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.     

Studies on cotton-acrylic bulked yarns produced from different spinning technologies. Part II: fabric characteristics

The present work is concerned with the study of the characteristics of plain woven fabric produced with cotton-acrylic high-bulk yarns from different spinning technologies. The effects of different factors, namely spinning technologies (ring, rotor and DREF-II, i.e. Group A fabrics), position of shrinkable acrylic feed sliver in DREF-II friction spinning system (Group B fabrics) and proportion of shrinkable acrylic core fibre in core-sheath type DREF-III friction spun yarns (Group C fabrics) on various properties of cotton-acrylic blended bulked yarn fabrics have been reported. The influence of these three variables on the mechanical, handle and comfort properties of fabrics have been studied. The properties of fabrics made of bulked yarns from different spinning technologies are found to be different from the normal 100% cotton yarn fabrics in all respect. Even though the bulked yarns were used only in weft direction, the fabrics with modified yarn structures show appreciable improvement in thermal resistance, moisture vapour transmission, wicking and air permeability. The bending rigidity of the fabrics in weft direction also reduced with improvement in crease recovery in weft direction.     

Study on needle-punched non-woven fabrics made from shrinkable and non-shrinkable acrylic blends. Part II: transmission behaviour

This paper reports the transmission characteristics, i.e. air permeability, thermal conductivity and moisture vapour transmission, of needle-punched non-woven fabrics made from shrinkable and non-shrinkable acrylic blends. The basic idea of this work is to explore the possibility of structural changes in needle-punched non-woven fabrics made from blends of shrinkable and non-shrinkable acrylic-fibres, as in case of an acrylic bulked-yarn. The effects of variables, namely fabric mass per unit area, needling density and the proportion of shrinkable acrylic-fibre in the blend, on various transmission-related properties of needle-punched non-woven fabrics have been studied by relaxing shrinkable component of the fabric using hot steam 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 transmission properties of these fabrics. Shrinkable acrylic proportion found to have significant effect on transmission properties after steam treatment.     

Investigation on permeability and moisture management properties of different denim fabrics after repeated laundering

The physiological comfort determined by air permeability and moisture management properties of fabrics is influenced by various constructional parameters of the fabric which give woven fabric a porous structure. Evaporation of sweat during wear has the potential to cool the body besides restricting the additional weight of sweat being absorbed by the fabric. In this study, comfort characteristics of denim fabrics with different weft yarn of cotton, polyester and core spun Lycra have been discussed. Effect of enzyme washing and repeated laundering on air permeability, moisture management and drying rate has also been discussed. It was observed that air permeability and water vapour permeability of unwashed denim fabrics with cotton weft yarn are significantly higher than the fabric with polyester and Lycra cotton weft yarns. The wetting time is higher for cotton and Lycra cotton yarn fabrics. One-way transport index is highest for Lycra cotton weft fabrics and lowest for fabrics with polyester weft. Fabrics with polyester weft yarns show highest spreading rate, spreading radius and drying rate due to better wicking and hydrophobic nature of polyester fibres.     

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.     

Study on effect of blend ratio on thermal comfort properties of cotton/nylon-blended fabrics with high-performance Kermel fibre

This study presents the thermal comfort properties of woven fabrics made of Kermel, cotton/nylon and cotton/nylon /Kermel-blended yarns. Our aim in this study is to combine the high comfort properties of cotton/nylon fibres with high thermal protective properties of Kermel fibre in different woven fabrics. Thus, Kermel (100%), cotton/nylon (50:50) and four blends of the 50% cotton fibres with nylon and Kermel (40:10, 30:20, 20:30 and 10:40) were spun on a ring-spinning frame and twisted into two-folded yarns with the same yarn count of 30/2(Ne) and twist level of 560 TPM. Using the produced yarns, woven fabrics with identical characteristic and structure were also produced. Then, the thermal comfort and physical properties of fabrics were studied in terms of fabric porosity, thermal resistance, thermal conductivity, water vapour resistance and air permeability. The results show that the porosity, air permeability and thermal resistance increase with Kermel fibre blend ratio. Conversely, the water vapour resistance decreases with increase of Kermel fibre blend ratio up to 40%, while 100% Kermel-woven fabric exhibits a higher water vapour resistance value. Nevertheless, the thermal conductivity of cotton/nylon-blended Kermel woven fabric is unchanged with increase of Kermel fibre blend ratio up to 40%, whereas at 100% Kermel fibre blend ratio, the lowest thermal conductivity is obtained. The obtained results implied that woven fabric produced from cotton/nylon (50/10) blended with 40% Kermel fibre resulted in proper thermal comfort properties.     

A study on thermophysiological comfort properties of fabrics in relation to constituent fibre fineness and cross-sectional shapes

The present study reports the effect of linear densities and profiles of polyester fibres on the physiological properties of their fabrics. Four different polyester fibre finenesses along with microdenier and four cross-sectional shapes (circular, scalloped oval, tetrakelion and trilobal) were selected to produce two sets of 2/1 twill fabrics; one composed of 100% polyester and the other 67:33 P/V blends. In studying the thermophysiological component of the clothing comfort, heat, air and moisture transmission characteristics of the fabrics were assessed. The principal thermal properties, such as thermal absorptivity, thermal resistance and thermal conductivity, were experimentally evaluated, using the Alambeta instrument. The study of the obtained results established the fabrics of non-circular cross-sections as against circular ones, and increase in the linear density results in higher thermal resistance, lower thermal conductivity and lower thermal absorptivity. Wicking behaviour of fabrics was studied under two conditions–wicking from an infinite liquid reservoir (transverse wicking) and wicking from a finite liquid reservoir (single drop wicking into the fabrics). Increase in fibre linear density enhances transplaner wicking but slows down the spreading speed of water drops. Air permeability and moisture vapour permeability are found to be positively correlated with fibre decitex. The role of fibre cross-sectional shapes in influencing mass-flow characteristics is quite considerable. Use of non-circular polyester in place of a circular one augments the wickability of liquid water along with the permeability of air and moisture vapour through the fabrics, revealing their high porosity, which assists air and moisture to propagate. Mixing viscose into polyester brings down the air permeability and moisture vapour transmission rate (MVTR) of fabrics. Results show that moisture absorption of viscose is an important factor in influencing the moisture transport characteristics including both wickability and MVTR of 100% viscose and P/V-blended fabrics.     

Thermo-physiological comfort characteristics of polyester air-jet-textured and cotton-yarn fabrics

Air-jet-textured polyester yarns were produced using two feed yarns differing in filament fineness and number of filaments. By varying the overfed rates of feed yarns and changing their positions in core and effect, five textured yarns were produced. Woven fabrics were prepared using these textured yarns as weft and cotton yarns in warp. To study the effect of air-jet-texturing parameters on the thermo-physiological comfort characteristics of fabric, the woven fabrics were tested for thickness, thermal properties, transverse wicking and air permeability. It is observed that thermal conductivity and resistance of fabrics are not influenced by the texturing parameters/textured yarn structure. These properties are mainly dependent on the entrapped air present in fabrics. Thermal absorptivity is a transient phenomenon of heat flow reflecting that the ‘warm-cool feeling’ effect of fabrics depends on smoothness/roughness of fabric surface. Fabrics with smooth surfaces have higher thermal absorptivity values as they provide a large area of contact with human skin. The roughness of fabrics depends on the number of surface loops and filament fineness. Transverse wicking of fabrics depends on the size, continuity and alignment of the capillaries present in the core of textured yarns.     

改性聚丙烯酸类纤维吸湿发热机织物的开发

为研究吸湿发热保暖机织物的热湿舒适性,开发了6种不同结构的改性聚丙烯酸类纤维吸湿发热机织物。通过热湿舒适相关性能测试与分析,得出不同机织物结构参数对透气性、热阻、芯吸高度、液态水分管理以及吸湿发热性能的影响规律,为设计出兼具吸湿发热和导湿排汗性能的热湿舒适机织物提供参考。经测试发现:蜂巢组织能明显改善织物的保暖性和透气性,且织物由内层向外层形成回潮率递增的梯度结构,对水分管理和提高单向导湿性能有积极作用,三层蜂巢组织在提升织物吸湿发热性能上具有一定潜力。     

改性聚丙烯酸类纤维吸湿发热机织物的开发

为研究吸湿发热保暖机织物的热湿舒适性,开发了6种不同结构的改性聚丙烯酸类纤维吸湿发热机织物。通过热湿舒适相关性能测试与分析,得出不同机织物结构参数对透气性、热阻、芯吸高度、液态水分管理以及吸湿发热性能的影响规律,为设计出兼具吸湿发热和导湿排汗性能的热湿舒适机织物提供参考。经测试发现:蜂巢组织能明显改善织物的保暖性和透气性,且织物由内层向外层形成回潮率递增的梯度结构,对水分管理和提高单向导湿性能有积极作用,三层蜂巢组织在提升织物吸湿发热性能上具有一定潜力。     

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.     

The effect of different knitted fabrics’ structures on the moisture transport properties

In this study, fabrics with different plain, tuck and float stitch combinations in three different tightness levels as tight, medium and loose are produced from combed ring spun cotton yarn. It is aimed at determining the effect of fabric structure on liquid absorption, transport and permeability properties, which are important factors in the people’s perception of wear comfort. The air permeability, wicking ability and moisture management measurements of the produced fabrics are made. It is determined that the increase in the fabric tightness decreases the air permeability and increases the wicking ability especially in 60?min measurements. The fabric tightness has also different effects on different knitting types in terms of moisture management properties. It is observed that structures with float stitches show high wicking ability and moisture management properties in terms of plain, tuck and float stitches combinations.     

Effect of Design and Method of Creating Wicking Channels on Moisture Management and Air Permeability of Cotton Fabrics

Garments made from cotton fabrics can readily absorb perspiration during strenuous activities but give poor performance in terms of wicking and evaporation of the perspiration, resulting in wet sticky feeling to the wearer. The aim of this study was to investigate the effect of design and method of creating wicking channels on the moisture management and air permeability of cotton fabrics. The fabric specimens were printed with hydrophobic fluorocarbon finish using four different print designs, each with two different types of printing squeegees. It was found that both the type of print design and squeegee type significantly affect most of the moisture management properties of the fabric. The study concluded that by selecting a suitable print design and squeegee type, moisture management capability of cotton fabrics can be significantly improved without sacrificing the fabric air permeability.     

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.     

竹浆纤维针织产品性能测试与分析

为了更好地了解竹浆纤维产品特点,提高产品开发的针对性,选择了1组竹浆纤维针织物和其他与其规格相近的纤维素纤维针织物进行性能测试及对比分析。结果表明:竹浆纤维产品手感柔软,悬垂性好,表面光泽明亮,透气透湿,芯吸效果明显,具有良好的抗菌抑菌、抗紫外线效果;特别是采用竹浆纤维/棉混纺内包涤纶长丝的3组分包芯纱产品,在保持竹浆纤维良好性能的同时,其抗皱性、强力明显提高,各项服用性能接近或超过天丝产品。同时指出竹浆纤维针织产品在开发中应注意的问题。     

Coolmax纤维含量对交织物舒适性能的影响

对5种Coolmax／棉交织织物的吸水性、透湿性、透气性进行了测试,建立了Coolmax纤维含量与织物经向、纬向芯吸高度,透湿量、透气率的回归方程。结果表明随着纬纱中Coolmax纤维含量的增加,Coolmax／棉交织织物的吸水性、透湿性和透气性越好。     

干爽涤纶织物的研发

在阐述织物湿传导途径的基础上,分析织物的吸湿、润湿特性和导湿机制,推导织物中毛细管液态水运输总流量公式,并介绍五叶形涤纶纤维Coolfibre的截面形状和芯吸特性,得出芯吸时间与芯吸高度的回归方程。分析了人体出汗时如要迅速达到干爽,织物从内向外应具备的材料结构和几何结构。通过试验发现采用Coolfibre涤纶长丝作为经纱形成的经支持面织物,有利于保持皮肤与织物内侧微气候区的干爽。设计并分析了5种织物的强伸性能、透气性、透湿性、芯吸高度、润湿保湿性和干燥性能,为干爽织物的开发提供参考。     

21—STT YARNS: TECHNOLOGICAL ASPECTS OF TWISTED SELF-TWIST YARNS

The STT system is one in which unidirectional twist is added to self-twist yarns to produce two-ply weaving yarns. The added twist required for the elimination of fabric patterning due to cyclic twist variation in the yarn has been determined and has been expressed in terms of the amount of self-twist in the yarn. Fabrics woven from STT yarns have been evaluated, and the dependence of fabric properties on initial self-twist and on added-twist levels has been investigated. This has resulted in recommendations for the spinning and twisting of STT yarns for use in making high-quality worsted fabrics.     

Investigation on thermo-physiological and compression characteristics of weft-knitted 3D spacer fabrics

The thermo-physiological comfort and compression properties of knitted spacer fabrics have been evaluated by varying the different spacer fabric parameters. Air permeability and water vapor transmission of the fabrics were measured using the Textest FX-3300 air permeability tester and PERMETEST. Thermal behavior of fabrics was evaluated by (TCi) thermal conductivity analyzer and overall moisture management capacity was evaluated by moisture management tester. Spacer fabrics compression properties were also tested using KES-FB3. In the KES testing, the compression resilience, work of compression, linearity of compression, and other parameters were calculated from the pressure–thickness curves. Analysis of variance was performed using new statistical software named QC expert trylobite and Darwin in order to compare the influence of different fabric parameters on thermo-physiological and compression behavior of samples. This study established that the raw materials, type of spacer yarn, density, thickness, and tightness of surface layer have significant influence on both thermal conductivity and work of compression in spacer fabrics. The parameter which mainly influences the water vapor permeability of these fabrics is the property of raw material i.e. the wetting and wicking properties of fibers. The Pearson correlation between moisture capacity of the fabrics and water vapor permeability was found.     

Effect of Pique and Honeycomb Structures on Moisture Management Properties of Eri Silk Knitted Fabrics

ABSTRACT

The present study aims to investigate the moisture management and wicking properties of eri knitted fabrics. In this study, two different knit structures, namely, single pique and honeycomb fabric, were developed with the combinations of two different tightness values of slack and tight by using 2/80s Nm and 2/140s Nm eri silk yarns. The developed fabrics were analyzed for vertical wicking, moisture management properties such as wetting time, spreading speed, absorption rate, maximum wetting radius, accumulative one-way transport index (AOTI), and overall moisture management capacity (OMMC). Variables such as yarn linear density, tightness, and knitting structure have a significant influence on the wicking and moisture management properties. The overall OMMC indices of eri silk knitted fabric lie in the ‘very good’ to ‘excellent’ category, indicating the suitability of eri silk yarn for skin fit as well as active wear applications.