Single Yarn Research Articles

A multispectral imaging approach to colour measurement and colour matching of single yarns without winding

This paper investigates a multispectral imaging approach to colour measurement and colour matching of single yarns. The small size of a single yarn makes it impossible for spectrophotometers directly to acquire its spectral reflectance. Multispectral imaging systems, on the other hand, have the potential to measure the reflectance of single yarns as they can record both the spectral and the spatial information of a sample. A multispectral imaging system, namely imaging colour measurement, has been developed to conduct colour measurement of single yarns. A single yarn is first detected from backgrounds by a modified K‐means clustering method. The reflectance of the single yarn is then specified by an averaging method. Comparative experiments based on 100 pairs of single yarns and corresponding yarn windings show that the reflectance magnitude of a single yarn acquired by imaging colour measurement is smaller than that of corresponding yarn winding measured by a Datacolor 650 spectrophotometer. Experiments on 16 single yarns show that the repeatability and spatial reproducibility of the imaging colour measurement system in measuring a single yarn colour are 0.1185 and 0.2827 CMC(2:1) units. A colour matching comparison experiment (pass or fail), using 24 pairs of single yarns and corresponding pairs of solid‐colour yarn dyed fabrics, shows that single yarns measured by imaging colour measurement can achieve similar colour matching results to solid‐colour yarn dyed fabrics measured by the Datacolor 650 spectrophotometer, with degrees of similarity of 87.5 and 83.3% when the CMC(2:1) and CIE2000(2:1:1) colour difference formulas are employed.

The Effect of Single and Double Yarns in Cotton Fabrics on the Removal of Stain

Woven fabrics are considered one of the most important uses of a person in his daily life, from which clothing and furnishings of all kinds are made, and all fabrics are exposed to environmental factors that make them vulnerable to dirt and pollutants present in that environment. Hence the research problem lies in trying to produce cotton fabrics that are easy to remove dirt from them using some variables of the structural composition For threads and fabrics. The research aims to obtain these fabrics and the extent of the impact of the variables used in the research to remove dirt. Assuming that the types of strings are “single-applied” and the length of the tissue structure and the inter-spaces within the fabrics affect the removal of dirt. The research has followed the experimental approach where production Single strings and their applied counterparts Each single thread and its counterpart had one tigress and one twirl number, different from the other two strings. Fabrics were produced from those strings using a plain woven composition 1 | 1 and cooler 3 | 1 of the weft. The dirt removal test was done, as the fabric samples were dirty using specific proportions of grinded vegetable carbon, mineral oils and melted grease in carbon tetrachloride, then a detergent solution was used with heating for two hours with samples. Each sample was placed in a soap solution inside cups that are closed to be placed in a special washing machine It is rotated inside the washing machine for half an hour. After samples exit from the washing machine, they were rinsed with plain water and left to dry. The gray scale was used to determine the degree of dirtiness of the samples. The most important results were that the fabrics produced with a single thread were better in removing dirt from those produced with the applied thread where most of them recorded the highest values To the degree of removing dirt, as the length of the fabric structure has a clear effect. The higher the length, the more difficult it is to remove dirt from them. Also, the distances between the smaller the area, the smaller the degree of dirt removal.

Ultrasensitive and highly selective graphene-based single yarn for use in wearable gas sensor.

Electric components based on fibers or textiles have been investigated owing to their potential applications in wearable devices. High performance on response to gas, drape-ability and washing durability are of important for gas sensors based on fiber substrates. In this report, we demonstrate the bendable and washable electronic textile (e-textile) gas sensors composed of reduced graphene oxides (RGOs) using commercially available yarn and molecular glue through an electrostatic self-assembly. The e-textile gas sensor possesses chemical durability to several detergent washing treatments and mechanical stability under 1,000 bending tests at an extreme bending radius of 1 mm as well as a high response to NO2 gas at room temperature with selectivity to other gases such as acetone, ethanol, ethylene, and CO2.

The effectiveness of combined gripping method in tensile testing of UHMWPE single yarn

This paper presents the experimental study on the effectiveness of combined gripping method employed in the tensile testing of UHMWPE (Dyneema® SK75) single yarn. Seven different solutions including epoxy, acrylic, and ethyl cyanoacrylate adhesives were tested under quasi-static loadings in order to determine the most effective adhesive for bonding UHMWPE single yarn to aluminium sheets. The ethyl cyanoacrylate adhesive combined with polyolefin surface primer was found to be the best choice which could prevent yarn slippage and ensure the failure of yarn occurs in the gauge section. The single yarns were then tested at three strain rates of 3.3×10-5, 3.3×10-3, and 0.33 s-1. The tensile strength, maximum strain, and Young's modulus were determined from the measured stress-strain curves and compared with the values from literature; the results showed these tensile properties of single yarn depend on strain rate over the range tested.

Research on the Compact-Siro Spun Yarn Structure

Compact-Siro spinning technology is one of the most widely used spinning methods. It is conducted on a compact ring frame by simultaneously feeding two rovings into the drafting zone at a predetermined separation. In fact, Compact-Siro spinning incorporates the features of both Compact and Siro-spinning systems. In this paper, the structure of CompactSiro spun yarn is investigated. By using a DZ3 video microscope, the horizontal structure of Compact-Siro spun yarn, Sirospun yarn, Compact yarn and Ring spun yarn were obtained. It is shown that compared with Compact single yarn, Compact-Siro spun yarn has a more compact and clear surface structure, a more uniform and smooth shape, and less hairiness. Then the cross section structure of Compact yarn and Compact-Siro spun yarn were obtained by using Hardy’s Y172 thin cross-section sampling device and the DZ3 video microscope. It is shown that compared with Sirospun yarn, the cross-section of Compact-Siro spun yarn is smoother and closer to being circular. Meanwhile in the Compact-Siro spun yarn body, the fibers of two substrands show axial symmetrical distribution approximately, which is beneficial for spun yarn qualities, especially for improving the yarn evenness and hairiness. Finally the results obtained were illustrated in spinning experiments.

Characteristics of carbon nanotube yarn structure unveiled by acoustic wave propagation

The strength transfer efficiency from individual carbon nanotubes (CNTs) to micro-sized yarns is an order of magnitude lower than that for conventional textile yarns. To improve the strength transfer efficiency, a good understanding of the frictional interaction between the nanotubes in the yarn (yarn internal friction, or viscoelasticity) is needed. Here, an acoustic wave propagation method is employed to elucidate the relationship between the structural characteristics and the viscoelastic behaviours of several types of dry-spun CNT yarns. The insertion of a high twist increases the CNT packing density in a yarn but results in a decrease of yarn modulus whilst the internanotube friction peaks at an intermediate twist level. Crosslinking increases the CNT yarn modulus and reduces the internanotube friction. Folding single twisted yarns into a torque-free plied yarn, a common practice in textile processing, leads to reductions in both modulus and internanotube friction. CNTs in densely packed twistless CNT yarns are highly aligned with each other, leading to very high modulus and very low internanotube friction.

Towards the development of laser shock test for mechanical characterisation of fibre/matrix interface in eco-composites

This paper deals with the possibility of using the laser shock test for studying the adhesion between fibre and matrix in composite materials. Single hemp yarn in epoxy matrices - a fully synthetic one, Epolam 2020, and a partially bio-based one, Greenpoxy 56 - specimens have been tested. The water sorption effect on interfacial adhesion quality has been studied. Two different types of damage induced by laser shock have been observed: resin cracks appear only for high laser intensity levels, and specific cone-shaped interfacial damage appears for lower intensity values. The reproducibility of the threshold value evaluation has been demonstrated for the two resins. A numerical simulation by finite elements has also been performed to enhance the understanding of laser shock wave propagation in such samples. These preliminary results demonstrate the ability of the laser shock test to study and quantify the mechanical quality of yarn/matrix interface, which is needed to help design of such composites.

Response of Slub Characteristics on Tensile Properties of Injected Slub Yarn

Injected slub yarn is one of the most promising among different types of slub yarns. Present study embodies the effect of some important parameters like base yarn twist level, number of base yarn, twist direction and injected fibre components on injected slub yarn performance in terms of tensile strength and breaking elongation. In case of single base slub yarn, final yarn tenacity and elongation increases with the reduction of base yarn twist level keeping final yarn twist multiplier constant. However, the effect of base yarn twist level is marginal in case of injected slub yarn made with double base yarn. Yarn tenacity and elongation significantly higher in case of double base injected yarns as compared to single base injected yarn. The aforementioned tensile parameters of single base injected slub yarns reduce with the reduction of yarn linear density. However, in case of double base injected slub yarns, highest tenacity and elongation value are achieved for 2/80s yarn having finest yarn liner density among 2/40s, 2/60s and 2/80s yarns. In case of single base injected slub yarn, tensile strength is slightly higher and elongation values are significantly higher when injection component fibres changed from 100 % cotton to 50/50 polyester/cotton blended fibres which is just opposite to that of double base injected slub yarn. Results also showed that the twist direction in the base and final yarn influence the strength and elongation of injected slub yarns.

UV protection performance of textiles affected by fiber cross-sectional shape

In this study, a model was set up for simulating the effects of varying fiber cross-sectional shapes on ultraviolet protection of fibers. The fiber diameter and fiber type were also involved in the model setting. Experiments of diffuse reflectance spectra measurement on natural (wool, cotton, silk), regenerated (bamboo viscose) and synthetic (polyester, nylon) fibers were conducted to verify the model predicted results. When a more complex shape was assumed as the fiber cross-section for model calculation, the predicted results have a better agreement with the actual results. The effects on ultraviolet absorption from fibers with different cross-sectional shapes were investigated at a single fiber, fiber bundle and yarn levels. With the same material, when the fiber cross-sectional area and the areal coverage of a single fiber were constant, the triangular shape had the lowest ultraviolet transmittance and the highest ultraviolet reflectance for a single fiber and also for a fiber bundle. The difference of fiber cross-sectional shapes was also significant in the ultraviolet protection of a single yarn.

Electrical conductivity, strength and microstructure of carbon nanotube multi-yarns

Since the inception of carbon nanotubes (CNTs), there has been a great deal of effort in developing CNT applications. One possible application is to utilize CNT yarn(s) in structural and electrical devices. This study investigated 13 different variations of CNT multi-yarns. The multi-yarns were evaluated and compared in terms of tensile load behavior and electrical conductivity as well as interrelationship and interdependence of these two properties with physical parameters and micro-structural features. The electrical conductivity of the CNT multi-yarn is not affected by the apparent diameter, number of yarns, tex or density, but instead by its interior compactness and acid treatment. The construction of single CNT yarn or multi-yarn can be tailored to achieve stress–strain behavior ranging from a stiff to ductile or highly non-linear behavior. CNT single-yarn is stronger and stiffer than a multi-yarn. The decrease in strength and stiffness of a multi-yarn does not depend directly upon the number of yarns. Thus, larger diameter CNT multi-yarn can be developed with less or no reduction in tensile properties in comparison to that of CNT array. Finally, this study’s observations provide useful information for further improvement of the tensile and electrical conductivity performance of CNT yarn(s).

A variable metric stochastic theory of textile composites with random geometric parameters of yarn cross-section

A variable metric stochastic theory of the elastic constants of textile composites with stochastic yarn (or tow) geometry has been developed in the current study. A variable metric coordinate transformation is utilized in this theory to introduce the cross-section shape fluctuations of yarn into the compliance of textile composites. Six parameters are defined to describe the positioning and cross-section shape of yarn completely. Then, the Taylor expansions of the local stochastic variable metric basis and the compliance of yarn are executed. Finally, the volumetric averaging method is employed to obtain the elastic properties of textile composites. The numerical simulations show that the fluctuations of geometric parameters may affect the elastic response of textile composites considered. The example of single straight yarn proves the validity of the theory and presents the explicit formulas of influence of stochastic yarn geometry on elastic constants. Within the example of plain weave composite, random yarn cross-section shape and twist degrade all of the elastic constants except the shear moduli and Poisson’s ratios in 1–3 and 2–3 directions, which are determined by the comprehensive effect of the stochastic scaling and twist.

天然繊維撚糸内のマイグレーション構造の同定と引張強度へ及ぼす影響

Natural fibers are often used as a form of continuous twisted yarn, which are suitable for reinforcement of fibrous composites. In the twisted yarn, we often encounter phenomenon called ‘migration’, such that single yarns (spun yarns) shift from outer layer to inner and vice versa. Thus, we first observed migration structure of ramie twisted yarn through an X-ray CT scanner. Results show that migration occurred irregularly in the yarn, so this phenomenon was simulated by Markov chain model. In addition, the effect of migration on tensile properties was clarified. Although Markov chain model is not necessarily enough in predicting the migration occurrence probability, this model can predict well the state probabilities which single yarns exist in each zone after twisting. Finally, we found two structural parameters of twisted yarns which can be correlated with tensile strength. First parameter, i.e. the number of migration existing in a twisted yarn, had a weak correlation, whereas second parameter, i.e. the number of single yarns causing migration, showed a stronger correlation.

An Overview of Modeling Yarn’s 3D Geometric Configuration

Modeling the 3D geometric configuration of yarn is the base of building the 3D fabric structure. The surfaces of the yarns are modeled by many facets. To improve the efficiency of modeling, 3D yarn is usually designed by Bezier curve, spline curve or B-spline curve on the principle of Computer Graphics. The paper reviews different 3D modeling methods for single yarn from the view of cross-section and central line. Some improvements for a better visual effect such as inserting twist and hairiness are illustrated as well. Based on the single yarn, the folded yarn and some fancy yarns can also be modeled in 3D space as long as the cross-sections of the control sections of the component single yarn are determined. Applications of the various 3D yarns are demonstrated. The advantages and the drawbacks of various methods are explained and compared as well. Comparatively speaking, modeling technology based on spline curve is more convenient and flexible, perhaps it is the most popular tool since it is capable of designing different kinds of yarns mentioned above and gets the maximum support from the different developing platforms such as OpenGL, 3DS-MAX, Solid Works CAD, etc.

Structural characterizations of three-dimensional crimped silk yarns

Silk yarns which are composed of two single yarns with different twist directions are treated with calcium nitrate solution at 95 ?C, and a 3-D crimped structure is formed. The Fourier transform infrared spectroscopy spectrum is used to reveal the change of the secondary structures of silk fiber.

Influence of Knits Structure on Flammability and Comfortability

Abstract Investigations of the influence of the knit structure, i.e. the loop length and the number of yarns in a loop, on flammability and comfortability are presented in this paper. The investigations were carried out using single jersey knits from Delta TA 18 tex × 2 yarns with five variants of a loop length. Single yarn as well as folded yarn from two single yarns was used in the investigations. Comparison of the results of single-layer knits flammability and air permeability with those of multilayer packet was made. The results obtained show that an increase in the loop length of the knit increases their permeability to air and decreases the burning time as well as increase in the number of layers decreases the air permeability and increases the burning time. Moreover, the similar burning time with significantly different permeability to air can be achieved changing the basic knitting parameters, i.e. the loop length and/or the yarn linear density.

Improved mechanical properties of carbon nanotubes-coated flax fiber reinforced composites

Plant fiber reinforced polymeric composites are increasingly applied in engineering applications, while the incompatible interface between the hydrophilic cellulose fibers and the hydrophobic polymer matrix remains a bottleneck for obtaining high mechanical performances. In this study, carboxyl-functionalized carbon nanotubes (COOH-CNTs) were successfully coated onto flax fibers using a “soaking or spraying-drying” process by taking advantage of the unique chemical composition of plant fibers. Single yarn tensile, single yarn pull-out, double cantilever beam, short beam shear, and drop-weight impact tests were performed to assess the effects of CNT coating on the properties of flax fiber reinforced composites. The maximum enhancements for interfacial shear strength (IFSS), mode I interlaminar fracture toughness, and interlaminar shear strength (ILSS) were 26, 31, and 20 %, respectively. Though the impact strength was kept unchanged, a maximum of 10 % reduction in the impact damage area was obtained due to the presence of CNTs. Fourier transform infrared (FTIR) suggested that hydrogen bonds between the hydroxyl groups of flax fiber and carboxyl groups of CNTs were formed which could strongly bind CNTs to the fibers. Microscopic analysis also showed the insertion of CNTs into the fibers, further strengthening the interaction between plant fiber, CNTs, and polymer matrix by interlocking. The multi-scale microstructures of flax fibers induced new mechanisms for enhancing the mechanical properties of flax fiber reinforced composites.

Relationships between wearer assessment and the instrumental measurement of the handle and prickle of knitted wool fabrics

The relationships between wearer-assessed comfort and objectively measured comfort and handle parameters were investigated using 19 pure wool single jersey garments made of single ply yarns. Wearer trials were used to determine prickle discomfort, and whether wearers “liked” the garments. Fabrics then were objectively evaluated using the Wool HandleMeter, which measures seven primary handle attributes; and the Wool ComfortMeter (WCM), to predict a wearer's perception of fabric-evoked prickle. Wearer responses and the relationships within and between objective measurements and the effect of fibre, yarn and fabrics attributes were analysed by general linear modelling. Mean fibre diameter, fibre diameter coefficient of variation, yarn count, fabric thickness, fabric density, fabric mass per unit area and decatising affected one or more handle parameters. The best model for predicting wearer prickle discomfort accounted for 90.9% of the variance and included only terms for the WCM and WCM2. The WCM was a good predictor whereas mean fibre diameter was a poor predictor of whether wearers “liked” garments. Wearer assessment of prickle and whether or not wearers “liked” fabrics were independent of fabric handle assessment. The results indicate that the handle and comfort properties of lightweight, wool jersey fabrics can be quantified accurately using the Wool HandleMeter and the Wool ComfortMeter. For fabric handle, fibre and yarn characteristics were less important than changes in the properties of the fabric.

Torsional behaviour of filament wound kenaf yarn fibre reinforced unsaturated polyester composite hollow shafts

Synthetic fibre is of higher strength in composites and is a low cost material, but the problem is that it does not degrade in the environment. Studies on single yarn natural fibre have been reported, especially those concerned with improving its mechanical properties. This can be used for lower end applications such as furniture and automotive dash board to reduce the utilization of synthetic fibre. Continuous yarn fibres are required to increase the strength for engineering applications and filament winding is a method to produce aligned technical composites which have high fibre content. This paper presents an experimental and simulation studies to investigate the behaviour of composite hollow shafts, with a specific focus on the maximum torsion capacity of the composite hollow shaft for different winding angles and aluminum reinforcement. The conventional filament winding machine was modified and added to a new resin bath mechanism in order to produce a new natural fibre composite hollow shaft using kenaf yarn fibre reinforced with unsaturated polyester resin. The results show that the torsion capacity is significantly affected by changing the winding angle and the presence of aluminum in the static torque test capacity properties. The maximum static torsion capacity of kenaf yarn fibre reinforces unsaturated polyester composite shaft at a winding angle of 45° was higher strength than 90° orientation while the presence of aluminum enhanced the torsion property significantly. Finite element analysis (FEA) using Abaqus software was carried out and showed a good agreement with the experimental results.

Effect of Fabric Weave on Stick-Slip Properties of Woven Fabrics

Abstract The aim of this study was to understand the stick-slip properties of dry polyester plain, ribs and satin woven fabric weaves. It was found that the amount of stick-slip force was related to the number of interlacement points in the fabric, whereas the amount of accumulative retraction force was related to fabric structural response. Stick-slip force and accumulative retraction force depend on fabric weave, fabric density, the number of pulled ends in the fabric and fabric sample dimensions. The weft directional single and multiple yarn stick-slip and accumulative retraction forces of dry plain fabrics in fabric edge and centre regions were higher than those in the satin fabric due to fabric weave. In addition, the warp directional single and multiple yarn stick-slip and accumulative retraction forces in the meso-cell-1 to the meso-cell-6 of dry wide and long satin fabric in fabric edge were higher than those in the weft direction due to fabric density. Stick-slip and accumulative retraction forces of polyester fabric in the multiple yarn pull-out test were higher than those of the single yarn pull-out test.

Blind weave detection for woven fabrics

For the purpose of textile quality assurance, an algorithmic framework for fully automatic detection of weave patterns in woven fabrics is presented. The proposed method is able to handle fabrics of any rotation, material, and binding. Periodicity features within highly resolved fabric images are found and structured in a compact yarn matrix representation which allows to estimate the trajectories of single yarns. Fourier analysis, template matching, and fuzzy clustering are some of the key methods employed during the process. From the yarn matrix, the fabric's weave and density can directly be derived. Since a multitude of factors may falsify the output, a feedback loop is integrated to iteratively find an optimal result. The framework works completely blind, i.e., without any a priori knowledge of the fabric. The evaluation has been conducted on an extensive image database of 140 real-world fabric images including cotton, polyester, viscose, and carbon materials of plain, twill, or satin weave. The system proved to be robust and versatile as a 97 % detection accuracy could be achieved. Source codes and image databases are provided.