Comparison of fabric properties knitted by pin spacer compact and conventional compact yarns

This study examined the influence of pin spacer apparatus attachment on compact yarn quality parameters and physical properties of knitted fabrics manufactured using those 100% cotton compact yarns. Two groups of compact yarns were spun on regular compact yarn spinning frame with and without addition of pin spacer apparatus which is placed at the end of the drawing unit of regular compact yarn spinning frame. Totally eight yarns were spun at four different yarn number levels (Ne 24/1, Ne 30/1, Ne 36/1 and Ne 40/1) and two different spinning conditions (with and without pin spacer apparatus). Spun yarn types were then knitted on the industrial sized plain knitting machine. Knitted fabrics were used in the greige and dyed form to evaluate their bursting strength (kPa), dimensional change, abrasion related mass loss (%), pilling resistance, air permeability (mm/s) and colour difference. Test results were then statistically evaluated and influence of pin spacer attachment on yarn quality parameters and fabric properties was determined. In the frame of this experimental work, attachment of pin spacer apparatus improved compact yarn characteristics especially at yarn evenness, imperfection and hairiness values. In case of knitted fabric properties, it was found that pin spacer apparatus attached compact yarn utilization significantly improved air permeability properties of knitted fabrics.     

纺纱工艺对弹性转杯纱结构和性能的影响

描述了由上海东华大学开发的用以纺制不同结构性能弹性转杯纱的一种弹性转杯纱纺纱系统。研究了在改变加捻参数和氨纶丝牵伸倍数时弹性转杯纱的结构与性能。结果表明加捻参数和氨纶丝牵伸倍数对弹性转杯纱的结构和性能均有一定的影响,氨纶丝线密度也会影响纱线的性能。     

弹性纤维在转杯纺中的应用

在经过改进的转杯纺纱机上引入弹性纤维以生产不同类型的弹性转杯纱.分析了转杯速度、牵伸倍数、捻系数对弹性转杯纱性能的影响,并通过正交试验对工艺参数进行了优化.这三个参数对弹性转杯纱的性能都有较大的影响,其中牵伸倍数的影响最大.弹性纤维在转杯纱中与棉纤维纱条捻合成纱.与常规转杯纱相比,弹性转杯纱的表面更加规则和光洁,主要性能也得到了改善.     

Comfort properties of bamboo/cotton blended knitted fabrics produced from rotor spun yarns

The comfort characteristics of bamboo/cotton-blended knitted fabrics made from rotor-spun yarns were studied in this research work. Five different blend proportions namely 100% bamboo, 100% cotton, 50:50 cotton:bamboo, 70:30 cotton:bamboo and 30:70 cotton:bamboo were used to produce rotor-spun yarns of 30^sNe_c. The yarn samples developed out of these different blend proportions were evaluated for yarn strength and elongation, yarn unevenness, yarn imperfections and used to produce single-jersey-knitted fabrics. All the fabric samples were dyed and finished. Fabric samples were evaluated for geometrical properties such as course/inch, wales/inch, stitch density and thickness apart from measuring comfort properties such as airpermeability, thermal conductivity, thermal resistance and water vapour permeability. The results indicated that 50/50 bamboo/cotton-blended knits have comparable fabric quality in terms of comfort properties with respect to 100% bamboo fabrics.     

The electromagnetic shielding properties of some conductive knitted fabrics produced on single or double needle bed of a flat knitting machine

In recent years, the use of electrical and electronic devices has grown rapidly. These devices cause electromagnetic interferences, which could threaten human life. In order to solve this problem, intensive research to develop textile surfaces having electromagnetic shielding properties continues. In this paper, we study textile surfaces knitted with conductive copper and stainless steel wires wrapped with acrylic yarns and also core yarns produced by using conductive yarns to test the electromagnetic shielding properties of the fabrics. It was concluded that the knitted structure of the fabrics affected the electromagnetic shielding effectiveness (EMSE). Besides, the fabrics knitted on a double needle bed of the knitting machine with higher amounts of conductive yarns and unit weights could not provide the targeted improvement in the EMSE values with respect to the fabrics produced on a single needle bed of the knitting machine.     

低扭矩环锭纺纱原理及其单纱的结构和性能

本文主要回顾了低扭矩环锭纺纱技术的发展。通过讨论其纺纱三角区的特点,利用高速摄影技术对纺纱区捻度和张力分布的观察分析,系统地介绍了低扭矩纱的成纱原理。此外,结合示踪纤维技术,利用纱线结构连续测量分析系统对低扭矩环锭单纱和传统环锭单纱的内部结构进行分析,揭示了低扭矩纱独特的结构特点,如非同轴异形螺旋线结构,纤维片段局部反转现象等。这些特点解释了低扭矩纱及其织物具有优良物理性能的原因。同时,通过多个生产厂家提供的测试数据,对比分析了几代低扭矩环锭纱与传统环锭纱及其织物的物理性能,结果表明低扭矩环锭纱具有低捻高强、低残余扭矩和毛羽少等特点,其针织物经多次水洗后歪斜变形小和手感好,机织物具有较好的撕裂强力,断裂强力和耐磨擦性。最新一代低扭矩环锭纺纱技术显著地改善了高支纯棉纱的物理性能。     

Measuring loop lengths of elasticised knitted fabrics

The methods for loop length measurement have mostly been developed for knitted fabrics made from conventional yarns. When measuring the loop lengths of knitted structures made from highly extensible staple yarns, problems arise because of an uncontrolled yarn extension at the low stresses. The present study proposes a test method for knitted loop length determination in which variable preloads are applied. In the study, the loop lengths measured on an INSTRON dynamometer using variable preloads and a HATRA Course Length Tester using a fixed preload were compared. The results demonstrated that knitted structures made from elasticised yarns exhibit only small changes in loop length after relaxation. The addition of elastane does not significantly influence loop lengths for fabrics knitted using the same machine, the same cam setting and relaxed by the same process. The loop lengths measured on an INSTRON dynamometer exceed the loop lengths measured on a HATRA Course Length Tester.     

仪纶~(TM)纬平针织物的抗起毛起球性能

本文分别选用环锭纺、赛络纺、赛络紧密纺纺纱工艺,制备了同等纱支的仪纶~(TM)纯纺、仪纶~(TM)/棉(65/35)混纺针织纱线及其纬平针织物,对比测试了纱线性能及其织物抗起毛起球性能。实验结果显示:不同纺纱工艺的仪纶~(TM)针织纱线总体性能相似,赛络紧密纺纱线纱体结构更均匀;赛络纺织物的抗起毛起球性较环锭纺织物高0.5级,赛络紧密纺织物的抗起毛起球性明显好于环锭纺织物;混纺织物的抗起毛起球等级和起球粒数均有所改善。     

The effect of air-jet nozzle structural parameters on new cotton rotor-jet spun yarn properties

In this paper, a hybrid spinning system the so-called “rotor-jet spinning method” which utilizes the air-jet nozzle in rotor spinning process is presented. Thus, air-jet nozzles with different structures of 90S, 90Z, 60Z, and 30Z (the values of 90, 60, and 30 are orifice angles and S and Z are air rotational directions) were designed and constructed and then mounted between the take-up nozzle position and doffing tube in a rotor spinning machine. The air-jet pressure was changed at 0.2, 0.5, 0.8, 1, 1.2 and 1.5 bar values. The physical properties of cotton rotor-jet spun yarns with yarn count 20 Tex and nominal yarn twist of 938 TPM were investigated and compared with that of normal rotor-spun yarn. The experimental results indicated that by utilizing a 90Z air-jet nozzle at 1 bar air pressure, the highest yarn tensile strength, abrasion resistance, and twist, and lowest elongation are obtained compared with those of normal rotor as well as rotor-jet spun yarns with 30Z, 60Z, and 90S air-jet nozzle types. However, the rotor-jet spun yarn irregularity produced with 90Z air-jet nozzle is almost identical to normal rotor-spun yarn. It is also shown that the rotor-jet spun yarn hairiness properties which were produced with a 90Z air-jet nozzle at air pressure values of 0.2, 0.5 and 1 bar is almost similar to normal rotor-spun yarn while the lowest yarn hairiness is achieved at air pressure value of 0.8 bar. The experimental results of this paper suggest that the newly developed rotor-jet spun yarn is superior to normal rotor-spun yarn from the point of view of yarn tensile, abrasion resistance, twist, and partially hairiness properties.

     

Electromagnetic shielding effectiveness of carbon/stainless steel/polypropylene hybrid yarn-based knitted fabrics and their composites

In this study, a range of conductive hybrid knitted fabrics and their composites have been investigated for shielding effectiveness in the frequency ranges of 50 MHz to 1.5 GHz (low frequency) and 4 to 8 GHz (C-Band). Carbon and stainless steel (SS) filaments were combined in Dref-3 spinning machine and different hybrid yarns were prepared. The plain- and rib-knitted fabrics were made in V-bed flat knitting machine from the prepared hybrid yarns. The composite laminate was prepared by sandwiching a ply of fabric between the polypropylene films in compression moulding machine at 180 °C for 5 min under a consolidation pressure of 12 bar. All the fabrics and composites were tested for shielding effectiveness (SE) in coaxial transmission line and C-band waveguide with the help of vector network analyser. It was observed that fabric having both conductive loop and inlaid yarns exhibited higher SE of 20.2 dB than other fabrics in low-frequency range. However, in the composite form, carbon composite with SS inlaid yarn showed better SE of 45 dB than other composites. In C-band frequency range, conductive loop fabric structures yielded high shielding effect in course direction compared to wales direction. Compared to fabric form, the composite showed higher SE for all frequency ranges. This study proposes that knitted fabrics and their composites can be utilized as electromagnetic shields in wide frequency ranges.     

Investigation on moisture management properties of knitted fabrics produced from vortex-spun yarns

Abstract

The aim of this study was to investigate the liquid moisture management performance of knitted fabrics produced from vortex-spun yarns using different kinds of fibers and ratios. For this purpose, the vortex-spun yarns with 19.7 tex were obtained in different blend ratios in Murata Vortex Spinner by using different fibers. Then, these yarns were knitted in a circular knitting machine at two different stitch lengths and dyed considering fiber types. Moisture management properties of the produced fabrics were tested. The results revealed that moisture management properties of vortex knitted fabrics were much affected by fiber types in comparison with fabric tightness. Modal and nylon fibers have shown very positive results in terms of moisture management performance. The vortex-spun yarns having a low diameter, high shape values that are more rounded, and high density improved moisture management performance of the fabrics whereas the hairy yarns and higher fabric thickness reduced it.     

Characterization of fabric properties knitted from multifilament polyester textured yarns with various number of filaments

The purpose of this study is to investigate the physical and mechanical properties of fabrics knitted from textured polyester multifilament yarns with various numbers of filaments in the yarn cross-section. In this regard, some of the characteristics of yarns and fabrics, knitted from the mentioned yarns, were measured and analysed. Analysis of results showed that increasing the number of filaments in the yarn cross-section leads to a decrease in yarn’s diameter and abrasion resistance. Moreover, examining the properties of the weft-knitted fabrics revealed that increasing the number of filaments causes a rising trend in the compressibility and bursting strength of fabric. On the contrary, the thickness, air permeability and abrasion resistance decreases due to a growth in the number of filaments. A decline in the strength and elongation of yarns and fabrics produced from them is also another result of increasing the number of filaments in the yarn cross section.     

29—THE INFLUENCE OF FIBRE LENGTH AND YARN TWISTS ON THE PERFORMANCE OF CERTAIN COARSE-GAUGE WEFT-KNITTED FABRICS

A study is reported of the effects of fibre length and yarn twists on the performance of 2 × 2 rib-knitted fabrics. Wool from a 54s-quality top was given three different fibre lengths by the use of a Rieter converter and then spun into 1/16s-worsted-count (55.5-tex) worsted yarns with various spinning, folding, and cabling twists. These yarns were knitted into 2 × 2 rib fabrics and tested for resistance to pilling, abrasion, and snagging. The analysis of the results showed that yarns of 8½ × 4½ turns/in. (336 × 138 turns/m) single × folding twist are more resistant than others.     

长丝超喂率对转杯纺复合纱外观与结构的影响

介绍了转杯纺复合纱的纺纱原理,并在经过改装的转杯纺纱机上,通过调整涤纶长丝的超喂率生产不同外观和结构的转杯纺复合纱。经纱线外观和结构的测试分析,表明长丝超喂率对转杯纺复合纱中长丝的几何位置和空间形态有显著的影响。     

多重集聚纺纱结构成形机制及其针织物性能

为解决多毛羽传统环锭纱针织困难,而光洁的常规集聚纺纱线织物手感硬的技术难题,建立串联半开放式多重集聚纺纱方法,分析多重集聚纺纱机制和结构成形特征。理论分析结果表明,多重集聚纺纱线具有外紧而内柔的结构特征。基于理论解析,在相同工艺条件下,分别采用传统环锭、常规集聚和多重集聚纱线制成针织面料,对比分析了各针织物压缩回弹、透气、抗起毛起球、耐磨、染色等性能。测试结果表明：与传统环锭纱相比,多重集聚纱线针织物耐磨、透气性、抗起毛起球性改善;与常规集聚纱线相比,多重集聚纱线针织物悬垂性、压缩回弹性和染色性能明显提高。     

A study on thermal properties of single-jersey knitted fabrics produced from ring and compact folded yarns

This paper presents a study on the thermal properties of single-jersey knitted fabrics manufactured using ring, compact and ring/compact folded yarns. The variations in thermal properties depending on the yarn twist and traveller weight of folded yarn single-jersey knits were discussed. It was found that the thermal resistance of knitted fabrics generally increases as the traveller weight decreases, and also water vapour permeability reduces as the traveller weight decreases. The water vapour permeability and air permeability of knitted fabrics increase as the twist increases. The thermal conductivity of knitted fabrics decreases as the twist increases. The air permeability and water vapour permeability values were higher for compact folded yarn fabrics as compared to those values of ring and ring/compact folded yarn fabrics. It is observed that yarn twist and traveller weight have affected different thermal properties of single-jersey folded yarn fabrics.     

Electrical,electromagnetic shielding,and some physical properties of hybrid yarn-based knitted fabrics

Recently, increasing number of studies are performed on protective fabrics containing metal wires for electromagnetic shielding purposes. In the present paper, the hybrid fabrics in plain and rib structures were knitted by using single and double ply hybrid yarns obtained by acrylic (PAC) yarns plied with stainless steel wires having two different diameters. The physical properties including conductivity, air permeability, pilling, and abrasion resistance as well as electromagnetic shielding effectiveness (EMSE) were measured. The variations in EMSE as well as reflection, absorption, and transmission and in other physical properties of knitted hybrid fabrics were investigated considering wire content and weave structure. It was seen that an increase in the wire content significantly increased the conductivity. Rib fabrics exhibited better EMSE values as compared with plain fabrics. Fabrics using two-folded yarns exhibited better EMSE values. Fabrics using thinner wire exhibited higher EMSE values. The highest EMSE value was obtained for rib-knitted fabric with 35 micrometer (μm) stainless steel wire.     

不同混纺比犜犲狀犮犲犾/苎麻混纺针织物服用性能的测试与分析

测试6种不同混纺比针织物的主要服用性能指标,包括织物的悬垂性、起毛起球性、折皱回复性、刚柔性和吸湿性等,对测试的数据运用最小二乘法进行曲线拟合,得出不同混纺比对其针织物服用性能影响的函数关系式,并取得函数的极值点,为开发不同性能的Tencel/苎麻混纺针织物提供理论依据。     

转杯纺复合纱与sirofil复合纱的性能对比分析

纺纱方式的不同使得纱线的结构和性能也不同。通过将转杯轴中心开孔,借助转杯负压的作用引入长丝的方法纺制转杯纺复合纱;通过在传统环锭细纱机上加装1个长丝喂入装置的方法纺制sirofil复合纱。测试分析这2种复合纱在相同规格和纺纱条件下其纵向形态、起毛性、毛羽、纱线表面纤维抽拔力和强力等相关性能。研究结果表明,转杯纺复合纱表面光洁,毛羽少,不易起毛起球,耐磨性能好,其强力稍低于sirofil复合纱。     

The effect of core-sheath proportion on the characteristics of fabrics produced with hollow yarns: part II comfort and mechanical properties

The study aims to investigate the effect of hollow yarn structure and the sheath-core proportion of hollow yarns on the permeability properties of the knitted fabrics. In order to accomplish this, core yarns in the yarn count of 59 tex were produced by using cotton, viscose, wool, and polyester fibers in the sheath and different ratios of polyvinyl alcohol (PVA) in the core. After completion of yarn production on ring spinning frame, the yarns in the form of packages were used to produce plain knitted fabrics. Fabrics were then divided into two groups, one of which was washed during a time period in order to remove PVA from the core to obtain hollow yarn structure. Air and water permeability, and wicking properties of the knitted fabrics were measured before and after washing processes. Mechanical properties such as pilling and bursting strength of the fabrics were also examined. The results show that washing process and PVA proportion used to produce core spun yarns have a significant effect on the permeability and mechanical properties of the fabrics.