关于织物芯吸速率测试的研究

研究了织物的芯吸过程,探讨了测试芯吸速率的必要性,并综合芯吸速率与表征芯吸能力的芯吸效应指标进行对比分析,认为芯吸过程分为快速芯吸和趋于平衡两个阶段,全面评估织物的芯吸能力要从芯吸速率和芯吸效应两个方面进行研究。     

吸湿排汗功能织物研究现状及展望

文章针对影响织物吸湿排汗性能的因素,从润湿芯吸和蒸发排汗两个方面进行分析,介绍吸湿排汗过程中水分传递及分布的测试方法,综述织物吸湿排汗过程的理论模型,包括毛细管芯吸模型和蒸发排汗模型。研究发现,针对织物内部水分芯吸传递的理论研究还比较匮乏。最后,结合纺织品的发展现状与趋势,对吸湿排汗织物未来的研究重点、应用前景和绿色化生产进行展望,为织物性能优化与舒适性面料开发提供参考。     

温度对棉平布芯吸性能测试的影响研究

分析FZ/T 01071标准下织物芯吸性能测试结果与织物在使用环境中所表现的实际芯吸性能差异,论述了以三级水温度作为变量的不合理性,对毛细效应实验装置进行可整体控温改装,在25～65℃范围内对比测试了三级水温度梯度控制与整体温度梯度控制对织物芯吸性能测量结果的影响,结果表明:相同温度下整体控温时棉平布初始芯吸速率更大,30min最大芯吸高度更小;即棉平布在实际应用中表现出比FZ/T 01071标准测试结果更强的初始芯吸能力和更弱的液体铺展能力。     

几种环保纤维混纺纱的芯吸与吸放湿性能

本文对柔丝、蛹蛋白、天丝、彩棉等绿色纤维混纺纱进行芯吸性能和吸放湿过程测试,并利用Origin软件对测试结果进行对比,分析研究不同纱线的吸湿性及湿传递性能,以期找出影响纱线吸放湿性能的较为普遍性的规律,并为开发湿舒适性好的绿色服装面料提供依据。结果表明：含再生纤维的混纺纱的芯吸性能较强,尤其含有皮芯结构的蛹蛋白再生纤维的纱线芯吸性能最好,含有50%以上的柔丝纤维的纱线吸放湿能力最强,其回潮率和吸放湿速率都较高。天然棉/彩棉混纺纱的芯吸性很差,并且其回潮率及吸放湿速率都较低。     

织物孔径特性与织物结构及性能的关系

为了定量描述织物中水分传输过程中的两个关键因素——芯吸与蒸发的机制,确定影响织物吸湿快干性能的控制因素,采用精密电子天平组装了等液位分段快速响应毛细液体测试装置;并对3种织物的孔径分布与垂直于织物平面方向的芯吸速率进行了测量,对织物的蒸发速率进行了测试,分别比较了3种不同材质与结构织物的芯吸速率与蒸发速率,定量分析水分在织物表面蒸发的机制,分析了织物的孔隙率、平均半径、毛细管大小及孔径分布与织物蒸发速率的关系。试验表明织物的蒸发速率比芯吸速率慢,所以蒸发速率成为织物吸湿快干的速度控制因素。织物的结构应是粗毛细管比例多,外层的材质应疏水。疏水材质织物的芯吸与蒸发速率均快。     

织物孔径特性与织物结构及芯吸性能的关系

为了定量测定和描述水分传输的机制,利用精密电子天平组装的等液位分段快速响应毛细液体测试装置对垂直于机织物平面方向的毛细孔分布及芯吸速率进行测试,分析了毛细孔分布与织物芯吸性能的关系及织物结构对毛细孔分布的影响,探讨了机织物优化设计原则。结果表明:决定织物中液体输运速度的不仅是平均孔径、最大及最小孔径,孔径的分布也起到重要作用。织物纱线的线密度越大,织物的经纬密越小,织物就越疏松,则形成的毛细管中粗毛细管多,芯吸速率越快。对于快速芯吸过程,粗毛细管的作用是决定性的。     

碱处理对异形截面聚酯纱线芯吸效应及强力的影响

针对氢氧化钠可破坏聚酯纤维结构,影响异形截面聚酯纤维的芯吸效应、润湿性、强力、伸长性能和吸湿快干及吸湿凉爽功能这个问题,借助扫描电子显微镜,对氢氧化钠处理前后的纤维形态结构进行了表征,分析了影响该纱线芯吸效应的因素,研究了不同质量分数碱处理对异形截面聚酯纱线芯吸效应、润湿性能、强力及伸长的影响规律。结果表明:异形截面聚酯纤维横截面为十字形,沿纤维纵向有4道沟槽,起到毛细管作用,为水分的迁移提供了通道,使纤维及纱线具有良好的芯吸效应;氢氧化钠可有效清除异形截面聚酯纤维沟槽中的低聚物,当氢氧化钠质量分数在4%左右时,纱线芯吸效果显著提高;氢氧化钠处理可提高异形截面聚酯纱线的润湿性;随着氢氧化钠质量分数的提高,异形截面聚酯纱线强力及伸长下降,当氢氧化钠质量分数高于6%后,纱线的强力和伸长损失显著。     

空气喷射变形丝的芯吸效应

利用毛细管上升法和液滴吸收法研究了聚酯、黏胶、聚酰胺、聚酯/黏胶和聚酯/聚酰胺空气喷射变形丝的芯吸率和吸湿率。结果表明,空气变形后复丝的芯吸率提高。与聚酰胺和黏胶空气喷射变形丝相比,聚酯空气喷射变形丝显示出较大的芯吸率。黏胶空气喷射变形丝显示出最低的芯吸率。与同样的未变形丝相比,混合的空气喷射变形丝显示出较大的芯吸率。     

棉纱线垂直芯吸效应研究

针对棉纱线垂直芯吸高度预测难度大的问题,通过分别测试两种线密度的不同捻度棉纱线垂直芯吸性能,探究棉纱线线密度、捻度与其芯吸平衡高度的关系,以揭示芯吸高度在芯吸过程中的变化规律,在此基础上确定了可预测棉纱线垂直芯吸效应的模型.结果 表明,棉纱线捻度相同时,14.3 tex纱线芯吸平衡高度较20.0 tex纱线提高0.1～...     

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.     

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.     

A test apparatus to measure vertical wicking of fabrics – a case study on shirting fabrics

A test apparatus based on electrical conduction principle was designed and manufactured to overcome some difficulties and deficiencies in vertical wicking measurements of fabrics, which is one of the test methods used to determine liquid moisture transmission performance of fabrics. In order to test effectiveness of the apparatus, capillary time with regard to height was measured for woven shirting fabrics, which have different raw material, weave type and weft density. It was found that twill weave type and fabric looseness improved the wickability of fabrics. It was also revealed that raw material was an important factor for vertical wicking. The wicking rate of fabrics obtained from the new test apparatus correlated well with DIN 53924. Consequently, the test apparatus clearly demonstrated differences between the fabrics used in the study, and can be used to determine vertical wicking behaviour of fabrics.     

加捻对不同涤纶长丝芯吸性能的影响

以毛细效应和湿蒸发原理为基础 ,对不同截面形状和加工方式的涤纶长丝在不同捻度条件下芯吸高度的变化规律进行了实验研究。结果表明 :特殊异形截面涤纶长丝较圆形截面的芯吸效果好 ,加弹丝的芯吸效果好于平牵丝 ,捻度对长丝芯吸性能的影响呈Lorentzian曲线变化规律     

Investigation on wicking behavior of the knitted fabrics under different deformation state

Many researches have been carried out to analyze the wicking behavior of the knitted fabric based on different principles. In this study, an investigation on wicking behavior of knitted fabrics under different deformation condition is attempted. An instrument has been designed and developed to measure the wicking rate of the fabric based on the principle of image processing technique under dynamic states with respect to time by simulating different movements. This instrument has been aimed to quantify the rate of wicking under different deformations in required time intervals and also the pattern of wicking area on both sides of fabric simultaneously. The statistical result shows that wicking in fabric under dynamic condition has been increased significantly on the knitted fabrics than the static condition. The comparative study of wicking trend at the front and back has been carried out and shows that the area of wicking is higher in front than back side of the fabric at any given period of time. The result shows that wicking in fabric under dynamic condition has been increased significantly on all the knitted fabric. The developed novel instrument could be utilized to carry out the study of the wicking behavior of any kind of fabrics matching to the real situation with higher accuracy and precision.     

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.     

Study of wicking behavior of water on woven fabric using magnetic induction technique

An apparatus for measuring the wicking rise of water in fabrics has been developed and several types of fabrics were examined. The method is based on the electromagnetic field induction due to wicking penetration of water into capillary spaces of fabric samples. The measuring system is coupled with a personal computer, and the distance of water rise as a function of time is determined. Plain woven fabric samples with different weft yarn counts, density, and type of fiber in blend yarn were examined. The results obtained by wicking measurement were compared with water vapor permeability index data and the test method for wettability of textile fabrics on the same samples. The average wicking rise of water decreases with the increase of weft yarn density. The wicking of water along the cotton–polyester blend weft yarn is higher than 100% cotton weft yarn samples. The relation of water vapor permeability (WVP) index and the test method for wettability of the same fabric samples show the same behavior as the wicking rise. The equivalent geometric factor neglecting the Earth’s gravitational field is calculated by the average slope L ²/t from the experimental data of wicking of water into the samples. The radii of open channels in the woven fabric sample tends to decrease as a result of increasing weft yarn density.     

Validation of the integrated upward–horizontal–downward wicking test for providing intensive properties of textile fabrics

Traditional wicking tests provide information that is specific to the test fluid, apparatus, and conditions. As a result, this information cannot be used to make predictions about wicking rates beyond the respective test parameters. In contrast, a new upward–horizontal–downward (UHD) wicking test has been presented that provides intensive properties of fabrics in the form of permeability (k) and effective capillary radius (R _c) as functions of saturation (S). The UHD test was developed using water as the test fluid. If the k–S–R _c relationships are truly intrinsic to a given fabric, then they should not depend on the test fluid. Here, we conducted the UHD test on a knit fabric using three different test fluids characterized by different surface tensions, densities, and viscosities: dodecane, tetradecane, and hexadecane. All fluids fall on the same k vs. S and k vs. R _c curves, proving that these curves are intrinsic characteristics of the fabric. We then used the k–S–R _c properties to successfully predict the in-plane horizontal and downward wicking rates of two different fluids, octanol and water, in the fabric. These results validate the UHD wicking test as a method for providing intensive properties of textile fabrics which can then be used for predicting wicking rates.