Effect of cyclic stress on the transverse wicking behaviour of cotton/lycra knitted fabrics

It is extremely important to evaluate transverse wicking behaviour of elastic knitted fabric while the fabric simulated in different body motions. In this paper, the effects of short interval dynamic extension and recovery on fabric transverse wicking behaviour were evaluated as the samples were subjected to different rate of extension (speed), different percentage of cyclic extension and different liquid flow rate. For this application, a new cyclic stress instrument was designed and developed to apply repeated dynamic extension and recovery on the fabric. The developed instrument is operated through embedded micro controller programme. The effect of speed, percentage of cyclic extension and flow rate with respect to the dynamic transverse wicking behaviour of elastic knitted fabric has been studied using Box–Behnken experiment model. The experiment model identifies the principal experimental variables such as flow rate, percentage of cyclic extension which has the greatest effect on the transverse wicking behaviour of elastic knitted fabric.     

羊毛与37.5涤纶混纺针织物的热湿舒适性研究

选择8种不同的羊毛与普通涤纶、37.5涤纶混纺针织物试样,测试试样的密度、面密度、未充满系数和厚度等基本参数,以及回潮率、透气率、芯吸高度、瞬间接触凉感(Q-max)及恒定加热条件下的干、湿态升温性能等织物的热湿舒适性能,分析和评价了针织物的基本参数对其热湿舒适性能的影响。试验结果显示,与普通涤纶相比,采用37.5涤纶有助于提高织物的回潮率、芯吸高度和Q-max;透气率随针织物未充满系数的增大而增大;当织物的纤维组成成分基本一致,组织结构相同时,针织物的面密度越大,透气性越差;含37.5涤纶的纬平针织物的瞬间接触凉感性能较好。     

Thermophysiological comfort properties of selected knitted fabrics and design of T-shirts

Thermal comfort is one of the most important components of comfort which shows physiological, psychological, and physical harmony between human body and environment. The heat and moisture transfer capacity of fabric from skin to environment affects the thermal comfort of garments. The transfer capacity depends on the characteristic features of raw materials and fabric structural properties. In this study, it is aimed to determine the advantages of knitted fabric types, taking into account the environmental condition and activity level by measuring the thermal comfort properties such as air permeability, wicking, moisture management, thermal and water vapor resistances. Two knitted structures composed of tuck and float combinations and six raw materials were chosen for the fabrics produced. According to the measurement results, the polyester and cotton/Coolmax fabrics with float stitches have had good liquid moisture transport properties. Besides, high air permeability and low water vapor resistance have been obtained in viscose and Tencel LF fabrics with tuck stitches. On the basis of the results obtained in this investigation, and taking into consideration thermal behavior of human body, four women’s and five men’s T-shirts are designed. These T-shirt designs may be helpful for further approaches on the optimization of thermal comfort for sports activities in hot environment.     

Wicking and drying properties of conventional ring- and vortex-spun cotton yarns and fabrics

This study investigated the vertical wicking, water absorption and drying properties of vortex- and ring-spun combed cotton yarns and knitted fabrics comparatively. The yarns were produced in three different counts as 30 Ne, 40 Ne and 50 Ne. The experimental results revealed that vortex-spun yarns had lower yarn and fabric wicking and water absorption values than ring-spun yarns. In addition, it was observed that yarn type did not have a significant impact on the drying time of the fabrics.     

Mathematical model to predict vertical wicking behaviour. Part II: flow through woven fabric

The aim of the paper is to develop a mathematical model to predict vertical wicking behaviour of woven fabric. The first part of this series (Part I) has dealt with the mathematical model for predicting vertical wicking through yarn. In this part a model has been proposed to predict vertical wicking of the woven fabric, based on the developed yarn model. In order to model the flow through woven fabric along with the vertical flow through liquid carrying threads, the horizontal flow through transverse threads has also been taken into account. A simplified fabric geometrical concept (inclined tube geometry) and Peirce geometry for plain woven fabric have been used to define the fabric structure. Warp and weft linear density, fabric sett and yarn crimp have been considered in the fabric modelling. The theoretical wicking values of the yarn and fabric made from that yarn have been compared. Experimental verification of the model has been carried out using polyester and polypropylene fabrics. The model is found to predict the wicking height with time through the yarns and fabrics with reasonable accuracy.     

水分沿针织物纵横向传递速度的研究

采用同一种棉纱织成6种同组织不同结构的针织物,运用水平芯吸的实验方法,分别测试水分沿针织物纵横向的芯吸速率,发现芯吸高度h与时间t可以很好地用h=atb表示.通过线性回归得出织物结构参数--纵密、横密、织物厚度对芯吸速率的影响,结果表明针织物的芯吸不能简单地用毛细上升的规律来描述.在织物结构参数影响中织物厚度的影响最大,织物越厚,芯吸速率越小;织物纵密、横密越小,芯吸也加快.此外,也对针织物的芯吸规律进行了一些探讨.     

碱减量对Coolmax针织物性能的影响

以不同碱浓对Coolmax导湿快干纤维双面针织物进行碱减量处理，探讨了烧碱浓度对Coolmax织物减量率、强力、染色性能、芯吸性能和柔软性的影响。试验表明，Coolmax纤维比表面积大，其针织物的减量率比常规涤纶针织物大得多，处理后芯吸性能变好，柔软度提高，能产生深色效应，但减量率过高会降低纤维的异形度，损伤纤维。     

Development of mathematical model to predict vertical wicking behaviour. Part I: flow through yarn

Theoretical models have been proposed in this article (Parts I and II) to predict the vertical wicking behaviour of yarns and fabrics based on different fibre, yarn and fabric parameters. The first part of this article deals with the modelling of flow through yarn during vertical wicking, whereas the second part deals with the modelling of vertical wicking through the fabric. The yarn model has been developed based on the Laplace equation and the Hagen–Poiseuille’s equation on fluid flow; pore geometry has been determined as per the yarn structure. Factors such as fibre contact angle, number of filaments in a yarn, fibre denier, fibre cross‐sectional shape, yarn denier and twist level in the yarn have been taken into account for development of the model. Lambertw, a mathematical function, has been incorporated, which helps to predict vertical wicking height at any given time, considering the gravitational effects. Experimental verification of the model has been carried out using polyester yarns. The model was found to predict the wicking height with time through the yarns with reasonable accuracy. Based on the proposed yarn model, a mathematical model has been developed to predict the vertical wicking through plain woven fabric in the second part of this article.     

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.     

织物吸湿性对织物和皮肤间动摩擦力的影响

为探明含水率不同织物与皮肤间的动摩擦力变化趋势,选取18种机织面料和9种针织面料与同一女性青年志愿者的前臂内侧皮肤进行摩擦实验,利用织物皮肤摩擦测试仪测试湿态条件下织物与皮肤间的动摩擦力。针对不同湿态条件的织物试样,采用完全浸润织物后悬挂自然晾置的方式,以织物的含水率定量表征织物的润湿程度。结果表明：相同原料的织物和皮肤间的动摩擦力变化趋势相似,反之亦然;织物含水率在10%~60%的范围内,随着织物含水率的增大,不同原料的织物与皮肤间的动摩擦力变化普遍存在先增大后减小的趋势;湿态条件下织物和皮肤间的动摩擦力达到峰值时,织物的含水率与纤维的公定回潮率存在正相关关系。     

Optimization and surface modification of silk fabric using DBD air plasma for improving wicking properties

It is necessary to study the suitable effect of plasma parameters, such as exposure time and applied voltage on the wicking properties of silk fabrics. Wicking property of silk fabric has been improved by using air dielectric barrier discharge plasma treatment. The plasma treatment has been utilized to modify the surface properties of silk fabrics. Untreated and plasma-treated fabrics have been characterized by contact angle Goniometer, wicking test, Wet-out time, scanning electron microscope, Attenuated Total Reflection Fourier Transforms Infrared spectrometer (ATR-FTIR) and dye uptake test. The ATR-FTIR characterization shows that the hydroxyl functional group has been increased after plasma treatment of silk fabric. The experimental results of wicking rate and Wet-out time of the plasma-treated silk fabrics have shown significant improvement in hydrophilic properties that could be confirmed by contact angle measurement which is close to 0°. The tensile strength of untreated and plasma-treated fabrics has been measured to confirm the enhanced surface property.     

Thermal and mass transport properties of polyester–cotton plated fabrics in relation to back layer fibre profiles and face layer yarn types

Clothing plays an important role in maintaining thermal equilibrium between a human body and the ambient environment by serving as a medium for heat, moisture vapour and liquid moisture transfer. The ability of fabric to maintain this equilibrium is related to thermo-physiological comfort. Plating is an innovative knitted fabric production technique to obtain bi-layered fabrics. An attempt has been made to engineer plated knit structures with such a combination of fibre cross section in the back (inner/next to skin) and the yarn type in the face (outer) layer, so that a rapid liquid transfer from back layer by wicking and quick liquid absorption and evaporation by the face layer can be achieved. Plated fabrics using the combination of triangular polyester fibre in the back and carded cotton yarn in the face layer showed the higher thermal resistance, higher absorbent capacity and would be warmer to the initial touch. However, the combination of combed cotton yarn with triangular polyester fibre resulted in fabrics with the higher air permeability, moisture vapour transmission rate and transplanar wicking.     

Mathematical model to predict vertical wicking profile of single weft knitted structure

Mathematical models has been proposed to predict the vertical wicking height in single weft knitted fabric considering two scales of capillary flow; macroscale capillary flow through capillaries formed between yarns in the fabric, and microscale capillary flow through capillaries formed with in yarn. Macroscale model has been developed based on the sinusoidal irregular capillary to predict wicking profile along the wale and course directions. Microscale capillary model was developed considering capillaries as tortuous stream tubes along the wale and along the course. Another model based on inclined tube capillary has been developed to predict the wicking along wale. Lambert function has been used to calculate wicking height at different intervals of time. Validation of theoretical results has been done with experimental results taking fabric knitted from polyester yarns. Three different levels of tightness and three different shape factors of filament have been taken in the experimental study and the significance of their effect has been evaluated using ANOVA. A good correlation has been found between theoretical and experimental results.     

Analysis of warp knitted fabric structure. Part V: experimental study on the initial modulus of warp knitted fabrics

In the previous parts of this series, tensile properties of warp knitted fabrics were investigated using energy method. For this purpose, the geometry of fully threaded two-guide bar structures, i.e. tricot, locknit, reverse locknit, satin and sharkskin were modeled by considering the fabric density, yarn diameter and the number of front and back bar underlaps. Then, the theoretical models for the initial modulus of aforementioned structures were obtained. In the present study, the initial modulus of actual fabrics has been calculated using presented models in previous parts. Then, a new test method was defined for tensile testing of warp knitted fabric, specifically. Thereafter, the initial modulus of prepared samples has been measured by using tensile tester in order to compare with theoretical values, based on derived test conditions. Reasonable agreements between theoretical and experimental results showed that generated models are capable to predict the initial modulus of fully threaded two-guide bar warp knitted fabrics, adequately.     

Analysis of some comfort and structural properties of cotton/spandex plain and 1×1 rib knitted fabrics

Spandex is increasingly used in either every course or alternating courses of knitted fabrics to impart a greater level of stretch and form stability than that can be achieved with cotton alone. The incorporation of spandex to the fabric structure effects many of the fabric properties. In this study, 100% cotton, half-plated and full-plated, plain and rib fabrics which are very commonly used in underwear and outerwear clothing are investigated for physical, dimensional, geometrical, and some comfort properties and compared to each other. Several conclusions could be obtained such as the wicking heights of the plain fabrics were higher than those of the 1×1 rib fabrics. Transfer wicking ratios of the half-plated fabrics were the highest, whereas the transfer wicking ratios of the full-plated fabrics were the lowest. Extension under constant load and residual deformation ratios decreased with the addition of spandex and the increase in spandex content. Plain fabrics generally performed better than 1×1 rib fabrics in terms of residual deformation ratios.     

基于MSC.Marc的针织物悬垂屈曲的数值模拟

 基于MSC.Marc良好的开放性语言接口,引入针织物的细观力学本构模型,建立完整的适合于针织物悬垂屈曲模拟的数值分析模型,模拟其在自重作用下的悬垂及屈曲,该细观本构模型描述了针织物由于其细观针织结构而特有的力学性质。采用8结点壳单元离散织物片,这种壳单元被特别设计,能描述织物片在悬垂中发生的大转动。分析了织物片的屈曲模态,计算了其后屈曲变形,并进行了方形织物片的悬垂和屈曲实验,模拟结果和实验观测结果一致。最后给出其变形的动态过程模拟。     

Thermal and water vapor transmission through porous warp knitted 3D spacer fabrics for car upholstery applications

This paper deals with water vapor transmission and thermal properties of various warp knitted spacer fabrics. In this work, thermal and water vapor permeability of different spacer fabrics have been evaluated by varying the structure, areal density, thickness, type of raw materials, etc. The air permeability and water vapor transmission of the fabrics were measured using the Textest FX-3300 air permeability tester and PERMETEST. The thermal behavior of fabrics was evaluated by Alambeta instrument. Analysis of Variance (ANOVA) was performed using new statistical software in order to compare the influence of different fabric parameters on thermo-physiological 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 thermal conductivity in spacer fabrics. The parameters which mainly influence the water vapor permeability of these fabrics are porosity, density, and thickness. The empirical model for thermal conductivity calculation shows very high accuracy when compared with experimental results. The statistical model for spacer fabrics also predicts the thermo-physiological properties with very high accuracy. These findings are important requirements for further designing of spacer fabrics for car seats and back supports.     

Wickability behaviour of single-knit structures

Wicking is the spontaneous flow of a liquid in a porous substrate, driven by capillary force. This flow in aporous medium, caused by capillary action, is governed by the properties of the liquid such as surface tension, viscosity and density as well as the surface-wetting forces and geometric configuration of the pore structure such as yarn construction, number of fibres in the cross section, the randomness of the internal structure, twist and the fabric structure. In this study of wickability, the most widely used structures such as single jersey, single pique, double pique and honeycomb with two structural-cell stitch lengths have been considered. Wickability increases with structural-cell stitch length. Among the different structures of fabrics, single jersey with higher structural-cell stitch length shows better performance of wickability and absorption of water when drop is placed on the fabric. The wickability of knitted fabrics was also evaluated in different directions such as wale, course, and bias direction. Among these, wale-wise specimen shows better wicking behaviour. The effect of different liquids like distilled water, artificial sweat solution, tap water, hot water and so on was also tested. The distilled water shows good wicking behaviour as compared with other liquids.     

基于AHP方法的作训服面料性能分析

本文选择5种机织面料和4种针织面料作为作训服面料,分别对其物理性能、热湿性能进行测试,并通过层次分析法(简称"AHP")将所测得的数据进行综合分析,计算出每种面料所占的权重。通过基于层次分析法的作训服面料性能分析,得出机织面料2#和针织面料4#较适合作训服面料,可采用在作训服适当部位拼接针织面料的方法来提高作训服的整体性能。     

高捻桑蚕丝针织物的服用性能与风格

为了解决普通桑蚕丝针织物的抗皱性、保型性和耐磨性差等问题,采用将桑蚕丝施加高捻的方式,改进桑蚕丝针织物的服用性能。通过对不同捻度桑蚕丝针织物力学性能、外观形态性能的实验研究以及织物风格的评定,系统地研究了高捻桑蚕丝针织物的性能和织物风格。采用KES织物风格测试仪测定不同捻度织物的16项力学指标,进而得到评定织物基本风格值的HV值,分析了高捻桑蚕丝针织物风格方面的综合性能。实验分析结果表明,高捻桑蚕丝针织物具有更加优良的性能,拓展了桑蚕丝针织物的应用领域。