Yarn Twist Research Articles

Optimization of air pressure and speed of air jet loom; impact on fabric tensile and tear strength properties using Response Surface Methodology

ABSTRACT Weaving industries that use air jet loom are always emphasized to increase production and keep up the quality of woven fabric. But due to faulty mill practices or negligence, fabric mechanical properties of the fabric made on air jet loom are impaired. Improving the fabric quality can be achieved by improving work practices and optimization. The aim of this research is to optimize the air pressure and loom speed to produce a fabric with optimum mechanical properties and twist loss of weft yarn after weaving. To perform the experiment, three independent variables (loom speed, left-side relay nozzle pressure, and right-side relay nozzle pressure) was taken. With the combination of the three independent variables at five levels each, nineteen fabric samples were produced and each tensile and tear strength of the fabric in the weft direction were tested. Central composite design (CCD) was used to design the experiment, analyze the results of the experiment, and optimize the process. The results of the experiment show that variation in loom speed and air pressure affects twist of the weft yarn and mechanical properties of the fabric significantly and loom speed had a most significant effect on yarn twist loss, fabric tensile, and tear strength.

Performance analysis of socks produced by auxetic yarns for protective applications

The present work reports application of auxetic yarns in development of abrasion resistant socks which can be used for better serviceability without shoes even on rough surfaces. Socks used in the current research were produced by using helical auxetic yarns which consist of different combinations of high performance and conventional materials e.g. Kevlar P-AR (para-aramid), cotton, elastomeric yarn, polyamide (PA6) and polyester with same linear density of 74 Tex. Three different types of fabrics were produced e.g. flat knit, sandwich half terry short and sandwich half terry long. For investigating the auxeticity, all samples were subjected to tensile loading and the resulting change in their thickness was measured. Abrasion resistance and other comfort related properties e.g. air permeability, vertical wicking and absorbency were also evaluated. The influence of different yarn combinations, twist levels and fabric types on abrasion resistance and breathability of socks were investigated by using fractional (half) factorial design. Statistical analysis was performed for the obtained results by using analysis of variance. Conventional socks samples were also produced in all fabric types for comparison with the auxetic materials. From the results it was concluded that the overall abrasion resistance of auxetic yarn-based sock is higher than conventional cotton sock. Results also revealed that abrasion resistance was increased by 46% in flat knit socks sample, 50% in sandwich half terry short sample and 58% in sandwich half terry long sample as compared to conventional cotton sock. In addition to this all the socks samples exhibited good comfort/breathability properties.

Thermal Design Method for Optimization of Dry Heat Transfer through Hemp-Based Knitted Fabrics

ABSTRACT In the present research, folding of yarns was applied as a method for designing thermal transport characteristics of hemp-based knits. The rib-knitted fabrics were made by combining one of two cotton two-folded yarns (differing in folding twist) with one of the two complex hemp yarns. The parameters describing the thermal properties in the steady-state and transient regimes of heat transfer were determined. The results indicated that the packing density of the fibers in the yarn plays a crucial role in the heat conduction through the fabric. The two-assembled hemp component appeared to be the main heat conductor in the knitted fabrics containing it. Between the knits composed of the two-folded hemp and two-folded cotton yarns, that having two-folded more twisted cotton yarn as a component was characterized by higher thermal conductivity. The higher thermal conductivity resulted in higher thermal absorptivity, but not necessarily in higher thermal diffusivity, as the increased volumetric heat capacity may limit the speed of heat spreading through the fabric. Therefore, the knits containing two-assembled hemp yarn differed in thermal diffusivity despite their similar thermal conductivity. Both knits with the two-folded more twisted cotton yarn as a component had similar thermal diffusivity despite their different thermal conductivity.

Twist-Controlled Force Amplification and Spinning Tension Transition in Yarn.

Combining experiments and numerical simulations with a mechanical-statistical model of twisted yarns, we discuss the spinning transition between a cohesionless assembly of fibers into a yarn. We show that this transition is continuous but very sharp due to a giant amplification of frictional forces which scales as expθ^{2}, where θ is the twist angle. We demonstrate that this transition is controlled solely by a nondimensional number H involving twist, friction coefficient, and geometric lengths. A critical value of this number H_{c}≃30 can be linked to a locking of the fibers together as the tensile strength is reached. This critical value imposes that yarns must be very slender structures with a given pitch. It also induces the existence of an optimal yarn radius. Predictions of our theory are successfully compared to yarns made from natural cotton fibers.

Prediction of Mechanical, Evenness and Imperfection Properties of 100% Cotton Ring Spun Yarns with Different Twist Levels

The purpose of this research work is to develop a model to predict the effect of twist on mechanical, evenness and imperfection properties of 100% cotton ring spun yarns. Eight yarns were manufactured from 30Tex with four yarn twist increments (700, 740, 780 and 820TPM), and 15Tex with twist levels of 900, 1020, 1080 and 1140TPM (turns/meter). Except yarn count and twist level, the yarns were made from the same fiber properties and machine settings. Yarn mechanical properties such as tensile strength, elongation and abrasion resistance, evenness (CVm) and imperfection characteristics like hairiness, neps, thin and thick places were measured and statistically analyzed. Equations were developed to predict the desired mechanical, evenness, and imperfection properties of yarns based on yarn count and twist levels. Statistical analysis showed that yarn properties are significantly influenced by count and twist level changes. The tensile strength, elongation, abrasion resistance, CVm, hairiness and thick places of the studied yarns were significant at P-values of 0.000, 0.003, 0.000, 0.004, 0.000 and 0.015 respectively. Generally, as yarn twist increases, breaking strength and abrasion resistance increase, whereas elongation, hairiness, coefficient of mass variation (CVm), thin and thick places, and nep of yarn decrease. Therefore, the formulated multiple regression equations would be useful in predicting yarn properties based on its count and twist.

YANGI TURDAGI TIBBIYOT BINTLARI UCHUN XOMASHYO XUSUSIYATLARI TADQIQI

This article presents the topicality of the problem, the sequence of technological processes in manufacture of silk twisted yarn from raw silk used for making of a medical bandage. In order to fold a few threads, and give them a twist, first raw silk is rewound onto a spool. Before rewinding, hanks are checked for gluing, in our case low gluing is determined, therefore, in order to soften the glued spots, the thread is treated with an emulsion by spraying. Then, the raw silk is kept in the common room and is rewound to the two flange reel using the MT-85 machine according to the Japanese technology. The principle of operation and technological drawings are provided. Torsion is carried out by adding 3 raw silk 2,33 tex to give the left twist S 350 tw/m and adding 8 raw silk 3,23 tex with the left twisting S 500 tw/m. The torsion process is performed on a TK-2 twisting machine. The process of fixing the twist of the finished twisted yarns is implemented using Japanese equipment SC-750. The quality indicators of twisted yarn are as follows: linear density, coefficient of variation in linear density, breaking load, breaking elongation, direction and amount of twist, and coefficients of variation in twisting.

Thermo-physiological properties of polyester chenille single Jersey knitted fabrics

This article sheds light on the important construction parameters of chenille yarn that characterize chenille single Jersey knitted fabric thermo-physiological properties. The study investigates the influence of selected yarn and fabric construction parameters, namely yarn twist, pile height of chenille yarn and loop length on the geometrical, physical and, thermo-physiological properties of chenille outerwear used in cold climates. Moreover, the effect of yarn and fabric parameters on the fabric abrasion resistance was studied as it is one of the main fabric defects. Furthermore, the study optimizes the knitted chenille fabric thermal properties to find out the most suitable for winter knitted outerwear. So, 40 tex chenille yarns were produced at 700 and 850 twist per meter and three levels of pile height, 1, 1.2, and 1.5 mm. Eighteen single Jersey knitted fabric samples were produced at three different loop lengths 1, 1.2, and 1.4 cm. Results revealed that the most prominent factor that influences the tested fabric properties at the given setting range is the fabric loop length followed by chenille yarn pile height then the chenille yarn twist level. As pile height and twist increase, the thermal resistance and conductivity increase while air permeability and water vapor resistance decrease.

Smooth appearance analysis of the finished cotton fabric affected by structural parameters based on Hopfield neural network

Cotton as the most important natural fibre is used to produce apparel in clothing industry. The appearance of the cotton garment is an important factor for consumers. Therefore, in textile industry, the cotton fabric is treated with anti-wrinkle finishing material. In this process, the cross-linking is the main parameter that produces the resiliency in the chemical structure of the fiber and gives the crease retention to the cellulosic fabrics. According to this introduction, is the crosslinking unique parameter in the wrinkle resistance appearance of treated cotton fabric or others important parameters related to the fabric structure lead to the wrinkle resistance? Reply of this question is the first novelty of this article. For this purpose, we intend to use a novel tool in computational intelligence to model the wrinkle appearance of the treated and non-treated cotton fabric due to the structural parameters of the fabric. Therefore, the effect of the fiber diameter, yarn twist, fabric thickness and bending length parameters are evaluated experimentally and theoretically on the wrinkle grade of the fabric. In experiments, the mentioned parameters are measured for various provided fabrics. Then wrinkle degree of the samples is ratted according to the light line method. In theoretical study, a new Hopfield neural network model is presented as one of the novelties of this article. Four mentioned parameters are considered as the inputs and the wrinkle degree is obtained as the output of the developed Hopfield NN model. This model approximated a nonlinear function between the output and all four inputs. Simulation and experimental results show the effect of four mentioned inputs on the wrinkle degree of the non-treated cotton samples. Simulation of the treated wrinkle grade shows that the fiber diameter, yarn twist, fabric thickness and bending length parameters affect the wrinkle grade and the crosslinking is not any effect on cotton wrinkle grade. Modeling results show that the proposed Hopfield neural network has high learning capability, fast convergence and accuracy (greater than 98%) and finally negligible error value (smaller than of 1%), so it can be reasonably used in clothing industry.

Fabrication and Mechanical Performance of Non-Crimp Unidirectional Jute-Yarn Preform-Based Composites.

This work developed novel jute-yarn, non-crimp, unidirectional (UD) preforms and their composites, with three different types of warp jute yarns of varying linear densities and twists in the dry UD preforms, in order to present a possible solution to the detrimental effects of higher yarn twists and crimp at the warp–weft yarn interlacements of traditional, woven, preform-based composites on their mechanical properties. In the developed UD preforms, warp jute yarns were placed in parallel by using a wooden picture-frame pin board, with the minimal number of glass weft yarns to avoid crimp at the warp–weft yarns interlacements, which can significantly enhance the load-bearing ability of UD composites compared to traditional, woven, preform composites. It was found that an optimal combination of jute warp yarn linear densities and twists in the UD preforms is important to achieve the best possible mechanical properties of newly developed UD composites, because it encourages a proper polymer-matrix impregnation on jute fibres, leading to excellent fibre–matrix interface bonding. Composites made from the 25 lb/spindle jute warp yarn linear density (UD25) exhibited higher tensile and flexural properties than other UD composites (UD20, UD30). All the UD composites showed a much better performance compared to the traditional woven preform composites (W20), which were obviously related to the higher crimp and yarn interlacements, less load-carrying capacity, and poor fiber–matrix interfaces of W20 composites. UD25 composites exhibited a significant enhancement in tensile modulus by ~232% and strength by ~146%; flexural modulus by 138.5% and strength by 145% compared to W20 composites. This reveals that newly developed, non-crimp, UD preform composites can effectively replace the traditional woven composites in lightweight, load-bearing, complex-shaped composite applications, and hence, this warrants further investigations of the developed composites, especially on long-term and dynamic-loading mechanical characterizations.

Determination of suitable traveller for definite yarn count: A comparative study

The traveller imparts twist to the yarn and enables winding of the yarn on the cop. Yarn quality parameters can be improved by proper traveller weight selection which results in reducing yarn breakage, mass variation, twist variation and hairiness. High contact pressure (up to 35N/mm) is generated between the ring travellers during winding, mainly due to centrifugal force the pressure includes strong frictional forces which in turn lead to significant generation of heat. This is the kernel of the ring/ traveller problem. The low mass of the traveller does not permit dissipation of the generated heat in the short time available. Uster Evenness Tester 5 was used to determine the yarn properties such as unevenness, percentage, imperfection index, hairiness, standard variation of hairiness. Traveller number 5/0 was the best for card 30 Ne compare between traveller number 4/0 Most preeminence fact is that, the traveller speed remained same both for 5/0 and 4/0.

Performance Properties of Half-bleached Weft Knitted Fabrics Made of 100% Cotton Ring Yarns with Different Parameters

Knitted fabrics are distinguished by their outstanding comfort for clothing and for their rapid mass production. Though cotton knitted fabrics can provide better comfort, their physical appearance and service life are affected by many factors, and they have a propensity for pilling, abrasion and snagging. The main goal of this research work was to investigate the effect of yarn parameters on the abrasion, pilling and snagging resistance of half-bleached knitted fabrics. Six knitted fabrics were manufactured from 100% cotton carded ring yarn with a linear density of 21, 25, and 30 tex, with two yarn twist levels for each linear density. Except for yarn linear density and twist, the remaining yarn and machine parameters were constant, including fabric manufacturing. The knitted fabrics were treated using a half-bleach treatment before property evaluation. The results showed that knitted fabric made from a finer count of 21 tex with a higher yarn twist of 920 m−1 had the highest mass loss ratio of 2.12–10.76%, and the lowest abrasion resistance of 89–97.88% between 5,000 to 20000 abrasion cycles. The highest abrasion resistance of 96.4–98.9% (mass loss ratio of 1–3.5%) was recorded for a single jersey knitted fabric made from coarser yarn (30 tex) with the lower twist of 826 m−1. The abrasion resistance of knitted fabrics was significantly affected by the thickness of the fabric, while regression analysis proved that fabric thickness and mass loss ratio had very good correlation, with an adjusted R2 value of 93.8%. The snagging resistance of knitted fabrics increased as yarn twist and fineness increased. Pilling propensity increased as yarn linear density increased and twist decreased. Linear regression results revealed that yarn linear density and twist were highly correlated to abrasion resistance (mass loss method) at an adjusted R2 value of 98.6% or 0.986 after 20,000 rubs.

IDENTIFICATION OF FIBERS AND WEAVING TECHNOLOGY IN THE REMAINS OF FABRICS DISCOVERED FROM KUH-E KHWAJA, A PARTHIAN ARCHAEOLOGICAL SITE IN SISTAN, IRAN

The aim of this study is to characterize fibers, spinning and weaving techniques of fabric remains found in Kuh-e Khwaja, a Parthian archaeological site in Sistan, Iran. For this purpose, 26 samples, including fabric remains (17 cases) and separate yarns (9 cases), were examined. The fibers were identified using light microscopy and FTIR spectroscopy, and the yarn twist directions, the angle of pretwist of the fibers, and the weaving pattern of the fabrics were examined by light microscopy. The results showed that a similar type of fiber was used for both warp and weft in each fabric. Among the study, 12 cases (46%) and 14 cases (54%) have been characterized as wool and cotton respectively, which indicates the prosperity of both agriculture and animal husbandry in the Parthian period in the Sistan region. The yarn twist directions in both warp and weft were the same in all fabrics and were Z/Z type, except for one sample (Z/S). Also, single-ply (21 samples, 81%) and double-ply yarns (5 samples, 19%) showed Z-twist and S(2z)-twist, respectively. Most of the fabrics showed a plain weave; however, warp rib, irregular matt, twill, basket weave, and also knitted fabric were observed among them. In addition, the results showed that wool yarns have a lower angle of pretwist compared with cotton yarns. Therefore, this issue can be used in the primary classification of fabrics found from this archaeological site.

Quality optimization and process capability analysis of ring spun Supima cotton yarn

Abstract The response surface method and process capability analysis were conducted in this study to improve evenness, hairiness, imperfections, and tensile strength of ring spun Supima cotton yarn by optimizing values of spinning parameters including traveler mass, yarn density, spindle speed, and yarn twist. The yarns were spun into three densities: 20 Ne, 30 Ne, and 38 Ne. An USTER Tester 5-S800 was used to evaluate the irregularity parameters of yarn. A Lloyd tester was also used to determine the yarn breaking load. The response surface method was applied to optimize the statistical values obtained from the tests of the yarns produced based on the combination values of system parameters. Each response was subjected to a response surface design study, and the optimal values were achieved by using a response optimizer to perform multiple response optimization. Interpreting the response surface design results yielded information such as the absolute values of effects, response degree of significance, data compatibility, and model suitability. Individual desirability, composite desirability, different estimates for each response, and the relationship between response and system variables were all revealed by interpreting the response optimization results. The capability indices of process capability analysis were used to compare process performance before and after response optimization. By interpreting the capability indices’ values of process capability analysis, the capability of the process to meet requirements and improvement potential were acquired. The data was analyzed by implementing Minitab software (Version 19).

Effect of Different Yarn Combinations on Auxetic Properties of Plied Yarns

Abstract This study presents the effects of a novel plied yarn structure consisting of different yarn components and yarn twist levels on the Poisson's ratio and auxetic behavior of yarns. The plied yarn structures are formed with bulky and soft yarn components (helical plied yarn [HPY], braided yarn, and monofilament latex yarn) and stiff yarn components (such as high tenacity [HT] and polyvinyl chloride [PVC]-coated polyester yarns) to achieve auxetic behavior. Experimental results showed that as the level of yarn twist increased, the Poisson's ratios and the tensile modulus values of the plied yarns decreased, but the elongation values increased. A negative Poisson's ratio (NPR) was obtained in HT–latex and PVC–latex plied yarns with a low twist level. The plied yarns formed with braid–HPY and braid–braid components gave partial NPR under tension. A similar result was achieved for yarns with HT–latex and PVC–latex components. Since partial NPR was seen in novel plied yarns with braided and HPY components, it is concluded that yarns formed with bulky–bulky yarn components could give an auxetic performance under tension.

Effects of Ag-coated twisted-yarns and equivalent circuits on textile pressure sensors

Wearable sensors have become an indispensable part of life because they reflect different aspects of human interactions and surroundings. However, the complex technologies, materials, and structures still limit their applicability. Herein, we propose an adjustable pressure sensor by designing the structure of the e-textiles. Through the tilt of the conductive yarns on the spacer fabrics, the resistance behavior can be analyzed by an equivalent circuit. These sensors show high sensitivity (gauge factor ~ 16.7) under slight pressure. In addition, the effects of conductive yarns (Ag-coated twisted yarns) are evaluated in detail based on the difference of spacer fabrics, the sensing yarns, the buckling of the conductive spun yarns, as well as the conductive twisted yarns. The technique and the analyzing method from the equivalent circuits are expected to bring great contributions to analyze the wearable pressure-touch sensors in the future.

Parametric study on mechanical properties of basalt leno textile applied as concrete reinforcement

In this study, the mechanical properties of the basalt leno textile applied as concrete reinforcement were experimentally investigated considering different parameters including the impregnation materials, geometrical characteristics (the number of yarns, yarn structure, and yarn spacing), and loading rate. The tensile strength, elastic modulus, and failure mode were examined. Furthermore, the force mechanism of impregnated leno textile under tensile load was analyzed. The experimental results showed that the textile with a stiff impregnation material exhibited a higher strength and modulus than that with a flexible material. The leno textile with the straight yarn had a better performance than those with the twisted yarns. Besides, the constraint of the weft yarns is obvious to the textile in the warp direction, while the warp yarn makes no contributions to the bearing capacity of textile in the weft direction. The weft yarn spacing had a significant impact on mechanical properties of the textile in the warp direction. Furthermore, the loading rate of approximately 1.2 mm/min was suggested to determine the maximum force of the impregnated basalt leno textile. A tensile strength model was proposed considering the effects of the impregnation material, consistent deformation, torsion damage, and twisted angle.

Effect of yarn twist on tensile strength, abrasion and pilling resistance of plain-woven cotton fabric

The effect of twist on tensile strength, abrasion resistance, and pilling resistance of plain-woven fabric has been studied. The plain-woven fabric has been produced from open-end spun cotton yarn. The weft yarn has been produced at 4 different twist levels (900, 905, 910, and 915 TPM) and the effect of twist levels is also studied. To examine the effect of twist, four different samples of plain-woven fabric are produced from these yarns. From the ANOVA results, it is found that with an increment in twist level of the yarn, there is a significant increment in tensile strength, abrasion resistance, and pilling resistance of the fabric.

Real-Time Information-Variable Invisible Barcode Comprising Freely Deformable Infrared-Emitting Yarns.

Barcodes are utilized for product information management in shops, offices, hospitals, passenger facilities, and factories because they enable substantial amounts of data to be processed quickly and accurately. However, a limited amount of information can be loaded on the currently used monochrome barcodes that are based on thin-film coatings. Therefore, these barcodes require constant replacement with new barcodes to update the information; furthermore, they cannot be applied to textile products. This study demonstrated the performance of wearable invisible infrared (IR)-emitting barcodes by using twisted yarns that comprised five highly elastic/conductive spandex fibers. The barcode information can be actively updated via the selective IR emission from specific yarns of the barcode by controlling the applied voltage to the IR-emitting yarns. Therefore, the IR barcode required a relatively small number of bars to express a higher volume of information compared to the existing monochrome barcodes. Because the emitted IR light from the yarns was invisible to the human eye and was only recognized by an IR camera, the information-variable IR-emitting yarn-based barcode exhibited an aesthetic design and was composed of a sustainable fabric-type material that could be easily applied to clothes, bags, and shoes. It is expected that the fabricated barcode will be widely utilized as wearable invisible barcodes, whose information will remain invisible to humans and can be updated in real time to ensure information fluidity.

A relative hairiness index for evaluating the securities of fiber ends in staple yarns and its application

Hairiness is a prominent property of staple yarns, but the existing evaluation parameters mainly describe the fiber ends already protruding out of yarn bodies. The potential fiber ends in yarns also play a crucial role in the performance of yarns in the subsequent processes and the resultant fabric quality. In our previous studies, maximum hairiness and its theoretical model have been proposed, which indicate the maximum fiber ends of a staple yarn having the potential to protrude out of yarn bodies and become hairy. On this basis, the relative hairiness index (RHI) is developed in this study to evaluate the fiber end tucking and securities of yarns. This index is treated as a ratio of the measured hairiness of sample yarns and the maximum hairiness of ring yarns in the same twist level and yarn count. A lower RHI indicates more fiber ends being tucked into yarn bodies, and a slower increment of the RHI with the increasing winding times represents more stable securities of fiber ends in yarns. The experimental results demonstrate that the RHI can directly reveal the effectiveness of different spinning parameters and methods in tucking and securing fiber ends; also, the changes of the RHI with increasing winding times visually present the stableness of fiber ends in various yarns experiencing abrasion, as well as predict the possibility of the potential fiber ends being pulled out to form hairiness during successive processes. The proposed RHI, therefore, provides a significant reference for the spinning process design and yarn quality control.

Twisting in improving processing of waste-derived yarn into high-performance reinforced composite

Waste cotton fibers was spun into yarns for potential use as high performance composites in order to recycle the ever-increasing waste textiles generation and solve the disposal problem. This study investigates the effects of different twist levels (550–1050 TPM), twist ratios (0.1–0.5 plied yarn twist to single yarn twist), and epoxy resin impregnation rates (0.2–1.0 cm/s) on tensile properties of single yarns, plied yarns, and yarn reinforced composites derived from waste cotton fibers. The detection of the failure mechanisms of the examined yarns was confirmed via SEM analysis and images captured by high-speed camera. The twist factor at low twist level (550 TPM), twist ratio (0.1) and impregnation rate (0.3 cm/s) were determined as optimum twist factors to produce plied yarn-reinforced composite with high tensile strength of 286 MPa. The optimum twist of single yarn reinforced composites was 0.76 times the optimum twist of the single yarn alone. Twisting significantly influenced the manufacturing of high-performance composites from waste-derived yarn. The obtained results provide a new paradigm for high value utilization of waste textile through conversion into high-performance composites.