机织土工织物结构参数与渗透性关系探讨

探讨了机织土工织物的织物组织、纱线细度、经纬纱密度等因素对织物渗透性的影响。确定了织物组织结构参数与渗透系数之间的回归关系。通过改变织物的组织结构参数使土工布具有不同的水力学性能，从而满足不同工程的要求。     

机织物光泽的研究进展

通过对机织物表面光泽的分析，探究影响织物光泽的因素，着重从机织物的经纬纱线、纤维和织物组织几个方面进行详细的剖析。经过分析认为，机织物光泽是由纤维性状，纱线结构，织物组织等几个因素共同决定。     

金属纤维织物的结构与电磁屏蔽效能研究

介绍了金属纤维织物屏蔽的机理与屏蔽效能的测试以及金属纤维屏蔽织物的结构参数对屏蔽效能的影响，如金属纤维含量、经纬纱线排列、织物组织结构、金属纤维在纱线结构中的分布等对屏蔽效能的影响。     

织物结构对机织物热传导的影响

主要分析了织物结构参数,包括织物厚度、容重、织物组织等对织物热阻的影响。试验中采用层层叠加的方式实现了织物厚度的线性增加。结果表明:当其他因素一定时,织物热阻与织物厚度呈线性增加的关系;容重越大,织物的热阻越小;织物组织对织物热阻的影响主要与织物单元组织循环纱线数n有关。同时,探讨了厚度和容重对织物热阻的组合影响。结果表明,织物热阻是织物厚度、容重和组合参数三者的多元函数。     

导电丝嵌织型织物防静电性能影响因素评述

研究导电丝嵌织型织物防静电性能的影响因素。分析了有机导电纤维种类、导电丝基材、导电纱的成纱结构、导电纱与织物的结合方式、织物组织结构、织物单位面积质量及厚度这几方面对织物防静电性能的影响。实践经验表明:有机导电纤维种类和导电丝基材对有机导电纤维导电性有显著影响;导电纱成纱结构和与织物的结合方式以及织物组织、单位面积质量和厚度都对织物防静电性具有较显著影响。认为在具体生产中必须综合考虑以上各因素,并结合防静电织物后道加工、使用及交货要求进行防静电织物的设计生产。     

织物防电磁辐射性能影响因素的研究

通过对不同金属纤维、不同金属纤维含量、不同纱线结构、不同织造方式、不同织物组织等防电磁辐射织物的屏蔽效能进行检测,探讨了织物防电磁辐射性能的影响因素,为防电磁辐射织物的开发设计提供参考。     

组织结构对针织物电磁屏蔽效能的影响

设计了几种代表性织物组织结构的不锈钢纤维混纺针织物,研究了织物组织结构对针织物电磁屏蔽效能的影响。织物组织结构选择充满系数较高的双罗纹组织、打鸡双面组织、添纱衬垫组织、衬纬组织和绕经组织,以降低织物厚度、密度、孔隙等因素对织物电磁屏蔽效能的影响。对所有织物进行了电磁屏蔽效能测试,结果显示:双罗纹织物、双面织物、添纱衬垫织物、衬纬织物的电磁屏蔽效能都很不理想,且远远低于含不锈钢纤维机织平纹布,但是绕经织物的电磁屏蔽效能要比其他组织的针织物的屏蔽效能高得多,基本能达到国标上对屏蔽服的屏蔽效能要求。绕经织物与其他几种针织物最大的不同就是在纵向多了一些连续的含不锈钢纤维的混纺纱。说明针织物组织结构是影响电磁屏蔽效能的关键因素,可通过在织物纵横向形成纵横交错的导通的金属网栅的方式来改善不锈钢纤维混纺针织物的屏蔽效能。     

阻燃棉织物结构与性能关系研究

以8种阻燃棉织物为试样,分析并测定织物组织、面密度、织物密度、纱线线密度和织物紧度等织物结构参数,以及拉伸性能、耐磨性、透气性、透湿性、刚柔性、悬垂性和阻燃性能等服用性能,并采用多因素方差分析、回归分析,探讨织物结构参数对服用性能的影响,最后通过模糊决策分析方法综合评价服用性能的优劣程度及织物适用性。结果表明织物组织和面密度对织物的拉伸性能、刚柔性、阻燃性能均有显著影响,且面密度与阻燃性能呈线性正相关;织物组织相同时,随着织物经密和纬密的增加,织物透湿率下降;6#试样适宜用作阻燃防护服,5#和6#两个试样都较适用于装饰用织物。     

织物的覆盖系数和组织结构对纯棉织物燃烧性能的影响

本研究中,织物组织由组织系数和交织指数表示,这两个因素之间的关系为r=0.85,R2=0.72。以100%纯棉织物的织物组织和覆盖系数为参考,用续燃时间和阴燃时间来评价织物的燃烧性能。织物的燃烧性能取决于织物结构,织物性能及纱线参数。     

角度联锁三维机织物的设计与生产

介绍了三维织物在国内外的应用及角度联锁三维机织物及其变化织物的特点与使用情况,重点对角度联锁三维机织物及其变化织物(加有衬型纱的角度联锁织物和正交机织物)的交织原理进行分析,对其织物组织结构、织物组织的设计要点以及织物形成过程进行了探讨.     

Cross‐sectional shapes of the yarn in cotton gray woven fabric

This experimental work looks into the geometry of the yarn cross‐section at the weaving and relaxed stages using microscopic and digital image processing techniques. A total of 54 plain‐weave cotton fabric samples (different in the yarn twist and the fabric density) were produced and the cross‐sectional shapes of the wefts at the early stage of weaving (in which the wefts were also under tension by full‐width temples) and at the relaxed state were compared with the ideal circular shape. The measurements of the samples showed that the cross‐sectional shapes of the yarns at the early stage of weaving are circular, elliptical or a combination of two circles or an asymmetric elliptical. Moreover, the effect of the fabric tightness on the yarn cross‐sectional shape and dimension was negligible. The measurements of the cross‐sectional dimensions of the relaxed fabric (released from weaving tension) showed an increase in the area occupied by the yarn inside the fabric and did not follow the Peirce standard model. The measurement and the comparison showed that the cross‐sections of the yarns inside the woven fabric could be categorized into five different shapes, namely; circular (C), elliptical (E), sharp symmetrical amygdaloidal (SSA), asymmetrical amygdaloidal (AA) and sharp asymmetrical amygdaloidal (SAA), but the number of each group depends upon the yarn properties and the fabric structures. The fabrics with the highest density and the highest twisted yarns had a circular cross‐sectional shape, whereas the fabrics with the lowest fabric density and the lowest twisted yarns had the most flattened yarn cross‐sections in the form of sharp symmetrical or asymmetrical amygdaloidal shapes.     

用变截面纱线模型模拟平纹织物的研究

为了逼真模拟平纹织物,采用变化尺寸大小的锯齿形椭圆截面的纱线模型,结合B样条曲面造型技术,利用Peirce机织物模型构造平纹织物的几何立体结构.根据VC程序运行结果来看,该纱线模型结合捻度结构用于模拟平纹织物的效果逼真.     

New computer geometric modeling approach with filament assembly model for woven fabric structures

This paper presents a new computer geometric modeling approach for three-dimensional woven fabric structures. Pierce’s geometry of the weave fabric of yarn from an arc abscissa (Peirce’s) model is presented. Then, new algorithms with a filament assembly model for a single yarn composed of many filaments by twisting along the crimp shape in the warp/weft is developed. The concept of a virtual location is used to simulate the fiber distributions in the yarn cross-section. Each cross-section is rotated along the yarn length by a pre-determined amount to allow for the yarn twist. The curve of each filament in each two successive cross-sections is approximated by NURBS and then each curve is created by sweeping a closed curve along the centerline of the yarn path. The method described is demonstrated by the CAD model of woven fabrics with plain and twill weaves. The simulated woven fabrics using this approach can demonstrate a wider variety and improved visual simulations of real woven fabric and can then be further generalized for different and more complicated fabrics. The method is necessary as an input to many computational models, such as modeling the mechanical properties or the heat transfer of fabrics or composite parts.     

Computer simulation of plain woven fabric appearance from yarn photographs

This article proposes a method for simulating plain woven fabric appearance based on photographs taken by still camera of actual yarns along their lengths. The survey mathematically models the transformation of yarns from a straight circular cylinder to a flattened and crimped form in the fabric structure. The simulation is performed by yarn images that are obtained by image processing techniques and resized according to mathematical models developed by means of the software prepared. Transforming circular yarn cross-section to elliptical one for simulating yarn flattening and modelling the crimped shape of yarn by an elastica curve are both convenient and realistic. The simulation of plain woven fabric can be performed by a method based on raster graphics. This article provides a model for yarn shape in fabric structure as well as a method for simulating plain woven fabric appearance. This method may be used in textile industry for design and quality control.     

Solid Modeling Applied to Fibrous Assemblies. Part II: Woven Fabric

In the previous paper, we proposed a methodology for studying the potential effects of compressibility on a twisted assembly. The approach was to assume that an individual yarn could be approximated in compression by a single element with an elliptical cross section. In a similar manner, one can study an assembly that is primarily two-dimensional in nature – a woven fabric composed of interlaced three-dimensional yarns. For demonstration purposes, we will use the basic plain weave pattern.     

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.     

不同横截面形状丝道网络器中三维流场特征

本研究计算了七个不同横截面形的网络器丝道内压缩气流的特征,并将这些特征和网络器的性能联系起来,为设计出性能优良的网络器提供理论依据。流场计算用的是商业计算流体力学软件ANSYS CFX。网络器的性能通过网络丝的网络度和网络牢度评价。通过流场计算可以得出：包含喷嘴轴线的丝道横截面上的涡流可以为长丝的旋转提供较大的空间;丝道轴线上,较大的流体速度有利于长丝的开松。但是,太大的流体速度会使长丝粘贴在丝道壁上,阻碍了长丝的相互纠缠,降低了网络丝的网络度。     

利用切片技术测试织物结构参数

为了得到织物结构中的一些隐性参数,利用切片技术,结合显微观测技术和相应的采图软件,得到纱线在机织物中的截面形态,认为纱线在机织物中的截面形态不能一概而论,存在一定的规律,并把试验测得的数据应用到织物几何结构相的确定当中,从而用于指导实际生产是否达到预期的目标,证明了利用切片技术检验织物的隐性指标具有重要的意义,但该技术还需在密度较大、纱线较细的织物中推广.     

Length of the yarn in plain‐weave crimp wave

Yarn axis geometry in plain‐weave fabrics has been described by different models. Yet, they do not capture its exact shape, because (1) the geometry of each crimp wave in a fabric is unique to that fabric and as such it differs from any generalized model, and (2) the length of the yarn axis, an important parameter, is more influenced by the height of the crimp wave than by any arbitrary definition of its shape. Crimp of the warp/weft is defined as the ratio of the length of the yarn axis in one wave and its wave length; the latter is the spacing (pitch) of the neighboring weft/warp yarns. Crimp can be calculated in accordance with the crimp wave shape definition, which differs from reality. In this paper, a new and very simple method of calculating the yarn crimp is proposed and validated through experimental measurements. The results provide an instrument for easy calculation of yarn lengths when crimp wave amplitudes and wavelengths are known.     

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.