A study on thermal properties of single-jersey knitted fabrics produced from ring and compact folded yarns

This paper presents a study on the thermal properties of single-jersey knitted fabrics manufactured using ring, compact and ring/compact folded yarns. The variations in thermal properties depending on the yarn twist and traveller weight of folded yarn single-jersey knits were discussed. It was found that the thermal resistance of knitted fabrics generally increases as the traveller weight decreases, and also water vapour permeability reduces as the traveller weight decreases. The water vapour permeability and air permeability of knitted fabrics increase as the twist increases. The thermal conductivity of knitted fabrics decreases as the twist increases. The air permeability and water vapour permeability values were higher for compact folded yarn fabrics as compared to those values of ring and ring/compact folded yarn fabrics. It is observed that yarn twist and traveller weight have affected different thermal properties of single-jersey folded yarn fabrics.     

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.     

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.     

Comparison of thermal comfort properties of single jersey fabrics produced by hollow yarns with different hollowness ratio

In this study, the thermal comfort properties of single jersey fabrics produced by conventional and hollow cotton yarns with different hollowness ratio have been investigated and compared. For this purpose, thermal conductivity, thermal resistance, thermal absorptivity, air permeability and water vapour permeability of core spun, hollow and conventional yarn fabrics were measured and evaluated statistically. It was observed that thermal comfort properties of single jersey fabrics were affected by the yarn structure and the fibre distribution within the yarn. The results showed that hollow yarn fabrics had better thermal comfort properties than that of conventional yarn fabrics. In hollow yarns, as the hollowness ratio increases, air permeability and thermal conductivity of single jersey fabrics decrease but thermal resistance, thermal absorptivity and water vapour permeability increase. Statistical analysis also indicated that the differences between properties of hollow yarn fabrics and conventional yarn fabrics were significant. Furthermore, the yarn hollowness ratio significantly affects thermal comfort properties of single jersey fabrics.     

Effect of blend proportion on thermal behaviour of bamboo knitted fabrics

This study presents the thermal comfort properties of single jersey knitted fabric structures made from cotton, regenerated bamboo and cotton–bamboo blended yarns. Cotton, bamboo fibre and blends of the two fibres (100% cotton, 100% bamboo, 50:50 cotton:bamboo, 67:33 cotton:bamboo, 33:67 cotton:bamboo) were spun into yarns of identical linear density (20?tex). Each of the yarns so produced was converted to single jersey knitted fabrics with loose, medium and tight structures. The thermal conductivity of the fabrics was generally found to decrease with increase in the proportion of bamboo fibre. The relative water vapour permeability and air permeability of the fabrics were observed to increase with increase in bamboo fibre content. Statistical analysis also indicates that the results are significant for air permeability, thermal resistance, thermal conductivity and relative water vapour permeability of the fabrics.     

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.     

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.     

Comfort properties of bamboo/cotton blended knitted fabrics produced from rotor spun yarns

The comfort characteristics of bamboo/cotton-blended knitted fabrics made from rotor-spun yarns were studied in this research work. Five different blend proportions namely 100% bamboo, 100% cotton, 50:50 cotton:bamboo, 70:30 cotton:bamboo and 30:70 cotton:bamboo were used to produce rotor-spun yarns of 30^sNe_c. The yarn samples developed out of these different blend proportions were evaluated for yarn strength and elongation, yarn unevenness, yarn imperfections and used to produce single-jersey-knitted fabrics. All the fabric samples were dyed and finished. Fabric samples were evaluated for geometrical properties such as course/inch, wales/inch, stitch density and thickness apart from measuring comfort properties such as airpermeability, thermal conductivity, thermal resistance and water vapour permeability. The results indicated that 50/50 bamboo/cotton-blended knits have comparable fabric quality in terms of comfort properties with respect to 100% bamboo fabrics.     

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.     

Comparison of fabric properties knitted by pin spacer compact and conventional compact yarns

This study examined the influence of pin spacer apparatus attachment on compact yarn quality parameters and physical properties of knitted fabrics manufactured using those 100% cotton compact yarns. Two groups of compact yarns were spun on regular compact yarn spinning frame with and without addition of pin spacer apparatus which is placed at the end of the drawing unit of regular compact yarn spinning frame. Totally eight yarns were spun at four different yarn number levels (Ne 24/1, Ne 30/1, Ne 36/1 and Ne 40/1) and two different spinning conditions (with and without pin spacer apparatus). Spun yarn types were then knitted on the industrial sized plain knitting machine. Knitted fabrics were used in the greige and dyed form to evaluate their bursting strength (kPa), dimensional change, abrasion related mass loss (%), pilling resistance, air permeability (mm/s) and colour difference. Test results were then statistically evaluated and influence of pin spacer attachment on yarn quality parameters and fabric properties was determined. In the frame of this experimental work, attachment of pin spacer apparatus improved compact yarn characteristics especially at yarn evenness, imperfection and hairiness values. In case of knitted fabric properties, it was found that pin spacer apparatus attached compact yarn utilization significantly improved air permeability properties of knitted fabrics.     

Polylactic acid/lyocell fibre as an eco-friendly alternative to polyethylene terephthalate/cotton fibre blended yarns and knitted fabrics

Abstract

Polylactic acid (PLA) and lyocell fibres blend can offer an eco-friendly alternative to commonly employed blend of polyethylene terephthalate (PET) and cotton fibres in textiles. PET fibre is non-biodegradable and depletes fossils fuels and adds to landfill sites whereas conventional cotton, dominant part of global cotton production, requires large quantity of water and pesticides during its production. In this study, 100% PLA, 100% lyocell and PLA-lyocell (PL) blended yarns, in varying ratios, were ring spun and subsequently weft knitted and compared with the PET/cotton blend (50/50). The yarns were evaluated for tensile properties while the fabrics were investigated for bursting strength, bending length, pilling propensity, water vapour resistance, thermal resistance and air permeability. The economic comparisons of the two blends were also included. The results indicated that comparatively PL blends (in particular lyocell fibre rich blends) can offer environmental and performance advantages compared to PC blended knitted fabrics for casual summer clothing and active wear.     

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.     

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.     

低扭矩环锭纺纱原理及其单纱的结构和性能

本文主要回顾了低扭矩环锭纺纱技术的发展。通过讨论其纺纱三角区的特点,利用高速摄影技术对纺纱区捻度和张力分布的观察分析,系统地介绍了低扭矩纱的成纱原理。此外,结合示踪纤维技术,利用纱线结构连续测量分析系统对低扭矩环锭单纱和传统环锭单纱的内部结构进行分析,揭示了低扭矩纱独特的结构特点,如非同轴异形螺旋线结构,纤维片段局部反转现象等。这些特点解释了低扭矩纱及其织物具有优良物理性能的原因。同时,通过多个生产厂家提供的测试数据,对比分析了几代低扭矩环锭纱与传统环锭纱及其织物的物理性能,结果表明低扭矩环锭纱具有低捻高强、低残余扭矩和毛羽少等特点,其针织物经多次水洗后歪斜变形小和手感好,机织物具有较好的撕裂强力,断裂强力和耐磨擦性。最新一代低扭矩环锭纺纱技术显著地改善了高支纯棉纱的物理性能。     

Characterization of fabric properties knitted from multifilament polyester textured yarns with various number of filaments

The purpose of this study is to investigate the physical and mechanical properties of fabrics knitted from textured polyester multifilament yarns with various numbers of filaments in the yarn cross-section. In this regard, some of the characteristics of yarns and fabrics, knitted from the mentioned yarns, were measured and analysed. Analysis of results showed that increasing the number of filaments in the yarn cross-section leads to a decrease in yarn’s diameter and abrasion resistance. Moreover, examining the properties of the weft-knitted fabrics revealed that increasing the number of filaments causes a rising trend in the compressibility and bursting strength of fabric. On the contrary, the thickness, air permeability and abrasion resistance decreases due to a growth in the number of filaments. A decline in the strength and elongation of yarns and fabrics produced from them is also another result of increasing the number of filaments in the yarn cross section.     

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.     

多重集聚纺纱结构成形机制及其针织物性能

为解决多毛羽传统环锭纱针织困难,而光洁的常规集聚纺纱线织物手感硬的技术难题,建立串联半开放式多重集聚纺纱方法,分析多重集聚纺纱机制和结构成形特征。理论分析结果表明,多重集聚纺纱线具有外紧而内柔的结构特征。基于理论解析,在相同工艺条件下,分别采用传统环锭、常规集聚和多重集聚纱线制成针织面料,对比分析了各针织物压缩回弹、透气、抗起毛起球、耐磨、染色等性能。测试结果表明：与传统环锭纱相比,多重集聚纱线针织物耐磨、透气性、抗起毛起球性改善;与常规集聚纱线相比,多重集聚纱线针织物悬垂性、压缩回弹性和染色性能明显提高。     

改性黏胶/棉纬编面料开发

采用改性黏胶纤维ComfortechTM与长绒棉纤维按质量比40/60混合,经赛络紧密纺工艺纺制成19.44 tex改性黏胶/棉混纺纱,测试并分析该混纺纱的捻度、毛羽、摩擦因数、条干不匀和力学性能等指标;再经组织结构设计、针织和染整加工,开发含成圈、集圈、浮线等花色组织的改性黏胶/棉纬编面料,测试与分析该面料的扭曲性、刚柔性、抗起毛起球性、透气性、缩水性、染色牢度、pH值、甲醛含量、偶氮含量和抗菌性等指标。结果显示改性黏胶/棉纬编面料不仅具有手感柔软、透气性好等优良的服用性能,且染色牢度高,抗菌功能良好。     

Studies on moisture transmission properties of PV-blended fabrics

Moisture transmission properties are most important for fabric comfort. We have studied the moisture transmission properties of the plain-woven fabric produced with polyester–viscose-(PV) blended yarns. PV-blended yarns of varying blend proportion, yarn count and twist levels have been used for fabric manufacture. A three-variable Box and Behnken factorial design technique has been used to study the interaction effects of the above variables on the aforesaid characteristics of fabrics. The interactive effect of these three variables on the air permeability, water vapour permeability, in-plane wicking and vertical wicking of PV-blended fabrics has been studied and the response surface equations for all the properties have been derived; also, the design variables have been optimized for all the moisture transmission-related properties. Most of the moisture transmission characteristics were found to be affected significantly by blend proportion, count and twist levels at 95% level of significance with the present variables.     

仪纶~(TM)纬平针织物的抗起毛起球性能

本文分别选用环锭纺、赛络纺、赛络紧密纺纺纱工艺,制备了同等纱支的仪纶~(TM)纯纺、仪纶~(TM)/棉(65/35)混纺针织纱线及其纬平针织物,对比测试了纱线性能及其织物抗起毛起球性能。实验结果显示:不同纺纱工艺的仪纶~(TM)针织纱线总体性能相似,赛络紧密纺纱线纱体结构更均匀;赛络纺织物的抗起毛起球性较环锭纺织物高0.5级,赛络紧密纺织物的抗起毛起球性明显好于环锭纺织物;混纺织物的抗起毛起球等级和起球粒数均有所改善。