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.     

Total porosity,theoretical analysis,and prediction of the air permeability of woven fabrics

Air permeability is one of the most important properties of textile materials that ensure their comfort. For many materials for technical applications (filters, sails, vacuum cleaners, parachutes, etc.), this is one of the main properties that determine their quality. The air permeability of woven textile fabrics depends on many parameters of fabric. Thus, the determination of air permeability of woven fabric is highly complex and difficult. In this study, we attempted to establish a theoretical model for the porosity and predicted the air permeability of woven fabrics. A theoretical model was created to predict the total porosity and the air permeability of a fabric structure depending on the geometrical parameters such as pore size, warp density, weft density, fabric thickness, number of yarn, diameter of yarn, and fiber density. For the purpose, a theoretical model of porous systems on D’Arcy’s law was used, and the validity of the model was confirmed by experimental results using 100% cotton and 97/3 cotton/lycra woven fabrics. Since the amount of air passing through both the pores between yarns and the interstices in the fibers constituting the yarn structure was calculated, theoretical values of air permeability were obtained very close to the experimental values.     

The functionality of woven fabric from air-jet yarn from the mixture of CO/PA and CO/PES fibres in the weft direction

The purpose of presented research is to find out the influence of air-jet yarn from the mixture of CO/PA (50/50) and CO/PES (67/33) fibres on functionality of woven fabric in the plain weave.The first part of the study is directed to the mechanical and physical properties of air-jet yarns (16.7 tex) from CO/PA and CO/PES fibres, while the second part of the study focuses on permeability properties of fabrics with air-jet yarns in the weft. The results show that air-jet yarn in the weft direction influences on the water vapor transmission and thermal conduction increase and air permeability decrease.Incorporation of air-jet yarn in the weft direction also improves breaking extension level.The results of presented research also show that the incorporation of air-jet yarn in the weft has statistical important influence on thermal conduction, water-vapor and air permeability changes.     

Elastic Recovery and Performance of Denim Fabric Prepared by Cotton/Lycra Core Spun Yarns

ABSTRACT

Elastic performance coefficient (EPC) and recovery behavior of denim fabrics prepared with cotton/lycra core spun stretch yarns have been presented in this article. The denim fabrics are woven as broken twill weaves in an air-jet weaving machine by the insertion of core spun yarns (lycra filament in core, cotton fiber on sheath) as weft and using 100% cotton yarns as warp. The effect of linear density and stretch percentage of the core spun weft yarns on tensile and recovery behavior of denim fabric have been investigated by employing full factorial design of experiments. It has been observed that the tensile strength and EPC of fabric increase with decrease in linear density and stretch percentage of the core spun stretch yarn. The immediate elastic recovery and delayed elastic recovery increase with decrease in linear density and stretch percentage of the yarns.     

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.     

Thermo-physiological comfort properties of double-face knitted fabrics made from different types of polyester yarns and cotton yarn

Double-face knitted fabrics with hydrophobic inner and hydrophilic outer layers are characterised by their advantageous thermo-physiological comfort property that facilitates the transport of sweat from skin to outer fabric layer where it can be evaporated easily. In this study, for the production of double-face knitted fabrics, cotton yarn as hydrophilic yarn type and five different polyester filament yarns consisting of standard polyester, hollow polyester, micro polyester, textured polyester and textured micro polyester as hydrophobic yarn type were used. In order to determine the thermo-physiological comfort properties of the fabrics, air permeability, water vapour permeability, thermal conductivity, thermal resistance and overall moisture management capacity were measured. The results were comparatively analysed using statistical methods. The experimental results demonstrated that the polyester-type yarns and the combinations of them with the cotton yarn in fabric layers affected the thermo-physiological comfort properties significantly. The fabrics with polyester-type inner face and cotton outer face showed the best moisture transmission properties.     

Effect of cotton fiber and yarn characteristics on color variation in woven fabric dyed with vat dyes

The aim of this study was to investigate the effect of cotton fiber and yarn characteristics on the color variation of woven fabrics dyed with vat dyes. A fabric length of 31?m was woven so that each meter of the fabric comprised weft yarns of slightly different cotton fiber or yarn characteristics as compared to the other. The woven fabric was pretreated and dyed with vat dyes using industrial-scale, pad-dry-chemical-pad-steam process. After dyeing it was found that the fabric containing weft yarns made from cotton with higher reflectance (Rd) values gave poor color strength as compared to that of lower Rd values. Fabric comprising combed weft yarns showed better color depth (K/S) values as compared to that comprising carded weft yarns made from the same raw cotton. Furthermore, the fabric comprising finer- or lower-twist weft yarns gave higher color depth as compared to that with coarser or higher-twist weft yarns. It was concluded that slight variations in the cotton or yarn characteristics in the weft yarns could result in significant shade variations in the vat-dyed 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.     

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.     

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.     

Effect of weft density and percentage of stainless steel fiber content of weft yarn on electrical properties of woven fabric strain sensors

Textile-based strain sensors have been used in smart textiles frequently. In this study, effect of percentage of stainless steel fiber of spun yarn (i.e. 28 and 40%) and weft density (i.e. 14, 18, and 22 per cm) of conductive yarn on performance and sensitivity of woven fabrics strain sensor under tensile cyclic loading in 3 mm elongation and also behavior of woven fabric strain sensors under simple tensile loading, was studied. Our finding showed the interaction between weft density and percentage of conductive fiber of spun yarns on performance and sensitivity of strain sensors under cyclic loading. Samples prepared by conductive yarns with 40% stainless steel fiber showed no clear cyclic variation in 18 and 22 weft per cm. This trend for samples woven with conductive yarn with 28% stainless steel fiber was only observed in 22 weft per cm. All samples showed the same trend of resistance variation during simple tensile loading, although the level of resistance variation was different. The slope of resistance variation during tensile cyclic loading confirmed plastic deformation of samples. Finally, by comparing the sensitivity of strain sensors during cyclic loading no obvious advantage was obtained for samples woven with conductive yarn with 40% stainless steel fiber compared with samples woven with conductive yarn with 28% stainless steel fiber.     

Acoustic performance of woven fabrics in relation to structural parameters and air permeability

This work deals with the study of the acoustic characteristics of woven fabrics in relation to fabric structural parameters and air permeability. In order to achieve the objectives of the research, sound absorption coefficient of woven fabric samples was determined via impedance tube method. Samples with various pick densities and yarn twist were used. The effect of fabric thickness was analyzed using three and six layered test samples. Results showed that, while for all samples the minimum values of sound absorption were observed at frequency bands of 250 and 2000?Hz, the maximum sound absorption occurred at the frequency of 1000?Hz. Results also indicated that fabrics woven at pick density of 30?thread/cm exhibited higher sound absorption than fabrics woven at other pick densities. It was found that, noise reduction coefficient of three and six layered samples, woven at low pick densities showed significant increases in comparison to those woven at high pick densities. It was also established that samples woven with lower weft yarn twist absorb sound wave more efficiently. It was concluded that fabric air permeability can be used as a criterion of sound absorption behavior of woven fabrics.     

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.     

用Dref 3摩擦纺多组分纬纱织造的织物的风格特征

研究分析了3种用Dref3摩擦纺多组分纬纱织造的平纹织物的风格特征。3种不同的纬纱是：芯皮均为粘纤;水溶性PVA作皮,粘胶无捻纱条作芯;PVA无捻纱条作芯,粘纤作皮。3种纱均在Dref3型摩擦纺机上按芯皮50／50比例纺成,经纱统一采用2合股纯棉纱线。将3种纱分别织成织物,然后用热水将PVA溶解去除。织物性能的测定结果：织物性能与组成织物的纱组分性能并不一致。无捻芯纱(溶掉PVA表皮)织物具有较高的拉伸强力、撕裂强力、折皱回复性和耐磨性;而空心纱(溶掉PVA作芯)织物具有丰满、蓬松的结构和良好的耐压缩性能。     

纯棉纱线合股数对织物性能的影响

为研究纯棉纱线合股数对织物力学性能和保形性的影响,采用线密度相同的单纱、双股线、3股线、4股线4种股线类型,以适当的经、纬密分别织制成平纹、斜纹、缎纹组织的织物。对织物的拉伸性能、撕裂强力、拉伸弹性、折皱回复性、悬垂性、弯曲性进行测试与分析。结果表明:3股线织物的断裂强力和撕裂强力较大,4股线织物的断裂伸长率较大,双股线织物的拉伸弹性回复率较大;平纹织物仅有双股线织物的折皱回复性优于单股线织物,斜纹和缎纹织物的折皱回复性随合股数的增加均变差;双股线平纹织物悬垂性相对较好,但均没有斜纹和缎纹织物的悬垂性好;单纱织物的弯曲性能比股线织物好。     

涤纶与芳纶及超高分子量聚乙烯纤维复合纱防刺织物的制备及其性能

为降低高性能纤维防刺织物的成本,改善产品的舒适性,通过将芳纶、超高分子量聚乙烯纤维与涤纶进行复合纺纱并制备防刺织物,测试分析了复合纱线基织物以及铺叠层数等对其静态防刺、透气和透湿性能的影响.结果表明:织物穿刺载荷随着面密度的增加而增加,复合纱中引入涤纶可保持或提高织物的防穿刺性能;增加复合纱线织物堆叠层数,织物刺破载荷...     

Ultraviolet radiation protection by cotton fabrics: role of porous yarn structure,fabric thickness and pore size

The effect of porous yarn structure on ultraviolet (UV) radiation protection by cotton fabric has been investigated. Fabrics with porous yarn structure showed higher ultraviolet protection factor (UPF) in comparison with that of fabrics woven from equivalent normal yarns. Fabric samples having different thickness and individual pore size, at same cover %, were produced by adjusting yarn count and thread density. UPF of UV absorber treated cotton fabrics increased continuously with decreasing thickness and reducing individual pore size when the fabric cover was kept constant at relatively higher levels (93 and 96%). For UV absorber treated cotton fabrics, individual pore size is the dominating factor for determining the UPF.     

The effect of yarn twist direction on the formability of woven fabrics

This experimental work examines the influence of the yarn twist on the formability of a woven fabric. Consideration is given to the phenomenon of bedding between warp and weft yarns, as affected by the local helix angles of bent yarns. A total of 28 plain weave woven fabrics (four groups, each with seven samples) were produced, using Solospun? yarns as warp and weft threads. The fabric bending length and the initial modulus of each sample were measured from which the formability was calculated. Results indicated that the fabrics in which the warp and weft twists are unidirectional (Z &; Z) have higher formability in comparison to those fabrics in which the warp and weft twists are opposite to each other (Z &; S). In addition, among the former fabrics the highest formability belongs to those in which the total helix angle of the warp and weft is close to 90 degree whereas the lowest formability belongs to the latter fabrics with least amount of twist.     

组织结构对UHMWPE短纤纱织物防刺性能的影响

UHMWPE短纤纱具有优秀的抗切割性与较好的树脂浸润性,非常适用于制作防刺材料。文章试织了12种不同织物规格的试样,进行准静态穿刺实验,探究5种因素(组织、紧度、纱线线密度、经纬密和面密度)对织物防刺性能的影响,并比较不同穿刺角度下织物防刺性能的差异。结果表明:与方平织物与接结双层织物相比,平纹织物的防刺性能最好;同种经纬密或同紧度下,粗特纱织制的平纹织物防刺性能好;随着经密增加,紧度增加,面密度增加,防刺性能逐渐增加,但织物过于紧密时,防刺性能反而降低;平纹织物的穿刺性能具有各向异性,经纬向的防刺性能优于45°方向。     

柔洁纺粘胶强捻纱及其织物性能

为更好地探究柔洁纺技术对粘胶强捻纱质量和其机织物服用性能的影响,对相同工艺参数下粘胶强捻柔洁纺纱线与环锭纺纱线的均匀度、毛羽、单纱强力、捻缩率和表观结构进行测试对比,同时分析了相同规格柔洁纺和环锭纺粘胶强捻纱织物的强伸性、顶破性能、撕破性能、透气透湿性、吸湿性、柔软性和抗起毛起球性能。结果表明:柔洁纺粘胶强捻纱的毛羽少,条干均匀,强力高,捻缩率低;相比环锭纺粘胶强捻纱织物,柔洁纺粘胶强捻纱机织物的强伸性、顶破性能、撕破性能、透气透湿性、柔软性和抗起毛起球性显著提高,但吸湿性有所降低;柔洁纺粘胶强捻纱具有柔顺、整洁、牢固等特点,其机织物的综合服用性能优于环锭纺。