Stretch Yarn Research Articles

Structure and properties evolution of UV crosslinked ultra‐high molecular weight polyethylene fiber during processing

AbstractWith the development of heat and creep‐resistant UHMWPE fiber via UV crosslinking, its structure‐properties evolution during processing needs attention. The structures of UHMWPE fiber in different forms, the pre‐oriented yarn (POY), the full stretch yarn (FDY) and UV crosslinked FDY (UVFDY), obtained from our pilot line were systematically studied with differential scanning calorimetry (DSC), wide‐angle X‐ray diffraction (WAXD), small‐angle X‐ray scattering (SAXS), and solid‐state 13C NMR. Additionally, the heat and creep resistance of UVFDY were evaluated by the temperature at break (Tb), glass transition temperature (Tg), time at break (tb) for a given aging temperature, and creep elongation (Lc). The results demonstrated that UVFDY possessed high gel content (89.0%), high crystallinity (84.2%), and high orientation (91.7%). These characteristics caused UVFDY not only with excellent mechanical properties but also process extraordinary heat and creep resistance, especially for its much higher Tb (220 °C), Tg (−75.7 °C) and tb (20 h) while lower Lc (7.8%), comparing with FDY (Tb = 158 °C, Tg = −86.8 °C, tb = 1.3 h and Lc = 38.2%). This work provides insights into the structure‐properties relationship of UVFDY, which will aid in the development of UV crosslinked UHMWPE fiber with better heat and creep resistance.

Influence of honeycomb structures on fluids transmission and heat retention properties; An initiative towards stretchable weaves

The aesthetics and functionality of honeycomb woven assemblies qualifies them for a range of applications expanding across home textiles, fashion, functional apparels, and technical products. Researchers have explored honeycomb assemblies with the focus on shrinkage, sound absorption, thermal conductivity, and heat protection properties analysis via variation in their cell sizes. However, very minimal research is found on analysis of honeycomb woven fabric assemblies’ thermal comfort characteristics by employing different weft insertion sequence and materials (cotton and stretchable yarns). This study reflects the thermal conductivity, dry fluid transmission (air permeability), wet fluid transmission (moisture management), and stiffness attributes of twelve stretchable honeycomb woven assemblies consisting of single ridge, double ridge, and brighton honeycomb weave structures along with different weft sequences of cotton and Type 400 (T-400) stretch yarns. Characterization data showed that single ridge honeycomb structure supports the highest dry fluid transmission property; however, brighton honeycomb offers the highest heat retention property. Double ridge honeycomb highlights the capability of the highest wet fluid transmission property, and brighton honeycomb has immense stiffness. Statistical analysis (ANOVA) also showed that honeycomb structures, weft yarn sequence and material have a statistically significant impact on thermal conductivity and fluid transmission behaviors with p-values less than 0.05.

Reliability analysis of stretchable workwear fabric under abrasive damage: influence of stretch yarn composition

ABSTRACT Movement comfort is an important performance parameter for workwear fabric. The lower value of load developed in the fabric at a certain extension level indicates lower stress on the skin and easier body movement. After repeated usage, there is a possibility of degradation in this movement comfort due to abrasion and cyclic loading. Measurement of the probability of successful performance of the workwear fabric in terms of movement comfort during usage is possible through reliability analysis. The present study is concerned with the reliability analysis of the body movement comfort of the workwear fabric under abrasive damage. The effect of composition and structure of different types of stretch yarn, i.e. cotton core spun, polyester core spun and polyester multifilament air-covered yarn, on this reliability has been studied. It is seen that after repeated cyclic loading there is a degradation in the movement comfort of the fabrics. The extent of degradation depends on the composition of the stretch yarn. Although the workwear fabric with the elastane contained cotton core spun weft yarn showed lower abrasion resistance, it showed the best reliability values in terms of movement comfort. Abrasive damage resulted in improvement in the level of movement comfort at higher levels of loading cycles.

Effect of anisotropic abrasive damage on mass loss and ultimate tensile properties of the stretch denim fabric

PurposeIn recent times, stretch denim garments have become very popular amongst consumers as the garment is able to provide body fit and body comfort at the same time. The purpose of this study is to investigate the effect of abrasion on the change in surface appearance, mass loss and ultimate tensile properties of the stretch denim fabric in different directions (warp, weft and biased).Design/methodology/approachAfter abrading the fabrics in three different directions (warp, weft and biased), the loss in ultimate tensile properties, mass loss and surface appearance has been investigated in the respective directions of abrasion (warp, weft and biased). The study also encompasses the effect of different types of stretch yarn with varying levels of elastane content on such unidirectional abrasive damage.FindingsIt is seen that with the same level of abrasion cycles, the fabric's response in terms of mass loss and loss in ultimate tensile properties are different in different directions. The mass loss due to abrasion in biased direction is found to be minimum. The loss in ultimate tensile properties due to abrasion was highest in the weft direction. It is also found that the higher mass loss due to abrasion does not always result in a greater loss in ultimate tensile properties. The composition and the structure of the weft yarn significantly affected the extent of the mass loss and the loss in ultimate tensile properties during abrasive damage.Originality/valueThe impact of abrasive damage in terms of mass loss and loss in tensile strength along the different directions of denim fabric has not been explored till date. Abrasion of fabric can be done both in multi-direction (Lissajous motion) as well as in uni-direction (linear motion). The multidirectional abrasion provides a holistic or comprehensive idea of the fabric's response to the abrasive damage but does not take into consideration the fabric's anisotropic response to the abrasive damage. Most of the earlier investigation related to abrasive damage of denim fabric has been done in instruments where the motion of the abrader is multidirectional (Lissajous) in nature. For greater depth of understanding about the fabric performance under abrasive damage along the various direction (warp, weft and biased), unidirectional abrasion is conducted in this study.

Characterization of the structural configuration and tensile properties of medical bandages

Bandages are a group of medical textiles that are available in various types for use in different applications such as wound dressing, compression therapy, treatment of burns, cramps, and sprains. In the present research, the structural and tensile characteristics of various medical bandages produced by different companies have been compared. According to the results, different bandages commercially sold under the same category demonstrate quite varied tensile properties, depending on their structure and constructional parameters. Consequently, compression bandages of the same type produced under different trade names would exert various amount of pressure to the body under constant stretch. In other word, various amount of stretch must be applied to different compression bandages to achieve and maintain the required pressure. Hence, to obtain better treatment outcomes, it is essential to provide the required information about the features of each medical bandage for the consumers. Furthermore, it was observed that the knitted compression bandages due to their higher stiffness (elastic modulus) provide higher pressure under minimum stretch in comparison with woven samples. Moreover, incorporation of higher number of stretch yarns to the bandage structure as well as using tighter structure increases the stiffness of the bandage, and in turn enhances the power of the bandage to cling on the limb for a longer period of time, in case of compression bandages.

Design, Development and Preparation of Pouched Scuba-Knitting Spaced Fabric

Objective To improve the protection of human joints and avoid the injury caused by falls in the elderly. By testing and evaluating the wearability and mechanical properties of the pouched scuba-knitting fabric with no filling material, filled with EPS and POM, this paper provides a theoretical basis for the development of the protection products for the elderly. Methodology Using nylon filament and spandex stretch yarn as raw materials, two kinds of cushioning materials, EPS and POM, are respectively filled into pouched scuba-knitting weft-knitted structure. Results Due to the limit of 3mm spacing between front and rear needle beds of the computerized flat knitting machine, among all kinds of samples tested, the air permeability of EPS is stronger than that of POM with the increase of EPS sphere diameter. Because EPS spheres are more easily attached to water, the moisture permeability is shown to be the best. The mass loss of non-filled fabric is the greatest in the wear resistance test. Due to the characteristics of weft-knitted fabrics, there is no obvious difference among the three kinds of knitted fabrics in the tests of bursting, stretch recovery, pilling. Conclusion The pouched scuba-knitting structure filled with EPS is more suitable for the design and production of the protective fabric for the elderly afterwards.

Elastic Recovery and Performance of Denim Fabric Prepared by Cotton/Lycra Core Spun Yarns

ABSTRACT Elastic performance coefficient (EPC) and recovery behavior of denim fabrics prepared with cotton/lycra core spun stretch yarns have been presented in this article. The denim fabrics are woven as broken twill weaves in an air-jet weaving machine by the insertion of core spun yarns (lycra filament in core, cotton fiber on sheath) as weft and using 100% cotton yarns as warp. The effect of linear density and stretch percentage of the core spun weft yarns on tensile and recovery behavior of denim fabric have been investigated by employing full factorial design of experiments. It has been observed that the tensile strength and EPC of fabric increase with decrease in linear density and stretch percentage of the core spun stretch yarn. The immediate elastic recovery and delayed elastic recovery increase with decrease in linear density and stretch percentage of the yarns.

Tensile and Elastic Performance of Cotton/Lycra Core Spun Denim Yarn

Various cotton/lycra core spun yarns are prepared in modified ring frame. The core of the yarn consists of a 70 dtex lycra filament and sheath consists of staple cotton fibers. The cotton/lycra core spun yarns are explored for the suitable application of stretch denim fabric. The tensile and elastic performance properties of the prepared stretch yarns are evaluated. The influence of various parameters viz. pre-load, linear density, stretch percentage, twist multiplier and applied load during tensile testing, on the properties of the stretch yarns are investigated by employing a full factorial design and statistical analysis.

Prediction of False Twist Textured Yarn Properties by Artificial Neural Network Methodology

The false twist texturing method is one of the most common texturing techniques. This process depends on parameters such as tension, twist, and heater temperature. As false-twist texturing is a process which includes close interactions between machine working parameters and textured yarn properties, the effect of process parameters on yarn properties have been widely investigated. In this study the effect of first heater temperature, setting overfeed, and D/Y on the tenacity of set yarns and the effect of twist, texturing speed, and first heater temperature on crimp stability of stretch yarns are predicted using artificial neural network methodology.

Mechanics of Texturing Thermoplastic Yarns Part X: Effect of Frictional Snubbing on Pseudo False Twisting During Set Texturing

The occurrence of temporary twist in a torque stretch yarn passing through the resetting heater is confirmed. Separate measurements are made of threadline torque development during reheating of the yarn and of the corresponding twist required to relieve said torque. These data are used in a graphical explanation of the uptwist/ untwist phenomenon that occurs in the resetting heater and is termed pseudo false twisting because of the absence of a mechanical device. The presence of a snub pin in the threadline downstream of the second heater modifies the yarn torque level across the resetting zone, reducing uptwist levels and suppressing residual torque of the set textured yarn. A graphical explanation of the pin effect is also provided.

Structure and properties of dyed stretch yarn

Structure and properties of dyed stretch yarn

Structure of High Stretch Yarns and Their Tensile Properties

To clarify the structure of high stretch yarns in helical coils, various photographs of them and of other textured yarns or models are taken, and the relation between their tensile properties and the structure is studied. Results obtained are:1. Hard-twist two-ply yarns are studied as a model having two first twists per one pitch. They have hollow parts in the center of the yarn, and the radius can be expressed by: a=0.896 2. We have explained the configuration of the crimps or loops of the constituent filaments when hard-twist two-ply yarns are twisted, heat-set and untwisted. 3. We have found that the tensile properties of high stretch yarns are dependent on the configuration of the constituent filaments and on the complexity of assembly of these filaments, and that the fundamental shape of crimps of the yarn consists of a series of rings which develop the high extension property.

Properties of 3.3 tex textured Capron stretch yarn

Properties of 3.3 tex textured Capron stretch yarn

Processing conditions for stretch yarn as a source of the deformation and reversible twist of the filaments

Processing conditions for stretch yarn as a source of the deformation and reversible twist of the filaments

Dyes for suspension dyeing of polyamide

Coloured Capron stretch yarn intended mainly for hosiery has been in large-scale production at the Klin Man-Made Fibre Combine since 1966. The large output was made possible when the Combine adopted the suspension method of colouring in which the extracted polyamide chips are treated with a solution of a suspension or with a leuco compound of one dye alone or in mixtures with others /I/. The method was introduced after laboratory trials with Soviet-produced and imported specimens of certain classes of dyes which form solutions or suspensions in water or leuco compounds.

Structure of High Stretch Yarn and Its Tensile Properties

We have tried to clarify the structure of high stretch yarn in the shape ofspring-coil taking various photographs of it and other textured yarns and models for this purpose, and the relations between tensile properties of high stretch yarn and its structure.Results obtained are : 1. Hard-twisted two-ply yarn, which is a. model of having two bottom twists per one final twist, has been studied. The yarn has a hollow part in the center of the yarn which has a radius a as followw : a=r (2√π2+1-1) /π_??_1.7806r 2. We have explained the configuration of the crimps or loops of the constituent filaments when the hard-twisted two-ply yarn is twisted, heat-set and untwisted.3. We have found that the tensile properties of high stretch yarn are dependent on the configuration of the constituent filaments and the complexity of assembly of these filaments, and that the fundamental shape of crimps of the yarn is consist of a series of rings which arises a high extension property.

Sources of shrinkage in stretch yarn

Sources of shrinkage in stretch yarn

The Mechanics of Torque–Stretch Yarns: a Correction

The Mechanics of Torque–Stretch Yarns: a Correction

Mechanism of Failure in Women's Hosiery

Analysis of failure in women's hosiery reveals that hose durability is strongly related to the amount of stretch in the hose as well as to yarn strength. Although snagging is the major cause of hose failure, only about 1% of the total snags result in failure because the snagging force is usually removed or reduced prior to yarn breakage. At equivalent yarn breaking strength, hose from stretch yarns are more durable than nonstretch hose because longer snags develop and reduce the probability of the snagged yarn exceeding its breaking strength. Long snags occur when the hosiery structure collapses easily and there is low resistance to yarn withdrawal. A high propensity for snagging, irrespective of snag length, does not necessarily result in poor durability and evidence is presented to show this. The analysis of the above mechanism of failure is supported by wear test data with both stretch and conventional hose.

The draw ratio of the Capron filament yarn as a factor in the physico-mechanical indices of stretch yarn

The draw ratio of the Capron filament yarn as a factor in the physico-mechanical indices of stretch yarn