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As one kind of filament/staple fiber composite yarn, core spun yarn has been widely used, especially on Jeans. However, there is only one filament in the commonly used core spun yarn, such as spandex, and the performance of the one filament often is influenced during dyeing and finishing. Therefore, in the paper, twin-core spun yarns with two different filaments feeding simultaneously were spun on ring spinning frame modified by one kind of filament feeding numerical control device. The paper aims to discuss these issues.

Four kinds of twin-core spun yarns, cotton/spandex/PBT, cotton/spandex/CM800, cotton/spandex/T400, cotton/spandex/SPH with linear density 36.4tex/40D/50D were spun. For improving the covering effect of the two filaments, the filament feeding position, filament pre-drafting multiple, distance between two staple roving, designed twist factor of the core spun yarn were optimized.

It is shown that comparing with the core spun yarn, the breaking strength and elongation of the twin-core spun yarns are improved since the addition of another elastic filament, while the evenness is a little worse.

By using the twin-core spun yarns, corresponding knitted and woven fabrics are produced. Meanwhile, for simulating the dyeing and finishing process, the knitted fabrics were treated during the 150°C high temperature. It is shown that comparing with the fabrics produced by cotton/spandex yarn, addition of another elastic filament can improve the fabric strength and resistant and has positive effect on worsen prevention for high temperature treated fabric elastic recovery, and on change prevention during the dyeing and finishing process for fabric handle properties, and improves the fabric stability.

Pneumatic compact spinning is the most widely used compact spinning method at present, in which the negative pressure airflow is used to condense the fiber in order to decrease the spinning triangle and improve the yarn qualities. Therefore, the research on flow field in the condensing zone is always the emphasis for pneumatic compact spinning. The paper aims to discuss these issues.

By using finite element method (FEM), the flow field in two kinds of pneumatic compact spinning was studied. Taking three kinds of cotton yarns as examples, with the help of high-speed camera system OLYMPUS i-SPEED3, the motion trajectory of fiber strand in the condensing zone was obtained. Three-dimensional physical models of the condensing zone of the two compact spinning systems were obtained according to the measured parameters of practical spinning systems.

It is shown that on the both left edge of B1 line and right edge of B2 line, the airflow inflows to the center line of suction slot, and the condensed effects are produced, correspondingly. In the condensing zone, there are three condensing processes acting on the fiber strand, including the rapid condensing effects in the front condensing zone, the adequately condensing effects in the middle condensing zone, and stable output effects in the back condensing zone.

By using FEM, numerical simulations of three-dimensional flow field in condensing zone for two kinds of pneumatic compact spinning with lattice apron were presented, and corresponding spun yarn qualities were analyzed.

As a natural fiber, yakwool has attracted much attention in textile processing due to its excellent properties and wearabilities. However, the main colors of yakwool are black and brown. Therefore, for extending the application scopes of the fiber, the decolorization of the yakwool fiber is usually needed, especially for the black fiber. The paper aims to discuss this issue.

In the paper, the properties of the yakwool fiber were tested first, especially the melanin granules in the fiber. Then, the decolorization of the yakwool fiber was studied using the oxidation–reduction decolorization method, and corresponding optimal process of the decolorization was given. Then, the properties of the decolorized yakwool fiber were tested and compared with those of the original fiber.

It is shown that, after decolorization, the physical and mechanical properties of the fiber were deteriorated, especially in terms of the strength and elongation. Therefore, the fiber became shorter and thinner, and the scales were damaged. When compared with the yarn spun from the original yakwool fiber, it was observed that the properties of the yarn spun from the decolorized yakwool fiber deteriorated because of the deterioration in the properties of the original fiber.

In the paper, for extending the application scopes of the yakwool fiber, the decolorization of the yakwool fiber was studied.

The purpose of this paper is to theoretically study the effects of ring spinning triangle division on spun yarn torques.

The case that the spinning triangle is divided into two parts, primary triangles and final triangle, is investigated. Theoretical model of yarn torque was given by linking the fiber tension in the spinning triangle to yarn torque under the assumption that the arrangement of fibers (substrands) in the substrands (yarn) is hexagonal close packing. Then, as an application of the proposed method, 14.6tex cotton yarns were taken as an example for the numerical simulations.

The fiber tensions in the divided spinning triangles and corresponding yarn torques were simulated numerically by using MATLAB software. The effects of division proportions and number of primary triangles on spun yarn torques are analyzed theoretically.

It is shown that suitable spinning triangle division is benefit for reducing yarn torque.

In order to develop high shape retention yarn and investigate the effects of spinning process and core yarn contents on the shape retention of yarn, in this paper, three kinds of yarns, JC/T400 18.5tex (55.6dtex) core-spun yarn, JC/T400 18.5tex (44.4dtex) core-spun yarn and JC18.5tex pure cotton yarn were spun by using the complete condensing Siro-spinning technology. The paper aims to discuss these issues.

In this paper, the core-spun yarns were spun by using the complete condensing spinning and Siro-spinning technology. Two key spinning processes, yarn twist factor and core yarn pre-draft ratio, were optimized by using the orthogonal test method first. Then, via the variable control method, the position of the core yarn, the position of the bell mouth and the center distance between two bell mouths were optimized, respectively, and corresponding optimal spinning process of the three yarns was determined. Finally, the yarns were spun under the optimal process, and the performance of the spun yarns was tested and compared.

Results show that the yarn twist factor affects yarn strength and hairiness, the position of bell mouth affects the evenness and hairiness of the yarn mainly, and the position of the core yarn affects the coverage and hairiness of the yarn. For the Z-twist spinning, the core yarn enters the front roller from the left side of two strands center, which is beneficial to improve the covering effect of core yarn, and reduce the pilling phenomenon of the yarn. The contents of core yarn affect indicators of the yarn shape retention, such as yarn strength, elastic recovery and abrasion resistance.

The shape retention of yarns affects the shape retention of fabrics, and the production of yarn with high shape retention is a key step in achieving shape retention of fabrics. At present, there are little studies on the shape retention of yarns, most researchers shave focused on shape retention of fabrics. Using the complete condensing Siro-spinning method to spin the core-spun yarn can improve the quality of the yarn. Compared with traditional ring-spinning yarns, the addition of the core yarn can improve the shape retention of the yarn.

Through the tracer fiber method, we strive to more accurately obtain the hook degree, straightening degree, percentage and other characteristic indexes. In order to intuitively represent the hook state from sliver to yarn, and feed back production information in combination with quality test.

Taking the cotton fiber as an example, the hooked fibers were studied by using the tracer fiber method. Tracer fibers were made from cotton-type viscose fibers. Tracer fibers and combed cotton fibers were uniformly mixed for many times and used to produce the card sliver, semi-drawn sliver, drawn sliver, roving and yarn. With the help of ZF-20D ultraviolet analyzer, geometric parameters of hooked fibers were measured, and characterization indexes were calculated. And hook indexes and quality indexes were compared.

By redefining and reclassifying hooked fibers, the change of hooked fibers in the process was tracked and characterized carefully. Some hooks in card sliver are straightened but not eliminated, and will form longer zero-angled hooks in the subsequent process. The straightening degree and number of zero-angled hooks affect the evenness CV mainly.

The characterization of hooked fibers is important for reducing hooked fibers and spinning high quality yarns. There is no uniform standard for the characterization of hooked fibers at present. Most studies are about relationship between process and hook in carding and drawing. There is no research on hooked fibers in the whole spinning process. In the paper, hooked fibers were redefined and reclassified, the change of hooked fibers in the process was tracked and characterized carefully.

With the popularization of electronic products, the electromagnetic radiation pollution has been the fourth largest pollution after water, air and noise pollution. Therefore, electromagnetic shielding property of textiles is attracting more attention. In this paper, the properties of electromagnetic shielding yarns and fabrics were studied.

Ten kinds of yarn, stainless steel short fiber and polyester blend yarn with three different blending ratios T/S 90/10, T/S 80/20 and T/S 70/30, stainless steel short fiber, polyester and cotton blend yarn with blending ratio C/T/S 35/35/30, core-spun yarn with one 30 um stainless steel filament C/T28tex/S(30 um), core-spun yarn with two 15 um stainless steel filaments (C/T28tex/S(15 um)/S(15 um)), twin-core-spun yarn with one 30 um stainless steel filament and one 50D spandex filament C/T28tex/S(30 um)/SP(50D), sirofil wrapped yarn with one 30 um stainless steel filament feeding from left S(30 um)+C/T28tex, sirofil wrapped yarn with one 30 um stainless steel filament feeding from right C/T28tex+S(30 um), sirofil wrapped yarn with two 15 um stainless steel filaments feeding from two sides S(15 um)+C/T28tex+ S(15 um), were spun. The qualities of spun yarns were measured. Then, for analyzing the electromagnetic shielding properties of fabrics made of different spun yarns, 20 kinds of fabrics were woven.

The tested results show that comparing to the T/S 80/20 blend yarn, the resistivity of composite yarns with the same ratio of the stainless steel filament is smaller. The possible reason is that comparing to the stainless steel short fiber, the conductivity of stainless steel filament is better because of the continuous distribution of stainless steel in the filament. Comparing with the core-spun yarn, the conductivity of the sirofil wrapped yarn is a little better. Comparing to the fabric woven by the blend yarn, the electromagnetic shielding of the fabric woven by the composite yarn is better, and comparing to the fabric woven by the core-spun yarn, the electromagnetic shielding of the fabric woven by the sirofil yarn is a little better. The possible reason is that the conduction network can be produced by the stainless steel filament wrapped on the staple fiber yarn surface in the fabric, and the electromagnetic wave can be transmitted in the network.

In this paper, the properties of electromagnetic shielding yarns and fabrics were studied. Ten kinds of yarn, including three stainless steel short fiber and polyester blend yarns, one stainless steel short fiber, polyester and cotton blend yarn, two core-spun yarns, one twin-core-spun yarn, three sirofil wrapped yarn, were spun. Then, for analyzing the electromagnetic shielding properties of fabrics made of different spun yarns, 20 kinds of fabrics were woven. The effects of fabric warp and weft densities, fabric structures, yarn kinds, yarn distributions in the fabric on electromagnetic shielding were analyzed.

With the improvement of living standards and acceleration of working pace, the shape retention property of textiles has attracted more attention. Yarn spinning is the first fundamental process in making textiles and apparel, and the properties of yarn influence the performance of textiles directly. Filament/staple fiber composite yarn is a kind of yarn spun by filament and staple fiber, and comprehensive qualities of yarn can be improved. Therefore, the purpose of this paper is to study the shape retention properties of filament/staple fiber composite yarns and corresponding fabrics.

Four kinds of composite yarn, core-spun yarn with one 50D SPH filament feeding, sirofil wrapped yarn with one 50D SPH filament feeding from left, sirofil wrapped yarn with one 50D SPH filament feeding from right, sirofil wrapped yarn with two 25D SPH filaments feeding from two sides, were spun. The qualities of spun yarns were measured. Then, corresponding two kinds of twill fabrics were woven by core-spun yarn and sirofil wrapped yarn with two filaments, respectively. The handle parameters, crease recovery, appearance leveling after washing, dimensional change rate after washing, strength and elongation and tensile elasticity were tested by using corresponding test instruments.

The tested results of spun yarn qualities show that comparing with the core-spun yarn, the evenness of sirofil wrapped yarn is improved, the hairiness is reduced, and the breaking strength and elongation are increased. Comparing with sirofil wrapped yarn with one filament, the evenness of sirofil wrapped yarn with two filaments is improved. The measured results of fabrics properties show that under the same weaving process, comparing to the fabric woven by core-spun yarn, the dimension of fabric woven by sirofil wrapped yarn is small after desizing, and warp and weft density is large. The possible reason is that the shrinkage of the SPH filament outside the sirofil wrapped yarn happens after desizing, which also makes the dimensional change rate after washing of the corresponding fabric large, and crease recovery poor.

In the paper, for improving the shape retention properties of the pure cotton woven fabric, one kind of SPH filament was added to the woven fabric by spinning filament/staple fiber composite yarns. Four kinds of composite yarn, core-spun yarn with one 50D SPH filament, sirofil wrapped yarn with one 50D SPH filament feeding from the left side, sirofil wrapped yarn with one 50D SPH filament feeding from the right side, sirofil wrapped yarn with two 25D SPH filaments feeding from two sides, were spun. Two kinds of twill fabrics were weaving by core-spun yarn and sirofil wrapped yarn with two filaments, respectively.

Tensile property is one basic mechanics performance of the fabric. In general, not only the tensile values of the fabric are needed, but also the dynamic changing process under the tension is also needed. However, the dynamic tensile process cannot be included in the common testing methods by using the instruments after fabric weaving.

By choosing the weft yarn and warp yarn in the fabric as the minimum modeling unit, 1:1 finite element model of the whole woven fabrics was built by using AutoCAD software according to the measured geometric parameters of the fabrics and mechanical parameters of yarns. Then, the fabric dynamic tensile process was simulated by using the ANSYS software. The stress–strain curve along the warp direction and shrinkage rate curve along the weft direction of the fabrics were simulated. Meanwhile, simulation results were verified by comparing to the testing results.

It is shown that there are four stages during the fabric tensile fracture process along the warp direction under the tension. The first stage is fabric elastic deformation. The second stage is fabric yield deformation, and the change rate of stress begins to slow down. The third stage is fiber breaking, and the change of stress fluctuates since the breaking time of the fibers is different. The fourth stage is fabric breaking.

In this paper, the dynamic tensile process of blended woven fabrics was studied by using finite element method. Although there are differences between the simulation results and experimental testing results, the overall tendency of simulation results is the same as the experimental testing results.

Due to the excellent functionality of graphene, the research on fiber modification by graphene has been receiving more and more attentions recently, and many research findings have been conducted. However, the purpose of this paper is to focus on the fiber modification method and corresponding modified fiber properties, but the research on processing of the modified fiber, especially the textile process, is little. Therefore, in the paper, the properties of one kind of textile GN fiber and the spinning method of the GN fiber blend yarn and the functionalities of corresponding fabric are studied.

In the paper, the properties of nylon fiber modified by graphene (GN) were studied first. Then, according to the tested results, one new blending process of the GN fiber and cotton fiber was given, and corresponding properties of the blend yarns were tested and analyzed. Finally, the knitted fabrics were produced using the spun blend yarns, and the antibacterial property, electromagnetic shielding property, anti-ultraviolet performance, anti-static performance and conventional mechanical, and appearance thermal-wet comfort properties were tested and comparatively analyzed.

The tested results showed that the functionality of all fabrics was effective due to the addition of the graphene in the fiber, especially the antibacterial property. With the increasing of the GN fiber in the blend yarns, the functionality of all fabrics was also increased first and then achieved stability.

One new blending process of the GN fiber and cotton fiber was given. In the spinning, the combed cotton sliver was produced first, and then was torn into small parts of combed cotton sliver fiber by hand. Then, the treated GN fibers and cotton fibers were mixed for the first time, and corresponding GN/C carding sliver was produced. In this blend processing, the mixed cotton fiber was used to improve the sliver processing of the GN fiber. Then, in the drawing process, the required number of GN/C carding sliver and combed cotton sliver were fed simultaneously, and GN fibers and cotton fibers were mixed for the second time, and corresponding four kinds of GN/JC blend yarns were produced. In this blend processing, the mixed cotton fiber was used to regulate the blending ratio.