Effect of structural parameters of porous yarns and fabric on air permeability and moisture transfer of double-face woven fabrics

In this study, effect of fabric structural parameters of double-face woven fabrics including kind of porous yarn namely micro-porous yarn and hollow yarn, hole size of hollow yarn, percentage of these yarns in double-face woven fabric structure, and finally weft density on air permeability and moisture transfer of woven fabrics was evaluated. These yarns were produced by using water-soluble continuous polyvinyl alcohol filaments as core part for hollow yarns and as doubling yarn in micro-porous yarn. Results revealed the effect of kind of porous yarn, hole size of hollow yarn, and weft density on air permeability and moisture transfer of woven fabrics. The percentage of porous yarns as weft did not show obvious trend. Analysis of variance was used to study the effect of these variables on air permeability and moisture transfer of double-face woven fabrics statistically.     

机织物透气性能的预测研究

利用哈根伯肃叶定律,推导出机织物的纱线间孔隙透气量与织物结构参数的关系式。对于无法从理论上阐明的影响因素用逐步回归方法讨论它们的定量影响,得到织物透气量与纱线间孔隙透气量的理论计算值及织物紧度间的回归方程,并用新的试样验证此公式的准确性。     

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.     

单向弹性伞衣织物结构参数对其透气性的影响

为满足降落伞伞衣织物透气量能随气流冲击载荷的变化而改变的要求,设计了以锦/氨双包纱为纬纱的15种不同织物结构参数(如外包捻度、织物经密)的单向弹性伞衣织物.通过对织物结构参数与透气量关系的分析,找到了影响单向弹性伞衣织物透气量的主要因素.认为单向弹性伞衣织物的透气量随经密增大而减小,当外包捻度达到临界值(1 000捻/...     

薄型精纺毛织物透气性与织物结构参数的关系

采用Y561织物透气量仪对14种不同结构参数的精纺薄型毛织物进行透气性实验,并借助应用软件对实验数据进行分析.研究结果表明:薄型精纺毛织物的透气性不仅与纱线原料的吸湿性,经纬纱捻度、线密度有关,还与织物组织、经纬密有很大的关系,但薄型毛织物的厚度对透气性影响较小.     

机织物透气性预测的投影寻踪回归模型

针对机织物透气性预测中存在非线性建模困难的问题,选择机织物总紧度、厚度、面密度及平均浮长等结构参数作为机织物透气性预测的影响因素,建立机织物透气性预测的投影寻踪回归模型.对模型训练样本的拟合值及检验样本的预测值以相对误差的均值及标准差为指标进行分析,并与BP神经网络及多元线性回归模型进行对比.结果表明,投影寻踪回归模型...     

木棉纤维/棉混纺织物结构参数对其保暖透气性影响

为充分发挥木棉纤维的优良特性,使木棉纤维在纺织品设计开发中得到更好的应用,采用了木棉/白棉混纺纤维为原料,设计织造了13种不同组织、不同纬密,不同木棉纤维含量的木棉/白棉混纺纤维织物,并测试了织物厚度、保暖性、透气性,分析了织物不同结构参数对织物保暖性、透气性的影响。结果表明：在织物其他结构参数相同的情况下,经纬纱交织次数越少,组织结构越松厚,织物保暖性和透气性越好;织物保暖性随着体积密度增大而减少,透气性随着纬密的增加逐渐下降;随着木棉纤维含量的增加,织物的保暖性增加,透气性下降。     

Statistical model for predicting the air permeability of polyester/cotton-blended interlock knitted fabrics

Little information is available in the literature about double-rove spun yarn's low-stress mechanical properties. An experimental investigation has been made in a short-staple spinning system to study the effect of strand spacing, twist, and spindle speed on a double-rove yarn's compressive resilience, and compressibility at low-stress levels. The response-surface equations developed from the experimental results, have been used to explain the compressional behaviour of the yarn studied.     

石墨烯黏胶纤维机织物的功能改性研究

制备同规格的普通黏胶纤维机织物、石墨烯黏胶纤维机织物及不同不锈钢丝质量分数的石墨烯黏胶纤维/不锈钢丝机织物,对比它们的导电、防电磁辐射、防紫外线、抗静电、力学(拉伸、弯曲、耐磨)及透气等性能。结果表明:普通黏胶纤维经石墨烯改进后,所制成的石墨烯黏胶纤维机织物的导电、防电磁辐射、防紫外线、抗静电、力学(拉伸、弯曲、耐磨)等性能都有所改善,其中防紫外线与耐磨性能提高显著,透气性能下降明显;石墨烯黏胶纤维/不锈钢丝机织物的导电、防电磁辐射、防紫外线和抗静电、经向拉伸断裂强力、纬向抗弯刚度、透气性能都优于石墨烯黏胶纤维机织物,纬向拉伸断裂强力、经纬向拉伸断裂伸长率、经向抗弯刚度及耐磨性能不及石墨烯黏胶纤维机织物;随着不锈钢丝质量分数在7.0%~20.0%范围内的增加,石墨烯黏胶纤维/不锈钢丝机织物的导电、防紫外线、抗静电、经向拉伸断裂强力、纬向抗弯刚度及透气性能增强,纬向拉伸断裂强力、经纬向拉伸断裂伸长率、经向抗弯刚度、耐磨性能减小,不锈钢丝质量分数变化对防电磁辐射性能影响较小。当不锈钢丝质量分数为7.0%时,石墨烯黏胶纤维/不锈钢丝机织物的综合性能最佳。     

Effect of woven fabric structure on the air permeability and moisture management properties

In this study, six different woven samples were produced on air jet loom with two different weave designs (i.e. 3/1 twill and 1/1 plain), three different picking sequences (i.e. single pick insertion (SPI), double pick insertion (DPI) and three pick insertion (3PI)). All the woven samples were singed, desized, bleached and finished together at industrial scale, as a single lot. The effect of these factors on the wetting, wicking and air permeability (AP) of the fabric samples was analysed. It was revealed that the fabric weave design and picking sequence has statistically significant effect on fabric wetting time, water spreading speed and AP of the fabric. It was found that fabrics woven in twill weave design and with simultaneous 3PI give significantly better AP, shorter wetting time and better water spreading rate as compared to plain woven fabrics and those with double or SPI. It could be concluded that the thermophysiological comfort of woven fabrics may be significantly improved simply by selecting a suitable weave design and picking sequence.     

医用防护服织物在不同温湿条件下透湿量的研究

阐述了国内外织物透湿量主要测试标准和条件，观察了医用防护服织物的结构，分析了不同复合结构的特征．采用蒸发法测试了医用防护服织物在不同温湿度条件下的透湿量，对蒸汽压差与透湿量作回归分析．实验结果表明，聚四氟乙烯（PTFE）膜层压织物透湿量高，聚氨酯（PU）涂层织物及热塑性聚氨酯（TPU）涂层非织造布透湿量低，且有明显的涂层缺陷，有剥落现象，颗粒分布不均匀，说明了涂层的不可靠性．当相对湿度一定时，织物的透湿量基本上是随着温度的升高而增大；而当温度一定时，织物的透湿量基本上是随着相对湿度的增加而减少．对于被测试样，蒸汽压差与透湿量呈三次曲线关系，具有较高的相关性，相关系数的平方为0．719～0．973．     

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.     

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.     

前处理对涤纶长丝织物透气性的影响

针对染整前处理不同工艺参数影响涤纶长丝织物透气性这一问题,在实验室模拟染整前处理过程,改变热定型温度、张力和碱浓度,测试织物在不同缩率和碱减量率的条件下透气率的变化。并通过多项式回归确定了缩率及碱减量率与透气率之间的关系,即织物的面积缩率与透气率呈非线性负相关,碱减量率与透气率呈非线性正相关。最后对缩率和碱减量率建立多元非线性回归方程并用BP神经网络预测透气率,预测误差均较小,而且预测精度较高。     

Effects of spandex drawing ratio and weave structure on the physical properties of cotton/spandex woven fabrics

In this experimental study, we investigated the effects of spandex filament drawing ratio and weave structures on the properties of cotton/spandex woven fabrics. One-way analysis of variance was used to explore the significant effects of the independent variables on the fabric properties. A regression analysis was also used to derive regression relationships between each of fabric properties and spandex filament drawing ratio. Our findings show that the spandex drawing ratio and structures of the woven fabrics significantly affect the physical and mechanical properties of the cotton/spandex woven fabrics. Cotton woven fabrics containing spandex show higher contraction, crease recovery, and flexural rigidity with increasing spandex drawing ratio, whereas the rest of fabric properties decreases with the increasing drawing ratio. Because of higher contraction and then higher weight, thickness, and cover factor of cotton/spandex fabrics, unexpected results of fabric air permeability and breaking elongation were detected.     

Air permeability and bursting strength of weft-knitted fabrics from glass yarn. Part II: knit architecture effect

In this study; the effects of loop, skip, and tuck stitch types, and weft-inlay yarn, on air permeability and bursting strength of weft-knitted fabrics from glass yarn were revealed. Due to clockwise rotation of wales and their arrangement being one on top of the other, besides the dramatic shortening of fabrics after their removal from the machine; fabrics with tuck stitches exhibited the highest stitch density, fiber content, and the shortest loop length. This caused the lowest air permeability and the highest bursting strength. Contrary to expectations, weft-inlay yarn did not contribute to bursting strength as much as tuck stitch did. An overall negative correlation between air permeability and bursting strength was disrupted by structures with tuck stitches. While tuck stitches from cotton yarn increased air permeability and decreased bursting strength in previous studies; this study indicated that tuck stitches from glass yarn decreased air permeability and increased bursting strength.     

化学镀银织物电磁屏蔽效能及透湿透气性能研究

为研究化学镀银对织物性能的影响,采用葡萄糖作还原剂对涤纶织物进行镀银,借助扫描电镜、网络分析仪、织物透湿仪、织物透气量仪等,对镀银织物的表面镀层形貌、织物的电磁屏蔽效能,以及织物的透湿、透气性能进行测试分析。结果表明:随着增重率的变大,织物的屏蔽效能增加,当增重率达到37%时,电磁屏蔽效能增加不明显,故应根据需要合理选择面料的镀层厚度;研究还发现镀层厚度对织物的透湿、透气性有影响。     

纳米生色面料的防水透气性能与抗菌性能

简述了纳米生色技术的原理,归纳了纳米生色技术的6大优势;给出了纳米生色面料防水透气性能和抗菌性能的实验结果。与传统方法比较,纳米生色面料的防水透气性能与抗菌性能是该技术赋予面料本身的自然属性,并没有做专门的处理,既绿色环保,又有很高的性价比,为纳米生色面料的大面积推广应用奠定了基础。     

Multi-objective optimization of air permeability and thermal conductivity of knitted fabrics with desired ultraviolet protection

A simultaneous optimal solution of two objectives, namely air permeability and thermal conductivity has been derived for both single jersey and 1 × 1 rib knitted fabrics with desired ultraviolet (UV) protection. As these two objectives are conflicting with each other, a set of optimal solutions are possible which are non-dominating in nature. These set of optimal solutions are known as Pareto optimal solutions. In this work, the Pareto optimal solutions were derived with an elitist multi-objective evolutionary algorithm based on Non-dominated Sorting Genetic Algorithm (NSGA II). These Pareto optimal solutions helped to obtain the effective knitting and yarn parameters to engineer knitted fabrics with optimal comfort and desired level of UV protection.     

Air permeability and bursting strength of weft-knitted fabrics from glass yarn. Part I: cam setting and number of yarn ply effect

This study revealed the effect of cam setting and number of yarn ply on air permeability and bursting strength of weft-knitted fabrics from glass yarn. Change in cam setting from loose to tight level increased fiber content, and stitch-density; while it decreased loop length. Fabrics with 3-ply yarn exhibited higher fiber content; lower stitch-density; and longer loop length than fabrics with 2-ply yarn. Cam setting showed more pronounced effect on physical properties of fabric than number of yarn ply. Fabrics knitted via tight cam setting level exhibited less air permeability, and higher bursting strength than fabrics knitted via loose cam setting. Fabrics from 3-ply yarn showed less air permeability and higher bursting strength than fabrics from 2-ply yarn. Loop length, wale density, and fiber content were determined as the most effective physical properties on permeability and bursting strength. A negative correlation was detected between air permeability and bursting strength.