Textile Yarn Research Articles

Multifunctional and Washable Carbon Nanotube-Wrapped Textile Yarns for Wearable E-Textiles.

Carbon nanotube (CNT) yarns are promising for wearable electronic applications due to their excellent electromechanical and thermal properties and structural flexibility. A spinning system was customized to produce CNT-wrapped textile yarns for wearable applications. By adjusting the spinning parameters and core yarn, a highly tailored hybrid CNT yarn could be produced for textile processing, e.g., knitting and weaving. The electrical resistance and mechanical properties of the yarn are influenced by the core yarn. The high flexibility of the yarn enabled state-of-the-art three-dimensional (3D) knitting of the CNT-wrapped yarn for the first time. Using the 3D knitted technology, CNT-wrapped textile yarns were seamlessly integrated into a wrist band and the index finger of a glove. The knitted structure exhibited a large resistance change under strain and precisely recorded the signal under the different movements of the finger and wrist. When the knitted fabric was connected to a power source, rapid heating above skin temperature was observed at a low voltage. This work presents a novel hybrid yarn for the first time, which sustained 30 washing cycles without performance degradation. By changing the core yarn, a highly stretchable and multimodal sensing system could be developed for wearable applications.

Intelligent Computer Vision System for Analysis and Characterization of Yarn Quality

The quality of yarn is essential in the control of the fabrics processes. There is some commercial equipment that measures the quality of yarn based on sensors, of different types, used for collecting data about some textile yarn characteristic parameters. The irregularity of the textile thread influences its physical properties/characteristics and there may be a possibility of a break in the textile thread during the fabric manufacturing process. This can contribute to the occurrence of unwanted patterns in fabrics that deteriorate their quality. The existing equipment, for the above-mentioned purpose, is characterized by its high size and cost, and for allowing the analysis of only few yarn quality parameters. The main findings/results of the study are the yarn analysis method as well as the developed algorithm, which allows the analysis of defects in a more precise way. Thus, this paper presents the development and results obtained with the design of a mechatronic prototype integrating a computer vision system that allows, among other parameters, the analysis and classification, in real time, of the hairs of the yarn using artificial intelligence techniques. The system also determines other characteristics inherent to the yarn quality analysis, such as: linear mass, diameter, volume, twist orientation, twist step, average mass deviation, coefficient of variation, hairiness coefficient, average hairiness deviation, and standard hairiness deviation, as well as performing spectral analysis. A comparison of the obtained results with the designed system and a commercial equipment was performed validating the undertaken methodology.

Valorization of nylon and viscose-rayon textile yarn wastes for fabricating nanocomposite films

Valorization of nylon and viscose-rayon textile yarn wastes for fabricating nanocomposite films

The effect of weft yarn type and elastomer yarn threading on the properties of elastic warp knitted fabrics. Part II: Thermal comfort properties

The aim of this study is to determine the performance properties of elastic warp-knitted fabrics used for medical purposes. The samples were knitted using different weft yarn material and changing the threading order of elastomer yarn. The detailed results of the dimensional and elasticity performance of elastic warp-knitted fabrics had been reported in Part I of this series. In this part, the effects of weft yarn material and the threading order of elastomer yarn on the thermal comfort characteristics were investigated. It has been seen that the type and linear density of the transverse weft yarns and the number of elastomer yarns in the fabric structure affected significantly the thermal comfort and permeability characteristics of the developed elastic warp-knitted fabrics. According to the results, using polyester yarns as weft and reducing the number of elastomer yarns led to an increase in air permeability. Additionally, the thermal conductivity characteristics of the fabrics increased as the number of elastomer yarns in the structure increased. It has been seen that from the results, the water vapour resistance coefficient of the samples is appropriate for the usage of these fabrics in medical products.

The effect of weft yarn type and elastomer yarn threading on the properties of elastic warp knitted fabrics. Part 1: Structure and elasticity

The demand for medical textile products is increasing with awareness regarding better healthcare services and efficient medical treatments. Compared to other textiles, elastic warp knitted materials, which have elastomer threads in each wale have been widely used in producing medical and preventive products. Thus, in order to decrease the weight and cost of these products without effect on fabric’s stretchability, in this study, various elastic warp knitted fabrics were produced using different raw materials and elastomer threading arrangements, and their properties were investigated. The fabrics were produced on a crochet knitting machine with five different arrangements of elastomer threading and four different laid-in yarn materials as polyester, cotton, and linen. Then the dimensional properties and elastic behaviors of the samples were determined and evaluated comparatively. Statistical analysis showed that all studied elastic warp knitted fabrics have high provide elasticity at a higher than 95% level. On the other hand, the mass per unit area of the fabric is reduced, with the use of linen yarn as weft yarn, or when the total linear density of the weft yarn and the amount of elastomer threads decrease. Finally, the obtained results revealed the possibility to reduce elastomer consumption to decrease weight for elastic medical products, which were developed, without effect on fabric’s stretchability and elasticity as well as replacing synthetic threads with natural yarns in order to improve product comfort.

The Programmable Design of Large-Area Piezoresistive Textile Sensors Using Manufacturing by Jacquard Processing.

Among wearable e-textiles, conductive textile yarns are of particular interest because they can be used as flexible and wearable sensors without affecting the usual properties and comfort of the textiles. Firstly, this study proposed three types of piezoresistive textile sensors, namely, single-layer, double-layer, and quadruple-layer, to be made by the Jacquard processing method. This method enables the programmable design of the sensor’s structure and customizes the sensor’s sensitivity to work more efficiently in personalized applications. Secondly, the sensor range and coefficient of determination showed that the sensor is reliable and suitable for many applications. The dimensions of the proposed sensors are 20 × 20 cm, and the thicknesses are under 0.52 mm. The entire area of the sensor is a pressure-sensitive spot. Thirdly, the effect of layer density on the performance of the sensors showed that the single-layer pressure sensor has a thinner thickness and faster response time than the multilayer pressure sensor. Moreover, the sensors have a quick response time (<50 ms) and small hysteresis. Finally, the hysteresis will increase according to the number of conductive layers. Many tests were carried out, which can provide an excellent knowledge database in the context of large-area piezoresistive textile sensors using manufacturing by Jacquard processing. The effects of the percolation of CNTs, thickness, and sheet resistance on the performance of sensors were investigated. The structural and surface morphology of coating samples and SWCNTs were evaluated by using a scanning electron microscope. The structure of the proposed sensor is expected to be an essential step toward realizing wearable signal sensing for next-generation personalized applications.

An investigation into the potential of water retted fiber from agricultural waste ofCurcuma longaplant for textile application

PurposeThe purpose of this study was to characterize the fiber fromCurcuma longa(turmeric) stems. The fiber’s properties were used to assess its potential for textile yarn production.Design/methodology/approachThe natural fiber used in this investigation was extracted from agricultural waste through a cold water-retting process.FindingsTheCurcuma longafiber had a crystallinity of 50%. Cellulose, hemicellulose and lignin were detected in the fibers’ Fourier transform infrared spectra. ACurcuma longafiber bundle contains several constituent fibers. The fibers exhibited an irregular cross-section, with a variable oval shape for the lumen. The fibers ofCurcuma longaaveraged 30.22 cm in length. The fineness of the fibers was 6.58 Tex. In this study,Curcuma longafibers had an 11.30% moisture regain. The tensile strength of the fibers was 19.18 g/Tex.Curcuma longafibers showed a break elongation of 9.79%. The fiber coefficient of friction was 0.3.Originality/valueCurcuma longahas characteristics that make it appropriate for industrial uses like spinning. Thus, it is possible to useCurcuma longafiber as a raw material for textiles.

Investigation of the use of textile carbon yarns as sustainable shear reinforcement in concrete beams

In recent years, textile reinforcement has been widely researched and used in reinforced concrete beams, slabs, and thin plates. However, the design for bending is completely different from that of the shear case. The use of textile carbon yarns in place of or in addition to traditional steel stirrups to reinforce the shear has been investigated. Eight beams with dimensions of 200 mm × 300 mm × 1500 mm were used in this investigation. These beams were tested in shear under four load points. Two specimens were used with and without steel stirrups as reference specimens, while the other six beams used textile carbon yarns instead of steel stirrups. The variables of this study were the length of overlap, which was 30%, 60%, and 100%, the spacing was 90 mm and 130 mm, while inclination was 45° and 90°, and bonding with or without steel fibers. The results showed that using 100% overlap length, 90 mm spacing, a 45° angle, and adding steel fibers increased the shear capacity, increased the deflection, and made the cracking behavior better.

Automatic Modeller of Textile Yarns at Fibre Level.

This paper presents a geometrical modelling principle for the modelling of yarns at the fibre level. The woven and the knitted textile structures are built of yarns, which on the other side, are fibrous assemblies. In many yarn and fabric modelling works, yarns are considered as a single line element; however, most yarns are composed of a number of staple or filament fibres. It is then very important to understand the yarn at the micro level for a better understanding, production and application of the above structures. The current paper aims to present the modelling and implementation of yarn structures at the fibre level using the algorithmic geometrical modelling principle. The research work uses basic assumptions for the building of the models and various implementation issues, connected with the proper representation of the single multi-filament yarns, plied yarns and finally the staple fibre yarns. Except for visualization, the generated yarn models are prepared as a basis for mechanical, thermal, fluid flow and other simulations of textile structures using FEM, CFD and other numerical tools.

Adhesive free, conformable and washable carbon nanotube fabric electrodes for biosensing

AbstractSkin-mounted wearable electronics are attractive for continuous health monitoring and human-machine interfacing. The commonly used pre-gelled rigid and bulky electrodes cause discomfort and are unsuitable for continuous long-term monitoring applications. Here, we design carbon nanotubes (CNTs)-based electrodes that can be fabricated using different textile manufacturing processes. We propose woven and braided electrode design using CNTs wrapped textile yarns which are highly conformable to skin and measure a high-fidelity electrocardiography (ECG) signal. The skin-electrode impedance analysis revealed size-dependent behavior. To demonstrate outstanding wearability, we designed a seamless knit electrode that can be worn as a bracelet. The designed CNT-based dry electrodes demonstrated record high signal-to-noise ratios and were very stable against motion artifacts. The durability test of the electrodes exhibited robustness to laundering and practicality for reusable and sustainable applications.

Identification of Metal Threads from Croatian Fabrics

Abstract This article deals with the analysis of metal threads in weaving from historical Croatian textiles, liturgical vestments, and folk costumes from the seventeenth to the twentieth century. The independent narrow stripes, wires, and the srma that was formed by a combination of metal thread wrapped around a non-metal textile yarn were collected and analysed. Using physicochemical method scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDX), the metal composition and content in the threads were analysed. By cross-sectional analysis of metal threads by the SEM-EDX method, it was determined whether the metal threads were homogeneous, gilded, or silver-plated. The composition and structure of non-metal textile yarns were determined by light microscopy. Metal threads were primarily made of gold, silver, or copper and their alloys, but recently less valuable metals having a similar shine have generally been used. Non-metal textile threads in srma are most often made of silk, cotton, and linen. The aim of this study was to determine which type and composition of metal threads were used in different regions of Croatia, which can serve as a database for the restoration and conservation of valuable historical textiles. Also, according to the composition of metal threads, the technology of production threads can be determined and the temporal and spatial dating of textile objects can be determined approximately.

Combined, sequential dye analysis and radiocarbon dating of single ancient textile yarns from a Nazca tunic

The accessioning of ancient textiles into museum collections often requires objective information regarding the object’s appropriateness and authenticity before purchase or gift acceptance. In the case of colored fabrics, the identification of dyestuffs consistent with the attributed time period and culture builds confidence and reduces the chances of the object being a simple forgery or fake produced using modern materials. Moreover, this information adds to the technical, cultural, and conservation knowledge regarding the object. Increasingly, chronometric age estimates in the form of radiocarbon dating are also needed to establish the object’s age or to further prove the materials match the purported date range of the textile. Each of these analyses consumes a small sample of the object, and typically they are conducted separately by different laboratories on individual sample yarns. This report demonstrates for the first time the sequential, combined analysis of dyes by liquid chromatography-diode array detection-mass spectrometry and radiocarbon dating of the same residual dye-extracted sample. The chemicals and solvents used in various dye extraction protocols are shown not to contaminate the extracted yarns for radiocarbon dating purposes. The approach was used in the authentication study of an ancient Nazca tunic made from natural fibers (wool) and dyes (indigoids, anthraquinones, and flavonoids) shown to have most likely been produced between 595 and 665 CE.

A study on fatigue behaviour of cotton/lycra core spun yarns

Core spun yarn gives denim fabrics durability and flexibility, which has increased the focus on these yarns among denim manufacturers in recent years. These yarns undergo tensile fatigue loading, a typical phenomenon that happens on various parts of clothing, during use and wear. The study on the response of yarns during cyclic loading is essential because it leads to a better understanding of the growth characteristics when repeatedly loaded during the use of core spun yarn fabrics. In this study, the impact of various production parameters such as linear density, stretch percentage, twist multiplier, and the number of cyclic loading on the fatigue value of core-spun yarns was investigated. 18 different core spun yarns were manufactured by modified ring spinning to investigate the effect of various production parameters on fatigue value before and after 10, 20, and 30 load cycles. Experimental results showed that there is an increase in fatigue value with an increase in the number of load cycles. Statistical analysis showed that there is a significant effect of linear density, stretch percentage, and twist multiplier on the fatigue value of yarn. There is a reduction in fatigue value with an increase in linear density, stretch percentage, and twist multiplier of yarn. The contribution of the number of cyclic loading was found to be more dominating in comparison to other process parameters like linear density, twist multiplier, and stretch percentage on the fatigue value of core-spun yarns.

Electrochemically Driven Yarn and Textile Actuators

Conjugated polymers such as polypyrrole can be electrochemically oxidised and reduced. These redox reactions are accompanied by a flow of counter ions and solvent from the electrolyte into or out of the polymer matrix in order to maintain charge balance and osmotic pressure, resulting in an electrochemically induced volume change of the conjugated polymer. This volume change can be exploited to fabricate electrochemically driven actuators in various formats from bending bilayer microactuators to macroscopic textile actuators. Yarn and textile actuators are fabricated by coating commercially yarns and fabrics with the conjugated polymers. First a thin layer of PEDOT (poly(3,4-ethylenedioxythiophene)) is applied to make the yarns or fabrics electrically conductive. Thereafter the yarns/fabrics are coated with electromechanically active polypyrrole using electrochemical synthesis. Next the yarn or textile actuators can be actuated by applying the appropriate redox potentials. In order to achieve in-air actuation, the yarns or fabrics will be coated with novel ionogels (gelled semi-solid electrolytes), that function as the ion source/sink to drive the electrochemical reactions. Two of such ionogel coated yarns will be assembled forming the anode/cathode pair of the electrochemical circuit. Using advanced textile manufacturing such yarn actuators can be integrated into fabrics using knitting or weaving. The latest results of our textile actuators both operating in liquid electrolytes as in-air will be presented.Fig. 1 A textile actuator with 4 inlay-knitted, in-air operating yarn actuators. Figure 1

Flexible and lightweight Kevlar composites towards flame retardant and impact resistance with excellent thermal stability

The impact and thermal damage in extreme environments generally exist together. In this context, the design of safety protection materials ought to consider not only the single impact protection performance, but also thermal stability and flame resistance. In order to simultaneously achieve the impact resistance, thermal stability and flame resistance properties, a flexible and lightweight shear-hardened composite material (STF/Kevlar) was prepared by impregnating and drying shear thickening fluid (STF) on Kevlar fabric. Due to the favorable shear thickening performance of shear thickening fluid, STF/Kevlar composite material can increase the maximum yarn pull-out force of the fabric yarn from 3.3 N to 16.3 N with the impregnation weight gain of 55 wt%. Moreover, in bullet impact experiment, a single layer of STF/Kevlar fabric can nearly double the time it takes a bullet to penetrate pure Kevlar fabric. Additionally, STF/Kevlar composite material exhibits significant flame resistance as well. The limit oxygen index can reach 32 %, and after 30 min high temperature treatment at 400 °C, the composite still maintains good mechanical property and flexibility. This multi-functional composite material along with the performance of resisting both mechanical shock and thermal damage in extreme environments is expected to broadly apply in the field of lightweight protection.

Influence of material characteristics on impact response for fabrics made of glass and aramid fibers

This paper presents a meso-level FE model of unidirectional yarns in order to point out the difference in impact response for two materials: glass and aramid fibers. The architecture is kept the same, successive layers of yarns, oriented 0° and 90°. The constitutive model for each yarn material is bilinear with hardening, as taken from recent documentation. The projectile is a 9 mm FMJ with the geometry close to the actual one and the metallic alloys for core and jacket are also bilinear with hardening. There were analysed the stages of the impact and failure process, the equivalent stress distributions on yarns and, based on the simulation results, the authors made recommendations for an actual design of a ballistic protection system.

Flax Fibre Yarn Coated with Lignin from Renewable Sources for Composites.

The present experimental work analyses the potential of lignin as a matrix for materials made from renewable resources for composite components and the production of hybrid semi-finished products by coating a flax fibre yarn. Natural fibres, due to their low density, in combination with lignin can be a new renewable source for lightweight products. For this purpose, the extrusion process was adapted to lignin as a matrix material for bio-based composites and coating of natural fibre yarns. A commercial flax yarn is the basis for the lignin coating by extrusion. Subsequently, the coated flax yarn was characterised with regard to selected yarn properties. In order to produce composite plates, the lignin-coated flax yarn was used as warp yarn in a bidirectional fabric due to its insufficient flexibility transversely to the yarn axis. The commercial flax yarn was used as weft yarn to increase the fibre volume content. The tensile and flexural properties of the bio-based composite material were determined. There was a significant difference in the mechanical properties between the warp and weft directions. The results show that lignin can be used as matrix material for bio-based natural fibre composites and the coating of natural fibre yarns is an alternative to spun hybrid yarns.

Appearance and conductivity of weft-knitted unibody positioning flexible sensor

PurposeThe purpose of this research is to propose a flexible sensor with a weft-knitted float stitch structure and to explore knitting techniques that allow conductive yarns to be skin-tight and less exposed, reducing production processes and increasing productivity. Study its electrical conductivity in different yarn materials, knit processes and deformation ranges. The analysis is compared to provide some basis for the design of the electrodes.Design/methodology/approachThe method includes five operations: (1) Analysis of the morphological appearance, tensile variation, fiber material properties and electrical conductivity of high-elastic and filament silver-plated conductive yarns. (2) Based on the knitting process of the floating yarn structure, three-dimensional modeling of the flexible sensor was carried out to explore the influence of knitting process changes on appearance characteristics. (3) The fabric samples are knitted by different silver-plated conductive yarns with different structures. Processing of experimental samples to finished size by advance shrinkage. (4) Measure the resistance of the experimental sample after the machine has been lowered and after pre-shrinking. Use the stretching machine to simulate a wearing experiment and measure the change in resistance of the sample in the 0–15% stretching range. (5) Analyze the influence factors on the conductive performance of the flexible sensor to determine whether it is suitable for textile flexible sensors.FindingsFor the float knitted flexible sensors, the floating wire projection is influenced by the elasticity of the fabric and the length of the floating wire. Compared to the plain knitted flexible sensors, it has less resistance variation and better electrical properties, making it suitable for making electrodes for textile structures. In addition, the knitting method is integrated with the intelligent monitoring clothing, which saves the process for the integration of the flexible sensor, realizes positioning and fixed-point knitting.Practical implicationsThe sensor technology of the designed weft-knitted float structure is varied and can be freely combined and designed in a wide range. Within the good electrical conductivity, the flexible sensor can realize integrated knitting, positioning monitoring, integrating into the appearance of clothing. It can also focus on the wearing experience of wearable products so that the appearance of the monitoring clothing is close to the clothes we wear in our daily life.Originality/valueIn this paper, an integrated positioning knitting flexible sensor based on the weft knitting float structure is studied. The improved knitting process allows the sensing contact surface to be close to the skin and reduces the integration process. The relationship between the exposure of the silver-plated yarn on the clothing surface and the electrical conductivity is analyzed. Within a certain conductive performance, reduces the exposed area of the conductive yarn on the clothing surface and proposes a design reference for the flexible sensor appearance.

A mesoscale tensile model for woven fabrics based on Timoshenko beam theory

The yarn weave architectures highly influence the mechanical response of woven fabrics. To provide an accurate prediction of the mechanical behaviors of woven fabrics under tension, a mesoscale model is developed. The model takes into account yarn properties, yarn weaving pattern, and interactions between yarns. The yarn properties such as tensile modulus and yarn strength of yarns are considered as random variables. Each yarn in fabric is modeled as a Timoshenko beam with a weaving shape modeled by a parabolic function. The yarn shape evolution and mechanical response of undulated yarn under tension are computed based on Castigliano’s second theorem. The damage initiation and propagation of a yarn in fabric is introduced through a damage variable. The model is demonstrated on woven jute fabrics. Analytical and numerical analyses are carried out and show good prediction on the macroscopic tensile response of woven jute fabric. The model provides a quantitative understanding between yarn geometrical parameters and the expected material response, and makes it helpful for designing woven structural composites with high performance.

Phase-Inverted Copolymer Membrane for the Enhancement of Textile Supercapacitors.

This paper presents a universal fabrication process for single-layer textile supercapacitors, independent of textile properties such as weave pattern, thickness and material. To achieve this, an engineered copolymer membrane was fabricated within these textiles with an automated screen printing, phase inversion and vacuum curing process. This membrane, together with the textile yarns, acts as a porous, flexible and mechanically durable separator. This process was applied to four textiles, including polyester, two polyester-cottons and silk. Carbon-based electrodes were subsequently deposited onto both sides of the textile to form the textile supercapacitors. These supercapacitors achieved a range of areal capacitances between 3.12 and 38.2 mF·cm−2, with energy densities between 0.279 and 0.681 mWh·cm−3 with average power densities of between 0.334 and 0.32 W·cm−3. This novel membrane facilitates the use of thinner textiles for single-layered textile supercapacitors without significantly sacrificing electrochemical performance and will enable future high energy density textile energy storage, from supercapacitors to batteries.