knitted fabrics are depicted depending on knitted structures, wire properties and the applied mechanical load. Consequently, it is shown which metallic wires and yarns are most suitable to be integrated into knitted smart textiles.

Woven electrochemical fabric-based test sensors (WEFTS): a new class of multiplexed electrochemical sensors.

PubMed

Choudhary, Tripurari; Rajamanickam, G P; Dendukuri, Dhananjaya

2015-05-07

We present textile weaving as a new technique for the manufacture of miniature electrochemical sensors with significant advantages over current fabrication techniques. Biocompatible silk yarn is used as the material for fabrication instead of plastics and ceramics used in commercial sensors. Silk yarns are coated with conducting inks and reagents before being handloom-woven as electrodes into patches of fabric to create arrays of sensors, which are then laminated, cut and packaged into individual sensors. Unlike the conventionally used screen-printing, which results in wastage of reagents, yarn coating uses only as much reagent and ink as required. Hydrophilic and hydrophobic yarns are used for patterning so that sample flow is restricted to a small area of the sensor. This simple fluidic control is achieved with readily available materials. We have fabricated and validated individual sensors for glucose and hemoglobin and a multiplexed sensor, which can detect both analytes. Chronoamperometry and differential pulse voltammetry (DPV) were used to detect glucose and hemoglobin, respectively. Industrial quantities of these sensors can be fabricated at distributed locations in the developing world using existing skills and manufacturing facilities. We believe such sensors could find applications in the emerging area of wearable sensors for chemical testing.

Carded Tow Real-Time Color Assessment: A Spectral Camera-Based System

PubMed Central

Furferi, Rocco; Governi, Lapo; Volpe, Yary; Carfagni, Monica

2016-01-01

One of the most important parameters to be controlled during the production of textile yarns obtained by mixing pre-colored fibers, is the color correspondence between the manufactured yarn and a given reference, usually provided by a designer or a customer. Obtaining yarns from raw pre-colored fibers is a complex manufacturing process entailing a number of steps such as laboratory sampling, color recipe corrections, blowing, carding and spinning. Carding process is the one devoted to transform a “fuzzy mass” of tufted fibers into a regular mass of untwisted fibers, named “tow”. During this process, unfortunately, the correspondence between the color of the tow and the target one cannot be assured, thus leading to yarns whose color differs from the one used for reference. To solve this issue, the main aim of this work is to provide a system able to perform a spectral camera-based real-time measurement of a carded tow, to assess its color correspondence with a reference carded fabric and, at the same time, to monitor the overall quality of the tow during the carding process. Tested against a number of differently colored carded fabrics, the proposed system proved its effectiveness in reliably assessing color correspondence in real-time. PMID:27589765

Facilitators of community participation in an Aboriginal sexual health promotion initiative.

PubMed

Hulme Chambers, Alana; Tomnay, Jane; Stephens, Kylie; Crouch, Alan; Whiteside, Mary; Love, Pettina; McIntosh, Leonie; Waples Crowe, Peter

2018-04-01

Community participation is a collaborative process aimed at achieving community-identified outcomes. However, approaches to community participation within Aboriginal health promotion initiatives have been inconsistent and not well documented. Smart and Deadly was a community-led initiative to develop sexual health promotion resources with young Aboriginal people in regional Victoria, Australia. The principles of community-centred practice, authentic participatory processes and respect for the local cultural context guided the initiative. The aim of this article is to report factors that facilitated community participation undertaken in the Smart and Deadly initiative to inform future projects and provide further evidence in demonstrating the value of such approaches. A summative evaluation of the Smart and Deadly initiative was undertaken approximately 2 years after the initiative ended. Five focus groups and 13 interviews were conducted with a purposive sample of 32 participants who were involved with Smart and Deadly in one of the following ways: project participant, stakeholder or project partner, or project developer or designer. A deductive content analysis was undertaken and themes were compared to the YARN model, which was specifically created for planning and evaluating community participation strategies relating to Aboriginal sexual health promotion. A number of factors that facilitated community participation approaches used in Smart and Deadly were identified. The overarching theme was that trust was the foundation upon which the facilitators of community participation ensued. These facilitators were cultural safety and cultural literacy, community control, and legacy and sustainability. Whilst the YARN model was highly productive in identifying these facilitators of community participation, the model did not have provision for the element of trust between workers and community. Given the importance of trust between the project team and the Aboriginal

Creation of Woven Structures Impacting Self-cleaning Superoleophobicity

NASA Astrophysics Data System (ADS)

Lim, Jihye

For protection of human life from harmful or toxic liquids in working areas, solid surface resistance to liquid with low surface tension (e.g. oil) should be achieved in the outermost layer of protective clothing. Based on the literature review, multiscale structures were emphasized because they can increase roughness on a solid surface and create more void spaces of different sizes. The roughness and void spaces contribute to creating a liquid-vapor interface and reducing the liquid contact area to the solid surface. Woven fabric inherently consists of multiscale structures by its construction: microscale in a yarn structure and macroscale in a fabric structure. When the solid surface tension is low relative to oil, creating an appropriate structural geometry will become a critical way to obtain a superoleophobic surface for oil-resistance. Theoretical modeling and experiments with actual fabric samples were utilized to predict and prove the highest performing structural geometry in woven fabric, respectively. The theoretical geometric modeling accounted for the different weave structures, the yarn compression by the yarn flattening factor, e, and the void space by the void space ratio to the fiber or yarn diameter, T, impacting the liquid apparent contact angle on a fabric surface. The Cassie-Baxter equations were developed using Young's contact angle, thetae, thetae and e, or thetae, e, and T, to predict the liquid apparent contact angle for different geometries. In addition, to prevent a liquid's penetration into a solid structure, the ranges of the protuberance height (>> h2) and distance (< 4ℓ 2 cap) were predicted by the definition of the Laplace pressure, the capillary pressure, and the sagging phenomenon. Those predictions were in strong agreement with the results from the empirical experiment using the actual woven fabric samples. This study identified the impact of the geometries in yarn and woven fabric structures on the fabric resistance against oil

Optimization, Alternative Materials and Improvements in Body Armor Shields

DTIC Science & Technology

2007-05-10

performance structures such as protective clothing , bullet-proof vests and helmets due to their high-specific strength and stiffness. The ballistic...regard each layer of the woven composite as made of weft and warp yarns, and divide each yam into 3D solid elements. It is found that the frame...0.25 mm thick layers is modeled as an orthotropic material. Even though the woven composite armor is made of yams and each yarn is made of fibers

DRAPING SIMULATION OF WOVEN FABRICS

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

Rodgers, William; Jin, Xiaoshi; Zhu, Jiang

2016-09-07

Woven fabric composites are extensively used in molding complex geometrical shapes due to their high conformability compared to other fabrics. Preforming is an important step in the overall process, where the two-dimensional fabric is draped to become the three-dimensional shape of the part prior to resin injection. During preforming, the orientation of the yarns may change significantly compared to the initial orientations. Accurate prediction of the yarn orientations after molding is important for evaluating the structural performance of the final part. This paper presents a systematic investigation of the angle changes during the preform operation for carbon fiber twill andmore » satin weave fabrics. Preforming experiments were conducted using a truncated pyramid mold geometry designed and fabricated at the General Motors Research Laboratories. Predicted results for the yarn orientations were compared with experimental results and good agreement was observed« less

Image-Based Reverse Engineering and Visual Prototyping of Woven Cloth.

PubMed

Schroder, Kai; Zinke, Arno; Klein, Reinhard

2015-02-01

Realistic visualization of cloth has many applications in computer graphics. An ongoing research problem is how to best represent and capture cloth models, specifically when considering computer aided design of cloth. Previous methods produce highly realistic images, however, they are either difficult to edit or require the measurement of large databases to capture all variations of a cloth sample. We propose a pipeline to reverse engineer cloth and estimate a parametrized cloth model from a single image. We introduce a geometric yarn model, integrating state-of-the-art textile research. We present an automatic analysis approach to estimate yarn paths, yarn widths, their variation and a weave pattern. Several examples demonstrate that we are able to model the appearance of the original cloth sample. Properties derived from the input image give a physically plausible basis that is fully editable using a few intuitive parameters.

Electromagnetic absorption behaviour of ferrite loaded three phase carbon fabric composites

NASA Astrophysics Data System (ADS)

Jagatheesan, Krishnasamy; Ramasamy, Alagirusamy; Das, Apurba; Basu, Ananjan

2018-02-01

This article investigates the electromagnetic absorption behaviours of carbon helical yarn fabric reinforced composites and manganese-zinc (Mn-Zn) ferrite particles loaded 3 phase fabric composites. A carbon helical yarn having stainless steel core was prepared and made into single jersey knitted fabric. The composite was prepared by sandwiching a fabric with polypropylene films and thermal pressed. The absorption values of helical yarn fabric composite was observed to be less in the C band region (4-8 GHz). For improving the absorption coefficients of composite, Mn-Zn ferrite particles were dispersed in the polypropylene (PP) composite. The ferrite loaded PP composites exhibited better permittivity and permeability values, hence the absorption loss of the composite was improved. The helical yarn fabric reinforced with Mn-Zn ferrite/PP composite showed larger absorption coefficients than virgin PP/fabric composite. The change in thermal stability and particle size distribution in the Mn-Zn ferrite/PP composite was also analyzed. At higher ferrite concentration, bimodal particle distribution was observed which increased the conductivity and shielding effectiveness (SE) of the composite. In addition, complex permittivity value was also increased for higher incident frequency (4-8 GHz). As the ferrite content increases, the dielectric loss and magnetic permeability of PP/ferrite increases due to increased magnetic loss. Hence, ferrite loaded PP composite showed the total SE of -14.2 dB with the absorption coefficients of 0.717. The S1C7 fabric composite having ferrite dispersion showed the better absorption loss and lower reflection coefficient of 14.2 dB and 0.345 respectively compared to virgin PP/helical yarn fabric composite. The increasing ferrite content (45 wt%) improved the absorption loss and total SE. Though, ferrite based fabric composite exhibits moderate absorptive shielding, it can be used as shielding panels in the electronic industries.

Numerical and experimental analyses of out-of-plane deformation of triaxial woven fabric

NASA Astrophysics Data System (ADS)

Zhou, Hongtao; Xiao, Xueliang; Qian, Kun; Zhang, Kun; Zhang, Diantang

2018-05-01

With three sets of yarns interwoven in plane for angle-interlock structure, triaxial woven fabric (TWF) is a unique and perfect construction material for products subjected to multi-directional loads, as compared to classic fabrics of orthogonal structure. Finite-element analysis (FEA) and experimental methods are applied to study the out-of-plane deformation (OPD) behaviors of TWF and plain woven fabric (PWF). Among this, the yarn cross section, path and woven structure are obtained using optical microscopy, the related parameters are input to finite element model (FEM) for simulating the OPD behavior. This paper presents a detailed analysis on out-of-plane deformation behavior of TWF and PWF by the finite element method and experiment. In consideration of the comparability, TWF and PWF are designed and prepared with the same yarns and areal density (g/m2). The deformation profile, maximum stress and maximum deflection of TWF and PWF are obtained by FEA and experiment. It has been found that the maximum deflection and maximum stress of TWF is smaller than that of PWF under the same uniform negative pressure, both FEA and experiment. Furthermore, the stress distribution of TWF is more evenly than that of PWF, indicating that TWF exhibited superior isotropy in comparison with PWF for one more directional set of yarns in undertaking the OPD.

Effect of Mesoscale and Multiscale Modeling on the Performance of Kevlar Woven Fabric Subjected to Ballistic Impact: A Numerical Study

NASA Astrophysics Data System (ADS)

Jia, Xin; Huang, Zhengxiang; Zu, Xudong; Gu, Xiaohui; Xiao, Qiangqiang

2013-12-01

In this study, an optimal finite element model of Kevlar woven fabric that is more computational efficient compared with existing models was developed to simulate ballistic impact onto fabric. Kevlar woven fabric was modeled to yarn level architecture by using the hybrid elements analysis (HEA), which uses solid elements in modeling the yarns at the impact region and uses shell elements in modeling the yarns away from the impact region. Three HEA configurations were constructed, in which the solid element region was set as about one, two, and three times that of the projectile's diameter with impact velocities of 30 m/s (non-perforation case) and 200 m/s (perforation case) to determine the optimal ratio between the solid element region and the shell element region. To further reduce computational time and to maintain the necessary accuracy, three multiscale models were presented also. These multiscale models combine the local region with the yarn level architecture by using the HEA approach and the global region with homogenous level architecture. The effect of the varying ratios of the local and global area on the ballistic performance of fabric was discussed. The deformation and damage mechanisms of fabric were analyzed and compared among numerical models. Simulation results indicate that the multiscale model based on HEA accurately reproduces the baseline results and obviously decreases computational time.

Tailorable advanced blanket insulation using aluminoborosilicate and alumina batting

NASA Technical Reports Server (NTRS)

Calamito, Dominic P.

1989-01-01

Two types of Tailorable Advanced Blanket Insulation (TABI) flat panels for Advanced Space Transportation Systems were produced. Both types consisted of integrally woven, 3-D fluted core having parallel faces and connecting ribs of Nicalon yarns. The triangular cross section flutes of one type was filled with mandrels of processed Ultrafiber (aluminoborosilicate) stitchbonded Nextel 440 fibrous felt, and the second type wall filled with Saffil alumina fibrous felt insulation. Weaving problems were minimal. Insertion of the fragile insulation mandrels into the fabric flutes was improved by using a special insertion tool. An attempt was made to weave fluted core fabrics from Nextel 440 yarns but was unsuccessful because of the yarn's fragility. A small sample was eventually produced by an unorthodox weaving process and then filled with Saffil insulation. The procedures for setting up and weaving the fabrics and preparing and inserting insulation mandrels are discussed. Characterizations of the panels produced are also presented.

A Grey Fuzzy Logic Approach for Cotton Fibre Selection

NASA Astrophysics Data System (ADS)

Chakraborty, Shankar; Das, Partha Protim; Kumar, Vidyapati

2017-06-01

It is a well known fact that the quality of ring spun yarn predominantly depends on various physical properties of cotton fibre. Any variation in these fibre properties may affect the strength and unevenness of the final yarn. Thus, so as to achieve the desired yarn quality and characteristics, it becomes imperative for the spinning industry personnel to identify the most suitable cotton fibre from a set of feasible alternatives in presence of several conflicting properties/attributes. This cotton fibre selection process can be modelled as a Multi-Criteria Decision Making (MCDM) problem. In this paper, a grey fuzzy logic-based approach is proposed for selection of the most apposite cotton fibre from 17 alternatives evaluated based on six important fibre properties. It is observed that the preference order of the top-ranked cotton fibres derived using the grey fuzzy logic approach closely matches with that attained by the past researchers which proves the application potentiality of this method in solving varying MCDM problems in textile industries.

Knitting and weaving artificial muscles

PubMed Central

Maziz, Ali; Concas, Alessandro; Khaldi, Alexandre; Stålhand, Jonas; Persson, Nils-Krister; Jager, Edwin W. H.

2017-01-01

A need exists for artificial muscles that are silent, soft, and compliant, with performance characteristics similar to those of skeletal muscle, enabling natural interaction of assistive devices with humans. By combining one of humankind’s oldest technologies, textile processing, with electroactive polymers, we demonstrate here the feasibility of wearable, soft artificial muscles made by weaving and knitting, with tunable force and strain. These textile actuators were produced from cellulose yarns assembled into fabrics and coated with conducting polymers using a metal-free deposition. To increase the output force, we assembled yarns in parallel by weaving. The force scaled linearly with the number of yarns in the woven fabric. To amplify the strain, we knitted a stretchable fabric, exhibiting a 53-fold increase in strain. In addition, the textile construction added mechanical stability to the actuators. Textile processing permits scalable and rational production of wearable artificial muscles, and enables novel ways to design assistive devices. PMID:28138542

Design of an Electronic Chest-Band

NASA Astrophysics Data System (ADS)

Atakan, R.; Acikgoz Tufan, H.; Baskan, H.; Eryuruk, S. H.; Akalin, N.; Kose, H.; Li, Y.; Kursun Bahadir, S.; Kalaoglu, F.

2017-10-01

In this study, an electronic chest strap prototype was designed for measuring fitness level, performance optimization, mobility and fall detection. Knitting technology is used for production by using highly elastic nylon yarn. In order to evaluate comfort performance of the garment, yarn strength and elongation, air permeability, moisture management and FAST tests (Fabric Assurance Fabric Testing) were carried out, respectively. After testing of textile part of the chest band, IMU sensors were integrated onto the garment by means of conductive yarns. Electrical conductivity of the circuit was also assessed at the end. Results indicated that the weight and the thickness of the product are relatively high for sports uses and it has a negative impact on comfort properties. However, it is highly stretchable and moisture management properties are still in acceptable values. From the perspective of possible application areas, developed smart chest band in this research could be used in sports facilities as well as health care applications for elderly and disabled people.

The mechanical response of woven Kevlar fabric

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

Warren, W.E.

1991-01-01

Woven Kevlar fabrics exhibit a number of beneficial mechanical properties which include strength, flexibility, and relatively low density. The desire to engineer or design Kevlar fabrics for specific applications has stimulated interest in the development of theoretical models which relate their effective mechanical properties to specific aspects of the fabric morphology and microstructure. In this work the author provides a theoretical investigation of the large deformation elastic response of a plane woven Kevlar fabric and compares these theoretical results with experimental data obtained from uniaxially loaded Kevlar fabrics. The theoretical analysis assumes the woven fabric to be a regular networkmore » of orthogonal interlaced yarns and the individual yarns are modeled as extensible elastica, thus coupling stretching and bending effects at the outset. This comparison of experiment with theory indicates that the deformation of woven fabric can be quite accurately predicted by modeling the individual yarns as extensible elastica. 2 refs., 1 fig.« less

Mechanical behavior of a triaxially braided textile composite at high temperature

NASA Astrophysics Data System (ADS)

El Mourid, Amine

The work presented in this thesis aimed at understanding the influence of viscoelasticity, temperature and aging on the mechanical behaviour of a textile composite using experimental, analytical and numerical tools. The studied material was a triaxially braided composite with fibres in the 0°/+/-60° directions. The yarns were made of carbon fibres, embedded in an MVK10 temperature resistant polyimide matrix. The first step consisted in developing analytical and numerical frameworks to predict viscoelastic behaviour in textile composites. Simulations were performed for both braided and woven textile architectures, at different stiffness contrasts and yarns volume fractions. The analytical framework accuracy was verified with the help of the numerical simulations. An important finding of this study was that the analytical framework, combined with the Mori-Tanaka model, leads to relatively accurate predictions for both the permanent and transient parts. Therefore, the authors believe that the Mori-Tanaka model with an adjusted aspect ratio to take into account yarn curvature is reliable for predicting viscoelastic behaviour in textile composites. The textile composite that was studied in this project did not display viscoelastic behaviour, due to the high yarn volume fraction. However, the framework remains relevant for higher temperature applications or lower yarn volume fractions. The second step was to investigate the temperature effect on the tensile behavior of the carbon/MVK10 triaxially braided composite material studied in this project. To achieve this goal, a series of room and high temperature tensile tests on both matrix and composite samples were performed. The tests on composite samples were performed along two different material directions at the maximum service temperature allowed by the Federal Aviation Administration for aircraft components, and a dedicated replication technique was developed in order to track crack densities as a function of

A Study of Thermistor Performance within a Textile Structure.

PubMed

Hughes-Riley, Theodore; Lugoda, Pasindu; Dias, Tilak; Trabi, Christophe L; Morris, Robert H

2017-08-05

Textiles provide an ideal structure for embedding sensors for medical devices. Skin temperature measurement is one area in which a sensor textile could be particularly beneficial; pathological skin is normally very sensitive, making the comfort of anything placed on that skin paramount. Skin temperature is an important parameter to measure for a number of medical applications, including for the early detection of diabetic foot ulcer formation. To this end an electronic temperature-sensor yarn was developed by embedding a commercially available thermistor chip into the fibres of a yarn, which can be used to produce a textile or a garment. As part of this process a resin was used to encapsulate the thermistor. This protects the thermistor from mechanical and chemical stresses, and also allows the sensing yarn to be washed. Building off preliminary work, the behaviour and performance of an encapsulated thermistor has been characterised to determine the effect of encapsulation on the step response time and absolute temperature measurements. Over the temperature range of interest only a minimal effect was observed, with step response times varying between 0.01-0.35 s. A general solution is presented for the heat transfer coefficient compared to size of the micro-pod formed by the encapsulation of the thermistor. Finally, a prototype temperature-sensing sock was produced using a network of sensing yarns as a demonstrator of a system that could warn of impending ulcer formation in diabetic patients.

A Study of Thermistor Performance within a Textile Structure

PubMed Central

Hughes-Riley, Theodore; Lugoda, Pasindu; Dias, Tilak; Trabi, Christophe L.; Morris, Robert H.

2017-01-01

Textiles provide an ideal structure for embedding sensors for medical devices. Skin temperature measurement is one area in which a sensor textile could be particularly beneficial; pathological skin is normally very sensitive, making the comfort of anything placed on that skin paramount. Skin temperature is an important parameter to measure for a number of medical applications, including for the early detection of diabetic foot ulcer formation. To this end an electronic temperature-sensor yarn was developed by embedding a commercially available thermistor chip into the fibres of a yarn, which can be used to produce a textile or a garment. As part of this process a resin was used to encapsulate the thermistor. This protects the thermistor from mechanical and chemical stresses, and also allows the sensing yarn to be washed. Building off preliminary work, the behaviour and performance of an encapsulated thermistor has been characterised to determine the effect of encapsulation on the step response time and absolute temperature measurements. Over the temperature range of interest only a minimal effect was observed, with step response times varying between 0.01–0.35 s. A general solution is presented for the heat transfer coefficient compared to size of the micro-pod formed by the encapsulation of the thermistor. Finally, a prototype temperature-sensing sock was produced using a network of sensing yarns as a demonstrator of a system that could warn of impending ulcer formation in diabetic patients. PMID:28783067

Functional Circuitry on Commercial Fabric via Textile-Compatible Nanoscale Film Coating Process for Fibertronics.

PubMed

Bae, Hagyoul; Jang, Byung Chul; Park, Hongkeun; Jung, Soo-Ho; Lee, Hye Moon; Park, Jun-Young; Jeon, Seung-Bae; Son, Gyeongho; Tcho, Il-Woong; Yu, Kyoungsik; Im, Sung Gap; Choi, Sung-Yool; Choi, Yang-Kyu

2017-10-11

Fabric-based electronic textiles (e-textiles) are the fundamental components of wearable electronic systems, which can provide convenient hand-free access to computer and electronics applications. However, e-textile technologies presently face significant technical challenges. These challenges include difficulties of fabrication due to the delicate nature of the materials, and limited operating time, a consequence of the conventional normally on computing architecture, with volatile power-hungry electronic components, and modest battery storage. Here, we report a novel poly(ethylene glycol dimethacrylate) (pEGDMA)-textile memristive nonvolatile logic-in-memory circuit, enabling normally off computing, that can overcome those challenges. To form the metal electrode and resistive switching layer, strands of cotton yarn were coated with aluminum (Al) using a solution dip coating method, and the pEGDMA was conformally applied using an initiated chemical vapor deposition process. The intersection of two Al/pEGDMA coated yarns becomes a unit memristor in the lattice structure. The pEGDMA-Textile Memristor (ETM), a form of crossbar array, was interwoven using a grid of Al/pEGDMA coated yarns and untreated yarns. The former were employed in the active memristor and the latter suppressed cell-to-cell disturbance. We experimentally demonstrated for the first time that the basic Boolean functions, including a half adder as well as NOT, NOR, OR, AND, and NAND logic gates, are successfully implemented with the ETM crossbar array on a fabric substrate. This research may represent a breakthrough development for practical wearable and smart fibertronics.

Production Principles and Technological Development of Novel Woven Spacer Preforms and Integrated Stiffener Structures

NASA Astrophysics Data System (ADS)

Torun, Ahmet R.; Mountasir, Adil; Hoffmann, Gerald; Cherif, Chokri

2013-06-01

3D textile preforms offer a high potential to increase mechanical properties of composites and/or decrease manufacturing costs. Within the scope of this study, production principles were developed for complex spacer preforms and integrated stiffeners. These principles were applied through technological further development of the well-known face-to-face and terry weaving techniques. Various woven preforms were produced with Glass fibre/Polypropylene (GF/PP) Commingled yarns, however, the technology is suitable for any type of reinforcement yarns. U-shaped woven spacer preform was consolidated into a sandwich composite component for lightweight applications.

Evaluating the effect of spinning systems on thermal comfort properties of modal fabrics

NASA Astrophysics Data System (ADS)

Seçil Aydın, İ.; Kertmen, M.; Marmarali, A.

2017-10-01

In recent years the importance of clothing comfort became one of the most important feature of the fabrics. The aim of this study is to characterize thermal comfort properties of single jersey fabrics were knitted using 100% modal yarns which were spun in various types of yarn spinning methods such as ring spinning, compact spinning, rotor spinning and airjet spinning. Thermal comfort properties like air permeability, thermal resistance, thermal absorptivity and water vapour permeability of fabrics were tested. The results indicate that compact spinning technology will be appropriate for the summer climate casual wear.

Shuttle plate braiding machine

NASA Technical Reports Server (NTRS)

Huey, Jr., Cecil O. (Inventor)

1994-01-01

A method and apparatus for moving yarn in a selected pattern to form a braided article. The apparatus includes a segmented grid of stationary support elements and a plurality of shuttles configured to carry yarn. The shuttles are supported for movement on the grid assembly and each shuttle includes a retractable plunger for engaging a reciprocating shuttle plate that moves below the grid assembly. Such engagement at selected times causes the shuttles to move about the grid assembly in a selected pattern to form a braided article of a particular geometry.

Tactile Comfort Evaluation of Conductive Knitted Fabric Using KES-FB

NASA Astrophysics Data System (ADS)

Tadesse, M. G.; Chen, Y.; Wang, L.; Nierstrasz, V.; Loghin, C.

2018-06-01

Tactile comfort has a strong relation with low-stress mechanical properties of textile fabrics having close contact with the human skin. In this work, we attempt to analyse the low-stress mechanical properties of the functional knitted fabric obtained using Kawabata’s fabric evaluation system (KES-FB). The measured results were compared with those of the controlled polyester fabric. The bending ability of the product increased from 0.2448 to 0.8010gf.cm2/cm and hence the rigidity influenced when copper yarn is introduced. However, the compressibility increased from 0.173 to 0.449gf.cm/cm2 and hence the compressibility slightly boosted. The surface roughness (SMD) highly increased from 7.196 to 14.258 μm. It was observed that the incorporation of conductive copper yarn during knitting brought an effect on the tactile comfort of the fabrics and reduced by 69%. The overall comfort properties of the conductive textile fabric were reduced due to the introduction of copper yarn during knitting operations. Focus should be given when functional fabric developed which has close contact to the human skin.

The effect of warp tension on the colour of jacquard fabric made with different weaves structures

NASA Astrophysics Data System (ADS)

Karnoub, A.; Kadi, N.; Holmudd, O.; Peterson, J.; Skrifvars, M.

2017-10-01

The aims of this paper is to demonstrate the effect of warp tension on fabric colour for several types of weaves structures, and found a relationship between them. The image analyse technique used to determine the proportion of yarns colour appearance, the advantage of this techniques is the rapidity and reliability. The woven fabric samples are consisting of a polyester warp yarn with continuous filaments and density of 33 end/cm, a polypropylene weft yarn with a density of 24 pick/cm, and the warp tension ranged between 12-22 cN/tex. The experimental results demonstrated the effect of the warp tension on the colour of fabric, and this effect is related to several factors, where the large proportion of warp appearance leads to larger effect on fabric colour. The difference in the value of colour differences ΔEcmc is larger is in the range 16 to 20 cN/tex of warp tension. Using statistical methods, a mathematical model to calculate the amount of the colour difference ΔEcmc caused by the change in warp tension had been proposed.

Blunt Trauma Performance of Fabric Systems Utilizing Natural Rubber Coated High Strength Fabrics

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

Ahmad, M. R.; Ahmad, W. Y. W.; Samsuri, A.

2010-03-11

The blunt trauma performance of fabric systems against 9 mm bullets is reported. Three shots were fired at each fabric system with impact velocity of 367+-9 m/s and the depth of indentation on the modeling clay backing was measured. The results showed that 18-layer and 21-layer all-neat fabric systems failed the blunt trauma test. However, fabric systems with natural rubber (NR) latex coated fabric layers gave lower blunt trauma of between 25-32 mm indentation depths. Deformations on the neat fabrics upon impact were identified as broken yarns, yarn stretching and yarn pull-out. Deflections of the neat fabrics were more localised.more » For the NR latex coated fabric layers, no significant deformation can be observed except for peeled-off regions of the NR latex film at the back surface of the last layer. From the study, it can be said that the NR latex coated fabric layers were effective in reducing the blunt trauma of fabric systems.« less

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

Cooper, John; McCreight, Dan J.

This project was undertaken to develop and demonstrate on a pilot scale the use of electro-osmotic transport to increase the efficiency of textiles wet processing operations. In particular, we sought to develop a means of rinsing textiles to remove material entrapped between the individual fibers that constitute a yarn. Material trapped within the yarn is slow to exchange with rinse water flowing primarily in the open weave are abetween the yarns. The application of an external field (strength, 5-50 kV /m) requires only a few volts for most fabric thicknesses. This field is sufficient to promote a rapid exchange ofmore » material to enhance rinsing and reduce the water required for rinsing from about 20 kg/kg-fabric to 3-6 kg/kg-fabric. We successfully developed technical and economic models of application of the process to the rinsing of many materials of industrial importance, including dyes, tints, chemicals, detergents and dye electrolytes. We demonstrated the process on a pilot plant scale using a translator designed in cooperation with Milliken and Company (Spartanburg, SC).« less

Fabrication of continuous electrospun filaments with potential for use as medical fibres.

PubMed

Mouthuy, Pierre-Alexis; Zargar, Nasim; Hakimi, Osnat; Lostis, Emilie; Carr, Andrew

2015-05-19

Soft tissue injuries represent a substantial and growing social and economic burden. Medical fibres are commonly used to repair these injuries during surgery. Patient's outcomes are, however, not promising with around 40% of surgical repairs failing within the first few months after surgery due to poor tissue regeneration. The application of nanofibrous filaments and yarns as medical fibres and scaffolds has been suggested to improve soft tissue regeneration and enhance the quality of the repair. However, due to a lack of robustness and reliability of the current fabrication methods, continuous nanofibrous filaments cannot be manufactured and scaled up in industrial settings and are not currently available for clinical use. We have developed a robust and automated method that enables the manufacture of continuous electrospun filaments and which has the potential to be integrated into existing textile production lines. The technology uses a wire guide to form submicrofibres in a dense, narrow mesh which can be detached as a long and continuous thread. The thread can then be stretched and used to create multifilament yarns which can imitate the hierarchical architecture of tissues such as tendons and ligaments. Electrospun polydioxanone yarns produced by this method showed improved cellular proliferation and adhesion when compared to medical monofilament fibres in current clinical use. In vivo, the electrospun yarns showed a good safety profile with mild foreign body reaction and complete degradation within 5 months after implantation. These results suggest that this filament collection method has the potential to become a useful platform for the fabrication of future medical textiles.

Recent developments in multi-layer flat knitting technology for waste free production of complex shaped 3D-reinforcing structures for composites

NASA Astrophysics Data System (ADS)

Trümper, W.; Lin, H.; Callin, T.; Bollengier, Q.; Cherif, C.; Krzywinski, S.

2016-07-01

Constantly increasing prices for raw materials and energy as well as the current discourse on the reduction of CO2-emissions places a special emphasis on the advantages of lightweight constructions and its resource conserving production methods. Fibre-reinforced composites are already seeing a number of applications in automobile, energy and mechanical engineering. Future applications within the named areas require greater material and energy efficiency and therefore manufacturing methods for textile preforms and lightweight constructions enabling an optimal arrangement of the reinforcing fibres while in the same time limiting waste to a minimum. One manufacturing method for textile reinforced preforms fulfilling quite many of the named requirements is the multilayer weft knitting technology. Multilayer weft knitted fabrics containing straight reinforcing yarns at least in two directions. The arrangement of these yarns is fixed by the loop yarn. Used yarn material in each knitting row is adaptable e. g. according to the load requirements or for the local integration of sensors. Draping properties of these fabrics can be varied within a great range and through this enabling draping of very complex shaped 3D-preforms without wrinkles from just one uncut fabric. The latest developments at ITM are concentrating on the development of a full production chain considering the 3D-CAD geometry, the load analysis, the generation of machine control programs as well as the development of technology and machines to enable the manufacturing of innovative net shape 3D-multilayer weft knitted fabrics such as complex shaped spacer fabrics and tubular fabrics with biaxial reinforcement.

Utilizing Crochet to Showcase Temporal Patterns in Temperature Records from One Location and to Spark a Climate Conversation

NASA Astrophysics Data System (ADS)

Guertin, L. A.

2017-12-01

Scientists that seek to show temperature changes over time will typically select a line graph as the tool for data communication. However, one non-traditional way to showcase variations in data can be through an artistic visualization created with yarn. For several years, amateur and professional artisans have been using needlework (crocheting/knitting) to represent weather/climate records in scarves and blankets, sharing their work in online communities. Since the Sky Scarf project in 2011, a temporal record of data represented in yarn can include precipitation/snowfall to the air quality index. Here is an example of how crochet is being utilized to show maximum air temperature records over time for one location. Maximum daily temperature values have been collected for January through April in Philadelphia in fifty-year intervals (1917, 1967, 2017). This four-month interval was selected to match with the location and timing of a university's spring semester, as the target audience for this particular visualization is undergraduate students. Instead of trying to read differences in temperature across line graphs plotted for each year, three mini-temperature tapestries have been crocheted. A temperature scale has been developed with rainbow colors of yarn, where the purple and blue represent the coldest temperatures, and the orange and red represent the warmest temperatures. By using the same yarn temperature scale across the three mini-tapestries, the increase in daily maximum temperature in Philadelphia for a set time period can quickly and easily be observed. This form of science art, when presented to students, generates a series of questions, stories and predictions of a scientific and personal nature that are not typically part of a climate science instructional unit.

Hazards protection for space suits and spacecraft

NASA Technical Reports Server (NTRS)

Kosmo, Joseph J. (Inventor); Dawn, Frederic S. (Inventor)

1990-01-01

A flexible multi-layered covering article for protection against the hazards of exposure to the environment of outer space is disclosed. The covering includes an outer layer section comprising an outermost lamina of woven expanded tetrafluoroethylene yarns (Gore Tex) for protecting against abrasion and tearing, an underlying weave of meta-aramid yarns (Nomex) and para-aramid yarns (Kevlar) for particle impart protection, and electrostatic charge dissipation and control system incorporated therein, and a chemical contaminants control barrier applied as a coating. A middle section includes a succession of thermal insulating layers of polymeric thermoplastic or thermoforming material, each of which is coated with a metal deposit of high infra-red emissivity and low solar radiation absorption characteristics and separated from adjacent insulating layers by a low thermal conductance material. The covering further includes a radiation attenuating layer of a tungsten-loaded polymeric elastomer binder for protecting against bremsstrahlung radiation and an inner layer of rip-stop polyester material for abrasion protection. A chloroprene coating may be supplied the polyester-material for added micrometeroid protection. Securing means of low heat conductance material secures the multi-layers together as a laminar composite.

Biomimetic Transferable Surface for a Real Time Control over Wettability and Photoerasable Writing with Water Drop Lens

PubMed Central

Zillohu, Ahnaf Usman; Abdelaziz, Ramzy; Homaeigohar, Shahin; Krasnov, Igor; Müller, Martin; Strunskus, Thomas; Elbahri, Mady

2014-01-01

We demonstrate a transferable device that can turn wettability of surfaces to sticky or slippy, as per requirement. It is composed of polymeric yarn with a fibrous structure, which can be lifted and placed on any surface to render it the unique wettability properties. We introduce Polyvinylidenefluoride (PVDF) random fiber as biomimetic rose petal surface. When it is decorated with PVDF nanofibers yarns, the random mesh transform from rose petal sticky state into grass leaf slippy state. When it is placed on sticky, hydrophilic metal coin, it converts the surface of the coin to super hydrophobic. Adjustments in the yarn system, like interyarn spacing, can be done in real time to influence its wettability, which is a unique feature. Next, we load the polymer with a photochromic compound for chemical restructuring. It affects the sliding angle of water drop and makes the fibers optically active. We also demonstrate a “water droplets lens” concept that enables erasable writing on photochromic rose petal sticky fibrous surface. The droplet on a highly hydrophobic surface acts as a ball lens to concentrate light onto a hot spot; thereby we demonstrate UV light writing with water lenses and visible light erasing. PMID:25491016

Removing nickel from nickel-coated carbon fibers

NASA Astrophysics Data System (ADS)

Hardianto, A.; Hertleer, C.; De Mey, G.; Van Langenhove, L.

2017-10-01

Conductive fibers/yarns are one of the most important materials for smart textiles because of their electrically conductive functionality combined with flexibility and light weight. They can be applied in many fields such as the medical sector, electronics, sensors and even as thermoelectric generators. Temperature sensors, for example, can be made using the thermocouple or thermopile principle which usually uses two different metal wires that can produce a temperature-dependent voltage. However, if metal wires are inserted into a textile structure, they will decrease the flexibility properties of the textile product. Nickel-coated Carbon Fiber (NiCF), a conductive textile yarn, has a potential use as a textile-based thermopile if we can create an alternating region of carbon and nickel along the fiber which in turn it can be used for substituting the metallic thermopile. The idea was to remove nickel from NiCF in order to obtain a yarn that contains alternating zones of carbon and nickel. Due to no literature reporting on how to remove nickel from NiCF, in this paper we investigated some chemicals to remove nickel from NiCF.

Tissue-aware RNA-Seq processing and normalization for heterogeneous and sparse data.

PubMed

Paulson, Joseph N; Chen, Cho-Yi; Lopes-Ramos, Camila M; Kuijjer, Marieke L; Platig, John; Sonawane, Abhijeet R; Fagny, Maud; Glass, Kimberly; Quackenbush, John

2017-10-03

Although ultrahigh-throughput RNA-Sequencing has become the dominant technology for genome-wide transcriptional profiling, the vast majority of RNA-Seq studies typically profile only tens of samples, and most analytical pipelines are optimized for these smaller studies. However, projects are generating ever-larger data sets comprising RNA-Seq data from hundreds or thousands of samples, often collected at multiple centers and from diverse tissues. These complex data sets present significant analytical challenges due to batch and tissue effects, but provide the opportunity to revisit the assumptions and methods that we use to preprocess, normalize, and filter RNA-Seq data - critical first steps for any subsequent analysis. We find that analysis of large RNA-Seq data sets requires both careful quality control and the need to account for sparsity due to the heterogeneity intrinsic in multi-group studies. We developed Yet Another RNA Normalization software pipeline (YARN), that includes quality control and preprocessing, gene filtering, and normalization steps designed to facilitate downstream analysis of large, heterogeneous RNA-Seq data sets and we demonstrate its use with data from the Genotype-Tissue Expression (GTEx) project. An R package instantiating YARN is available at http://bioconductor.org/packages/yarn .

A mesoscopic approach for draping simulation of preforms manufactured by direct fibre placement

NASA Astrophysics Data System (ADS)

Engelfried, Mathias; Fial, Julian; Tartler, Manuel; Böhler, Patrick; Hägele, Dominik; Middendorf, Peter

2017-10-01

The draping of preforms made by automated fibre placement is a suitable way to generate complex, three-dimensional preforms. The absence of weaving or sewing yarns leads to a high tendency towards defects, such as gaps. To predict those defects a detailed simulation model of the material is necessary. This work deals with a method to describe the inter-ply friction of preforms that consists of carbon fibre yarns joined by a thermoplastic binder. Therefore, a friction model which is customised to the partial presence of molten binder is proposed. This model is used in a mesoscopic draping simulation and is validated by draping experiments.

Tall Tales and Ripping Yarns

ERIC Educational Resources Information Center

Dorling, Danny

2010-01-01

In a country in which, even after the economic crash, there are plenty of resources to go around, people need to think hard about why inequality persists so much more strongly in Britain than anywhere else in Europe. The cause, the author wants to suggest, is a set of deep-rooted, hidden and unacknowledged beliefs, each unjustified yet passed off…

A prototype yarn evaluation tester to rapidly assess comparative weavability of warp yarns without weaving

USDA-ARS?s Scientific Manuscript database

The art of weaving continues to be the most predominantly used method of converting textile fibers into fabrics for various end-use applications, including apparel. In fact, the weaving is by far the largest textile manufacturing sector, worldwide. However, the weaving process is complex and costly....

Method for preparing metallated filament-wound structures

DOEpatents

Peterson, George R.

1979-01-01

Metallated graphite filament-wound structures are prepared by coating a continuous multi-filament carbon yarn with a metal carbide, impregnating the carbide coated yarn with a polymerizable carbon precursor, winding the resulting filament about a mandrel, partially curing the impregnation in air, subjecting the wound composite to heat and pressure to cure the carbon precursor, and thereafter heating the composite in a sizing die at a pressure loading of at least 1000 psi for graphitizing the carbonaceous material in the composite. The carbide in the composite coalesces into rod-like shapes which are disposed in an end-to-end relationship parallel with the filaments to provide resistance to erosion in abrasive laden atmospheres.

40 CFR 61.144 - Standard for manufacturing.

Code of Federal Regulations, 2011 CFR

2011-07-01

..., twine, rope, thread, yarn, roving, lap, or other textile materials. (2) The manufacture of cement... manufacturing facility, including air cleaning devices, process equipment, and buildings housing material...

40 CFR 61.144 - Standard for manufacturing.

Code of Federal Regulations, 2013 CFR

2013-07-01

..., twine, rope, thread, yarn, roving, lap, or other textile materials. (2) The manufacture of cement... manufacturing facility, including air cleaning devices, process equipment, and buildings housing material...

40 CFR 61.144 - Standard for manufacturing.

Code of Federal Regulations, 2014 CFR

2014-07-01

..., twine, rope, thread, yarn, roving, lap, or other textile materials. (2) The manufacture of cement... manufacturing facility, including air cleaning devices, process equipment, and buildings housing material...

40 CFR 61.144 - Standard for manufacturing.

Code of Federal Regulations, 2010 CFR

2010-07-01

..., twine, rope, thread, yarn, roving, lap, or other textile materials. (2) The manufacture of cement... manufacturing facility, including air cleaning devices, process equipment, and buildings housing material...

40 CFR 61.144 - Standard for manufacturing.

Code of Federal Regulations, 2012 CFR

2012-07-01

..., twine, rope, thread, yarn, roving, lap, or other textile materials. (2) The manufacture of cement... manufacturing facility, including air cleaning devices, process equipment, and buildings housing material...

Knitting for heart valve tissue engineering

PubMed Central

Ayad, Nadia; Wojciechowska, Dorota; Zielińska, Dorota; Struszczyk, Marcin H.; Latif, Najma; Yacoub, Magdi

Knitting is a versatile technology which offers a large portfolio of products and solutions of interest in heart valve (HV) tissue engineering (TE). One of the main advantages of knitting is its ability to construct complex shapes and structures by precisely assembling the yarns in the desired position. With this in mind, knitting could be employed to construct a HV scaffold that closely resembles the authentic valve. This has the potential to reproduce the anisotropic structure that is characteristic of the heart valve with the yarns, in particular the 3-layered architecture of the leaflets. These yarns can provide oriented growth of cells lengthwise and consequently enable the deposition of extracellular matrix (ECM) proteins in an oriented manner. This technique, therefore, has a potential to provide a functional knitted scaffold, but to achieve that textile engineers need to gain a basic understanding of structural and mechanical aspects of the heart valve and in addition, tissue engineers must acquire the knowledge of tools and capacities that are essential in knitting technology. The aim of this review is to provide a platform to consolidate these two fields as well as to enable an efficient communication and cooperation among these two research areas. PMID:29043276

Statistical shear lag model - unraveling the size effect in hierarchical composites.

PubMed

Wei, Xiaoding; Filleter, Tobin; Espinosa, Horacio D

2015-05-01

Numerous experimental and computational studies have established that the hierarchical structures encountered in natural materials, such as the brick-and-mortar structure observed in sea shells, are essential for achieving defect tolerance. Due to this hierarchy, the mechanical properties of natural materials have a different size dependence compared to that of typical engineered materials. This study aimed to explore size effects on the strength of bio-inspired staggered hierarchical composites and to define the influence of the geometry of constituents in their outstanding defect tolerance capability. A statistical shear lag model is derived by extending the classical shear lag model to account for the statistics of the constituents' strength. A general solution emerges from rigorous mathematical derivations, unifying the various empirical formulations for the fundamental link length used in previous statistical models. The model shows that the staggered arrangement of constituents grants composites a unique size effect on mechanical strength in contrast to homogenous continuous materials. The model is applied to hierarchical yarns consisting of double-walled carbon nanotube bundles to assess its predictive capabilities for novel synthetic materials. Interestingly, the model predicts that yarn gauge length does not significantly influence the yarn strength, in close agreement with experimental observations. Copyright © 2015 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Material, process, and product design of thermoplastic composite materials

NASA Astrophysics Data System (ADS)

Dai, Heming

Thermoplastic composites made of polypropylene (PP) and E-glass fibers were investigated experimentally as well as theoretically for two new classes of product designs. The first application was for reinforcement of wood. Commingled PP/glass yarn was consolidated and bonded on wood panel using a tie layer. The processing parameters, including temperature, pressure, heating time, cooling time, bonding strength, and bending strength were tested experimentally and evaluated analytically. The thermoplastic adhesive interface was investigated with environmental scanning electron microscopy. The wood/composite structural design was optimized and evaluated using a Graphic Method. In the second application, we evaluated use of thermoplastic composites for explosion containment in an arrester. PP/glass yarn was fabricated in a sleeve form and wrapped around the arrester. After consolidation, the flexible composite sleeve forms a solid composite shell. The composite shell acts as a protection layer in a surge test to contain the fragments of the arrester. The manufacturing process for forming the composite shell was designed. Woven, knitted, and braided textile composite shells made of commingled PP/glass yarn were tested and evaluated. Mechanical performance of the woven, knitted, and braided composite shells was examined analytically. The theoretical predictions were used to verify the experimental results.

Rubber Impact on 3D Textile Composites

NASA Astrophysics Data System (ADS)

Heimbs, Sebastian; Van Den Broucke, Björn; Duplessis Kergomard, Yann; Dau, Frederic; Malherbe, Benoit

2012-06-01

A low velocity impact study of aircraft tire rubber on 3D textile-reinforced composite plates was performed experimentally and numerically. In contrast to regular unidirectional composite laminates, no delaminations occur in such a 3D textile composite. Yarn decohesions, matrix cracks and yarn ruptures have been identified as the major damage mechanisms under impact load. An increase in the number of 3D warp yarns is proposed to improve the impact damage resistance. The characteristic of a rubber impact is the high amount of elastic energy stored in the impactor during impact, which was more than 90% of the initial kinetic energy. This large geometrical deformation of the rubber during impact leads to a less localised loading of the target structure and poses great challenges for the numerical modelling. A hyperelastic Mooney-Rivlin constitutive law was used in Abaqus/Explicit based on a step-by-step validation with static rubber compression tests and low velocity impact tests on aluminium plates. Simulation models of the textile weave were developed on the meso- and macro-scale. The final correlation between impact simulation results on 3D textile-reinforced composite plates and impact test data was promising, highlighting the potential of such numerical simulation tools.

Novel fiber-based pure chitosan scaffold for tendon augmentation: biomechanical and cell biological evaluation.

PubMed

Nowotny, J; Aibibu, D; Farack, J; Nimtschke, U; Hild, M; Gelinsky, M; Kasten, P; Cherif, Ch

2016-07-01

One possibility to improve the mechanical properties after tendon ruptures is augmentation with a scaffold. Based on wet spinning technology, chitosan fibres were processed to a novel pure high-grade multifilament yarn with reproducible quality. The fibres were braided to obtain a 3D tendon scaffold. The CS fibres and scaffolds were evaluated biomechanically and compared to human supraspinatus (SSP) tendons. For the cytobiological characterization, in vitro cell culture experiments with human mesenchymal stem cells (hMSC) were performed. Three types of 3D circular braided scaffolds were fabricated. Significantly, higher ultimate stress values were measured for scaffold with larger filament yarn, compared to scaffold with smaller filament yarn. During cultivation over 28 days, the cells showed in dependence of isolation method and/or donor a doubling or tripling of the cell number or even a six-fold increase on the CS scaffold, which was comparable to the control (polystyrene) or in the case of cells obtained from human biceps tendon even higher proliferation rates. After 14 days, the scaffold surface was covered homogeneously with a cell layer. In summary, the present work demonstrates that braided chitosan scaffolds constitute a straightforward approach for designing tendon analogues, maintaining important flexibility in scaffold design and providing favourable mechanical properties of the resulting construct.

Effect of particle hardness on the penetration behavior of fabrics intercalated with dry particles and concentrated particle-fluid suspensions.

PubMed

Kalman, Dennis P; Merrill, Richard L; Wagner, Norman J; Wetzel, Eric D

2009-11-01

The penetration behavior of Kevlar fabric intercalated with dry particles and shear thickening fluids (STF), highly concentrated fluid-particle suspensions, is presented. In particular, the role of particle hardness is explored by comparing fabric treatments containing SiO(2) particles, which are significantly harder than Kevlar, to treatments containing softer poly(methyl methacrylate) (PMMA) particles. The fabric testing includes yarn pull-out, quasi-static spike puncture, and ballistic penetration resistance, performed on single fabric layers. It was found that both dry particle and STF treatments resulted in improvements in fabric properties relative to neat or poly(ethylene glycol) (PEG) treated fabrics. On comparison of treatments with different particle hardness, the SiO(2) materials performed better in all tests than comparable PMMA materials, although the SiO(2) treatments caused yarn failure in pull-out testing, reducing the total pull-out energy. In addition, resistance to yarn pull-out was found to be substantially higher for STF-treated fabrics than for dry particle treated fabrics. However, both dry particle addition and STF treatments exhibited comparable enhancements in puncture and ballistic resistance. These observations suggest that viscous stress transfer, friction, and physical entrainment of hard particles into filaments contribute to the demonstrated improvements in the properties of protective fabrics treated with shear thickening fluids.

Electrospun Nanofibers of Guar Galactomannan for Targeted Drug Delivery

NASA Astrophysics Data System (ADS)

Chu, Hsiao Mei Annie

2011-12-01

Guar galactomannan is a biodegradable polysaccharide used widely in the food industry but also in the cosmetics, pharmaceutical, oil drilling, textile and paper industries. Guar consists of a mannose backbone and galactose side groups that are both susceptible to enzyme degradation, a unique property that can be explored for targeted drug delivery especially since those enzymes are naturally secreted by the microflora in human colon. The present study can be divided into three parts. In the first part, we discuss ways to modify guar to produce nanofibers by electrospinning, a process that involves the application of an electric field to a polymer solution or melt to facilitate production of fibers in the sub-micron range. Nanofibers are currently being explored as the next generation of drug carriers due to its many advantages, none more important than the fact that nanofibers are on a size scale that is a fraction of a hair's width and have large surface-to-volume ratio. The incorporation and controlled release of nano-sized drugs is one way in which nanofibers are being utilized in drug delivery. In the second part of the study, we explore various methods to crosslink guar nanofibers as a means to promote water-resistance in a potential drug carrier. The scope and utility of water-resistant guar nanofibers can only be fully appreciated when subsequent drug release studies are carried out. To that end, the third part of our study focuses on understanding the kinetics and diffusion mechanisms of a model drug, Rhodamine B, through moderately-swelling (crosslinked) hydrogel nanofibers in comparison to rapidly-swelling (non-crosslinked) nanofibers. Along the way, our investigations led us to a novel electrospinning set-up that has a unique collector designed to capture aligned nanofibers. These aligned nanofiber bundles can then be twisted to hold them together like yarn. From a practical standpoint, these yarns are advantageous because they come freely suspended and

75 FR 56982 - Narrow Woven Ribbons With Woven Selvedge From Taiwan and the People's Republic of China: Amended...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-17

..., polypropylene, and polyethylene teraphthalate), metal threads and/or metalized yarns, or any combination thereof... Le Quan Enterprise Enterprise Co., Ltd./Novelty Handicrafts Co., Co., Ltd. Ltd. Shienq Huong...

Carbide coated fibers in graphite-aluminum composites

NASA Technical Reports Server (NTRS)

Imprescia, R. J.; Levinson, L. S.; Reiswig, R. D.; Wallace, T. C.; Williams, J. M.

1975-01-01

Thin, uniform coats of titanium carbide, deposited on graphite fibers by chemical vapor deposition with thicknesses up to approximately 0.1 microns were shown to improve fiber strength significantly. For greater thicknesses, strength was degraded. The coats promote wetting of the fibers and infiltration of the fiber yarns with aluminum alloys, and act as protective barriers to inhibit reaction between the fibers and the alloys. Chemical vapor deposition was used to produce silicon carbide coats on graphite fibers. In general, the coats were nonuniform and were characterized by numerous surface irregularities. Despite these irregularities, infiltration of these fibers with aluminum alloys was good. Small graphite-aluminum composite samples were produced by vacuum hot-pressing of aluminum-infiltrated graphite yarn at temperatures above the metal liquidus.

A Unit-Cell Model for Predicting the Elastic Constants of 3D Four Directional Cylindrical Braided Composite Shafts

NASA Astrophysics Data System (ADS)

Hao, Wenfeng; Liu, Ye; Huang, Xinrong; Liu, Yinghua; Zhu, Jianguo

2018-06-01

In this work, the elastic constants of 3D four directional cylindrical braided composite shafts were predicted using analytical and numerical methods. First, the motion rule of yarn carrier of 3D four directional cylindrical braided composite shafts was analyzed, and the horizontal projection of yarn motion trajectory was obtained. Then, the geometry models of unit-cells with different braiding angles and fiber volume contents were built up, and the meso-scale models of 3D cylindrical braided composite shafts were obtained. Finally, the effects of braiding angles and fiber volume contents on the elastic constants of 3D braided composite shafts were analyzed theoretically and numerically. These results play a crucial role in investigating the mechanical properties of 3D 4-directional braided composites shafts.

Textile-Based Weft Knitted Strain Sensors: Effect of Fabric Parameters on Sensor Properties

PubMed Central

Atalay, Ozgur; Kennon, William Richard; Husain, Muhammad Dawood

2013-01-01

The design and development of textile-based strain sensors has been a focus of research and many investigators have studied this subject. This paper presents a new textile-based strain sensor design and shows the effect of base fabric parameters on its sensing properties. Sensing fabric could be used to measure articulations of the human body in the real environment. The strain sensing fabric was produced by using electronic flat-bed knitting technology; the base fabric was produced with elastomeric yarns in an interlock arrangement and a conductive yarn was embedded in this substrate to create a series of single loop structures. Experimental results show that there is a strong relationship between base fabric parameters and sensor properties. PMID:23966199

19 CFR 10.850 - Verification of claim for duty-free treatment.

Code of Federal Regulations, 2011 CFR

2011-04-01

... yarn, fabric, fabric components, and knit-to-shape components that were used in the production of the..., fabric, fabric components and knit-to-shape components. The affidavit or statement of origin should...

19 CFR 10.521 - Goods eligible for tariff preference level claims.

Code of Federal Regulations, 2010 CFR

2010-04-01

... States-Singapore Free Trade Agreement Tariff Preference Level § 10.521 Goods eligible for tariff... assembled in Singapore from fabric or yarn produced or obtained outside the territory of Singapore or the...

37. MILL NO. 2, 2nd FLOOR, CLOSE SHOT OF 2 ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

37. MILL NO. 2, 2nd FLOOR, CLOSE SHOT OF 2 CREEL MACHINES, WHICH FEED YARN INTO KNITTING MACHINES. - Prattville Manufacturing Company, Number One, 242 South Court Street, Prattville, Autauga County, AL

3D Orthogonal Woven Triboelectric Nanogenerator for Effective Biomechanical Energy Harvesting and as Self-Powered Active Motion Sensors.

PubMed

Dong, Kai; Deng, Jianan; Zi, Yunlong; Wang, Yi-Cheng; Xu, Cheng; Zou, Haiyang; Ding, Wenbo; Dai, Yejing; Gu, Bohong; Sun, Baozhong; Wang, Zhong Lin

2017-10-01

The development of wearable and large-area energy-harvesting textiles has received intensive attention due to their promising applications in next-generation wearable functional electronics. However, the limited power outputs of conventional textiles have largely hindered their development. Here, in combination with the stainless steel/polyester fiber blended yarn, the polydimethylsiloxane-coated energy-harvesting yarn, and nonconductive binding yarn, a high-power-output textile triboelectric nanogenerator (TENG) with 3D orthogonal woven structure is developed for effective biomechanical energy harvesting and active motion signal tracking. Based on the advanced 3D structural design, the maximum peak power density of 3D textile can reach 263.36 mW m -2 under the tapping frequency of 3 Hz, which is several times more than that of conventional 2D textile TENGs. Besides, its collected power is capable of lighting up a warning indicator, sustainably charging a commercial capacitor, and powering a smart watch. The 3D textile TENG can also be used as a self-powered active motion sensor to constantly monitor the movement signals of human body. Furthermore, a smart dancing blanket is designed to simultaneously convert biomechanical energy and perceive body movement. This work provides a new direction for multifunctional self-powered textiles with potential applications in wearable electronics, home security, and personalized healthcare. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

New Textile Sensors for In Situ Structural Health Monitoring of Textile Reinforced Thermoplastic Composites Based on the Conductive Poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) Polymer Complex.

PubMed

Jerkovic, Ivona; Koncar, Vladan; Grancaric, Ana Marija

2017-10-10

Many metallic structural and non-structural parts used in the transportation industry can be replaced by textile-reinforced composites. Composites made from a polymeric matrix and fibrous reinforcement have been increasingly studied during the last decade. On the other hand, the fast development of smart textile structures seems to be a very promising solution for in situ structural health monitoring of composite parts. In order to optimize composites' quality and their lifetime all the production steps have to be monitored in real time. Textile sensors embedded in the composite reinforcement and having the same mechanical properties as the yarns used to make the reinforcement exhibit actuating and sensing capabilities. This paper presents a new generation of textile fibrous sensors based on the conductive polymer complex poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) developed by an original roll to roll coating method. Conductive coating for yarn treatment was defined according to the preliminary study of percolation threshold of this polymer complex. The percolation threshold determination was based on conductive dry films' electrical properties analysis, in order to develop highly sensitive sensors. A novel laboratory equipment was designed and produced for yarn coating to ensure effective and equally distributed coating of electroconductive polymer without distortion of textile properties. The electromechanical properties of the textile fibrous sensors confirmed their suitability for in situ structural damages detection of textile reinforced thermoplastic composites in real time.

Hybrid textile heart valve prosthesis: preliminary in vitro evaluation.

PubMed

Vaesken, Antoine; Pidancier, Christian; Chakfe, Nabil; Heim, Frederic

2016-09-22

Transcatheter aortic valve implantation (TAVI) is nowadays a popular alternative technique to surgical valve replacement for critical patients. Biological valve tissue has been used in these devices for over a decade now with over 100,000 implantations. However, material degradations due to crimping for catheter insertion purpose have been reported, and with only 6-year follow-up, no information is available about the long-term durability of biological tissue. Moreover, expensive biological tissue harvesting and chemical treatment procedures tend to promote the development of synthetic valve leaflet materials. Textile polyester (PET) material is characterized by outstanding folding and strength properties combined with proven biocompatibility and could therefore be considered as a candidate to replace biological valve leaflets in TAVI devices. Nevertheless, the material should be preferentially partly elastic in order to limit water hammer effects at valve closing time and prevent exaggerated stress from occurring into the stent and the valve. The purpose of the present work is to study in vitro the mechanical as well as the hydrodynamic behavior of a hybrid elastic textile valve device combining non-deformable PET yarn and elastic polyurethane (PU) yarn. The hybrid valve properties are compared with those of a non-elastic textile valve. Testing results show improved hydrodynamic properties with the elastic construction. However, under fatigue conditions, the interaction between PU and PET yarns tends to limit the valve durability.

78 FR 62443 - Perfluoroalkyl Sulfonates and Long-Chain Perfluoroalkyl Carboxylate Chemical Substances; Final...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-10-22

... manufacturing and petroleum refineries. Carpet and rug mills (NAICS code 314110). Fiber, yarn, and thread mills... the abrasion of carpets. This is of particular concern for children since they engage in a variety of...

Flexible thermal laminate

NASA Technical Reports Server (NTRS)

Dawn, F. S.; Sauers, D. G.

1977-01-01

Lightweight flexible laminate of interwoven conducting and insulating yarns, designed to provide localized controlled heating for propellant tanks on space vehicles, is useful for nonspace applications where weight, bulk, and flexibility are critical concerns.

19 CFR 208.3 - Petitions.

Code of Federal Regulations, 2010 CFR

2010-04-01

... demonstrates to the satisfaction of the Commission a proper interest in filing a petition. (b) Contents of... fabric or yarn to the customer identified in the order, and any other information that the interested...

Deodorizing Properties of Photocatalyst Textiles and Its Effect Analysis

NASA Astrophysics Data System (ADS)

Zhang, Hongxia; Ge, Caihong; Zhu, Chengyan; Li, Yanqing; Tian, Wei; Cheng, Dongzhi; Pan, Zhongxiang

In this paper, yarns of photocatalyst modified polyester staple fiber, cotton and blended yarn of bamboo fiber and photocatalyst modified polyester were selected. Series of woven fabric were manufactured.The photocatalyst fiber contents of woven fabrics were changed from 0% to 100% with 20% gap, that is 0%,40%,60%,80% and 100%. The deodorant performance of these fabrics were tested and analyzed, it can be concluded that when the content of the photocatalyst is 80% or 100%, the fabrics owns better deodorant; when the photocatalyst content in fabric is 40% or 60%, it has the deodorantion properties but the effect was not good. It can be shown from this experimental study that the deodorizing fabrics can be considered to develop if only the content of photocatalyst is above the 80%.

19 CFR 10.843 - Articles eligible for duty-free treatment.

Code of Federal Regulations, 2012 CFR

2012-04-01

..., or yarns from which the article is made: (1) Pajama bottoms and other sleepwear for women and girls... classifiable in subheading 6208.92.00, HTSUS; or (2) Pajama bottoms and other sleepwear for girls, of other...

19 CFR 10.843 - Articles eligible for duty-free treatment.

Code of Federal Regulations, 2013 CFR

2013-04-01

..., or yarns from which the article is made: (1) Pajama bottoms and other sleepwear for women and girls... classifiable in subheading 6208.92.00, HTSUS; or (2) Pajama bottoms and other sleepwear for girls, of other...

19 CFR 10.843 - Articles eligible for duty-free treatment.

Code of Federal Regulations, 2014 CFR

2014-04-01

..., or yarns from which the article is made: (1) Pajama bottoms and other sleepwear for women and girls... classifiable in subheading 6208.92.00, HTSUS; or (2) Pajama bottoms and other sleepwear for girls, of other...

Investigation of Mechanical and Electromagnetic Interference Shielding Properties of Nickel-CFRP Textile Composites

NASA Astrophysics Data System (ADS)

Tugirumubano, Alexandre; Vijay, Santhiyagu Joseph; Go, Sun Ho; Kwac, Lee Ku; Kim, Hong Gun

2018-05-01

The most common materials used for electromagnetic interference shielding are metals and their alloys. However, those materials are heavy and highly reflective. In order to eliminate or reduce the intensity of wave radiation in their working environment, lightweight materials that have interference shielding properties are needed. In this paper, nickel wire mesh yarns (warps) were woven into carbon fibers-reinforced plastic yarns (wefts) to produce metal-carbon textile composite materials. The plain weave and 2/2 twill weave techniques were used, and the woven fabrics were laminated to manufacture experimental test samples. The nickel, which has high magnetic permeability and good electric conductivity, and carbon fibers, which have good electrical, thermal and mechanical properties, were used together to achieve the desired properties. The shielding effectiveness of each sample was investigated using a network analyzer connected with coaxial transmission line test in accordance with ASTM 4935-99 standard, with the frequencies ranging from 500 MHz to 1.5 GHz. Here, the plain weave structure showed higher shielding effectiveness than twill weave. The absorption losses for both materials were relatively greater than reflection losses. In reference to the orientation of wire mesh yarns about the loading axis, the tensile strengths in the transversal direction were 19.04 and 16.34% higher than the tensile strengths in longitudinal direction for plain weave and twill weave, respectively. The fractography analysis with SEM showed a ductile fracture of wire mesh and brittle fracture of epoxy matrix and carbon fibers.

New Textile Sensors for In Situ Structural Health Monitoring of Textile Reinforced Thermoplastic Composites Based on the Conductive Poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) Polymer Complex

PubMed Central

Jerkovic, Ivona; Koncar, Vladan; Grancaric, Ana Marija

2017-01-01

Many metallic structural and non-structural parts used in the transportation industry can be replaced by textile-reinforced composites. Composites made from a polymeric matrix and fibrous reinforcement have been increasingly studied during the last decade. On the other hand, the fast development of smart textile structures seems to be a very promising solution for in situ structural health monitoring of composite parts. In order to optimize composites’ quality and their lifetime all the production steps have to be monitored in real time. Textile sensors embedded in the composite reinforcement and having the same mechanical properties as the yarns used to make the reinforcement exhibit actuating and sensing capabilities. This paper presents a new generation of textile fibrous sensors based on the conductive polymer complex poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) developed by an original roll to roll coating method. Conductive coating for yarn treatment was defined according to the preliminary study of percolation threshold of this polymer complex. The percolation threshold determination was based on conductive dry films’ electrical properties analysis, in order to develop highly sensitive sensors. A novel laboratory equipment was designed and produced for yarn coating to ensure effective and equally distributed coating of electroconductive polymer without distortion of textile properties. The electromechanical properties of the textile fibrous sensors confirmed their suitability for in situ structural damages detection of textile reinforced thermoplastic composites in real time. PMID:28994733

Finite element modelling of woven composite failure modes at the mesoscopic scale: deterministic versus stochastic approaches

NASA Astrophysics Data System (ADS)

Roirand, Q.; Missoum-Benziane, D.; Thionnet, A.; Laiarinandrasana, L.

2017-09-01

Textile composites are composed of 3D complex architecture. To assess the durability of such engineering structures, the failure mechanisms must be highlighted. Examinations of the degradation have been carried out thanks to tomography. The present work addresses a numerical damage model dedicated to the simulation of the crack initiation and propagation at the scale of the warp yarns. For the 3D woven composites under study, loadings in tension and combined tension and bending were considered. Based on an erosion procedure of broken elements, the failure mechanisms have been modelled on 3D periodic cells by finite element calculations. The breakage of one element was determined using a failure criterion at the mesoscopic scale based on the yarn stress at failure. The results were found to be in good agreement with the experimental data for the two kinds of macroscopic loadings. The deterministic approach assumed a homogeneously distributed stress at failure all over the integration points in the meshes of woven composites. A stochastic approach was applied to a simple representative elementary periodic cell. The distribution of the Weibull stress at failure was assigned to the integration points using a Monte Carlo simulation. It was shown that this stochastic approach allowed more realistic failure simulations avoiding the idealised symmetry due to the deterministic modelling. In particular, the stochastic simulations performed have shown several variations of the stress as well as strain at failure and the failure modes of the yarn.

Development of glass fibre reinforced composites using microwave heating technology

NASA Astrophysics Data System (ADS)

Köhler, T.; Vonberg, K.; Gries, T.; Seide, G.

2017-10-01

Fibre reinforced composites are differentiated by the used matrix material (thermoplastic versus duroplastic matrix) and the level of impregnation. Thermoplastic matrix systems get more important due to their suitability for mass production, their good shapeability and their high impact resistance. A challenge in the processing of these materials is the reduction of the melt flow paths of the thermoplastic matrix. The viscosity of molten thermoplastic material is distinctly higher than the viscosity of duroplastic material. An approach to reduce the flow paths of the thermoplastic melt is given by a commingling process. Composites made from commingling hybrid yarns consist of thermoplastic and reinforcing fibres. Fabrics made from these hybrid yarns are heated and consolidated by the use of heat pressing to form so called organic sheets. An innovative heating system is given by microwaves. The advantage of microwave heating is the volumetric heating of the material, where the energy of the electromagnetic radiation is converted into thermal energy inside the material. In this research project microwave active hybrid yarns are produced and examined at the Institute for Textile Technology of RWTH Aachen University (ITA). The industrial research partner Fricke und Mallah Microwave Technology GmbH, Peine, Germany develops an innovative pressing systems based on a microwave heating system. By implementing the designed microwave heating technology into an existing heat pressing process, FRTCs are being manufactured from glass and nanomodified polypropylene fibre woven fabrics. In this paper the composites are investigated for their mechanical and optical properties.

Woven-grid sealed quasi-bipolar lead-acid battery construction and fabricating method

NASA Technical Reports Server (NTRS)

Rippel, Wally E. (Inventor)

1989-01-01

A quasi-bipolar lead-acid battery construction includes a plurality of bipolar cells disposed in side-by-side relation to form a stack, and a pair of monoplanar plates at opposite ends of the stack, the cell stack and monopolar plates being contained within a housing of the battery. Each bipolar cell is loaded with an electrolyte and composed of a bipolar electrode plate and a pair of separator plates disposed on opposite sides of the electrode plate and peripherally sealed thereto. Each bipolar electrode plate is composed of a partition sheet and two bipolar electrode elements folded into a hairpin configuration and applied over opposite edges of the partition sheet so as to cover the opposite surfaces of the opposite halves thereof. Each bipolar electrode element is comprised of a woven grid with a hot-melt strip applied to a central longitudinal region of the grid along which the grid is folded into the hairpin configuration, and layers of negative and positive active material pastes applied to opposite halves of the grid on opposite sides of the central hot-melt strip. The grid is made up of strands of conductive and non-conductive yarns composing the respective transverse and longitudinal weaves of the grid. The conductive yarn has a multi-stranded glass core surrounded and covered by a lead sheath, whereas the non-conductive yarn has a multi-stranded glass core surrounded and covered by a thermally activated sizing.

Investigation of Mechanical and Electromagnetic Interference Shielding Properties of Nickel-CFRP Textile Composites

NASA Astrophysics Data System (ADS)

Tugirumubano, Alexandre; Vijay, Santhiyagu Joseph; Go, Sun Ho; Kwac, Lee Ku; Kim, Hong Gun

2018-04-01

The most common materials used for electromagnetic interference shielding are metals and their alloys. However, those materials are heavy and highly reflective. In order to eliminate or reduce the intensity of wave radiation in their working environment, lightweight materials that have interference shielding properties are needed. In this paper, nickel wire mesh yarns (warps) were woven into carbon fibers-reinforced plastic yarns (wefts) to produce metal-carbon textile composite materials. The plain weave and 2/2 twill weave techniques were used, and the woven fabrics were laminated to manufacture experimental test samples. The nickel, which has high magnetic permeability and good electric conductivity, and carbon fibers, which have good electrical, thermal and mechanical properties, were used together to achieve the desired properties. The shielding effectiveness of each sample was investigated using a network analyzer connected with coaxial transmission line test in accordance with ASTM 4935-99 standard, with the frequencies ranging from 500 MHz to 1.5 GHz. Here, the plain weave structure showed higher shielding effectiveness than twill weave. The absorption losses for both materials were relatively greater than reflection losses. In reference to the orientation of wire mesh yarns about the loading axis, the tensile strengths in the transversal direction were 19.04 and 16.34% higher than the tensile strengths in longitudinal direction for plain weave and twill weave, respectively. The fractography analysis with SEM showed a ductile fracture of wire mesh and brittle fracture of epoxy matrix and carbon fibers.

Effect of Bamboo Viscose on the Wicking and Moisture Management Properties of Gauze

NASA Astrophysics Data System (ADS)

Akbar, Abdul R.; Su, Siwei; Amjad, Bilal; Cai, Yingjie; Lin, Lina

2017-12-01

Bamboo viscose or regenerated cellulose fibers were used to check their absorbency properties effect on the wicking and moisture management in gauzes. Bamboo viscose and cotton fibers were spun into five different yarn samples with different fiber proportion by ring spinning. Fifteen different gauze samples were made of these yarn samples. The gauze samples were subjected to wicking test to check the wicking ability. Water vapor transmission test was applied to check the vapor transmission rate. These tests were applied to measure the effectiveness of bamboo viscose, cotton and blended gauze samples in wound healing. Pure bamboo gauzes and gauzes with high content of bamboo fiber, i.e. 75B:25C and 50B:50C, shows better wicking and vapor transmission properties. It makes gauzes with high bamboo viscose suitable for wound care applications because of moisture absorbency.

Improvement of carbon nanotubes films conductivity for use in biomedical application

NASA Astrophysics Data System (ADS)

Dybowska-Sarapuk, Łucja; Janczak, Daniel; Krzemiński, Jakub; Lepak, Sandra; Łekawa-Raus, Agnieszka; MłoŻniak, Anna; Jakubowska, Małgorzata

2017-08-01

Carbon nanotube (CNT) yarns and sheets due to their biocompatibility, very good mechanical strength and flexibility can find wide range of applications in nanomedicine, inter alia as mechanical actuators for artificial muscles or electrodes used for deep brain stimulation. However, because of CNT film behavior in liquid environment, before their using in biological applications, they should be coated with a special protective layer. The purpose of created coatings is not only to protect the films, but also to increase their conductivity. The aim of the research was to test various methods of achieving such coatings on CNT films and to evaluate quality and flexibility of coated CNT films. The coatings were made using various suspensions containing polymer materials such methyl polymethacrylate and conductive silver flakes. The methods tested in this study were: dipping, painting and flooding of the CNT yarns.

Scope of nanotechnology in modern textiles

USDA-ARS?s Scientific Manuscript database

This review article demonstrates the scope and applications of nanotechnology towards modification and development of advanced textile fibers, yarns and fabrics and their processing techniques. Basically, it summarizes the recent advances made in nanotechnology and its applications to cotton textil...

New definitions for cotton fiber maturity ratio

USDA-ARS?s Scientific Manuscript database

Cotton fiber maturity affects fiber physical, mechanical, and chemical properties, as well as the processability and qualities of yarn and fabrics. New definitions of cotton fiber maturity ratio are introduced. The influences of sampling, sample preparation, measurement method, and correlations am...

Influence of the vacuum resin process, on the ballistic behaviour of lightweight armouring solutions

NASA Astrophysics Data System (ADS)

Lefebvre, M.; Boussu, F.; Coutellier, D.; Vallee, D.

2012-08-01

The armour of vehicles against conventional threats is mainly composed with steel or aluminium panels. Efficient heavy solutions exist, but the involved industries require new lightweight structures. Moreover, unconventional threats as IEDs (Improvised Explosive Devices) may cause severe damages on these structural and protective panel solutions. Thus, combination of aluminium or steel plates with textile composite structures used as a backing, leads to the mass reduction and better performance under delamination behaviour against these new threats. This paper is a part of a study dealing with the impact behaviour of three warp interlocks weaving structures under Fragment Simulating Projectile (FSP) impact. During this research, several parameters has being studied as the influence of the yarns insertions [1-4], the degradation of the yarns during the weaving process [5-7], and the influence of the resin rate on the ballistic behaviour. The resin rate inside composite materials is dependant on the final application. In ballistic protection, we need to control the resin rate in order to have a deformable structure in order to absorb the maximum of energy. However, with the warp interlocks weaving structure, the yarns insertions induce empty spaces between the yarns where the resin takes place without being evacuated. The resin rate inside the warp interlocks structures is in the most of cases less than 50%, which lead to have brittle and hard material during the impact. Contrary to interlocks structures, the existing protection based on prepreg structure have a high fibres ratio around 88% of weight. That leads to have the best ballistic properties during the impact and good deformability of the structure. The aim of this paper is to evaluate the influence of the resin rate on the ballistic results of the composites materials. For that, we have chosen two kinds of warp interlocks fabrics which were infused with epoxy resin following two processes. The first is a

An investigation to determine the producibility of a 3-D braider and bias direction weaving loom

NASA Technical Reports Server (NTRS)

Huey, Cecil O., Jr.

1991-01-01

The development of prototype machines for the production of generalized braid patterns is described. Mechanical operating principles and control strategies are presented for two prototype machines which were fabricated and evaluated. Both machines represent advances over current techniques for forming composite material preforms by enabling near ideal control of fiber orientation. Furthermore, they overcome both the lack of general control of produced fiber architectures and the complexity of other weaving processes that were produced for the same purpose. One prototype, the modified Farley braider, consists of an array of turntables which can be rotated 90 degrees and returned; hence, they can form tracks in the x and y axis. Yarn ends are transported about the surface formed by the turntables using motorized tractors. These tractors are controlled using an optical link with a control circuit and host computer. The tractors are powered through electrical contact with the turntables. The necessary relative motions are produced by a series of linear tractor moves combined with a sequence of turntable rotations. The movement of the tractors about the surface causes the yarns to produce the desired braiding pattern. The second device, the shuttle plate braider, consists of a braiding surface formed by an array of square elements, each separated from its neighbor by a gap. Beneath this surface lies a shuttle plate, which reciprocates first in one axis and then in the other. As this movement takes place, yarn carrying shuttles engage and disengage the plate by means of solenoid activated pins. By selective engagement and disengagement, the shuttles can move the yarn ends in any desired pattern, forming the desired braid. Control power, and control signals, are transmitted from the electronic interface circuit and host computer, via the braiding surface through electrical contact with the shuttles. Motive power is proved to the shuttles by motion of the shuttle plate

Variations and relationship of quality and NIR spectral characteristics of cotton fibers collected from multi-location field performance trials

USDA-ARS?s Scientific Manuscript database

High volume instrumentation (HVITM) and advanced fiber information system (AFIS) measurements are increasingly being utilized as primary and routine means of acquiring fiber quality data by cotton breeders and fiber processors. There is amount of information regarding fiber and yarn qualities, but l...

76 FR 71831 - Defense Federal Acquisition Regulation Supplement: Fire-Resistant Fiber for Production of...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-18

..., suppliers, or distributors of fire-resistant fibers, yarns, fabrics, or military uniforms) submitted.... The law does not restrict DoD's selection and use of fabrics containing fire-resistant rayon fiber... from selecting fabrics that include fire- resistant rayon fibers. Response: These responses have...

7 CFR 319.8 - Notice of quarantine.

Code of Federal Regulations, 2010 CFR

2010-01-01

... seed cotton; cottonseed; cotton lint, linters, and other forms of cotton fiber (not including yarn, thread, and cloth); cottonseed hulls, cake, meal, and other cottonseed products, except oil; cotton waste... ordinarily used, for containing cotton, grains (including grain products), field seeds, agricultural roots...

Botanical trash mixtures analyzed with near-infrared and attenuated total reflectance fourier transform spectroscopy and thermogravimetric analysis

USDA-ARS?s Scientific Manuscript database

Botanical cotton trash mixed with lint reduces cotton’s marketability and appearance. During cotton harvesting, ginning, and processing, trash size reduction occurs, thus complicating its removal and identification. This trash causes problems by increasing ends down in yarn formation and thus proce...

Harvesting electrical energy from torsional thermal actuation driven by natural convection.

PubMed

Kim, Shi Hyeong; Sim, Hyeon Jun; Hyeon, Jae Sang; Suh, Dongseok; Spinks, Geoffrey M; Baughman, Ray H; Kim, Seon Jeong

2018-06-07

The development of practical, cost-effective systems for the conversion of low-grade waste heat to electrical energy is an important area of renewable energy research. We here demonstrate a thermal energy harvester that is driven by the small temperature fluctuations provided by natural convection. This harvester uses coiled yarn artificial muscles, comprising well-aligned shape memory polyurethane (SMPU) microfibers, to convert thermal energy to torsional mechanical energy, which is then electromagnetically converted to electrical energy. Temperature fluctuations in a yarn muscle, having a maximum hot-to-cold temperature difference of about 13 °C, were used to spin a magnetic rotor to a peak torsional rotation speed of 3,000 rpm. The electromagnetic energy generator converted the torsional energy to electrical energy, thereby producing an oscillating output voltage of up to 0.81 V and peak power of 4 W/kg, based on SMPU mass.

Process for making ceramic hot gas filter

DOEpatents

Connolly, Elizabeth Sokolinski; Forsythe, George Daniel; Domanski, Daniel Matthew; Chambers, Jeffrey Allen; Rajendran, Govindasamy Paramasivam

2001-01-01

A ceramic hot-gas candle filter having a porous support of filament-wound oxide ceramic yarn at least partially surrounded by a porous refractory oxide ceramic matrix, and a membrane layer on at least one surface thereof. The membrane layer may be on the outer surface, the inner surface, or both the outer and inner surface of the porous support. The membrane layer may be formed of an ordered arrangement of circularly wound, continuous filament oxide ceramic yarn, a ceramic filler material which is less permeable than the filament-wound support structure, or some combination of continuous filament and filler material. A particularly effective membrane layer features circularly wound filament with gaps intentionally placed between adjacent windings, and a filler material of ceramic particulates uniformly distributed throughout the gap region. The filter can withstand thermal cycling during backpulse cleaning and is resistant to chemical degradation at high temperatures.

Ceramic hot-gas filter

DOEpatents

Connolly, Elizabeth Sokolinski; Forsythe, George Daniel; Domanski, Daniel Matthew; Chambers, Jeffrey Allen; Rajendran, Govindasamy Paramasivam

1999-01-01

A ceramic hot-gas candle filter having a porous support of filament-wound oxide ceramic yarn at least partially surrounded by a porous refractory oxide ceramic matrix, and a membrane layer on at least one surface thereof. The membrane layer may be on the outer surface, the inner surface, or both the outer and inner surface of the porous support. The membrane layer may be formed of an ordered arrangement of circularly wound, continuous filament oxide ceramic yarn, a ceramic filler material which is less permeable than the filament-wound support structure, or some combination of continuous filament and filler material. A particularly effective membrane layer features circularly wound filament with gaps intentionally placed between adjacent windings, and a filler material of ceramic particulates uniformly distributed throughout the gap region. The filter can withstand thermal cycling during backpulse cleaning and is resistant to chemical degradation at high temperatures.

Ceramic hot-gas filter

DOEpatents

Connolly, E.S.; Forsythe, G.D.; Domanski, D.M.; Chambers, J.A.; Rajendran, G.P.

1999-05-11

A ceramic hot-gas candle filter is described having a porous support of filament-wound oxide ceramic yarn at least partially surrounded by a porous refractory oxide ceramic matrix, and a membrane layer on at least one surface thereof. The membrane layer may be on the outer surface, the inner surface, or both the outer and inner surface of the porous support. The membrane layer may be formed of an ordered arrangement of circularly wound, continuous filament oxide ceramic yarn, a ceramic filler material which is less permeable than the filament-wound support structure, or some combination of continuous filament and filler material. A particularly effective membrane layer features circularly wound filament with gaps intentionally placed between adjacent windings, and a filler material of ceramic particulates uniformly distributed throughout the gap region. The filter can withstand thermal cycling during back pulse cleaning and is resistant to chemical degradation at high temperatures.

Highly stretchable and wearable graphene strain sensors with controllable sensitivity for human motion monitoring.

PubMed

Park, Jung Jin; Hyun, Woo Jin; Mun, Sung Cik; Park, Yong Tae; Park, O Ok

2015-03-25

Because of their outstanding electrical and mechanical properties, graphene strain sensors have attracted extensive attention for electronic applications in virtual reality, robotics, medical diagnostics, and healthcare. Although several strain sensors based on graphene have been reported, the stretchability and sensitivity of these sensors remain limited, and also there is a pressing need to develop a practical fabrication process. This paper reports the fabrication and characterization of new types of graphene strain sensors based on stretchable yarns. Highly stretchable, sensitive, and wearable sensors are realized by a layer-by-layer assembly method that is simple, low-cost, scalable, and solution-processable. Because of the yarn structures, these sensors exhibit high stretchability (up to 150%) and versatility, and can detect both large- and small-scale human motions. For this study, wearable electronics are fabricated with implanted sensors that can monitor diverse human motions, including joint movement, phonation, swallowing, and breathing.

Nondestructive Evaluation Techniques for Development and Characterization of Carbon Nanotube Based Superstructures

NASA Technical Reports Server (NTRS)

Wincheski, Buzz; Kim, Jae-Woo; Sauti, Godfrey; Wainwright, Elliot; Williams, Phillip; Siochi, Emile J.

2014-01-01

Recently, multiple commercial vendors have developed capability for the production of large-scale quantities of high-quality carbon nanotube sheets and yarns. While the materials have found use in electrical shielding applications, development of structural systems composed of a high volume fraction of carbon nanotubes is still lacking. A recent NASA program seeks to address this by prototyping a structural nanotube composite with strength-toweight ratio exceeding current state-of-the-art carbon fiber composites. Commercially available carbon nanotube sheets, tapes, and yarns are being processed into high volume fraction carbon nanotube-polymer nanocomposites. Nondestructive evaluation techniques have been applied throughout this development effort for material characterization and process control. This paper will report on the progress of these efforts, including magnetic characterization of residual catalyst content, Raman scattering characterization of nanotube diameter, defect ratio, and nanotube strain, and polarized Raman scattering for characterization of nanotube alignment.

19 CFR 10.844 - Value-content requirement.

Code of Federal Regulations, 2010 CFR

2010-04-01

... preference program. The producer ships to the United States four shipments during the initial applicable one... this subpart. (5) Inclusion of the cost of fabrics or yarns not available in commercial quantities in..., Singapore, Chile, Australia, Morocco, Bahrain, El Salvador, Honduras, Nicaragua, Guatemala, Dominican...

75 FR 7236 - Narrow Woven Ribbons with Woven Selvedge from Taiwan: Preliminary Determination of Sales at Less...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-02-18

... their manufacturing processes, as well as their purchases of ribbons from unaffiliated suppliers. Also..., polypropylene, and polyethylene teraphthalate), metal threads and/or metalized yarns, or any combination thereof... in the Harmonized Tariff Schedule of the United States (HTSUS), Section XI, Note 13) or rubber thread...

Comparative fiber property and transcriptome analyses reveal key genes potentially related to high fiber strength in cotton (Gossypium hirsutum L.) line MD52ne

USDA-ARS?s Scientific Manuscript database

Background: Individual fiber strength is an important quality attribute that greatly influences the strength of the yarn spun from cotton fibers. Fiber strength is usually measured from bundles of fibers due to the difficulty of reliably measuring strength from individual cotton fibers. However, bun...

Vibrational spectroscopic determination of botanical trash samples

USDA-ARS?s Scientific Manuscript database

Cotton trash present with cotton lint can drastically affect the yarn properties and marketability of cotton. Cotton trash usually comes into contact with cotton lint from field to fabric processing operations of cotton. Conventional methods to determine cotton lint currently do not present the or...

40 CFR 410.72 - Effluent limitations representing the degree of effluent reduction attainable by the application...

Code of Federal Regulations, 2010 CFR

2010-07-01

... degree of effluent reduction attainable by the application of the best practicable control technology... (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS TEXTILE MILLS POINT SOURCE CATEGORY Stock and Yarn Finishing... application of the best practicable control technology currently available (BPT). (a) Except as provided in 40...

The hydroentanglement system of producing nonwoven fabrics of certain specific attributes and functionalities

USDA-ARS?s Scientific Manuscript database

Although the traditional technologies and processes of producing fabric structures, via yarn spinning, weaving, knitting, lacing, tufting, or the like, continue to be the ‘major league’ players in textile manufacturing today, the modern hydroentanglement system, commonly known as “spunlacing,” has a...

Lightweight, variable solidity knitted parachute fabric. [for aerodynamic decelerators

NASA Technical Reports Server (NTRS)

Matthews, F. R., Jr.; White, E. C. (Inventor)

1973-01-01

A parachute fabric for aerodynamic decelerator applications is described. The fabric will permit deployment of the decelerator at high altitudes and low density conditions. The fabric consists of lightweight, highly open, circular knitted parachute fabric with ribbon-like yarns to assist in air deflection.

77 FR 75147 - Proposed Information Collection; Comment Request; Interim Procedures for Considering Requests...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-12-19

... specifications and the production capabilities of Panamanian and U.S. textile producers to determine whether... information collection instrument and instructions should be directed to Laurie Mease, Office of Textiles and... Agreement, pursuant to the textile provisions of the Agreement, fabric, yarn, and fiber produced in Panama...

40 CFR 63.3310 - What definitions are used in this subpart?

Code of Federal Regulations, 2013 CFR

2013-07-01

... organic HAP emissions generated by a process that is delivered to a control device, expressed as a... non-woven material made of filaments, fibers, or yarns including thread. This term includes material... into new processes and products where such equipment is operated under the close supervision of...

19 CFR 10.222 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-04-01

... together of all components (including thread, decorative embellishments, buttons, zippers, or similar...,” when used with reference to yarns, means that all of the production processes, starting with the... country, and, when used with reference to fabric(s), means that all of the production processes, starting...

40 CFR 63.3310 - What definitions are used in this subpart?

Code of Federal Regulations, 2011 CFR

2011-07-01

... organic HAP emissions generated by a process that is delivered to a control device, expressed as a... non-woven material made of filaments, fibers, or yarns including thread. This term includes material... into new processes and products where such equipment is operated under the close supervision of...

19 CFR 10.222 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-04-01

... together of all components (including thread, decorative embellishments, buttons, zippers, or similar...,” when used with reference to yarns, means that all of the production processes, starting with the... country, and, when used with reference to fabric(s), means that all of the production processes, starting...

19 CFR 10.222 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-04-01

... together of all components (including thread, decorative embellishments, buttons, zippers, or similar...,” when used with reference to yarns, means that all of the production processes, starting with the... country, and, when used with reference to fabric(s), means that all of the production processes, starting...

40 CFR 63.3310 - What definitions are used in this subpart?

Code of Federal Regulations, 2010 CFR

2010-07-01

... organic HAP emissions generated by a process that is delivered to a control device, expressed as a... non-woven material made of filaments, fibers, or yarns including thread. This term includes material... into new processes and products where such equipment is operated under the close supervision of...

40 CFR 63.3310 - What definitions are used in this subpart?

Code of Federal Regulations, 2014 CFR

2014-07-01

... organic HAP emissions generated by a process that is delivered to a control device, expressed as a... non-woven material made of filaments, fibers, or yarns including thread. This term includes material... into new processes and products where such equipment is operated under the close supervision of...

40 CFR 63.3310 - What definitions are used in this subpart?

Code of Federal Regulations, 2012 CFR

2012-07-01

... organic HAP emissions generated by a process that is delivered to a control device, expressed as a... non-woven material made of filaments, fibers, or yarns including thread. This term includes material... into new processes and products where such equipment is operated under the close supervision of...

Double the Benefits: Use Museum Collections.

ERIC Educational Resources Information Center

Ory, Norma R.

1984-01-01

A project for elementary school children based on a museum's collection of Alexander Calder's art is described. After studying Calder's works of art, students created their own three-dimensional stabiles, molded clay into animals, and made circus figures from cork, fabric, yarn, and colored paper. (RM)

49 CFR 372.115 - Commodities that are not exempt under 49 U.S.C. 13506(a)(6).

Code of Federal Regulations, 2010 CFR

2010-10-01

..., slaughtered Charcoal Cheese Coal Cocoa beans Coffee, beans, roasted, or instant Copra meal Cotton yarn... Flaxseed meal Flour Forest products: Resin products, such as turpentine Fruits and Berries: Bananas, fresh... extracted from grain Popcorn, popped Rice, precooked Wheat germ Gravel Hair, hog or other animal, product of...

Mapping by sequencing in cotton (Gossypium hirsutum) line MD52ne identified candidate genes for fiber strength and its related quality attributes

USDA-ARS?s Scientific Manuscript database

Fiber strength, length, maturity and fineness determine the market value of cotton fibers and the quality of spun yarn. Cotton fiber strength has been recognized as a critical quality attribute in the modern textile industry. Fine mapping along with quantitative trait loci (QTL) validation and candi...

48 CFR 205.301 - General.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 48 Federal Acquisition Regulations System 3 2011-10-01 2011-10-01 false General. 205.301 Section 205.301 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT OF... acquisition threshold that are for the acquisition of any clothing, fiber, yarn, or fabric items described in...

48 CFR 205.301 - General.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false General. 205.301 Section 205.301 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT OF... acquisition threshold that are for the acquisition of any clothing, fiber, yarn, or fabric items described in...

19 CFR 208.1 - Applicability of part.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 19 Customs Duties 3 2010-04-01 2010-04-01 false Applicability of part. 208.1 Section 208.1 Customs Duties UNITED STATES INTERNATIONAL TRADE COMMISSION NONADJUDICATIVE INVESTIGATIONS INVESTIGATIONS WITH RESPECT TO COMMERCIAL AVAILABILITY OF TEXTILE FABRIC AND YARN IN SUB-SAHARAN AFRICAN COUNTRIES § 208.1...

19 CFR 208.5 - Public hearing.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 19 Customs Duties 3 2010-04-01 2010-04-01 false Public hearing. 208.5 Section 208.5 Customs Duties UNITED STATES INTERNATIONAL TRADE COMMISSION NONADJUDICATIVE INVESTIGATIONS INVESTIGATIONS WITH RESPECT TO COMMERCIAL AVAILABILITY OF TEXTILE FABRIC AND YARN IN SUB-SAHARAN AFRICAN COUNTRIES § 208.5 Public...

19 CFR 208.7 - Determinations and reports.

Code of Federal Regulations, 2010 CFR

2010-04-01

... WITH RESPECT TO COMMERCIAL AVAILABILITY OF TEXTILE FABRIC AND YARN IN SUB-SAHARAN AFRICAN COUNTRIES... beneficiary sub-Saharan African countries is available in commercial quantities for use in lesser developed beneficiary sub-Saharan African countries, and an explanation of the basis for the determination; (2) If the...

78 FR 6068 - Proposed Information Collection; Comment Request; Interim Procedures for Considering Requests...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-01-29

... United States--Peru Trade Promotion Agreement (US-PERU TPA) AGENCY: International Trade [email protected] . SUPPLEMENTARY INFORMATION: I. Abstract The United States and Peru negotiated the US-Peru..., fabric, yarn, and fiber produced in Peru or the United States and traded between the two countries are...

Entropy Generation Analysis through Helical Coil Heat Exchanger in an Agitated Vessel

NASA Astrophysics Data System (ADS)

Ashok Reddy, K.

2018-03-01

Entropy Generation have been obtained while conducting the experiments for different sodium carboxymethyl cellulose concentrations 0.05%,0.1%,0.15% and 0.2% of Newtonian and non Newtonian fluids and the data made available by passing the test fluid at different flow rates through a helical coil in a mixing coil using paddle impeller. Heating of fluids depend on operational parameters, geometry of the mixing vessel and the type of impeller used. A new design of heating element was design and fabricated by providing kanthal wire inserted into a glove knitted with fiber glass yarn as glass fabric is flexible, heat resistant and can accommodate to adopt small difference in size of the vessel, perfectly. The knitted fabric is made to the shape of vessel used in the experiment and the heating elements are inserted so that it gets embedded and forms part of the glove knitted with yarn of fiber glass.

Modeling Cyclic Fatigue Hysteresis Loops of 2D Woven Ceramic Matrix Composites at Elevated Temperatures in Steam

PubMed Central

Li, Longbiao

2016-01-01

In this paper, the cyclic fatigue hysteresis loops of 2D woven SiC/SiC ceramic matrix composites (CMCs) at elevated temperatures in steam have been investigated. The interface slip between fibers and the matrix existing in matrix cracking modes 3 and 5, in which matrix cracking and interface debonding occurred in longitudinal yarns, is considered as the major reason for hysteresis loops of 2D woven CMCs. The hysteresis loops of 2D SiC/SiC composites corresponding to different peak stresses, test conditions, and loading frequencies have been predicted using the present analysis. The damage parameter, i.e., the proportion of matrix cracking mode 3 in the entire matrix cracking modes of the composite, and the hysteresis dissipated energy increase with increasing fatigue peak stress. With increasing cycle number, the interface shear stress in the longitudinal yarns decreases, leading to transition of interface slip types of matrix cracking modes 3 and 5. PMID:28773544

Hostel for the Hajjis

NASA Technical Reports Server (NTRS)

1982-01-01

Skidmore, Owings and Merrill (SOM), architects and engineers for the Haj Terminal, and the Saudi Ministry of Defense and Aviation needed to design some type of covered space that would process as many as 5,000 persons an hour and shelter up to 100,000 at a time during the annual haji pilgrimage. In this area, the temperature may reach 130 degrees Fahrenheit. The answer came from a fabric used by NASA in 1967 when they were looking for a new fabric for astronaut space suits. Owens Corning had been experimenting with an ultrafine pure glass finer yarn called Beta. The yarn was woven into a fabric, coated with Teflon and tailored for astronaut wear. SOM decided upon an open-sided, tented-roof structure with white Fiberglas fabric, coated with Teflon on both sides that reflects 75 percent of the solar radiation reaching the roof, thus helping to curb the intense heat.

Characterization and modeling of tensile behavior of ceramic woven fabric composites

NASA Technical Reports Server (NTRS)

Kuo, Wen-Shyong; Chen, Wennei Y.; Parvizi-Majidi, Azar; Chou, Tsu-Wei

1991-01-01

This paper examines the tensile behavior of SiC/SiC fabric composites. In the characterization effort, the stress-strain relation and damage evolution are studied with a series of loading and unloading tensile test experiments. The stress-strain relation is linear in response to the initial loading and becomes nonlinear when loading exceeds the proportional limit. Transverse cracking has been observed to be a dominant damage mode governing the nonlinear deformation. The damage is initiated at the inter-tow pores where fiber yarns cross over each other. In the modeling work, the analysis is based upon a fiber bundle model, in which fiber undulation in the warp and fill directions and gaps among fiber yarns have been taken into account. Two limiting cases of fabric stacking arrangements are studied. Closed form solutions are obtained for the composite stiffness and Poisson's ratio. Transverse cracking in the composite is discussed by applying a constant failure strain criterion.

Tensile Properties and Microstructural Characterization of Hi-Nicalon SiC/RBSN Composites

NASA Technical Reports Server (NTRS)

Bhatt, Ramakrishna T.

1998-01-01

The room temperature physical and mechanical properties of silicon carbide fiber-reinforced reaction-bonded silicon nitride matrix composites (SiC/RBSN) were measured, and the composite microstructure was analyzed. The composites consist of nearly 24 vol% of aligned Hi-Nicalon SiC fiber yarns in a approx. 30 vol% porous silicon nitride matrix. The fiber yarns were coated by chemical vapor deposition with a 0.8 mm layer of boron nitride (BN) followed by a 0.2 mm layer of SiC. In the as-fabricated condition, both 1-D and 2-D composites exhibited high strength and graceful failure, and showed improved properties w en compared with unreinforced matrix of comparable density. No indication of reaction between the SiC fiber and BN coating was noticed, but the outer SiC layer reacted locally with the nitridation enhancing additive in the RBSN matrix. A comparison is made between the predicted and measured values of matrix cracking strength.

Tensile Properties and Microstructural Characterization of Hi-Nicalon SiC/RBSN Composites

NASA Technical Reports Server (NTRS)

Bhatt, Ramakrishna T.

1998-01-01

The room temperature physical and mechanical properties of silicon carbide fiber-reinforced reaction-bonded silicon nitride matrix composites (SiC/RBSN) were measured, and the composite microstructure was analyzed. The composites consist of nearly 24 vol% of aligned Hi-Nicalon SiC fiber yarns in a approx. 30 vo1% porous silicon nitride matrix. The fiber yarns were coated by chemical vapor deposition with a 0.8 micron layer of boron nitride (BN) followed by a 0.2 micron layer of SiC. In the as-fabricated condition, both 1-D and 2-D composites exhibited high strength and graceful failure, and showed improved properties when compared with unreinforced matrix of comparable density. No indication of reaction between the SiC fiber and BN coating was noticed, but the outer SiC layer reacted locally with the nitridation enhancing additive in the RBSN matrix. A comparison is made between the predicted and measured values of matrix cracking strength.

Improved method facilitates debulking and curing of phenolic impregnated asbestos

NASA Technical Reports Server (NTRS)

Gaines, P.

1966-01-01

Workpieces covered with phenolic impregnated asbestos tape and then wrapped with a specified thickness of nylon yarn under pressure, are debulked and cured in a standard oven. This method of debulking and curing is used in the fabrication of ablative chambers for the Gemini and Apollo attitude control engines.

16 CFR 1609.1 - Text of the Flammable Fabrics Act of 1953, as amended in 1954.

Code of Federal Regulations, 2014 CFR

2014-01-01

... be worn by individuals except hats, gloves, and footwear: Provided, however, That such hats do not... form an integral part of another garment: And provided further, That such footwear does not consist of...) The term fabric means any material (other than fiber, filament, or yarn) woven, knitted, felted, or...

16 CFR 1609.1 - Text of the Flammable Fabrics Act of 1953, as amended in 1954.

Code of Federal Regulations, 2012 CFR

2012-01-01

... be worn by individuals except hats, gloves, and footwear: Provided, however, That such hats do not... form an integral part of another garment: And provided further, That such footwear does not consist of...) The term fabric means any material (other than fiber, filament, or yarn) woven, knitted, felted, or...

19 CFR 10.242 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-04-01

... knitting machine. Several components with finished edges may be linked by yarn or thread as they are... reference to fabric components, means that all of the production processes, starting with the production of... fabric(s), means that all of the production processes, starting with polymers, fibers, filaments, textile...

19 CFR 10.242 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-04-01

... knitting machine. Several components with finished edges may be linked by yarn or thread as they are... reference to fabric components, means that all of the production processes, starting with the production of... fabric(s), means that all of the production processes, starting with polymers, fibers, filaments, textile...

19 CFR 10.242 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-04-01

... knitting machine. Several components with finished edges may be linked by yarn or thread as they are... reference to fabric components, means that all of the production processes, starting with the production of... fabric(s), means that all of the production processes, starting with polymers, fibers, filaments, textile...

19 CFR 10.242 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-04-01

... knitting machine. Several components with finished edges may be linked by yarn or thread as they are... reference to fabric components, means that all of the production processes, starting with the production of... fabric(s), means that all of the production processes, starting with polymers, fibers, filaments, textile...

19 CFR 10.242 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-04-01

... knitting machine. Several components with finished edges may be linked by yarn or thread as they are... reference to fabric components, means that all of the production processes, starting with the production of... fabric(s), means that all of the production processes, starting with polymers, fibers, filaments, textile...

32 CFR 507.3 - Explanation of abbreviations and terms.

Code of Federal Regulations, 2010 CFR

2010-07-01

... OF HERALDIC DESIGNS AND HERALDIC QUALITY CONTROL PROGRAM Introduction § 507.3 Explanation of... times actual size, showing placement of stitches, color and size of yarn and number of stitches. (2... items worn on the uniform to indicate unit, skill, branch, award or identification and a design has been...

Genome-wide analysis of gene expression of EMS-induced short fiber mutant Ligon lintless-y (liy) in cotton (Gossypium hirsutum L.)

USDA-ARS?s Scientific Manuscript database

The length of cotton fiber is an important agronomic trait characteristic that directly affects the quality of yarn and fabric. Cotton fiber mutants have been useful tools to study the molecular processes of fiber development. In this work we describe a chemically-induced short fiber mutant Ligon-li...

Job Task Analysis.

ERIC Educational Resources Information Center

Clemson Univ., SC.

This publication consists of job task analyses for jobs in textile manufacturing. Information provided for each job in the greige and finishing plants includes job title, job purpose, and job duties with related educational objectives, curriculum, assessment, and outcome. These job titles are included: yarn manufacturing head overhauler, yarn…

Deconstructive Misalignment: Archives, Events, and Humanities Approaches in Academic Development

ERIC Educational Resources Information Center

Holmes, Trevor M.; Sutherland, Kathryn A.

2015-01-01

Using poetry, role play, readers' theatre, and creative manipulations of space through yarn and paper weaving, a workshop in 2008 challenged one of educational development's more pervasive and least questioned notions ("constructive alignment" associated most often with the work of John Biggs). This paper describes the reasoning behind…

Unravel the key genes potentially related to high strength of cotton fiber by comparative phenotypic and genomic analyses

USDA-ARS?s Scientific Manuscript database

The demand of high strength of cotton fibers has been increased dramatically with the advent of modern high speed spinning technology for producing yarn. Bundle fiber strength is affected by fiber-to-fiber interactions in addition to the individual fiber strength. The bundle fiber strength is not al...

RECYCLING ZINC IN VISCOSE RAYON PLANTS BY TWO STAGE PRECIPITATION

EPA Science Inventory

In an EPA demonstration grant, a process for precipitating a dense sludge of high zinc assay was proven. The zinc in the sludge was recovered and recycled to the rayon manufacturing plant. This recycling of zinc was shown to have no ill effects on rayon yarn. This process greatly...

Learning Preferences and Impacts of Education Programs in Dog Health Programs in Five Rural and Remote Australian Indigenous Communities

ERIC Educational Resources Information Center

Constable, Sophie; Dixon, Roselyn; Dixon, Robert

2011-01-01

As part of strategies to improve dog and community health in rural and remote Indigenous communities, this study investigated preferences and impacts of dog health education programs. Semistructured interviews with 63 residents from five communities explored learning preferences. Though each community differed, on average yarning was preferred by…

Multiscale Modeling of Carbon Fiber Reinforced Polymer (CFRP) for Integrated Computational Materials Engineering Process

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

Gao, Jiaying; Liang, Biao; Zhang, Weizhao

In this work, a multiscale modeling framework for CFRP is introduced to study hierarchical structure of CFRP. Four distinct scales are defined: nanoscale, microscale, mesoscale, and macroscale. Information at lower scales can be passed to higher scale, which is beneficial for studying effect of constituents on macroscale part’s mechanical property. This bottom-up modeling approach enables better understanding of CFRP from finest details. Current study focuses on microscale and mesoscale. Representative volume element is used at microscale and mesoscale to model material’s properties. At microscale, unidirection CFRP (UD) RVE is used to study properties of UD. The UD RVE can bemore » modeled with different volumetric fraction to encounter non-uniform fiber distribution in CFRP part. Such consideration is important in modeling uncertainties at microscale level. Currently, we identified volumetric fraction as the only uncertainty parameters in UD RVE. To measure effective material properties of UD RVE, periodic boundary conditions (PBC) are applied to UD RVE to ensure convergence of obtained properties. Properties of UD is directly used at mesoscale woven RVE modeling, where each yarn is assumed to have same properties as UD. Within woven RVE, there can be many potential uncertainties parameters to consider for a physical modeling of CFRP. Currently, we will consider fiber misalignment within yarn and angle between wrap and weft yarns. PBC is applied to woven RVE to calculate its effective material properties. The effect of uncertainties are investigated quantitatively by Gaussian process. Preliminary results of UD and Woven study are analyzed for efficacy of the RVE modeling. This work is considered as the foundation for future multiscale modeling framework development for ICME project.« less

Molecular Dynamics Modeling of Carbon Nanotube Composite Fracture Using ReaxFF

NASA Technical Reports Server (NTRS)

Jensen, Benjamin D.; Wise, Kristopher E.; Odegard, Gregory M.

2016-01-01

Carbon nanotube (CNT) fiber reinforced composites with specific tensile strengths and moduli approaching those of aerospace grade carbon fiber composites have recently been reported. This achievement was enabled by the emerging availability of high N/tex yarns in kilometer-scale quantities. While the production of this yarn is an impressive advance, its strength is still much lower than that of the individual CNTs comprising the yarn. Closing this gap requires understanding load transfer between CNTs at the nanometer dimensional scale. This work uses reactive molecular dynamics simulations to gain an understanding at the nanometer scale of the key factors that determine CNT nanocomposite mechanical performance, and to place more realistic upper bounds on the target properties. While molecular dynamics simulations using conventional force fields can predict elastic properties, the ReaxFF reactive forcefield can also model fracture behavior because of its ability to accurately describe bond breaking and formation during a simulation. The upper and lower bounds of CNT composite properties are investigated by comparing systems composed of CNTs continuously connected across the periodic boundary with systems composed of finite length CNTs. These lengths, effectively infinite for the continuous tubes and an aspect ratio of 13 for the finite length case, result from practical limitations on the number of atoms that can be included in a simulation. Experimentally measured aspect ratios are typically on the order of 100,000, so the calculated results should represent upper and lower limits on experimental mechanical properties. Finally, the effect of various degrees of covalent crosslinking between the CNTs and amorphous carbon matrix is considered to identify the amount of CNT-matrix covalent bonding that maximizes overall composite properties.

Multiple faces of contemporary hand knitting

NASA Astrophysics Data System (ADS)

Pavko-Čuden, A.

2017-10-01

Knitting and crocheting are traditional textile techniques with great significance both in history and modern times. Similar to other textile techniques, knitting has developed into a diversified industrial sector, comprising the production of knitted fabrics, knitwear, hosiery and fashion accessories. At the same time, contemporary knitting and crocheting became hobbies as well as arts-and-crafts activities, extending to various areas of work and leisure. Historical and traditional ethnic knitting and crocheting patterns keep inspiring designers’ collections and also other industrial products. Not so long ago, knitting was seen as an ordinary and unchanging indoor activity and, in its domestic history, it was the preserve of older women making products of dainty work and taste. Today, knitting deals with urban population of all classes. The popularity of leisure hand knitting is increasing; moreover, hand knitting is becoming more and more widespread among young people. With the emergence of artistic and handicraft markets, hand-knitting and crocheting developed into a profitable market activity. Positive effects of hand knitting have become increasingly important - from generating creativity and innovativeness, through knitting and socializing in groups, to medical and therapeutic effects as well as social and global connections. Yarn bombing, yarn storming or graffiti knitting has been used to describe urban social practices of knitted objects placed, or tagged, in public spaces. Knitting became means of communication, artistic and social expression and statement. The advantage of hand knitting is its mobility. One can knit almost everywhere, and for hand knitting, only a ball of yarn and knitting needles are required. Handknitted products have nice touch, they are custom-made and therefore personalized.

Influence of triaxial braid denier on ribbon-based fiber reinforced dental composites.

PubMed

Karbhari, Vistasp M; Wang, Qiang

2007-08-01

The aim of the study was to compare the mechanical characteristics of two ultrahigh molecular weight polyethylene (UHMWPE) fiber-based triaxial braided reinforcements having different denier braider yarns used in fiber reinforced dental composites to elucidate differences in response and damage under flexural loading. Two commercially available triaxial braided reinforcing systems, differing in denier of the axial and braider yarns, using ultra high molecular weight polyethylene (UHMWPE) were used to reinforce rectangular bars towards the tensile surface which were tested in flexure. Mechanical characteristics including energy absorption were determined and results were compared based on Tukey post-test analysis and Weibull probability. Limited fatigue testing was also conducted for 100, 1000, and 10,000 cycles at a level of 75% of peak load. The effect of the braid denier on damage mechanisms was studied microscopically. The use of the triaxially braided ribbon as fiber reinforcement in the dental composite results in significant enhancement in flexural performance over that of the unreinforced dental composite (179% and 183% increase for the "thin" and "dense" braid reinforced specimens, respectively), with a fairly ductile, non-catastrophic post-peak response. With the exception of strain at peak load, there was very little difference between the performance from the two braid architectures. The intrinsic nature of the triaxial braid also results in very little decrease in flexural strength as a result of fatigue cycling at 75% of peak load. Use of the braids results in peak load levels which are substantially higher than those corresponding to points at which the dentin and unreinforced dental composites would fail. The total energy at peak load level is 56.8 and 60.7 times that at the level that dentin would fail if the reinforcement were not placed for the "thin" and "dense" reinforced braid reinforced composites, respectively. The research shows that in

77 FR 47363 - Narrow Woven Ribbons With Woven Selvedge From the People's Republic of China: Preliminary Results...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-08

..., polyester, rayon, polypropylene, and polyethylene teraphthalate), metal threads and/or metalized yarns, or... original length as defined in the (HTSUS, Section XI, Note 13) or rubber thread; (4) Narrow woven ribbons... comprised at least 85 percent by weight of threads having a denier of 225 or higher; (9) Narrow woven...

21 CFR 886.1170 - Color vision tester.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Color vision tester. 886.1170 Section 886.1170...) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1170 Color vision tester. (a) Identification. A color vision tester is a device that consists of various colored materials, such as colored yarns...

21 CFR 886.1170 - Color vision tester.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Color vision tester. 886.1170 Section 886.1170...) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1170 Color vision tester. (a) Identification. A color vision tester is a device that consists of various colored materials, such as colored yarns...

21 CFR 886.1170 - Color vision tester.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Color vision tester. 886.1170 Section 886.1170...) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1170 Color vision tester. (a) Identification. A color vision tester is a device that consists of various colored materials, such as colored yarns...

Long-Term Interference at the Semantic Level: Evidence from Blocked-Cyclic Picture Matching

ERIC Educational Resources Information Center

Wei, Tao; Schnur, Tatiana T.

2016-01-01

Processing semantically related stimuli creates interference across various domains of cognition, including language and memory. In this study, we identify the locus and mechanism of interference when retrieving meanings associated with words and pictures. Subjects matched a probe stimulus (e.g., cat) to its associated target picture (e.g., yarn)…

46 CFR 164.018-5 - Specifications and standards incorporated by reference.

Code of Federal Regulations, 2013 CFR

2013-10-01

... (August 12, 1970), entitled “Cloth, Drill, Cotton.” (4) Federal Specification CCC-C-443 E (December 2, 1974), entitled “Cloth, Duck, Cotton (Single and Plied Filling Yarns, Flat).” (5) Federal Test Method... MIL-C-17415 E (April 16, 1964), entitled “Cloth, Coated, and Webbing, Inflatable Boat and...

46 CFR 164.018-5 - Specifications and standards incorporated by reference.

Code of Federal Regulations, 2011 CFR

2011-10-01

... (August 12, 1970), entitled “Cloth, Drill, Cotton.” (4) Federal Specification CCC-C-443 E (December 2, 1974), entitled “Cloth, Duck, Cotton (Single and Plied Filling Yarns, Flat).” (5) Federal Test Method... MIL-C-17415 E (April 16, 1964), entitled “Cloth, Coated, and Webbing, Inflatable Boat and...

46 CFR 164.018-5 - Specifications and standards incorporated by reference.

Code of Federal Regulations, 2014 CFR

2014-10-01

... (August 12, 1970), entitled “Cloth, Drill, Cotton.” (4) Federal Specification CCC-C-443 E (December 2, 1974), entitled “Cloth, Duck, Cotton (Single and Plied Filling Yarns, Flat).” (5) Federal Test Method... MIL-C-17415 E (April 16, 1964), entitled “Cloth, Coated, and Webbing, Inflatable Boat and...

46 CFR 164.018-5 - Specifications and standards incorporated by reference.

Code of Federal Regulations, 2012 CFR

2012-10-01

... (August 12, 1970), entitled “Cloth, Drill, Cotton.” (4) Federal Specification CCC-C-443 E (December 2, 1974), entitled “Cloth, Duck, Cotton (Single and Plied Filling Yarns, Flat).” (5) Federal Test Method... MIL-C-17415 E (April 16, 1964), entitled “Cloth, Coated, and Webbing, Inflatable Boat and...

29 CFR 1910.1043 - Cotton dust.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 29 Labor 6 2012-07-01 2012-07-01 false Cotton dust. 1910.1043 Section 1910.1043 Labor Regulations...) OCCUPATIONAL SAFETY AND HEALTH STANDARDS (CONTINUED) Toxic and Hazardous Substances § 1910.1043 Cotton dust. (a... cotton dust in all workplaces where employees engage in yarn manufacturing, engage in slashing and...

29 CFR 1910.1043 - Cotton dust.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 29 Labor 6 2011-07-01 2011-07-01 false Cotton dust. 1910.1043 Section 1910.1043 Labor Regulations...) OCCUPATIONAL SAFETY AND HEALTH STANDARDS (CONTINUED) Toxic and Hazardous Substances § 1910.1043 Cotton dust. (a... cotton dust in all workplaces where employees engage in yarn manufacturing, engage in slashing and...

29 CFR 1910.1043 - Cotton dust.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 29 Labor 6 2014-07-01 2013-07-01 true Cotton dust. 1910.1043 Section 1910.1043 Labor Regulations...) OCCUPATIONAL SAFETY AND HEALTH STANDARDS (CONTINUED) Toxic and Hazardous Substances § 1910.1043 Cotton dust. (a... cotton dust in all workplaces where employees engage in yarn manufacturing, engage in slashing and...

29 CFR 1910.1043 - Cotton dust.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 29 Labor 6 2013-07-01 2013-07-01 false Cotton dust. 1910.1043 Section 1910.1043 Labor Regulations...) OCCUPATIONAL SAFETY AND HEALTH STANDARDS (CONTINUED) Toxic and Hazardous Substances § 1910.1043 Cotton dust. (a... cotton dust in all workplaces where employees engage in yarn manufacturing, engage in slashing and...

21 CFR 886.1170 - Color vision tester.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Color vision tester. 886.1170 Section 886.1170...) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1170 Color vision tester. (a) Identification. A color vision tester is a device that consists of various colored materials, such as colored yarns...

21 CFR 886.1170 - Color vision tester.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Color vision tester. 886.1170 Section 886.1170...) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1170 Color vision tester. (a) Identification. A color vision tester is a device that consists of various colored materials, such as colored yarns...

19 CFR 208.2 - Definitions applicable to this part.

Code of Federal Regulations, 2010 CFR

2010-04-01

... INVESTIGATIONS WITH RESPECT TO COMMERCIAL AVAILABILITY OF TEXTILE FABRIC AND YARN IN SUB-SAHARAN AFRICAN COUNTRIES § 208.2 Definitions applicable to this part. (a) Beneficiary sub-Saharan African country. The term “beneficiary sub-Saharan African country” means those countries so designated by the President under 19 U.S.C...

Nanocellulose in spun continuous fibers: A review and future outlook

Treesearch

Craig Clemons

2016-01-01

Continuous fibers are commonly manufactured for a wide variety of uses such as filters, textiles, and composites. For example, most fibrous reinforcements (e.g., carbon fiber, glass fiber) for advanced composites are continuous fibers or yarns, fabrics, and preforms made from them. This allows broad flexibility in design and manufacturing approaches by controlling...

75 FR 32676 - Revision of Department of Homeland Security Acquisition Regulation; Restrictions on Foreign...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-09

... needed to meet the fire resistant standards and had an exemption to have the uniform makers purchase the... restrictions on clothing and fabrics. Neither section 604 nor the DFARS define these terms; their meaning is... manufactured from or containing any of the fibers, yarns, fabrics, or materials listed in this paragraph (b...

19 CFR 10.16 - Assembly abroad.

Code of Federal Regulations, 2013 CFR

2013-04-01

... steps or steps incidental to assembly. Example 3. The manufacture abroad of cloth on a loom using thread... weaving operation, and the thread or yarn does not qualify for the exemption. However, American-made thread used to sew buttons or garment components is qualified for the exemption because it is used in an...

19 CFR 10.16 - Assembly abroad.

Code of Federal Regulations, 2010 CFR

2010-04-01

... steps or steps incidental to assembly. Example 3. The manufacture abroad of cloth on a loom using thread... weaving operation, and the thread or yarn does not qualify for the exemption. However, American-made thread used to sew buttons or garment components is qualified for the exemption because it is used in an...

19 CFR 10.16 - Assembly abroad.

Code of Federal Regulations, 2011 CFR

2011-04-01

... steps or steps incidental to assembly. Example 3. The manufacture abroad of cloth on a loom using thread... weaving operation, and the thread or yarn does not qualify for the exemption. However, American-made thread used to sew buttons or garment components is qualified for the exemption because it is used in an...

75 FR 75664 - Determination Under the Textile and Apparel Commercial Availability Provision of the Dominican...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-12-06

.../or staple fiber; textured and/or non- textured). Yarn Size(s): Various. Thread Count (warp): 43 to 56 ends per cm. Thread Count (weft): 29 to 38 filling pics per cm. Weave Type: Woven twill. Fabric Weight...-dyed. Finishing Processes: Napped on both sides. Janet E. Heinzen, Acting Chairman, Committee for the...

19 CFR 10.16 - Assembly abroad.

Code of Federal Regulations, 2012 CFR

2012-04-01

... steps or steps incidental to assembly. Example 3. The manufacture abroad of cloth on a loom using thread... weaving operation, and the thread or yarn does not qualify for the exemption. However, American-made thread used to sew buttons or garment components is qualified for the exemption because it is used in an...

19 CFR 10.16 - Assembly abroad.

Code of Federal Regulations, 2014 CFR

2014-04-01

... steps or steps incidental to assembly. Example 3. The manufacture abroad of cloth on a loom using thread... weaving operation, and the thread or yarn does not qualify for the exemption. However, American-made thread used to sew buttons or garment components is qualified for the exemption because it is used in an...

Mexican Folkart for Children.

ERIC Educational Resources Information Center

Dominguez, Graciela; And Others

Directions, suggested materials, and illustrations are given for making paper mache pinatas and masks, cascarones, Ojos de Dios, maracas, dresser scarf embroidery, burlap murals, yarn designs, paper plate trays, paper cut designs, the poppy, sarape aprons, and paper Mexican dolls. Filled with candy and broken, the pinata is used on most Mexican…

"Working" Culture: Exploring Notions of Workplace Culture and Learning at Work

ERIC Educational Resources Information Center

Somerville, Margaret

2005-01-01

This article is based on research into the practical problem of masculinity and learning and practising safety in the mining industry. The research began with a post-structural analysis of gendered subjectivity in miners' yarns but argues that a concept of "culture" is needed to elucidate a middle-level relationship between individual…

19 CFR 141.89 - Additional information for certain classes of merchandise.

Code of Federal Regulations, 2012 CFR

2012-04-01

... and 29, HTSUS. Colors, dyes, stains and related products provided for under heading 3204, HTSUS—The... threads); (7) Exact weight per square meter in grams; (8) Average yarn number use this formula: EC14NO91... sheets containing such information: (1) Weight of paper in grams per square meter; (2) Thickness, in...

19 CFR 141.89 - Additional information for certain classes of merchandise.

Code of Federal Regulations, 2013 CFR

2013-04-01

... and 29, HTSUS. Colors, dyes, stains and related products provided for under heading 3204, HTSUS—The... threads); (7) Exact weight per square meter in grams; (8) Average yarn number use this formula: EC14NO91... sheets containing such information: (1) Weight of paper in grams per square meter; (2) Thickness, in...

19 CFR 141.89 - Additional information for certain classes of merchandise.

Code of Federal Regulations, 2014 CFR

2014-04-01

... and 29, HTSUS. Colors, dyes, stains and related products provided for under heading 3204, HTSUS—The... threads); (7) Exact weight per square meter in grams; (8) Average yarn number use this formula: EC14NO91... sheets containing such information: (1) Weight of paper in grams per square meter; (2) Thickness, in...

Bending Behavior of Plain-Woven Fabric Air Beams: Fluid-Structure Interaction Approach

DTIC Science & Technology

2006-09-01

hoses . The warp yarns were aligned in the longitudinal direction of the fire hose and the weft yams, orthogonal to the warp yams, were aligned in the...both terms. Plain-woven air beams typically operate at low-pressure levels (less than those for triaxial-woven or braided air beams) because of safety

Stories Return Personal Narrative Ways of Knowing to the Professional Development of Doctoral Supervisors

ERIC Educational Resources Information Center

McCormack, Coralie

2009-01-01

Storytellers have always known that there is more to a story than "just a good yarn". It is through stories that individuals construct and reconstruct their sense of self as they learn "to be" in the world. Learning through stories is common across a number of professional contexts. However, storied approaches are…

16 CFR § 1609.1 - Text of the Flammable Fabrics Act of 1953, as amended in 1954.

Code of Federal Regulations, 2013 CFR

2013-01-01

... clothing worn or intended to be worn by individuals except hats, gloves, and footwear: Provided, however... footwear does not consist of hosiery in whole or in part and is not affixed to or does not form an integral part of another garment. (e) The term fabric means any material (other than fiber, filament, or yarn...

19 CFR 10.842 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-04-01

... controls the production process in Haiti through a contractual relationship or other indirect means; (g... process in Haiti; (n) Self-start edge. “Self-start edge,” when used with reference to knit-to-shape... components with finished edges may be linked by yarn or thread as they are produced from the knitting machine...

19 CFR 10.842 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-04-01

... controls the production process in Haiti through a contractual relationship or other indirect means; (g... process in Haiti; (n) Self-start edge. “Self-start edge,” when used with reference to knit-to-shape... components with finished edges may be linked by yarn or thread as they are produced from the knitting machine...

19 CFR 10.842 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-04-01

... controls the production process in Haiti through a contractual relationship or other indirect means; (g... process in Haiti; (n) Self-start edge. “Self-start edge,” when used with reference to knit-to-shape... components with finished edges may be linked by yarn or thread as they are produced from the knitting machine...

16 CFR 1611.37 - Reasonable and representative tests under section 8 of the Act.

Code of Federal Regulations, 2012 CFR

2012-01-01

... FLAMMABLE FABRICS ACT REGULATIONS STANDARD FOR THE FLAMMABILITY OF VINYL PLASTIC FILM Rules and Regulations... has a dense cut pile of uniform short length or looped yarns, does not exhibit a surface flash and does not ignite, such test shall suffice for any such fabric having a dense cut pile of the same length...

19 CFR 10.882 - Goods eligible for tariff preference claims.

Code of Federal Regulations, 2012 CFR

2012-04-01

...; DEPARTMENT OF THE TREASURY ARTICLES CONDITIONALLY FREE, SUBJECT TO A REDUCED RATE, ETC. United States-Oman... knit to shape, or both, and sewn or otherwise assembled in the territory of Oman from fabric or yarn produced or obtained outside the territory of Oman or the United States are eligible for a TPL claim filed...

19 CFR 10.882 - Goods eligible for tariff preference claims.

Code of Federal Regulations, 2014 CFR

2014-04-01

...; DEPARTMENT OF THE TREASURY ARTICLES CONDITIONALLY FREE, SUBJECT TO A REDUCED RATE, ETC. United States-Oman... knit to shape, or both, and sewn or otherwise assembled in the territory of Oman from fabric or yarn produced or obtained outside the territory of Oman or the United States are eligible for a TPL claim filed...

19 CFR 10.882 - Goods eligible for tariff preference claims.

Code of Federal Regulations, 2011 CFR

2011-04-01

...; DEPARTMENT OF THE TREASURY ARTICLES CONDITIONALLY FREE, SUBJECT TO A REDUCED RATE, ETC. United States-Oman... knit to shape, or both, and sewn or otherwise assembled in the territory of Oman from fabric or yarn produced or obtained outside the territory of Oman or the United States are eligible for a TPL claim filed...

19 CFR 10.882 - Goods eligible for tariff preference claims.

Code of Federal Regulations, 2013 CFR

2013-04-01

...; DEPARTMENT OF THE TREASURY ARTICLES CONDITIONALLY FREE, SUBJECT TO A REDUCED RATE, ETC. United States-Oman... knit to shape, or both, and sewn or otherwise assembled in the territory of Oman from fabric or yarn produced or obtained outside the territory of Oman or the United States are eligible for a TPL claim filed...

Proceedings: Nozzle Initiative Industry Advisory Committee on Standardization of Carbon-Phenolic Test Methods and Specifications

NASA Technical Reports Server (NTRS)

1992-01-01

The proceedings of the meeting is presented in conversational form. Some areas of discussion are as follow: resin advancement at NASA Marshall new technologies studies; NMR studies; SPIP/PAN development summary; computer modeling support; composite testing; carbon assay testing; activity and aerospace computer database; alternate rayon yarn sizing; fiber morphology; and carbon microballoons specifications.

Impact resistance and interlaminar fracture toughness of through-the-thickness reinforced graphite/epoxy

NASA Technical Reports Server (NTRS)

Dexter, H. B.; Funk, J. G.

1986-01-01

Five through-the-thickness stitch configurations are analyzed to determine the effect of impact resistance and interlaminar fracture toughness on T3000/3501-6 graphite/epoxy. The test specimens were stitched with either polyester or Kevlar yarns and with various stitch parameters. Tension and compression mechanical, impact and compression-after-impact, and double cantilever beam tests were conducted. It is observed that the stitched laminates have tension and compression strengths 20-25 percent lower than the strengths of unstitched laminates, the tension strength of stitched laminates is reduced with increasing number of stitches, and the compression strength increases as the number of stitches are increased. The impact data reveal that the Kevlar stitched laminates have less damage than unstitched laminates; the most effective configuration for suppressing impact damage and improving interlaminar fracture toughness consists of Kevlar yarns 1/4 inch apart with eight stitches per inch. The mode 1 critical strain energy release rate for the 1/4 inch Kevlar eight stitch laminate was calculated as 30 times higher than that of the unstitched.

Study on airflow characteristics in the semi-closed irregular narrow flow channel

NASA Astrophysics Data System (ADS)

Jin, Yuzhen; Hu, Xiaodong; Zhu, Linhang; Hu, Xudong; Jin, Yingzi

2016-04-01

The air-jet loom is widely used in the textile industry. The interaction mechanism of airflow and yarn is not clear in such a narrow flow channel, the gas consumption is relatively large, the yarn motion is unstable and the weft insertion is often interrupted during the operation. In order to study the characteristics of the semi-closed flow field in profiled dents, the momentum conservation equation is modified and the model parameters and boundary conditions are set. Compared with the different r, the ratio of profiled dent's thickness and gap, the results show that the smaller the r is, the smaller the velocity fluctuations of the airflow is. When the angle of profiled dents α is close to zero, the diffusion of the airflow will be less. The experiment is also conducted to verify the result of the simulation with a high-speed camera and pressure sensor in profiled dents. The airflow characteristics in the semi-closed irregular narrow flow channel in the paper would provide the theoretical basis for optimizing the weft insertion process of the air-jet loom.

Surface activation of dyed fabric for cellulase treatment.

PubMed

Schimper, Christian B; Ibanescu, Constanta; Bechtold, Thomas

2011-10-01

Surface activation of fabric made from cellulose fibres, such as viscose, lyocell, modal fibres and cotton, can be achieved by printing of a concentrated NaOH-containing paste. From the concentration of reducing sugars formed in solution, an increase in intensity of the cellulase hydrolysis by a factor of six to eight was observed, which was mainly concentrated at the activated parts of the fabric surface. This method of local activation is of particular interest for modification of materials that have been dyed with special processes to attain an uneven distribution of dyestuff within the yarn cross-section, e.g., indigo ring-dyed denim yarn for jeans production. Fabrics made from regenerated cellulose fibres were used as model substrate to express the effects of surface activation on indigo-dyed material. Wash-down experiments on indigo-dyed denim demonstrated significant colour removal from the activated surface at low overall weight loss of 4-5%. The method is of relevance for a more eco-friendly processing of jeans in the garment industry. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Modeling and characterization of through-the-thickness properties of 3D woven composites

NASA Technical Reports Server (NTRS)

Hartranft, Dru; Pravizi-Majidi, Azar; Chou, Tsu-Wei

1995-01-01

The through-the-thickness properties of three-dimensionally (3D) woven carbon/epoxy composites have been studied. The investigation aimed at the evaluation and development of test methodologies for the property characterization in the thickness direction, and the establishment of fiber architectures were studied: layer-to-layer Angle Interlock, through-the-thickness Orthogonal woven preform with surface pile was also designed and manufactured for the fabrication of tensile test coupons with integrated grips. All the preforms were infiltrated by the resin transfer molding technique. The microstructures of the composites were characterized along the warp and fill (weft) directions to determine the degree of yarn undulations, yarn cross-sectional shapes, and microstructural dimensions. These parameters were correlated to the fiber architecture. Specimens were designed and tested for the direct measurement of the through-the-thickness tensile, compressive and shear properties of the composites. Design optimization was conducted through the analysis of the stress fields within the specimen coupled with experimental verification. The experimentally-derived elastic properties in the thickness direction compared well with analytical predictions obtained from a volume averaging model.

Stretchable Triboelectric Fiber for Self-powered Kinematic Sensing Textile

PubMed Central

Sim, Hyeon Jun; Choi, Changsoon; Kim, Shi Hyeong; Kim, Kang Min; Lee, Chang Jun; Kim, Youn Tae; Lepró, Xavier; Baughman, Ray H.; Kim, Seon Jeong

2016-01-01

Stretchable fiber and yarn triboelectric nanogenerator are sought for such applications as wearable sensing system such as cloth communication devices, electronic textiles, and robotic sensory skin. Unfortunately, previously reported triboelectric fiber and yarn are difficult to have stretchable property. We introduce here a new type of stretchable and weavable triboelectric fibers with microdiameter dimensions. The stretchable triboelectric fibers can be reversibly stretched up to 50% in tensile direction while generating voltage output proportional to the applied tensile strain. The reversible distance change induced by the Poisson’s ratio difference between the core fiber (silver-coated nylon/polyurethane) and the shell (wrinkled polyvinylidene fluoride-co-trifluoroethylene/carbon nanotube layer) during tensile deformation is the key working principle for electrical generation. Owing to exceptional structural stability, the stretchable triboelectric fibers show high performance retention after 10,000 times repeated stretching/releasing cycle. Furthermore, the stretchable triboelectric fibers are mechanically strong to be woven into a commercial textile for textile based sensors, which can detect magnitude as well as direction of the motion. PMID:27725779

Combat Sports Bloggers, Mad Scientist Poets, and Comic Scriptwriters: Engaging Boys in Writing on Their Own Terms

ERIC Educational Resources Information Center

Loeper, Rachel

2014-01-01

As the program director of a community writing center that serves children and youth ages 5-18, Rachel Loeper sees it all, from 15-year-old spoken word poets to six-year-olds whose first "books" are strung together with yarn. In all of her roles--administrator, teacher, volunteer trainer--she values engaging the most reluctant of young…

16 CFR 303.1 - Terms defined.

Code of Federal Regulations, 2012 CFR

2012-01-01

... Identification Act (approved September 2, 1958, 85th Congress, 2d Sess.; 15 U.S.C. 70, 72 Stat. 1717). (b) The... thereof. (n) The term elastic material means a fabric composed of yarn consisting of an elastomer or a... material mean any materials, used in the direct sale or direct offering for sale of textile products, that...

16 CFR 303.1 - Terms defined.

Code of Federal Regulations, 2014 CFR

2014-01-01

... Identification Act (approved September 2, 1958, 85th Congress, 2d Sess.; 15 U.S.C. 70, 72 Stat. 1717). (b) The... thereof. (n) The term elastic material means a fabric composed of yarn consisting of an elastomer or a... material mean any materials, used in the direct sale or direct offering for sale of textile products, that...

16 CFR 303.1 - Terms defined.

Code of Federal Regulations, 2013 CFR

2013-01-01

... Identification Act (approved September 2, 1958, 85th Congress, 2d Sess.; 15 U.S.C. 70, 72 Stat. 1717). (b) The... thereof. (n) The term elastic material means a fabric composed of yarn consisting of an elastomer or a... material mean any materials, used in the direct sale or direct offering for sale of textile products, that...

Systematic investigation of drip stains on apparel fabrics: The effects of prior-laundering, fibre content and fabric structure on final stain appearance.

PubMed

de Castro, Therese C; Taylor, Michael C; Kieser, Jules A; Carr, Debra J; Duncan, W

2015-05-01

Bloodstain pattern analysis is the investigation of blood deposited at crime scenes and the interpretation of that pattern. The surface that the blood gets deposited onto could distort the appearance of the bloodstain. The interaction of blood and apparel fabrics is in its infancy, but the interaction of liquids and apparel fabrics has been well documented and investigated in the field of textile science (e.g. the processes of wetting and wicking of fluids on fibres, yarns and fabrics). A systematic study on the final appearance of drip stains on torso apparel fabrics (100% cotton plain woven, 100% polyester plain woven, blend of polyester and cotton plain woven and 100% cotton single jersey knit) that had been laundered for six, 26 and 52 cycles prior to testing was investigated in the paper. The relationship between drop velocity (1.66±0.50m/s, 4.07±0.03m/s, 5.34±0.18m/s) and the stain characteristics (parent stain area, axes 1 and 2 and number of satellite stains) for each fabric was examined using analysis of variance. The experimental design and effect of storing blood were investigated on a reference sample, which indicated that the day (up to five days) at which the drops were generated did not affect the bloodstain. The effect of prior-laundering (six, 26 and 52 laundering cycles), fibre content (cotton vs. polyester vs. blend) and fabric structure (plain woven vs. single jersey knit) on the final appearance of the bloodstain were investigated. Distortion in the bloodstains produced on non-laundered fabrics indicated the importance of laundering fabrics to remove finishing treatments before conducting bloodstain experiments. For laundered fabrics, both the cotton fabrics and the blend had a circular to oval stain appearance, while the polyester fabric had a circular appearance with evidence of spread along the warp and weft yarns, which resulted in square-like stains at the lowest drop velocity. A significant (p<0.001) increase in the stain size on

Light up My Life

ERIC Educational Resources Information Center

Kellett, Sarah

2015-01-01

Simply stated, light is nature's way of transferring energy through space. Discussions of light usually refer to visible light, which is perceived by the human eye and is responsible for the sense of sight. We see however, only a small part of the light spectrum. Light connects us as we sit and tell yarns around camp fires. Yet, one in every four…

Vacuum barrier for excimer lasers

DOEpatents

Shurter, R.P.

1992-09-15

A barrier for separating the vacuum area of a diode from the pressurized gas area of an excimer laser. The barrier is a composite material comprising layers of a metal such as copper, along with layers of polyimide, and a matrix of graphite fiber yarns impregnated with epoxy. The barrier is stronger than conventional foil barriers, and allows greater electron throughput. 3 figs.

Vacuum barrier for excimer lasers

DOEpatents

Shurter, Roger P.

1992-01-01

A barrier for separating the vacuum area of a diode from the pressurized gas area of an excimer laser. The barrier is a composite material comprising layers of a metal such as copper, along with layers of polyimide, and a matrix of graphite fiber yarns impregnated with epoxy. The barrier is stronger than conventional foil barriers, and allows greater electron throughput.

Multi-Length Scale-Enriched Continuum-Level Material Model for Kevlar (registered trademark)-Fiber-Reinforced Polymer-Matrix Composites

DTIC Science & Technology

2013-03-01

of coarser-scale materials and structures containing Kevlar fibers (e.g., yarns, fabrics, plies, lamina, and laminates ). Journal of Materials...Multi-Length Scale-Enriched Continuum-Level Material Model for Kevlar -Fiber-Reinforced Polymer-Matrix Composites M. Grujicic, B. Pandurangan, J.S...extensive set of molecular-level computational analyses regarding the role of various microstructural/morphological defects on the Kevlar fiber

78 FR 16661 - Determination Under the Textile and Apparel Commercial Availability Provision of the Dominican...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-18

... fabric). Overall weight: 287-351 grams per square meter. Overall width: Selvedge: 150.4-154.4 cm; Minimum... per cm x 43-45 picks per cm Weight: 121.5-148.5 grams per square meter Width: Selvedge: 150.4-154.4 cm... yarns: filament Knitting gauge: 27-29 Weight: 140.4-171.6 grams per square meter Width: Selvedge: 150.4...

In Vitro Evaluation and Mechanism Analysis of the Fiber Shedding Property of Textile Pile Debridement Materials

PubMed Central

Fu, Yijun; Xie, Qixue; Lao, Jihong; Wang, Lu

2016-01-01

Fiber shedding is a critical problem in biomedical textile debridement materials, which leads to infection and impairs wound healing. In this work, single fiber pull-out test was proposed as an in vitro evaluation for the fiber shedding property of a textile pile debridement material. Samples with different structural design (pile densities, numbers of ground yarns and coating times) were prepared and estimated under this testing method. Results show that single fiber pull-out test offers an appropriate in vitro evaluation for the fiber shedding property of textile pile debridement materials. Pull-out force for samples without back-coating exhibited a slight escalating trend with the supplement in pile density and number of ground yarn plies, while back-coating process significantly raised the single fiber pull-out force. For fiber shedding mechanism analysis, typical pull-out behavior and failure modes of the single fiber pull-out test were analyzed in detail. Three failure modes were found in this study, i.e., fiber slippage, coating point rupture and fiber breakage. In summary, to obtain samples with desirable fiber shedding property, fabric structural design, preparation process and raw materials selection should be taken into full consideration. PMID:28773428

A Multivariate Quality Loss Function Approach for Optimization of Spinning Processes

NASA Astrophysics Data System (ADS)

Chakraborty, Shankar; Mitra, Ankan

2018-05-01

Recent advancements in textile industry have given rise to several spinning techniques, such as ring spinning, rotor spinning etc., which can be used to produce a wide variety of textile apparels so as to fulfil the end requirements of the customers. To achieve the best out of these processes, they should be utilized at their optimal parametric settings. However, in presence of multiple yarn characteristics which are often conflicting in nature, it becomes a challenging task for the spinning industry personnel to identify the best parametric mix which would simultaneously optimize all the responses. Hence, in this paper, the applicability of a new systematic approach in the form of multivariate quality loss function technique is explored for optimizing multiple quality characteristics of yarns while identifying the ideal settings of two spinning processes. It is observed that this approach performs well against the other multi-objective optimization techniques, such as desirability function, distance function and mean squared error methods. With slight modifications in the upper and lower specification limits of the considered quality characteristics, and constraints of the non-linear optimization problem, it can be successfully applied to other processes in textile industry to determine their optimal parametric settings.

Stretchable, weavable coiled carbon nanotube/MnO2/polymer fiber solid-state supercapacitors.

PubMed

Choi, Changsoon; Kim, Shi Hyeong; Sim, Hyeon Jun; Lee, Jae Ah; Choi, A Young; Kim, Youn Tae; Lepró, Xavier; Spinks, Geoffrey M; Baughman, Ray H; Kim, Seon Jeong

2015-03-23

Fiber and yarn supercapacitors that are elastomerically deformable without performance loss are sought for such applications as power sources for wearable electronics, micro-devices, and implantable medical devices. Previously reported yarn and fiber supercapacitors are expensive to fabricate, difficult to upscale, or non-stretchable, which limits possible use. The elastomeric electrodes of the present solid-state supercapacitors are made by using giant inserted twist to coil a nylon sewing thread that is helically wrapped with a carbon nanotube sheet, and then electrochemically depositing pseudocapacitive MnO2 nanofibers. These solid-state supercapacitors decrease capacitance by less than 15% when reversibly stretched by 150% in the fiber direction, and largely retain capacitance while being cyclically stretched during charge and discharge. The maximum linear and areal capacitances (based on active materials) and areal energy storage and power densities (based on overall supercapacitor dimensions) are high (5.4 mF/cm, 40.9 mF/cm(2), 2.6 μWh/cm(2) and 66.9 μW/cm(2), respectively), despite the engineered superelasticity of the fiber supercapacitor. Retention of supercapacitor performance during large strain (50%) elastic deformation is demonstrated for supercapacitors incorporated into the wristband of a glove.

Development of 2D and 3D structured textile batteries processing conductive material with Tailored Fiber Placement (TFP)

NASA Astrophysics Data System (ADS)

Normann, M.; Grethe, T.; Zöll, K.; Ehrmann, A.; Schwarz-Pfeiffer, A.

2017-10-01

In recent years smart textiles have gained a significant increase of attention. Electrotherapeutic socks, light emitting dresses or shirts with integrated sensors, having the ability to process data of vital parameters, are just a few examples and the full potential is not yet exhausted: Smart textiles are not only used for clothing purposes. Sensors for the care of the elderly, light applications for home textiles and monitoring systems in the automotive section are promising fields for the future. For all these electrical and electronic features, the supply of power is needed. The most common used power supplies, however, are not flexible, often not lightweight and therefore a huge problem for the integration into textile products. In recent projects, textile-based batteries are being developed. Metal-coated fabrics and yarns (e.g. silver, copper, nickel, zinc) as well as carbon based materials were used to create textile based energy sources. This article gives an overview of textile based electrochemical cells by combining different conductive yarns and a gel-electrolyte. The available materials will be processed by embroidering utilizing tailored fiber placement (TFP). The electrical characteristics of different embroidered patterns and material combinations are examined.

Coatings for Graphite Fibers

NASA Technical Reports Server (NTRS)

Galasso, F. S.; Scola, D. A.; Veltri, R. D.

1980-01-01

Several approaches for applying high resistance coatings continuously to graphite yarn were investigated. Two of the most promising approaches involved (1) chemically vapor depositing (CVD) SiC coatings on the surface of the fiber followed by oxidation, and (2) drawing the graphite yarn through an organo-silicone solution followed by heat treatments. In both methods, coated fibers were obtained which exhibited increased electrical resistances over untreated fibers and which were not degraded. This work was conducted in a previous program. In this program, the continuous CVD SiC coating process used on HTS fiber was extended to the coating of HMS, Celion 6000, Celion 12000 and T-300 graphite fiber. Electrical resistances three order of magnitude greater than the uncoated fiber were measured with no significant degradation of the fiber strength. Graphite fibers coated with CVD Si3N4 and BN had resistances greater than 10(exp 6) ohm/cm. Lower pyrolysis temperatures were used in preparing the silica-like coatings also resulting in resistances as high as three orders of magnitude higher than the uncoated fiber. The epoxy matrix composites prepared using these coated fibers had low shear strengths indicating that the coatings were weak.

Manufacturing technology of integrated textile-based sensor networks for in situ monitoring applications of composite wind turbine blades

NASA Astrophysics Data System (ADS)

Haentzsche, Eric; Mueller, Ralf; Huebner, Matthias; Ruder, Tristan; Unger, Reimar; Nocke, Andreas; Cherif, Chokri

2016-10-01

Based on in situ strain sensors consisting of piezo-resistive carbon filament yarns (CFYs), which have been successfully integrated into textile reinforcement structures during their textile-technological manufacturing process, a continuous load of fibre-reinforced plastic (FRP) components has been realised. These sensors are also suitable for structural health monitoring (SHM) applications. The two-dimensional sensor layout is made feasible by the usage of a modular warp yarn path manipulation unit. Using a functional model of a small wind turbine blade in thermoset composite design, the sensor function for basic SHM applications (e.g. static load monitoring) are demonstrated. Any mechanical loads along the pressure or suction side of the wind turbine blade can be measured and calculated via a correlative change in resistance of the CFYs within the textile reinforcement plies. Performing quasi-static load tests on both tensile specimen and full-scale wind turbine blade, elementary results have been obtained concerning electro-mechanical behaviour and spatial resolution of global and even local static stresses according to the CFY sensor integration length. This paper demonstrates the great potential of textile-based and textile-technological integrated sensors in reinforcement structures for future SHM applications of FRPs.

The Testing of Airplane Fabrics

NASA Technical Reports Server (NTRS)

Schraivogel, Karl

1932-01-01

This report considers the determining factors in the choice of airplane fabrics, describes the customary methods of testing and reports some of the experimental results. To sum up briefly the results obtained with the different fabrics, it may be said that increasing the strength of covering fabrics by using coarser yarns ordinarily offers no difficulty, because the weight increment from doping is relatively smaller.

Multipurpose Prepregging Machine

NASA Technical Reports Server (NTRS)

Johnston, N. J.; Wilkinson, Steven; Marchello, J. M.; Dixon, D.

1995-01-01

Machine designed and built for variety of uses involving coating or impregnating ("prepregging") fibers, tows, yarns, or webs or tapes made of such fibrous materials with thermoplastic or thermosetting resins. Prepreg materials produced used to make matrix/fiber composite materials. Comprises modules operated individually, sequentially, or simultaneously, depending on nature of specific prepreg material and prepregging technique used. Machine incorporates number of safety features.

Area Handbook Series. Sri Lanka, A Country Study

DTIC Science & Technology

1988-10-01

labor force; major industrial output consumer goods, especially garments and textiles , and processed agriculture commodities. State plays major role in...equipment, food (including rice, wheat, flour, sugar), fertilizer, yarn, and textiles . Principal trading partners Japan, Saudi Arabia, and the United...seems to have retarded the resettlement of the dry zone was the outbreak of malaria in the thirteenth century. The mosquito found ideal breeding grounds

4. Interior of second floor of Dixie Cotton Mill, view ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

4. Interior of second floor of Dixie Cotton Mill, view facing west. This area is now designated the upstairs yarn storage room. Note the change of column type and roof structure from the first to second column in foreground of photograph. The round columns were used in the 1913 addition to the original 1895 structure. - Dixie Cotton Mill, 710 Greenville Street, La Grange, Troup County, GA

Active devices based on organic semiconductors for wearable applications.

PubMed

Barbaro, Massimo; Caboni, Alessandra; Cosseddu, Piero; Mattana, Giorgio; Bonfiglio, Annalisa

2010-05-01

Plastic electronics is an enabling technology for obtaining active (transistor based) electronic circuits on flexible and/or nonplanar surfaces. For these reasons, it appears as a perfect candidate to promote future developments of wearable electronics toward the concept of fabrics and garments made by functional (in this case, active electronic) yarns. In this paper, a panoramic view of recent achievements and future perspectives is given.

Method and apparatus for three dimensional braiding

NASA Technical Reports Server (NTRS)

Farley, Gary L. (Inventor)

1997-01-01

A machine for three-dimensional braiding of fibers is provided in which carrier members travel on a curved, segmented and movable braiding surface. The carrier members are capable of independent, self-propelled motion along the braiding surface. Carrier member position on the braiding surface is controlled and monitored by computer. Also disclosed is a yarn take-up device capable of maintaining tension in the braiding fiber.

Method and apparatus for three dimensional braiding

NASA Technical Reports Server (NTRS)

Farley, Gary L. (Inventor)

1995-01-01

A machine for three-dimensional braiding of fibers is provided in which carrier members travel on a curved, segmented and movable braiding surface. The carrier members are capable of independent, self-propelled motion along the braiding surface. Carrier member position on the braiding surface is controlled and monitored by computer. Also disclosed is a yarn take-up device capable of maintaining tension in the braiding fiber.

Engaging Australian Aboriginal narratives to challenge attitudes and create empathy in health care: a methodological perspective.

PubMed

Wain, Toni; Sim, Moira; Bessarab, Dawn; Mak, Donna; Hayward, Colleen; Rudd, Cobie

2016-06-02

Unconscious bias and negative attitudes towards minority groups have detrimental effects on the way health care is, or is not, provided to these groups. Recognition of racist attitudes and behaviours as well as understanding clients' experiences of health and health care are pivotal to developing better health care strategies to positively impact on the quality and safety of care provided to Indigenous people. Indigenous research demands inclusive research processes and the use of culturally appropriate methodologies. This paper presents a methodological account of collecting narratives which accurately and respectfully reflect Aboriginal Australians' experiences with health care in Western Australia. The purpose of these narratives is to provide health students and professionals with an opportunity to 'walk-in the shoes' of Aboriginal people where face-to-face interaction is not feasible. With the incorporation of Indigenous peoples' voices being an important link in cultural safety, the project was led by an Indigenous Reference group, who encouraged active participation of Aboriginal people in all areas of the project. Using a phenomenological approach and guided by the Indigenous Reference group, yarning data collection was implemented to collect stories focusing on Aboriginal people's experiences with health care services. An open-access, on-line website was established to host education resources developed from these "yarns". Yarning provided a rich source of information on personal experiences and encouraged the story provider to recognise their facilitative role in the research process. While the methodology used in this project was lengthy and labour-intensive it afforded a respectful manner for story collection and highlighted several innate flaws when Western methods are applied to an Indigenous context. Engagement of an Indigenous Reference Group was pivotal to designing an appropriate methodology that incorporated the voices of Aboriginal people in a

Variation in flexural properties of photo-pultruded composite archwires: analyses of round and rectangular profiles.

PubMed

Fallis, D W; Kusy, R P

2000-11-01

Prototype continuous, unidirectional, fiber-reinforced composite archwires were manufactured into round and rectangular profiles utilizing a photo-pultrusion process. Both 0.022 inch (0.56 mm) diameter and 0.021 x 0.028 inch (0.53 x 0.71 mm) rectangular composites were formed utilizing commercially available S2-glass reinforcement within a polymeric matrix. Reinforcement was varied according to the number, denier and twists per inch (TPI) of four S2-glass yarns to volume levels of 32-74% for round and 41-61% for rectangular profiles. Cross-sectional geometry was evaluated via light microscopy to determine loading characteristics; whereas two flexural properties (the elastic moduli and flexural strengths) were determined by 3-point bending tests. Morphological evaluation of samples revealed that as the TPI increased from 1 to 8, the yarns were more separated from one another and distributed more peripherally within a profile. For round and rectangular profiles utilizing 1 TPI fibers, moduli increased with fiber content approaching theoretical values. For round profiles utilizing 1 TPI and 4 TPI fibers, flexural strengths increased until the loading geometry was optimized. In contrast, the flexural strengths of composites that were pultruded with 8 TPI fibers were not improved at any loading level. Doubling the denier of the yarn, without altering the loading, increased both the moduli and flexural strengths in rectangular samples; whereas, the increases observed in round samples were not statistically significant. At optimal loading the maximum mean moduli and strengths equaled 53.6 +/- 2.0 and 1.36 +/- 0.17 GPa for round wire and equaled 45.7 +/- 0.8 and 1.40 +/- 0.05 GPa for rectangular wires, respectively. These moduli were midway between that of martensitic NiTi (33.4 GPa) and beta-titanium (72.4 GPa), and produced about one-quarter the force of a stainless steel wire per unit of activation. Values of strengths placed this composite material in the range of

Direct Integration of Dynamic Emissive Displays into Knitted Fabric Structures

NASA Astrophysics Data System (ADS)

Bellingham, Alyssa

Smart textiles are revolutionizing the textile industry by combining technology into fabric to give clothing new abilities including communication, transformation, and energy conduction. The advent of electroluminescent fibers, which emit light in response to an applied electric field, has opened the door for fabric-integrated emissive displays in textiles. This thesis focuses on the development of a flexible and scalable emissive fabric display with individually addressable pixels disposed within a fabric matrix. The pixels are formed in areas where a fiber supporting the dielectric and phosphor layers of an electroluminescent structure contacts a conductive surface. This conductive surface can be an external conductive fiber, yarn or wire, or a translucent conductive material layer deposited at set points along the electroluminescent fibers. Different contacting methods are introduced and the different ways the EL yarns can be incorporated into the knitted fabric are discussed. EL fibers were fabricated using a single yarn coating system with a custom, adjustable 3D printed slot die coater for even distribution of material onto the supporting fiber substrates. These fibers are mechanically characterized inside of and outside of a knitted fabric matrix to determine their potential for various applications, including wearables. A 4-pixel dynamic emissive display prototype is fabricated and characterized. This is the first demonstration of an all-knit emissive display with individually controllable pixels. The prototype is composed of a grid of fibers supporting the dielectric and phosphor layers of an electroluminescent (EL) device structure, called EL fibers, and conductive fibers acting as the top electrode. This grid is integrated into a biaxial weft knit structure where the EL fibers make up the rows and conductive fibers make up the columns of the reinforcement yarns inside the supporting weft knit. The pixels exist as individual segments of

High Performance Artificial Muscles Using Nanofiber and Hybrid Yarns

DTIC Science & Technology

2015-07-14

provide 3.2% energy conversion efficiency (twice that of our CNT fiber muscles and 10X that of conducting polymer muscles ). They maintain stroke without...rubber dielectric muscle layer in twisted fiber drives torsional actuation. (2) One hundred times higher torsional stroke per muscle length...artificial muscles that provide giant stroke, fast response, high force generation, and long cycle life while optimizing energy conversion efficiencies

Garment Selection for Cleanrooms and Controlled Environments for Spacecraft

DTIC Science & Technology

1991-04-01

visually undetectable, making it diffi- cult for a worker to select a treated garment. The optimal solution has been to weave a grid of synthetic coated ...make the base fabric static-dis- sipative must be selected carefully. Nylon- coated conductive yarns are readily subject to acid attack, while...Cations (+ ) which must be eliminated from garments include sodium, potassium, lithi- um, aluminum, boron , and arsenic. The standard mtwhod for

U.S.-Peru Economic Relations and the U.S.-Peru Trade Promotion Agreement

DTIC Science & Technology

2007-11-06

assessment of harvesting practices.36 The Peruvian non-government organization, Native Federation of Madre de Dios (FENAMAD) recently teamed with...over five years old, and heavy trucks over eight years old. U.S. industry is concerned about enforcement of Peru’s intellectual property rights (IPR...on the yarn forward standard to encourage production and economic integration. A “ de minimis” provision would allow limited amounts of specified third

Angle-Ply Weaving

NASA Technical Reports Server (NTRS)

Farley, Gary L.

1990-01-01

Bias-direction or angle-ply weaving is proposed new process for weaving fibers along bias in conventional planar fabric or in complicated three-dimensional multilayer fabric preform of fiber-reinforced composite structure. Based upon movement of racks of needles and corresponding angle yarns across fabric as fabric being formed. Fibers woven along bias increases shear stiffness and shear strength of preform, increasing value of preform as structural member.

Method for Fabricating Composite Structures Using Pultrusion Processing

NASA Technical Reports Server (NTRS)

Farley, Gary L. (Inventor)

2000-01-01

A method for fabricating composite structures at a low-cost, moderate-to-high production rate. A first embodiment of the method includes employing a continuous press forming fabrication process. A second embodiment of the method includes employing a pultrusion process for obtaining composite structures. The methods include coating yarns with matrix material, weaving the yarn into fabric to produce a continuous fabric supply and feeding multiple layers of net-shaped fabrics having optimally oriented fibers into a debulking tool to form an undebulked preform. The continuous press forming fabrication process includes partially debulking the preform, cutting the partially debulked preform and debulking the partially debulked preform to form a net-shape. An electron-beam or similar technique then cures the structure. The pultrusion fabric process includes feeding the undebulked preform into a heated die and gradually debulking the undebulked preform. The undebulked preform in the heated die changes dimension until a desired cross-sectional dimension is achieved. This process further includes obtaining a net-shaped infiltrated uncured preform, cutting the uncured preform to a desired length and electron-beam curing (or similar technique) the uncured preform. These fabrication methods produce superior structures formed at higher production rates, resulting in lower cost and high structural performance.

Method for Fabricating Composite Structures Using Continuous Press Forming

NASA Technical Reports Server (NTRS)

Farley, Gary L. (Inventor)

1997-01-01

A method for fabricating composite structures at a low-cost. moderate-to-high production rate. A first embodiment of the method includes employing a continuous press forming fabrication process. A second embodiment of the method includes employing a pultrusion process for obtaining composite structures. The methods include coating yarns with matrix material, weaving the yarn into fabric to produce a continuous fabric supply and feeding multiple layers of net-shaped fabrics having optimally oriented fibers into a debulking tool to form an undebulked preform. The continuous press forming fabrication process includes partially debulking the preform, cutting the partially debulked preform and debulking the partially debulked preform to form a net-shape. An electron-beam or similar technique then cures the structure. The pultrusion fabric process includes feeding the undebulked preform into a heated die and gradually debulking the undebulked preform. The undebulked preform in the heated die changes dimension until a desired cross-sectional dimension is achieved. This process further includes obtaining a net-shaped infiltrated uncured preform, cutting the uncured preform to a desired length and electron-beam curing (or similar technique) the uncured preform. These fabrication methods produce superior structures formed at higher production rates. resulting in lower cost and high structural performance.

A novel design for a wearable thermoelectric generator based on 3D fabric structure

NASA Astrophysics Data System (ADS)

Wu, Qian; Hu, Jinlian

2017-04-01

A flexible and wearable thermoelectric generator (TEG) could enable the conversion of human body heat into electrical power, which would help to realize a self-powered wearable electronic system. To overcome the difficulty of wearing existing flexible film TEGs, a novel 3D fabric TEG structure is designed in this study. By using a 3D fabric as the substrate and yarns coated with thermoelectric materials as legs, a wearable and flexible TEG can be realized. The designed generator has a sandwich structure, similar to the classical inorganic generator, which allows the generation of a temperature difference in the fabric thickness direction, thus making it wearable and showing promising application in body heat conversion. To verify the effectiveness of the designed generator structure, a prototype was fabricated, using a locknit spacer fabric as the substrate and yarns coated with waterborne polyurethane/carbon nanotube thermoelectric composites as legs. The results suggest that the fabricated spacer fabric TEG prototype could work successfully, although the performance of this prototype is of a low level. To further improve the efficiency of the 3D fabric generator and apply it in wearable electronics in the future, highly efficient inorganic thermoelectric materials can be applied, and modifications on the conductive connections can be made.

Seebeck Coefficient of Thermocouples from Nickel-Coated Carbon Fibers: Theory and Experiment.

PubMed

Hardianto, Hardianto; De Mey, Gilbert; Ciesielska-Wrόbel, Izabela; Hertleer, Carla; Van Langenhove, Lieva

2018-05-30

Thermocouples made of etched and non-etched nickel-coated carbon yarn (NiCCY) were investigated. Theoretic Seebeck coefficients were compared to experimental results from measurements of generated electric voltage by these thermocouples. The etching process for making thermocouples was performed by immersion of NiCCY in the solution containing a mixture of hydrochloric acid (HCl) (37% of concentration), and hydrogen peroxide (H₂O₂) in three different concentrations-3%, 6%, and 10%. Thirty minutes of etching to remove Ni from NiCCY was followed by washing and drying. Next, the ability to generate electrical voltage by the thermocouples (being a junction of the etched and the non-etched NiCCY) was measured in different ranges of temperatures, both a cold junction (291.15⁻293.15 K) and a hot junction (293.15⁻325.15 K). A formula predicting the Seebeck coefficient of this thermocouple was elaborated, taking into consideration resistance values of the tested samples. It was proven that there is a good agreement between the theoretical and experimental data, especially for the yarns etched with 6% and 10% peroxide (both were mixed with HCl). The electrical resistance of non-fully etched nickel remaining on the carbon fiber surface ( R 1 ) can have a significant effect on the thermocouples' characteristics.

Characterization of embroidered inductors

NASA Astrophysics Data System (ADS)

Roh, Jung-Sim; Chi, Yong-Seung; Lee, Jae-Hee; Nam, Sangwook; Kang, Tae Jin

2010-11-01

As the demand for wearable intelligent textile systems continues to expand, it is now essential to achieve a high-level of electronic circuit integration into textiles. By applying a commercial yarn manufacturing technique and a computer numerical control (CNC) embroidery process, metal composite embroidery yarns (MCEYs) comprised of three strands of fine metal filaments and polyester filaments, and embroidered circuits have been successfully produced. Using MCEYs, circular and square spiral inductors were embroidered on a textile substrate. Their inductive characteristics, i.e. inductance, self-resonance frequency, and quality factor, were investigated under three different environments, i.e. in free space, on a human body, and with a metal fabric ground. Their inductive characteristics could be easily modified by adjusting the circuit design. The validity of the MCEY inductors was demonstrated with Wheeler's formula and design equations for the MCEY inductors were proposed. When in contact with the human body, the self-resonance frequency of the circuit decreased but the inductance was not affected. Although the inductance and maximum quality factor decreased with a metal ground, the inductor gave a stable performance irrespective of the environment. The results also suggest that MCEY embroidery is a simple and eco-friendly process for producing flexible, light-weight, wearable circuitries in various designs.

Stretchable, Weavable Coiled Carbon Nanotube/MnO2/Polymer Fiber Solid-State Supercapacitors

PubMed Central

Choi, Changsoon; Kim, Shi Hyeong; Sim, Hyeon Jun; Lee, Jae Ah; Choi, A Young; Kim, Youn Tae; Lepró, Xavier; Spinks, Geoffrey M.; Baughman, Ray H.; Kim, Seon Jeong

2015-01-01

Fiber and yarn supercapacitors that are elastomerically deformable without performance loss are sought for such applications as power sources for wearable electronics, micro-devices, and implantable medical devices. Previously reported yarn and fiber supercapacitors are expensive to fabricate, difficult to upscale, or non-stretchable, which limits possible use. The elastomeric electrodes of the present solid-state supercapacitors are made by using giant inserted twist to coil a nylon sewing thread that is helically wrapped with a carbon nanotube sheet, and then electrochemically depositing pseudocapacitive MnO2 nanofibers. These solid-state supercapacitors decrease capacitance by less than 15% when reversibly stretched by 150% in the fiber direction, and largely retain capacitance while being cyclically stretched during charge and discharge. The maximum linear and areal capacitances (based on active materials) and areal energy storage and power densities (based on overall supercapacitor dimensions) are high (5.4 mF/cm, 40.9 mF/cm2, 2.6 μWh/cm2 and 66.9 μW/cm2, respectively), despite the engineered superelasticity of the fiber supercapacitor. Retention of supercapacitor performance during large strain (50%) elastic deformation is demonstrated for supercapacitors incorporated into the wristband of a glove. PMID:25797351

Method for Fabricating Composite Structures Including Continuous Press Forming and Pultrusion Processing

NASA Technical Reports Server (NTRS)

Farley, Gary L. (Inventor)

1995-01-01

A method for fabricating composite structures at a low-cost, moderate-to-high production rate is disclosed. A first embodiment of the method includes employing a continuous press forming fabrication process. A second embodiment of the method includes employing a pultrusion process for obtaining composite structures. The methods include coating yarns with matrix material, weaving the yarn into fabric to produce a continuous fabric supply, and feeding multiple layers of net-shaped fabrics having optimally oriented fibers into a debulking tool to form an undebulked preform. The continuous press forming fabrication process includes partially debulking the preform, cutting the partially debulked preform, and debulking the partially debulked preform to form a netshape. An electron-beam or similar technique then cures the structure. The pultrusion fabric process includes feeding the undebulked preform into a heated die and gradually debulking the undebulked preform. The undebulked preform in the heated die changes dimension until a desired cross-sectional dimension is achieved. This process further includes obtaining a net-shaped infiltrated uncured preform, cutting the uncured preform to a desired length, and electron-beam curing (or similar technique) the uncured preform. These fabrication methods produce superior structures formed at higher production rates, resulting in lower cost and high structural performance.

Method for Fabricating Composite Structures Using Pultrusion Processing

NASA Technical Reports Server (NTRS)

Farley, Gary L. (Inventor)

2000-01-01

A method for fabricating composite structures at a low-cost, moderate-to-high production rate. A first embodiment of the method includes employing a continuous press forming fabrication process. A second embodiment of the method includes employing a pultrusion process for obtaining composite structures. The methods include coating yarns with matrix material, weaving the yarn into fabric to produce a continuous fabric supply and feeding multiple layers of net-shaped fabrics having optimally oriented fibers into a debulking tool to form an undebulked preform. The continuous press forming fabrication process includes partially debulking the preform, cutting the partially debulked preform and debulking the partially debulked preform to form a netshape. An electron-beam or similar technique then cures the structure. The pultrusion fabric process includes feeding the undebulked preform into a heated die and gradually debulking the undebulked preform. The undebulked preform in the heated die changes dimension until a desired cross-sectional dimension is achieved. This process further includes obtaining a net-shaped infiltrated uncured preform, cutting the uncured preform to a desired length and electronbeam curing (or similar technique) the uncured preform. These fabrication methods produce superior structures formed at higher production rates, resulting in lower cost and high structural performance.

Epitaxial Growth of Aligned and Continuous Carbon Nanofibers from Carbon Nanotubes.

PubMed

Lin, Xiaoyang; Zhao, Wei; Zhou, Wenbin; Liu, Peng; Luo, Shu; Wei, Haoming; Yang, Guangzhi; Yang, Junhe; Cui, Jie; Yu, Richeng; Zhang, Lina; Wang, Jiaping; Li, Qunqing; Zhou, Weiya; Zhao, Weisheng; Fan, Shoushan; Jiang, Kaili

2017-02-28

Exploiting the superior properties of nanomaterials at macroscopic scale is a key issue of nanoscience. Different from the integration strategy, "additive synthesis" of macroscopic structures from nanomaterial templates may be a promising choice. In this paper, we report the epitaxial growth of aligned, continuous, and catalyst-free carbon nanofiber thin films from carbon nanotube films. The fabrication process includes thickening of continuous carbon nanotube films by gas-phase pyrolytic carbon deposition and further graphitization of the carbon layer by high-temperature treatment. As-fabricated nanofibers in the film have an "annual ring" cross-section, with a carbon nanotube core and a graphitic periphery, indicating the templated growth mechanism. The absence of a distinct interface between the carbon nanotube template and the graphitic periphery further implies the epitaxial growth mechanism of the fiber. The mechanically robust thin film with tunable fiber diameters from tens of nanometers to several micrometers possesses low density, high electrical conductivity, and high thermal conductivity. Further extension of this fabrication method to enhance carbon nanotube yarns is also demonstrated, resulting in yarns with ∼4-fold increased tensile strength and ∼10-fold increased Young's modulus. The aligned and continuous features of the films together with their outstanding physical and chemical properties would certainly promote the large-scale applications of carbon nanofibers.

Electrochemical Impedance Analysis of a PEDOT:PSS-Based Textile Energy Storage Device

PubMed Central

Gokceoren, Argun Talat; Odhiambo, Sheilla Atieno; De Mey, Gilbert; Hertleer, Carla; Van Langenhove, Lieva

2017-01-01

A textile-based energy storage device with electroactive PEDOT:PSS (poly(3,4-ethylenedioxythiophene)/poly(4-styrenesulfonate)) polymer functioning as a solid-state polyelectrolyte has been developed. The device was fabricated on textile fabric with two plies of stainless-steel electroconductive yarn as the electrodes. In this study, cyclic voltammetry and electrochemical impedance analysis were used to investigate ionic and electronic activities in the bulk of PEDOT:PSS and at its interfaces with stainless steel yarn electrodes. The complex behavior of ionic and electronic origins was observed in the interfacial region between the conductive polymer and the electrodes. The migration and diffusion of the ions involved were confirmed by the presence of the Warburg element with a phase shift of 45° (n = 0.5). Two different equivalent circuit models were found by simulating the model with the experimental results: (QR)(QR)(QR) for uncharged and (QR)(QR)(Q(RW)) for charged samples. The analyses also showed that the further the distance between electrodes, the lower the capacitance of the cell. The distribution of polymer on the cell surface also played important role to change the capacitance of the device. The results of this work may lead to a better understanding of the mechanism and how to improve the performance of the device. PMID:29283427

Weaving for heart valve tissue engineering.

PubMed

Liberski, Albert; Ayad, Nadia; Wojciechowska, Dorota; Kot, Radoslaw; Vo, Duy M P; Aibibu, Dilibaier; Hoffmann, Gerald; Cherif, Chokri; Grobelny-Mayer, Katharina; Snycerski, Marek; Goldmann, Helmut

2017-11-01

Weaving is a resourceful technology which offers a large selection of solutions that are readily adaptable for tissue engineering (TE) of artificial heart valves (HV). The different ways that the yarns are interlaced in this technique could be used to produce complex architectures, such as the three-layer architecture of the leaflets. Once the assembly is complete, growth of cells in the scaffold would occur in the orientation of the yarn, enabling the deposition of extra cellular matrixes proteins in an oriented manner. Weaving technology is a rapidly evolving field that, first, needs to be understood, and then explored by tissue engineers, so that it could be used to create efficient scaffolds. Similarly, the textile engineers need to gain a basic understanding of key structural and mechanical aspects of the heart valve. The aim of this review is to provide the platform for joining these two fields and to enable cooperative research efforts. Moreover, examples of woven medical products and patents as well as related publication are discussed in this review, nevertheless due to the large, and continuously growing volume of data, only the aspects strictly associated with HVTE lay in the scope of this paper. Copyright © 2017 Elsevier Inc. All rights reserved.

Embedding Carbon Fibre Structures in Metal Matrixes for Additive Manufacturing

NASA Astrophysics Data System (ADS)

Frostevarg, Jan; Robertson, Stephanie; Benavides, Vicente; Soldatov, Alexander

It is possible to reinforce structures and components using carbon fibres for applications in electronics and medicine, but most commonly used in reinforcing resin fibre composites for personal protection equipment and light weight constructions. Carbon fibres act as stress redistributors while having increased electrical and thermal conductivities. These properties could also be utilized in metal matrixes, if the fibres are properly fused to the metal and the structure remains intact. Another recently developed high potential carbon structure, carbon nanotube- (CNT) yarns, has similar but even greater mechanical properties than common carbon fibres. Via laser cladding, these reinforcing materials could be used in a plethora of applications, either locally (or globally) as surface treatments or as structural reinforcements using multi-layer laser cladding (additive manufacturing). The challenges of embedding carbon fibres or CNT-yarns in a CuAl mixture and SnPb solder wire using lasers are here investigated using high speed imaging and SEM. It is revealed that the carbon fibres have very high buoyancy in the molten metal and quickly degrades when irradiated by the laser. Wetting of the fibres is shown to be improved by a Tungsten coating and embedding of the structures after processing are evaluated using SEM and Raman spectroscopy.

Earth Day 2018 Activities

NASA Image and Video Library

2018-04-18

Students from Rockledge High School in Rockledge, Fla., make “plarn” – plastic yarn -- out of used plastic bags during Kennedy Space Center’s annual Earth Day celebration. The plarn was donated to be woven into mats for homeless veterans. The two-day Earth Day event featured approximately 50 exhibitors offering information on a variety of topics, including electric vehicles, sustainable lighting, renewable energy, Florida-friendly landscaping tips, Florida’s biking trails and more.

Hemp as an Agricultural Commodity

DTIC Science & Technology

2014-02-14

yarns and raw or processed spun fibers, paper, carpeting, home furnishings, construction and insulation materials, auto parts, and composites. The...interior stalk (hurd) is used in various applications such as animal bedding, raw material inputs, low-quality papers, and composites. Hemp seed and...oilcake are used in a range of foods and beverages, and can be an alternative food protein source. Oil from the crushed hemp seed is an ingredient in a

Non-Military Activities in Japan and Korea for the Months of September - October 1945

DTIC Science & Technology

1945-10-01

institutions, general elec- tions, woman suffrage, reorganization of government bureaus and pun- - 29 - ishment of high policy makers who engineered the war...which he was persecuted - 30 - during the war. This new Liberal Party has a women’s section and favors woman suffrage, lowering the voting age, and...textile goods. Spin - ners are inquiring as to the possibilities of importing raw cotton, yarn and other basic necessities inasmuch as cotton stocks on

Southeast Asia Report.

DTIC Science & Technology

1987-05-20

Vigilantism (Ninez Cacho-Olivares; BUSINESS DAY, 2 Apr 87) 29 - b ’Fanatical1 Anticommünist Group Initiation (THE MANILA TIMES, 3 Apr 87) J ...typical American pro- blem: the absence of effective law and order in a frontier re- gion," says Richard Maxwell Brown in an official report for the... j household wares, toys, ’ chinaware, tobacco, ply- wood, electronic, micro- circuits, tennis balls and acrylic yarn. Bananas are seen to have

Filament Winding Multifunctional Carbon Nanotube Composites of Various Dimensionality

NASA Astrophysics Data System (ADS)

Wells, Brian David

Carbon nanotubes (CNT) have been long considered an optimal material for composites due to their high strength, high modulus, and electrical/thermal conductivity. These composite materials have the potential to be used in the aerospace, computer, automotive, medical industry as well as many others. The nano dimensions of these structures make controlled alignment and distribution difficult using many production techniques. An area that shows promise for controlled alignment is the formation of CNT yarns. Different approaches have been used to create yarns with various winding angles and diameters. CNTs resemble traditional textile fiber structures due to their one-dimensional dimensions, axial strength and radial flexibility. One difference is, depending on the length, CNTs can have aspect ratios that far exceed those of traditional textile fibers. This can complicate processing techniques and cause agglomeration which prevents optimal structures from being created. However, with specific aspect ratios and spatial distributions a specific type of CNT, vertically aligned spinnable carbon nanotubes (VASCNTs), have interesting properties that allow carbon nanotubes to be drawn from an array in a continuous aligned web. This dissertation examines the feasibility of combining VASCNTs with another textile manufacturing process, filament winding, to create structures with various levels of dimensionality. While yarn formation with CNTs has been largely studied, there has not been significant work studying the use of VASCNTs to create composite materials. The studies that have been produces revolve around mixing CNTs into epoxy or creating uni-directional wound structures. In this dissertation VASCNTs are used to create filament wound materials with various degrees of alignment. These structures include 1 dimensional coatings applied to non-conductive polymer monofilaments, two dimensional multifunctional adhesive films, and three dimensional hybrid-nano composites. The

Development of generalized 3-D braiding machines for composite preforms

NASA Technical Reports Server (NTRS)

Huey, Cecil O., Jr.; Farley, Gary L.

1992-01-01

The development of prototype braiding machines for the production of generalized braid patterns is described. Mechanical operating principles and control strategies are presented for two prototype machines which have been fabricated and evaluated. Both machines represent advances over current fabrication techniques for composite materials by enabling nearly ideal control of fiber orientations within preform structures. They permit optimum design of parts that might be subjected to complex loads or that have complex forms. Further, they overcome both the lack of general control of produced fiber architectures and the complexity of other weaving processes that have been proposed for the same purpose. One prototype, the Farley braider, consists of an array of turntables that can be made to oscillate in 90 degree steps. Yarn ends are transported about the surface formed by the turntables by motorized tractors which are controlled through an optical link with the turntables and powered through electrical contact with the turntables. The necessary relative motions are produced by a series of linear tractor moves combined with a series of turntable rotations. As the tractors move about, they weave the yarn ends into the desired pattern. The second device, the shuttle plate braider, consists of a braiding surface formed by an array of stationary square sections, each separated from its neighbors by a gap. A plate beneath this surface is caused to reciprocate in two perpendicular directions, first in one direction and then in the other. This movement is made possibly by openings in the plate that clear short columns supporting the surface segments. Yarn ends are moved about the surface and interwoven by shuttles which engage the reciprocating plate as needed to yield the desired movements. Power and control signals are transmitted to the shuttles through electrical contact with the braiding surface. The shuttle plate is a passively driven prime mover that supplies the power

A Highly Damped, High-Strength, Puncture-Resistant Fabric for Multi-Threat Protective Uniforms. Phase 1

DTIC Science & Technology

1999-08-01

directional Nitinol- ~ Reinforced / • CoUpoly - Niti 10 . . . oUnyl - Nitl 10 ----- BOU fabric 30 40 50 blade travel (mm) 60 Tongue· Tear 140...To ughness Results 120 100 ;e i 80 ~ c .::; !!’ 60 .s 40 20 0 2 CoUnyl bi·directionai- Niti 20...and fill yarns that provides the ripstop effect. Cot/Nyl 5- Niti /in. (0.003") - Cot/Nyl-5 Baseline cotton/nylon plain weave with 5 Nitinol fibers per

Quantification of Changes in Mulberry Silk Fabrics due to Different Laundering: Using WAXS Technique

NASA Astrophysics Data System (ADS)

Parameswara, P.; Nivedita, S.; Somashekar, R.

2011-07-01

Loom finished mulberry silk fabrics (Taffeta) were machine laundered and hand laundered several times. X-ray diffractograms of pure and laundered fabrics were used to calculate microstructural parameters like average crystallite size (D) and lattice strain (Vegr) employing Williamson-Hall plot. Microstructural parameters were compared with measured mechanical properties like breaking load, tenacity, and elongation of warp yarns unraveled from fabrics. Surface morphology and texture of silk fabrics changed upon washing is evident from SEM images.

Investigating comfort properties of 3/1 Z twill weaved denim fabrics

NASA Astrophysics Data System (ADS)

Taştan Özkan, E.; Kaplangiray, B.

2017-10-01

Denim jeans are preferred because of durability and easy washing properties. Nowadays the expectations of consumers from denim fabrics are changed towards design and comfort properties. Fort this reason, thermal and moisture comfort properties of denim fabrics should be examined. This paper aims to investigate thermal, air permeability and moisture management properties of 3/1 Z twill weaved denim fabrics. These fabrics are produced mainly from cotton with different yarn count and cover factors are close to each other.

Deterioration of Synthetic Fiber Rope during Marine Usage. Appendix A.

DTIC Science & Technology

1981-12-31

Rigidity, Moisture and Fibre Structure, JTI 48(6), T163-%174 (1957). R394 Khosla, N.K., Shrinkage Properties of Continuous Filament Yarns with Different...8217D-Ai3i 685 DETERIORATION OF SYNTHETIC FIBER ROPE DURING MARINE i/i USAGE APPENDIX AU) MASSACHUSETTS INST OF TECH CAMBRIDGE S BACKER ET AL. 31 DEC...79 70A -. - - DETERIORATION OF SYNTHETIC FIBER ROPE DURING MARINE USAGE -- APPNDIX A PROGRESS REPORT PROJECT R/T-11 PERIOD JANUARY 1 - DECEMBER 31

Integrating Substrateless Electrospinning with Textile Technology for Creating Biodegradable Three-Dimensional Structures.

PubMed

Joseph, John; Nair, Shantikumar V; Menon, Deepthy

2015-08-12

The present study describes a unique way of integrating substrateless electrospinning process with textile technology. We developed a new collector design that provided a pressure-driven, localized cotton-wool structure in free space from which continuous high strength yarns were drawn. An advantage of this integration was that the textile could be drug/dye loaded and be developed into a core-sheath architecture with greater functionality. This method could produce potential nanotextiles for various biomedical applications.

Structural integrity of engineering composite materials: a cracking good yarn.

PubMed

Beaumont, Peter W R; Soutis, Costas

2016-07-13

Predicting precisely where a crack will develop in a material under stress and exactly when in time catastrophic fracture of the component will occur is one the oldest unsolved mysteries in the design and building of large-scale engineering structures. Where human life depends upon engineering ingenuity, the burden of testing to prove a 'fracture safe design' is immense. Fitness considerations for long-life implementation of large composite structures include understanding phenomena such as impact, fatigue, creep and stress corrosion cracking that affect reliability, life expectancy and durability of structure. Structural integrity analysis treats the design, the materials used, and figures out how best components and parts can be joined, and takes service duty into account. However, there are conflicting aims in the complete design process of designing simultaneously for high efficiency and safety assurance throughout an economically viable lifetime with an acceptable level of risk. This article is part of the themed issue 'Multiscale modelling of the structural integrity of composite materials'. © 2016 The Author(s).

Production of yarns composed of oriented nanofibers for ophthalmological implants

NASA Astrophysics Data System (ADS)

Shynkarenko, A.; Klapstova, A.; Krotov, A.; Moucka, M.; Lukas, D.

2017-10-01

Parallelized nanofibrous structures are commonly used in medical sector, especially for the ophthalmological implants. In this research self-fabricated device is tested for improved collection and twisting of the parallel nanofibers. Previously manual techniques are used to collect the nanofibers and then twist is given, where as in our device different parameters can be optimized to obtained parallel nanofibers and further twisting can be given. The device is used to bring automation to the technique of achieving parallel fibrous structures for medical applications.

Identification of "insoluble" red dyewoods by high performance liquid chromatography-photodiode array detection (HPLC-PDA) fingerprinting.

PubMed

Surowiec, Izabella; Nowik, Witold; Trojanowicz, Marek

2004-02-01

The paper describes a high performance liquid chromatography-UV/Vis spectrometry detection analytical approach to the identification of some redwood species of historical importance in textile dyeing. The group of extracted dyestuffs considered as "insoluble" because of their non-aqueous or alkaline extraction conditions is present in the wood of the Pterocarpus family and Baphia nitida species. First, the crude extracts of tinctorial and related species and their chromatographic fingerprints were studied. This part of work shows that some species not yet mentioned in the literature have potential dyeing properties. Subsequent experiments performed on the redwood cargo of a 200-year-old archaeological shipwreck allowed identification of the water-logged wood species. Furthermore, the different methods of dyestuff extraction used for dyeing according to traditional recipes and their impact on analytical results were studied. They show that standard recovery obtained by acid hydrolysis of dyestuff from dyed yarns is inadequate. Hence, alternative solvent-based procedures were proposed. The identification of species in textile threads then becomes possible. The applied approach was validated by analysis of dyed reference yarns with some indications of crude material extraction mode. The employed method of analysis seems to be useful for "insoluble" wood species identification in cultural heritage artifacts as well as for phytochemical purposes, despite the fact that very few detected color compounds were chemically identified.

Men's health and communities of practice in Australia.

PubMed

Henwood, Maree; Shaw, Amie; Cavanagh, Jillian; Bartram, Timothy; Marjoribanks, Timothy; Kendrick, Madeleine

2017-04-10

Purpose The purpose of this paper is to examine the social opportunities for Aboriginal and Torres Strait Islander men created through Men's Groups/Sheds across urban, regional and remote areas of Australia. Men's Sheds are a safe space, resembling a work-shop setting or backyard shed, where men are encouraged to socialise and participate in health promotion, informal learning and engage in meaningful tasks both individually and at the community level. Design/methodology/approach Explore five case study sites through Wenger's (1998) active communities of practice (CoP). Qualitative methods are presented and analysed; methods comprise semi-structured interviews and yarning circles (focus groups). Five Indigenous leaders/coordinators participated in semi-structured interviews, as well as five yarning circles with a total of 61 Indigenous men. Findings In a societal context in which Indigenous men in Australia experience a number of social and health issues, impeding their quality of life and future opportunities, the central finding of the paper is that the effective development of social relations and socially designed programs through Men's Groups, operating as CoP, may contribute to overcoming many social and health well-being concerns. Originality/value Contributions will provide a better understanding of how Indigenous men are engaging with Men's Sheds, and through those interactions, are learning new skills and contributing to social change.

Textile Supercapacitors

NASA Astrophysics Data System (ADS)

Jost, Kristy Alana

Innovative and interdisciplinary solutions to wearable textile energy storage are explored as power sources for wearable electronics and smart textiles. Due to their long cycle life, non-toxic and inexpensive materials, supercapacitors were converted into textiles. Textile supercapacitors were developed using scalable fabrication methods including screen-printing, yarn making, and 3D computerized knitting. The electrode materials reported in this thesis undergo thorough electrochemical analysis, and are capable of storing up to 0.5 F/cm2 which is on par with conventionally solid supercapacitors (0.6 F/cm2). Capacitive yarns are capable of storing up to 37 mF/cm and are shown to be knittable on industrial knitting equipment. Both are some of the highest reported capacitance for all-carbon systems in the field. Yet both are the only systems composed of inexpensive and non-toxic activated carbon, the most commonly used electrode material used in supercapacitors, opposed to carbon nanotubes or graphene, which are typically more 10-100 times more expensive. However, all of the fabrication techniques reported here are also capable of incorporating a wide variety of materials, ultimately broadening the applications of textile energy storage as a whole. Fully machine knitted supercapacitors are also explored and electrochemically characterized in order to determine how the textile structure affects the capacitance. In conclusion, a wide variety of fabrication techniques for making textile supercapacitors were successfully explored.

Energy harvesting “3-D knitted spacer” based piezoelectric textiles

NASA Astrophysics Data System (ADS)

Anand, S.; Soin, N.; Shah, T. H.; Siores, E.

2016-07-01

The piezoelectric effect in Poly(vinylidene fluoride), PVDF, was discovered over four decades ago and since then, significant work has been carried out aiming at the production of high p-phase fibres and their integration into fabric structures for energy harvesting. However, little work has been done in the area of production of “true piezoelectric fabric structures” based on flexible polymeric materials such as PVDF. In this work, we demonstrate “3-D knitted spacer” technology based all-fibre piezoelectric fabrics as power generators and energy harvesters. The knitted single-structure piezoelectric generator consists of high p-phase (~80%) piezoelectric PVDF monofilaments as the spacer yarn interconnected between silver (Ag) coated polyamide multifilament yarn layers acting as the top and bottom electrodes. The novel and unique textile structure provides an output power density in the range of 1.105.10 gWcm-2 at applied impact pressures in the range of 0.02-0.10 MPa, thus providing significantly higher power outputs and efficiencies over the existing 2-D woven and nonwoven piezoelectric structures. The high energy efficiency, mechanical durability and comfort of the soft, flexible and all-fibre based power generator is highly attractive for a variety of potential applications such as wearable electronic systems and energy harvesters charged from ambient environment or by human movement.

Modelling of Damage Evolution in Braided Composites: Recent Developments

NASA Astrophysics Data System (ADS)

Wang, Chen; Roy, Anish; Silberschmidt, Vadim V.; Chen, Zhong

2017-12-01

Composites reinforced with woven or braided textiles exhibit high structural stability and excellent damage tolerance thanks to yarn interlacing. With their high stiffness-to-weight and strength-to-weight ratios, braided composites are attractive for aerospace and automotive components as well as sports protective equipment. In these potential applications, components are typically subjected to multi-directional static, impact and fatigue loadings. To enhance material analysis and design for such applications, understanding mechanical behaviour of braided composites and development of predictive capabilities becomes crucial. Significant progress has been made in recent years in development of new modelling techniques allowing elucidation of static and dynamic responses of braided composites. However, because of their unique interlacing geometric structure and complicated failure modes, prediction of damage initiation and its evolution in components is still a challenge. Therefore, a comprehensive literature analysis is presented in this work focused on a review of the state-of-the-art progressive damage analysis of braided composites with finite-element simulations. Recently models employed in the studies on mechanical behaviour, impact response and fatigue analyses of braided composites are presented systematically. This review highlights the importance, advantages and limitations of as-applied failure criteria and damage evolution laws for yarns and composite unit cells. In addition, this work provides a good reference for future research on FE simulations of braided composites.