Investigation of the thermal comfort properties of knitted fabric produced from Estabragh (Milkweed)/cotton-blended yarns

In this research, the thermal comfort properties of a newly known fiber called Estabragh (Milkweed) have been investigated. Estabragh is a natural hollow fiber which is expected to provide excellent insulation properties due to their individual characteristics. Thermal comfort is one of the important fabric properties especially in the area of sport application which is considered in this research. For investigating this, 50–50% Estabragh/cotton-blended spun yarns was produced using short-staple spinning system. Two different sets of interlock-knitted samples using 100% cotton and Estabragh/cotton-blended yarns were produced individually on a flat knitting machine. Heat transfer rate, water vapor transmission, air permeability, and capillary absorption of produced fabrics were measured and compared. The results revealed that the vapor transmission rate through the knitted samples produced from Estabragh/cotton-blended yarns was 66.4% which is higher than that of the 100% cotton samples as 60.22%. It was also found that 100% cotton samples exhibited less moisture transfer rate than cotton/Estabragh samples. As far as heat transfer is concerned, it was concluded that the heat transfer ability of 100% cotton samples is higher than that of the Estabragh/cotton samples by about 47%. It was also shown that the capillary absorption of samples produced from Estabragh/cotton-blended yarns was higher than that of the 100% cotton samples. Compared to the 100% cotton samples, air permeability of Estabragh/cotton-knitted structures was found to be relatively low. The results totally proved that Estabragh fibers have a lot of advantages in order to be used in different fields of applications especially in sport areas.     

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.     

Novel engineering approach to optimization of thermal comfort properties of hemp containing textiles

The aim of this research was to investigate the possibilities of producing comfort hemp containing textile fabrics by assembling a pure hemp yarn with other-fibre containing yarn. The plain knitted fabrics were produced from two-assembled hemp and three variants of cotton yarns which differed in twist level, all having the same linear density. The transport properties (air permeability, water vapour permeability and thermal resistance) of the hemp-based knitted fabrics were quantitatively analysed. The results obtained demonstrated that the introduction of cotton into hemp-based textiles reduces air and water vapour permeability with the downward trend in thermal resistance. The extent to which the transport properties varied among the hemp/cotton knitted fabrics was dependent on the twist intensity of the cotton yarns. Therefore, the yarn assembling technique is an effective way not only to combine different fibre properties but to take advantage of intrinsic properties of component yarns.     

Analysis of mechanical and dimensional properties of the denim fabrics produced with double-core and core-spun weft yarns with different weft densities

Elastic structures are preferred for improving the elasticity and recovery properties of denim fabrics. With the intention of improving comfort during body movements in denim jeans, 10–35% elasticity is required. In this study, the effect of the composition of double-core (dual-core) and core-spun weft yarns and weft density on the mechanical properties of denim fabrics was investigated. For this purpose, different core materials were used in the production of elastic yarns. The sheath material was cotton for all yarn types. Yarn samples were spun with the same yarn count and twist coefficient. 100% cotton Ne 8/1 Ring slub warp yarns were used as warp yarn while double-core and core-spun yarns were used as weft yarns in weaving. The weaving process was performed with three different weft density values (16, 22, and 28 weft /cm) and the other production parameters were kept constant. Twill 3/1 woven fabrics were treated according to standard denim finishing procedures. After domestic washing processes, mechanical properties of the samples were tested and statistically evaluated.     

Effect of rotor spinning transfer channel modification on fiber orientation and yarn properties

The vortices are generated at the conventional transfer channel, having adverse effects on fiber configuration. In a former research, a conventional transfer channel was modified via rounding the transfer channel inlet corner and adding a bypass channel. The simulation results obtained with the modified transfer channel showed that the vortices were eliminated and the inlet air velocity increased. We present the impact of this modification on the yarn properties and fiber straightness. Four groups of yarn samples were spun using the conventional and modified spinning system. Yarn properties and fiber straightness along the rotor groove were evaluated. Results revealed that tenacities of the yarns spun on the modified system, increased in comparison to that of the conventionally spun yarns. The number of nearly straight fibers is increased by 25.55% by using the modified system, which was mainly attributed to the decrease in the number of fibers with trailing and leading hooks.     

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.     

带传动弹性滑动角和弹性滑动率的定量计算

通过对带传动的受力分析,推导出了弹性滑动角的计算公式;从定量分析带传动弹性滑动速度入手,给出了弹性滑动率的计算公式,指出带传动传递的功率和带的初拉力是影响弹性滑动角和弹性滑动率的主要因素.     

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.     

Physical properties of ring,compact, and air vortex yarns made of PTT/wool/modal and wearing comfort of their knitted fabrics for high emotional garments

This study examined the physical properties of PTT/wool/modal yarns according to the yarn structure and the wearing comfort of their knitted fabrics for high emotional garments. For this purpose, the air-vortex, compact, and ring yarns and their knitted fabrics were prepared to analyze the wear comfort according to the yarn structure and the possibility of applications of the PTT/wool/modal blend fibers to air-vortex yarn. The wicking and drying rates of the air-vortex yarn knitted fabrics were superior to those of the ring and compact yarns fabrics, and the heat-keeping capability of the air-vortex yarn knitted fabric was higher than those of the ring and compact yarns fabrics due to the low thermal conductivity and maximum heat flow rate. In addition, the pilling of the air-vortex yarn knitted fabric was less than those of the ring and compact ones due to the air-vortex yarn structure with parallel fibers in the core part and the periodical and fasciated twists on the sheath part of the yarns. The tactile hand of the air-vortex yarn knitted fabric was harsher than those of the ring and compact yarns knitted fabrics because of the low extensibility and compressibility, and the high bending and shear rigidities.     

Analysis of thermal comfort properties of fabrics for protective applications

Protective clothing protects the body from external influence like heat, chemicals, mechanical hazards, bad weather, etc. by shielding the human body from harsh environmental effects. The maintenance of thermal balance is one of the most important aspects of protective clothing. The study aims to investigate the thermal comfort properties of woven hybrid fabrics produced with high performance core spun yarns. For this purpose, meta-aramid, e-glass, Technora® and Dyneema® fibres were combined using core yarn spinning method in order to enhance the protective performance characteristics. The effects of the core/sheath ratio and type of core materials on the thermal comfort characteristics were investigated and evaluated statistically. The results revealed that, core/sheath ratio, types of core materials have significant effects on thermal comfort characteristics of the fabrics. As the core ratio increases from 19 to 56%, the air permeability of the fabrics increases whereas their thermal conductivity and thermal absorptivity properties decrease. Meta-aramid/E-glass core fabrics can be preferable for protective clothing due to high air permeability and thermal conductivity values.     

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.     

全聚赛络纺双芯纱及其弹性电磁屏蔽针织物的制备

为开发弹性回复性更强的防辐射针织物,在全聚纺细纱机上采用嵌入式纺纱方法纺制3 种不同线密度的棉/ 不锈钢/ 氨纶双芯纱和3 种对应线密度的棉/ 不锈钢包芯纱,设计织制成1+ 1罗纹组织织物,测试分析纱线的包覆效果和主要性能及织物的弹性回复性、电磁屏蔽等性能。结果表明：6 种纱线包覆效果及成纱性能均良好;相比不锈钢包芯纱线织物,双芯纱织物在弹性回复和屏蔽电磁波方面有很大的优势,达到一般性民用电磁屏蔽织物的要求且能保证人体舒适性,这种新结构纱线在全聚纺设备上生产是可行的;开发弹性电磁屏蔽织物时,不仅要合理选择长丝预牵伸倍数等工艺参数,还要考虑到织物的服用性、耐久性及生产成本。     

Characterization based on the thermal capabilities of metallized fabrics equipped with hybrid conductive yarns for protective clothing

Electronic textiles are recognized for their conductive characteristics in various fields of research including medicine, communications, power and for the development of protective clothing. Out of the several types of conductive textile available, multi-component yarns and fabrics, produced from continuous copper filament as spiral covering on hybrid cover yarns, have never been investigated for their thermal capabilities. In this study, characterization based on the thermal properties for conventional copper core yarn’s fabric and newly developed copper cover yarn’s fabrics was carried out. The results demonstrate better conductivity of copper cover yarn’s fabrics as compared to the copper core conventional fabrics, which is attributed to its better conduction due to greater percentage of copper and direct contact between the heat flux transducers. With the higher porosity values for the newly developed fabric, the liquid water, water vapour and air transport capabilities, which are key aspects of thermal comfort, significantly improved.     

竹/涤混纺弹力竹节纱衬衣面料的设计与生产

介绍了细旦涤纶/竹浆纤维混纺弹力竹节纱衬衣面料的产品设计过程,叙述了纺纱及织造工艺流程,根据纱线特性对生产工艺进行了研究和探索,优化了织造工艺参数,采取了一系列技术措施,使上机织造效率达90%以上。织出的面料经印染整理后平挺美观,吸湿透气,柔软细腻,服用舒适,且具有良好的强度、弹性和保形性。     

Study of the impact of elastane's ratio and finishing process on the mechanical properties of stretch denim

The wear comfort desired by the consumer is leading to increased use of fabrics containing elastane filaments. However, the elastane's ratio is an important factor influencing the fabric's mechanical properties. Thus, we study the effect of elastane's ratio and finishing process on the elasticity of denim whose weft yarns are cotton covered elastane-core spun yarns having the same twist factor and various elastane's ratio.     

室外高温环境下通风服装的传热模型与实验研究

为提高夏季室外高温日晒环境下作业人员的热舒适性,对人体、服装与环境之间传热过程进行分析,以此作为针对性降温方式的理论基础建立了通风服装在室外高温日晒环境下的传热模型,并采用真人实验的方法验证了该传热模型;分析了送风后衣下空间空气参数及人体主观反映的改变.结果表明:采用该模型计算得到的人体得热量与失热量误差仅为9.1％,...     

Development of seersucker fabrics using single warp beam and modelling of their stretch-recovery behaviour

Seersucker is a thin and puckered fabric used to make clothing for spring. Due to its specific structure, this fabric is held away from the skin when worn, facilitating heat dissipation and air circulation. Seersucker is produced by slack tension weaving using two warp beams. Due to the use of two beams, such fabrics were not possible to weave on conventional (with single warp beam) weaving machines. Additional twin beams arrangement was required for such weaving. The objective of the current study is to produce seersucker fabric on conventional looms using a single warp beam. For achieving this objective, two types of weft yarn: 100% cotton yarns and blended yarns of cotton and elastane (95.67% cotton and 4.33% Lycra) are used in groups. The viscoelastic behaviour of the produced fabric samples is tested using ASTM standard D3107-07. Instant deformation, elastic recovery, creep and relaxation were recorded and plotted as function of Lycra % age.     

通风服热舒适性研究现状与展望

为揭示通风服对人体热舒适影响的机制,阐明通风服与人体之间的热湿传递关系,在介绍通风服的起源和工作原理的基础上,通过对国内外相关研究成果的分析和总结,重点论述了通风服热舒适性的研究方法:出汗暖体假人测试法、人体着装实验法和数值模型构建法,并分析了各种方法的优缺点。结果表明,通风服对人体热舒适的影响机制是一门集环境传热学、人体生理传热学、服装面料学以及流体力学交叉结合的工程问题。最后对通风服热舒适性研究进行了展望,认为未来将在通风服衣下气流的精确测量与仿真,衣下气流和热流数值模型的构建以及通风引起的局部和整体热舒适不匀等方面开展研究。     

探析中国牛仔布与牛仔用纱的技术创新与发展动向

文章分析了牛仔布与牛仔服饰长盛不衰的原因以及随着人们对穿着服饰观念的变化,开发新型牛仔布及牛仔服饰的必要性。根据人们对穿着牛仔服饰要求时尚化、舒适化及健康卫生的诉求,促进生产企业加快新型牛仔布及牛仔用纱的开发步伐,先后开发出弹力牛仔布、功能性牛仔布、轻薄型牛仔布、针织牛仔布及仿针织牛仔布等新品种,改变了传统牛仔布使用原料单一(棉花)、织物厚重(粗支纱生产)及色泽单调(靛蓝色)的格局。文章还对新型牛仔布与牛仔用纱在开发生产过程中所采用的相关工艺技术措施作了简要分析,使开发的牛仔布及牛仔用纱符合生产高端牛仔服饰的要求。     

纬编间隔床品面料的结构及性能分析

采用3.3 tex涤纶单丝为间隔纱,8.3 tex涤纶和2.2 tex氨纶交织为表层,制备4种不同密度、厚度及间隔纱连接方式的纬编间隔织物。分析织物组织结构和编织工艺,并测试力学性能和热湿舒适性能,分析面料厚度、密度与各项性能关系,用数学模糊分析法对面料进行综合分析。结果表明,间隔纱连接方式对面料拉伸断裂性和顶破性有一定影响,对透气透湿性无明显影响;厚度、密度较小且间隔纱交叉连接的织物综合性能最好;选择床垫面料时考虑厚度、密度及间隔纱连接方式对面料性能影响。