捻系数和毛羽值与棉纱强力的相关性分析

通过测试得到环锭纺棉纱的捻度、毛羽值和断裂强力的数据。对数据进行回归分析,结果显示：棉纱的捻系数和毛羽值对断裂强力的影响显著;而且毛羽值与断裂强力之间的关系可以用三次项模型描述。     

涤纶长丝仿棉假捻变形纱的结构和基本性能

就新型仿棉假捻变形纱的纱线结构、卷曲性能、强伸性能、条干均匀度、表面浸润等性能进行了全面研究,并与纯棉纱和常规假捻变形纱进行对比分析.结果表明:较常规假捻变形纱,新型仿棉假捻变形纱具有明显的粗细节结构,使其具有一定的短纤纱外观特性;其热收缩率和和卷曲收缩率较常规假捻变形纱大,这可能与其纱体中含有2种长丝组分有关;其断裂强度和断裂伸长率明显比常规涤纶假捻变形纱小.在棉纱断裂伸长率范围内,新型仿棉假捻变形纱的强伸曲线与棉纱强伸曲线基本吻合;而其与水滴的接触角比纯棉纱和常规假捻变形纱小,水滴在新型仿棉假捻变形纱表面快速铺展浸润,表明该纱具有优异的导湿性能.新型仿棉假捻纱总体外观形态具有一定的仿棉效果,而其强伸、弹性回复和导湿性能超越纯棉纱.     

A comparative study on performance characteristics of multicomponent core-spun yarns containing cotton/PET/elastane

Abstract

This paper experimentally investigated the characteristics of different (filament and multicomponent) core-spun yarn type. Filament core-spun yarns comprised cotton covered drawn textured (DTY) polyester (PET) filaments with four different filament finenesses. Regarding the production of multicomponent (dual) core-spun yarns, both PET with four different filament finenesses and elastane with four levels of draft variable were fed simultaneously. Yarn samples were produced with modified ring spinning system at the same spinning conditions. As a control group, 100% cotton ring-spun yarn was also manufactured. Tensile properties, unevenness, imperfections and hairiness of yarn samples were determined. Also, fatigue characteristics of yarn samples were examined at two different loading of cycles. The results showed that filament fineness had a significant effect on all yarn properties being determined. Dynamic modulus and dynamic strain properties of yarns, filament fineness, elastane draft and number of cycle were found to be statistically significant at 0.05 level.     

Eco-friendly food products as source of natural colorant for wool yarn dyeing

ABSTRACT

Food products as a source of natural colorants are gaining widespread popularity around the globe due to their ayurvedic and eco-friendly nature. Current study is aimed with the utilization of food products (Saffron and madder) as a source of dye for woolen yarn. It is found that, for Saffron, irradiation of yarn for 6 min gives high color strength by dyeing for 45 min in the presence of 2% of salts using un-irradiated dye bath of 1 pH, whereas for madder, 4 min is optimal irradiation time for extract to dye irradiated yarn for 25 min in the presence of 6% of salts using the irradiated dye bath of pH 1. The mordanting carried out at optimal conditions show that using both extracts, woolen yarn dyed at optimal conditions has given good color characteristics. It is concluded that microwave radiation has not only improved natural dyeing process but also make the process more eco-friendly and sustainable as well.     

纬编针织机织针自由状态下固有频率测试方法

针对现有纬编针织机织针由于其结构尺寸微小、细长、横截面直径不定等特性带来的在其自由状态下织针的各阶模态特性难以测试的问题,提出采用小面积、低质量的锆钛酸铅压电陶瓷(PZT)贴于织针表面,形成PZT、织针黏合体结构。采用高性能阻抗分析仪对黏合体进行扫频测试,根据不同频率下复阻抗以及相位角曲线,得出PZT自由状态下的各阶模态。采用ANSYS有限元仿真软件对织针以及黏合体的各阶模态进行对比认证,并采用悬臂梁曲率、挠度理论以及织针振动理论进行分析。理论推算以及仿真测试结果表明,该实验测试方法能有效测试纬编针织机织针自由状态下的固有频率。     

包芯花式线性能的研究

研究包芯纱的性能对结子花式线拉伸性能的影响得出以下结论：不同线密度纱线对断裂伸长影响很大,而对强度影响不大;就原材料的影响来看,发现在研究的纱线中,对聚酯纱线断裂强度的影响最大,对棉纱的断裂伸长影响最大。试验结果表明：一种组分性质的微小变化都有可能对最终的花式线性能产生很大的影响。     

黄麻/棉混纺纱线的柔软改性整理与性能研究

选用不同线密度和混纺比例的4种黄麻/棉混纺纱线,测试了黄麻/棉混纺纱线的拉伸性能、柔软性能和毛羽,探讨了碱处理工艺中NaOH浓度对混纺纱线拉伸断裂强力和毛效的影响,以及生物酶柔软处理对混纺纱线失重率、拉伸性能、柔软性和毛羽的影响规律。试验结果显示：黄麻/棉混纺纱线刚度大,柔软性较差,毛羽多;对黄麻/棉混纺纱线进行NaOH碱处理和生物酶柔软处理后,黄麻/棉混纺纱线的柔软性能得到改善。     

Impact of structural variations in hollow yarn on heat and moisture transport properties of fabrics

The use of hollow/microporous yarns plays an important role in enhancing the thermo‐physiological comfort properties of fabrics. Depending on structural variations in hollow yarn, heat and moisture regulation behaviours of fabrics can be affected significantly. In this study, three types of hollow cotton yarn fabrics, produced by introducing polyvinyl alcohol (PVA) filament in the core, PVA staple fibres in the blend and PVA filament in doubling with cotton spun yarn, are studied. All three types of pre‐hollow yarns and reference yarns are made with a variation in spinning technique (single roving/double roving) to prepare eight single jersey knitted fabrics. The hollow/microporous structure of the yarn is created by dissolving the PVA fibres using hot washing of the fabrics. On overall evaluation of the fabric’s thermo‐physiological comfort properties, the doubled hollow yarn fabrics are found to be better than other fabrics. In general, thermal resistance, thermal absorptivity, wicking and drying properties of all types of hollow yarn fabrics increase after repeated laundering, while air permeability, water vapour permeability and water absorbency of hollow yarn fabrics mostly decrease. In contrast with fabrics made from yarn produced through single roving technique, use of double roving technique only improves fabric water vapour permeability.     

The dimensional and mechanical properties of wool/polyester fabrics made from vortex and ring-spun yarns

Fabric woven from wool/polyester (PES) Murata vortex spun (MVS) blend yarn is a commercially viable proposition particularly on the basis of advantageous wear-resistant properties, compared with fabric made from traditional worsted ring-spun yarn. However, in some early industrial trials with fabric made from 45/55-blend wool/PES MVS yarn, significantly greater relaxation shrinkage was found relative to comparable worsted ring-spun fabric. It was noted at the time that the amount of relaxation shrinkage in MVS fabric could be reduced to a large extent by using steamed MVS yarn.

In this study, the extent of variations in the dimensional and mechanical properties of fabric samples woven from a combination of steamed and unsteamed MVS yarn and equivalent worsted ring-spun yarn is examined. In general, greater hygral expansion and relaxation shrinkage were found in loom-state fabrics made from unsteamed MVS yarns, whereas the fabric made from steamed MVS and ring-spun yarns gave relatively low levels of relaxation shrinkage and hygral expansion. Permanent setting of fabrics, by pressure steaming, was found to be more effective than yarn pre-steaming in reducing relaxation shrinkage levels of fabrics made from unsteamed MVS yarn. After pressure steaming, all fabrics showed similar levels of relaxation shrinkage and hygral expansion.

Permanent setting of the fabrics, by pressure steaming, resulted in similar levels of relaxation shrinkage and hygral expansion, irrespective of the yarn production method; relaxation shrinkage fell to around 1% and hygral expansion increased by about 1%, relative to the loom-state samples. MVS fabrics were relatively heavier and fuller and had a firmer handle than the worsted ring-spun fabrics, reflecting the greater fabric weight, thickness and shear rigidity measured on these fabrics. These attributes are associated with different structures of the worsted ring-spun and MVS yarns used to make the fabrics.     

Development of image processing based system to study yarn structure during extension

The present study describes design and development and use of an image processing system to characterize and visualize the configuration of fibers in yarn in extended mode. An especially dedicated instrument and software for data acquisition and analysis are the unique features of the system. It is capable of grabbing the images of extended yarn in two orthogonal planes. The software can acquire data from these two orthogonal planes. The three‐dimensional trajectory of whole length of different colored tracer fibers can be plotted and can be viewed at different angles. The image processing system along with multi‐colored tracer fiber technique has been used for quantitative analysis of changes in the internal structure of ring yarn on extension.