Packing of micro-porous yarns: Part I. Optimization of yarn characteristics

The present paper deals with the factors affecting the packing of a micro-porous yarn, namely proportion of PVA fibre content, yarn twist multiplier (TM) and spindle speed at ring frame, and with their combined effect on various properties of the yarn. The micro-pores within the structure of the yarn have been created by dissolving the PVA fibres using washing treatment in hot water. A three-variable factorial design technique proposed by Box and Behnken is used to investigate the combined interaction effect of the above variables on the properties of the yarn. The present experiment variables, namely proportion of PVA fibre, yarn twist multiplier (TM) and spindle speed, were found to have significant impact on various properties of yarns before and after wash. For yarns before wash, the specific volume reduces with the increase in the PVA content, yarn twist and spindle speed. In the case of yarns after wash, there is reduction in the yarn specific volume with the increase in TM and spindle speed, but with the increase in the PVA percentage the yarn specific volume increases. The tenacity of yarns before wash increases with the increase in the PVA content, but for yarns after wash, the proportion of PVA content has comparatively less influence. The compressibility of yarns before wash reduces with the increase in the PVA content, but a reverse trend is observed in the case of yarns after wash. The design variables were optimized for all the yarn properties by using the response surface equations.     

Packing of micro-porous yarns. Part II: optimization of fabric characteristics

This paper is concerned with the study of the characteristics of plain woven fabric produced with micro-porous cotton yarns in weft. The micro-porous yarns with varying packing densities and level of pore volumes are produced by changing proportion of PVA fibre content in the blend, yarn twist multiplier (TM) and spindle speed at ring frame. The micro-pores within the structure of the yarn have been created by dissolving the PVA fibres using washing treatment in hot water. A three-variable factorial design technique proposed by Box and Behnken has been used to study the interaction effects of these variables on the characteristics of fabrics. The influence of these three variables on the mechanical, handle and comfort properties of fabrics are studied, the response-surface equations for all the properties have been derived and the design variables are optimized for various fabric properties. Improvements in bending resistance, abrasion resistance and compressional characteristics have been observed with incorporation of micro-pores within the yarn structure. These fabrics with micro-pores have improved thermal resistance and moisture vapour transmission compared to that of 100% cotton fabric.     

Influence of process parameters on properties of open-end and core-sheath friction spun acrylic yarns

The present paper is concerned with the influence of opening roller speed, difference in drum speed and suction air pressure on properties of acrylic open-end and core-sheath friction spun yarns. The results show that opening roller speed and suction air pressure have significant influence on properties of open-end friction spun yarns. In the case of core-sheath yarns, suction air pressure has influence on yarn tenacity and hairiness. However, yarn unevenness and imperfection are not significantly influenced by experimental variables. The results also show that core-sheath friction spun yarns have significantly higher yarn tenacity, modulus and work of rupture and have a lower level of yarn unevenness, imperfections, hairiness, and breaking elongation than open-end friction spun yarns.     

Influence of Friction Spinning Process Parameters on Spinnability of Pergularia/Cotton-Blended Yarns

In this study, spinnability of Pergularia daemia seed fiber (70%) and cotton fiber (30%) core/100% cotton fiber sheath DREF-3 core yarns of 74 tex were studied using different spinning parameters in order to understand their effect on yarn properties. Box-Behnken Design was used for the optimization of core ratio, drum speed, and suction pressure and to evaluate the effects and interactions of the process variables on the yarn properties at a constant opening roller speed of 12,000 rpm and delivery rate of 100 m/min. The effect of the core/sheath ratio on yarn quality index is significant. With an increase in the core/sheath ratio, yarn tenacity, and elongation decreases due to insufficient wrapper fibers in the yarn and yarn unevenness increases due to higher feed rate and draft at higher core ratio. An increase in the spinning drum speed increases the yarn quality index up to certain range and then decreases at higher speed due to damaging of fibers in the sheath and more number of hooks at the end of fibers. At a higher air suction pressure, yarn tenacity and the elongation at break increases which ultimately increases the yarn quality index. From the regression analysis, it is observed that the drum speed and suction pressure has no significant effect on yarn unevenness.     

Study of fiber packing density of lyocell ring‐spun yarns

The study of yarn structure and related yarn properties has been the subject of much research. However, the study of the fiber packing density, which has practical significance for a number of yarns and their characteristics, has been limited to circular yarns because of the disordered yarn structure. In this paper, the fiber packing density of lyocell ring‐spun yarns is determined with the image analysis method. This method does not have any limitation with regard to the fiber cross‐sectional shape. The effect of yarn count, twist factor, spindle speed, traveler weight and front roller diameter on the fiber packing density in the yarn cross‐section is analyzed. The results of this paper and the data published in other scientific works are in good agreement.     

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.     

83.3 tex花式变支数纱的拉伸性能

采用瑞士AmslerTex公司生产的花式纱装置,通过改变工艺参数,例如锭子速度、钢丝圈质量和合股捻系数等,可以在环锭细纱机上生产不同性能的83.3 tex花式股线纱.这些性能包括纱线强度、断裂强力、断裂伸长率,以及断裂功等.其中,纱线的强度和断裂强力随着钢丝圈质量的增加而增大.断裂功最大值则出现在锭速较低和钢丝圈质量较小时,而选定的合股捻系数对纱线性能的影响并不显著.     

复合纱体中长丝分布形态对纱线性能的影响

为研究长丝复合纺纱过程中由长丝与短纤维须条复合产生的不同纱线内部结构对纱线性能的影响,设计并建立了6种长丝复合纺纱线结构模型,分析和预测了模型对应的成纱性能,并进行实验验证,对比分析了各复合纺纱形式所得纱线的毛羽、条干、强伸性能。结果表明：相比单独的包芯结构和长丝单侧包缠结构,长丝由两侧对须条进行包缠优化了纱线结构,表现出更佳的复合纱拉伸和成纱条干性能;同时拥有长丝双侧包缠和包芯结构的复合纱,表现出最优的成纱强力和条干;较大的长丝与须条隔距与张力更有利于长丝束缚和控制纤维外露,有效降低成纱毛羽。     

Studies on cotton–acrylic bulked yarns and fabrics. Part I: Yarn characteristics

The effect of variables, namely yarn fineness, shrinkable acrylic proportion and twist level, on various properties of cotton–acrylic blended bulked yarns has been studied by relaxing shrinkable component of the yarns using boiling water treatment. A three-variable factorial design technique proposed by Box and Behnken was used to investigate the combined interaction effect of the above variables on the properties of these yarns. The design variables were optimized for all the yarn properties by using the response surface equations. The shrinkage percentage of yarn was found to be higher in the case of coarser yarn, yarn with higher proportion of acrylic fibre and higher twist level. During bulking treatment as the yarns shrink, the effective number of twist per unit length also increases significantly. It is observed that the specific volume of the yarn increases with an increase in the acrylic proportion and decreases with an increase in the twist factor. The breaking extension increases significantly after bulking with a slight increase in tenacity. The flexural rigidity and initial modulus of yarn considerably decrease on bulking. The vertical wicking heights for all the bulked yarns were found to be higher than comparable 100% cotton yarn.     

Effects of fiber types and blend ratios on Murata Vortex yarn properties

Murata Vortex spinning (MVS) system is one of the unconventional systems for yarn manufacturing. It is suitable for spinning of 100% cotton fibers, synthetic fibers, and cotton/synthetic fiber blends which are 1 inch or more in length. The production ranges are between Ne 15-60. Vortex yarn and fabrics have low hairiness, clear appearance, high resistance to pilling and abrasion. In this study, the vortex yarns with Ne 30 are produced in different blend ratios in Murata Vortex Spinner using carded cotton, viscose, modal, silver-added polyester (Flexsil-D2?), polyester, and nylon 6.6 fibers. Vortex spun yarns are tested to determine the yarn properties which are diameter, density, roundness (shape), unevenness, imperfection, Uster hairiness (H), Zweigle hairiness, tenacity, and elongation. The study reveals that the fiber type has quite significant effects on yarn properties. In terms of structural properties, cotton is the most negative fiber while regenerated cellulosic fibers are the most positive. As modal, nylon and polyester fiber increase yarn strength, nylon and viscose fiber increase breaking elongation. Viscose and modal reduce unevenness, imperfection and hairiness while polyester and nylon exhibit more negative effect on these properties.     

环锭纺和紧密纺纱线的比较研究

比较研究了以棉、聚酯纤维为原料、在不同的紧密纺系统上纺制的相应的 环锭纺和紧密纺纱线.结果表明紧密纺纱线与环锭纺纱线相比,弹性、拉伸性、耐磨性、刚度和紧密度较高,毛羽、条干不匀率和疵点较少,纱线直径较小.而且,紧密纺的弹性恢复参数比环锭纺要好得多.从改变比例的方面来说,RoCoS系统纺出来的纱线与Zinser和Suessen紧密纺系统纺出来的纱线相比较时,表现出弹性、直径和紧密度的改变量小,但是拉伸性变化大.     

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.     

驼绒／可溶性维纶包芯纱针织物的服用性能分析

采用驼绒／可溶性维纶包芯纱和纯驼绒纱线分别制备了纬平针及1＋1罗纹织物试样,测试分析了包芯纱织物退维前后及纯驼绒织物的服用性能。结果表明,驼绒／可溶性维纶包芯纱针织物退雏后尺寸稳定性良好,且透气性、保暖性、柔软性有所提高,透湿性、厚度略有减小;与纯驼绒织物相比,退维后织物的蓬松性、柔软性、保暖性较好。     

DREF-3纱线的线密度范围和性质

研究了用DREF-3摩擦纺设备加工粘胶和棉纤维时的纱线线密度范围以及随着线密度的变化带来的纱线性质的变化.对于粘胶和棉纤维来说,线密度范围分别为328～25 tex和328～16 tex.发现粘胶纱线的强度开始是增加的,然后随纱线变细而强度下降.然而对于棉纱来说,几乎在整个纱线线密度范围内其强度基本不变.随着纱线变细,所需的纱线捻度也不断增加.同时对这两种纱线来说,当纱线较粗时其断裂伸长都非常高.在整个纱线线密度范围内,两种纱线的捻度和直径都非常接近.     

A study on siro-, solo-, compact-, and conventional ring-spun yarns. Part II: yarn strength with relation to physical and structural properties of yarns

The strength of siro-, solo-, compact-, and conventional ring-spun yarns has been examined with reference to yarn migration parameters, spinning-in-coefficient, number of broken fibers, and yarn hairiness. The measured results are presented in the forms of diagrams and tables. Results reveal that at various levels of gage length and strain rate, siro-spun yarns exhibit the highest tenacity, followed by compact-spun yarns, solo-spun yarns, and conventional ring-spun yarns. Analysis of the results demonstrate that the higher tenacity values of siro-spun yarns can be attributed to the higher mean fiber position, higher migration factor, greater proportion of broken fibers, and lower hairiness. It is also found that the strength of yarns to a considerable extent is governed by yarn structure, gage length, and strain rate.     

无捻纱退维时间的分析

无捻纱的退维工艺是织制无捻纱织物的关键工艺,退维过程的控制一直是困扰水溶性维纶伴纺与混纺产品开发的难点。为准确测试无捻纱退维的时间,采用纱线强力测试法和称重法对无捻纱的退维时间进行验证测试,2种测试方法基本相符,30 min左右合股纱线上的维纶能够全部溶解,为实际生产中无捻纱织物退维时间的确定提供了可靠的依据。     

涡流纺纱线的包缠加捻对其力学性能的影响

为探究涡流纺纱线的包缠加捻与成纱力学性能的关系,从理论上分析了涡流纺纱线拉伸过程中的纤维形变与受力,详细研究了涡流压力和纺纱速度对涡流纺纱线力学性能的影响.结果表明:外层纤维螺旋包缠特性对涡流纺成纱的力学性能起着决定性作用,涡流压力和纺纱速度为影响涡流纺包缠和加捻效果的主要因素;当纺纱速度为280 m/min时,随着涡...     

基于包芯纱的空芯纱加工技术

以PVA长丝或短纤为芯纱，棉纤维为外包纱生产包芯纱，并通过退维得到空芯纱，由这种空芯纱制织的织物具有许多优良的性能。文章探讨了在传统环锭细纱机上生产包芯纱，并通过退维处理得到空芯纱的加工技术；并对空芯纱织物的透气性和厚度等进行了测试与分析。     

Influence of spinning parameters on milkweed/cotton DREF-3 yarn properties

In this study, Pergularia milkweed fibre (70%), cotton fibre (30%) core and 100% cotton fibre sheath DREF-3 core yarns of 74?tex were produced using different spinning parameters in order to understand their effect on yarn properties. Box–Behnken design was used for the optimization of core ratio, drum speed and suction pressure, and to evaluate the effects and interactions of the process variables on the yarn properties at a constant opening roller speed of 12,000?rpm and production speed of 100?m/min. The effects of the core/sheath ratio on all the yarn properties are significant. With an increase in the core/sheath ratio, yarn tenacity and elongation decrease due to insufficient wrapper fibres in the yarn and yarn unevenness; imperfection increases due to higher feed rate and draft at higher core ratio. The yarn hairiness increases at higher core ratio due to higher number of short fibres in milkweed and lesser sheath fibres to cover the core fibres effectively. An increase in the spinning drum speed damages fibre in the sheath and increases the number of hooks at the end of fibres, as a result of which the core yarn tenacity decreases at higher drum speed. At a higher air suction pressure, yarn tenacity and the elongation at break increases. The drum speed and suction pressure have no significant effect on yarn unevenness and imperfections. The yarn hairiness decreases slightly with increase in drum speed and suction pressure but is insignificant.     

Effect of key process variables on mechanical properties of blended vortex spun yarns

A study of significant factors and their interaction during vortex yarn spinning has been carried out to achieve desired mechanical properties of the polyethylene terephthalate/cotton blended yarns which can offer process and performance advantages. The key significant factors, i.e. feed ratio, air pressure and spindle size were varied in a mixed-level factorial design. The mechanical properties (count lea strength product, tenacity and elongation at break) were studied and feed ratio was found to significantly affect the tenacity and elongation at break of spun yarns. A significant effect of these parameters was observed on the diameter and hairiness of the Muratec vortex spun yarn.