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.     

Permeability properties of single jersey fabrics made of hollow yarns

In this work effect of using hollow yarns on the permeability properties of the single jersey knitted fabrics were studied. Firstly yarns were produced by ring spinning machine using cotton, viscose and acrylic fibres in the mantle and water soluble polyvinyl alcohol (PVA) fibre in the core. Single jersey fabrics were knitted and PVA core was removed subsequently by washing process to create hollow yarn. Weight, air permeability and water transmission rate properties of fabrics were measured before and after washing and compared with reference fabrics. Due to the removal of PVA fibres from the yarn core after washing treatment, air permeability and water vapour transmission rate of the all kind of single jersey fabrics which were produced with hollow yarns increased as well as weight of the fabrics decreased which will cause more comfort during any exercise. It was also found that mantle fibre type and PVA ratio have significant effect on the fabric properties.     

棉/维纶混纺空心纱针织物的服用性能

以棉/维纶混纺空心纱为原料,采用双罗纹组织进行试织,测定了混纺空心纱织物和纯棉织物的各项服用性能,并进行了详细的对比分析,结果表明混纺空心纱织物更有优势。     

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.     

纱线的动态力学性能

纱线的力学性能在很大程度上影响着织物的力学性能和耐用性,因此对纱线力学性能的研究,尤其是对纱线在动态拉伸情况下的动态力学性能的研究是十分重要的。应用美国劳森公司的CTT纱线性能测试仪,对纱线的动态力学性能进行了研究分析,通过测试发现,纱线的动态力学性能指标比静态测试的力学指标更能全面真实地反映纱线在织造过程中的实际受力情况和力学性能。     

毛中空纱加工技术与针织产品开发

利用Sirofil纺纱技术在毛粗纱中复合高支水溶性维纶，用所纺成的羊毛，维纶双组分纱织成的针织物经整理溶去水溶性PVA后形成中空结构，在纱线内层留有较大的孔隙，其产品手感柔和，具有优良的蓬松回弹性、良好的保暖性和透气性等优点。     

A study of the development and properties of carbon fiber bulk yarns

Initially, using carbon fiber tows as raw materials, the developed airflow dispersion method was adopted for bulking process. Subsequently, the bulk properties, the irregularity, the mechanical properties, the hairiness index and the ability to fix the resin of the carbon fiber bulk yarn were investigated. The results show that the basic variation range of the bulking intensity is 17.19–22.19%, the variation range of the irregularity is 21.65–29.11%, and the strength of carbon fiber tows after the blowing and spraying by the air is reduced by 18.7–25.6%. The tensile and breaking elongation of the carbon fiber bulk yarn is up to 13.80%; the length of the hairiness of the carbon fiber bulk yarn ranges between 1 and 3?mm. The hairiness level decreases dramatically with an increase of the hairiness length.     

An investigation on the effect of pigments on the texture ability and mechanical properties of polypropylene BCF yarns

Abstract

In this work, the effect of five pigments on the mechanical and texturing properties of polypropylene BCF yarns has been investigated. The results showed that depending on the type, pigments may have a significant decreasing or increasing effect on the mechanical properties of polypropylene BCF yarns, although some of these differences may not be practically significant. As far as the bulk properties of the BCF yarns are concerned, a trend could not be established for the effect of pigments on crimp contraction and crimp modulus, but increasing the amount of pigments decreased the crimp stability of all BCF yarns. XRD and DSC analyses showed that the addition of pigments decreased the crystallinity index of the yarns depending on the type of pigment. DSC analysis showed a higher onset melting point after adding pigments with the exception of white one. FTIR spectra show no considerable reaction or interaction between polypropylene and the pigments employed in the masterbatch.     

The effect of mass irregularities of weft yarns on fabric surface protrusion

Fabric surface unevenness and defects are usually created by yarn irregularity and defects in weaving process. These unevenness and irregularities appear on fabric and affect various fabric properties. In order to investigate weft yarn mass irregularities on fabric surface unevenness and defects, various plain fabric samples were prepared in which they differ only in weft yarn mass irregularity. One of the effective factors on fabric surface unevenness is yarn protrusion in fabric structure. Yarn protrusion in fabric structure is influenced by yarn’s physical and mechanical properties and fabric structural characteristics. In this work, relationship between mass irregularities of weft yarn and fabric surface unevenness was investigated using angular power spectrum curve, a measure of yarn protrusion in fabric structures. The results showed a high significant correlation between these two parameters.     

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.     

Studies of the hybrid effect in mechanical properties of tencel blended ring-, rotor- and air-jet spun yarns

This paper presents a study of hybrid effect on mechanical properties of tencel blended ring-, rotor- and Murata jet spinning yarns. The tensile strength, breaking elongation, flexural rigidity and abrasion resistance of tencel-polyester and tencel-cotton blended yarns are examined and compared with the value predicted using linear and quadratic rule of mixture (ROM). It is observed that there is no significant hybrid effect on abrasion resistance of tencel-polyester mix yarns and tenacity and breaking extension of tencel-cotton mix yarns; hence, a linear ROM is found better in predicting the yarn properties. Further, for all yarn types, there is a significant hybrid effect on tenacity, breaking extension and flexural rigidity of tencel-polyester mixes and flexural rigidity and abrasion resistance of tencel-cotton mixes. A quadratic ROM model suits well for these yarns. Overall, it is found that there is a negative hybrid effect on tenacity and breaking extension whereas there is a positive hybrid effect on flexural rigidity for all the yarn samples irrespective of fibre and yarn type. The abrasion resistance has a mixed trend. Further, tencel-polyester yarns yield more satisfactory results than the tencel-cotton yarns in terms of strength and breaking extension but behave poorly during abrasion test for 200 cycles. Increasing tencel content both in tencel-polyester and tencel-cotton fibre-mix produces a rigid yarn with reduced abrasion resistance.     

空芯棉纱织物性能的试验与分析

对棉 /PVA包芯纱织物进行了退维工艺处理 ,从而获得了空芯棉纱织物 ,并对该织物的性能进行了试验研究 ,同时将它与相同特数的传统纯棉织物的性能进行了比较和分析。研究结果表明 ,相同特数的空芯棉纱织物具有比传统纯棉织物更为优越的综合性能。     

A study on siro-, solo-, compact-, and conventional ring-spun yarns. Part I: structural and migratory properties of the yarns

Properties of spun yarns are mainly affected by fiber properties and yarn structure. Yarn structure is principally influenced by the spinning system. In fact, each spinning system tends to produce a distinctive yarn structure. Recent refinements in spinning technologies have yielded significant improvement in yarn structure. Siro, solo and compact spinning are the new spinning systems to have made a breakthrough until recently. Of the various structural parameters for staple yarns, fiber migration has a crucial influence on the yarn mechanical properties. Thus, the need for precise and concise information about fiber migration becomes important for better understanding of yarn structure and hence yarn mechanical behavior. The work presented here aims to analyze fiber migration in siro-, solo-, compact-, and conventional ring-spun yarns by varying the twist factor. The results demonstrate that the siro-spun yarns exhibit the highest fiber migration parameters, followed by compact-spun yarns, solo-spun yarns, and conventional ring-spun yarns.     

Effect of polyester and elastane linear density on the physical and mechanical properties of dual-core-spun cotton yarns

ABSTRACT

The use of single-core elastic spun cotton yarns is well established in textiles and denim industry but interest in the use of dual-core-spun yarns has started to grow only recently. The aim of this study was to investigate the effect of polyester and elastane linear density on the physical and mechanical properties of dual-core-spun cotton yarns. Yarn samples were prepared on industrial-scale spinning machines using cotton as the sheath fibers and two different linear densities of polyester and three different linear densities of elastane filaments in the core. Statistical analysis of the results revealed that yarn tenacity, elongation, uniformity, and hairiness are significantly affected by the linear densities of both the polyester and elastane filaments in the core, with statistically significant interaction between them. Yarn imperfections (IPI), however, are affected mainly by the polyester denier, while the elastane linear density did not show statistically significant effect on the IPI. Regression equations for different yarn properties were also developed which showed fairly high values of coefficient of determination (R-sq).     

摩擦空心纱的结构特点和拉伸性能

对以PVA短纤维纱为芯纱,棉纤维为外包纤维的摩擦包芯纱,通过水煮处理去除可水溶的PVA芯纱后,制得摩擦空心纱。对摩擦空心纱以及具有加强芯纱的摩擦空心纱的结构特点和拉伸性能进行了试验研究。摩擦空心纱的结构特点是空心部分位于纱线的中心,溶芯后纱线结构膨松,直径增大。试验结果表明溶芯后摩擦空心纱的强力很低,其原因为去除了高强力的芯纱,溶芯后纱线膨胀引起纤维间抱合力减小;用涤纶长丝作为加强芯纱可以显著提高摩擦空心纱的强力。     

Study on the blend irregularity in blended yarns

A new model is developed to evaluate the theoretical blend irregularity of a two‐component blended yarn. By introducing the variation of the number of fibers per cross‐section along the yarn, the obtained expression can offer insight into the cause of blend irregularity. Two experiments show that the results from the new model have essentially the same changing tendency as experimental values. The value of the blend irregularity of one component is shown to decrease with the increase of its proportion and the blend irregularity also decreases in the case of finer fibers.     

A comparative study on properties of dual-core yarns

Core-spun yarns containing Spandex have been widely used for the production of elastic textile materials. However, it has been encountered various problems not only during the usage but also during textile processes due to its high recovery property. In order to solve these problems, multicomponent core-spun yarns called as dual-core (DC) yarns, have been developed. DC yarns can be produced on the modified ring spinning machine in two different ways. In the first method, previously combined two core yarns are fed simultaneously, whereas in the second method, two core yarns are given separately into the centre of sheath fibre bundle. In present study, it was aimed to research the effect of these production methods on yarn features. Polyester and Spandex core components and cotton wrapping fibres were brought together in both two ways and the properties of multicomponent core-spun yarns were compared with cotton ring counterparts for three different yarn counts.     

A study on the quality of kapok blended yarns through different processing methods

In this paper, 14 types of kapok blended yarns and four types of cotton yarns manufactured through different spinning technologies and processing methods were selected in order to explore the most efficient spinning technology for kapok fiber. Four yarn characteristics were measured: yarn fineness/unevenness, yarn defects, yarn hairiness, and breaking tenacity. According to Uster Statistics 2007, GB-T/398-2008, and FZ12001-1992 standards, the analytical results of the four characteristics showed that the quality of kapok blended yarns achieved a higher level with the improvement of spinning technology. The compact spinning and processing technology IV was a preferred way to spin high-quality kapok blended yarn, which lent support to widening the application of kapok fibers in various end-use products.     

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.