纤维集合体压缩力学行为的研究

研究了羊毛、山羊绒、腈纶、鹅绒、木棉5种常用纤维集合体的压缩性能。通过单向施力挤压，对纤维集合体的压缩特征曲线进行了表征，同时完成特征值的提取。发现5种纤维集合体的压缩曲线、压缩应力应变曲线、压缩模量曲线存在明显差异，这主要与纤维的形态及结构有关，并将压缩过程分为3个区：近似线性区、转变区（或滑移变形区）、模量线性增加区。     

纤维集合体压缩力学行为的研究：1. 压缩特征曲线的表征与特征值的提取

 研究了羊毛、山羊绒、腈纶、鹅绒、木棉5种常用纤维集合体的压缩性能。通过单向施力挤压，对纤维集合体的压缩特征曲线进行了表征，同时完成特征值的提取。发现5种纤维集合体的压缩曲线、压缩应力应变曲线、压缩模量曲线存在明显差异，这主要与纤维的形态及结构有关，并将压缩过程分为3个区：近似线性区、转变区（或滑移变形区）、模量线性增加区。     

一种研究纤维集合体透气性能的新方法

纤维集合体的透气性不仅取决于纤维性状,更依赖于集合体的填充密度.文章针对纤维集合体不同密度条件下透气性能测量领域的空白,提出测量集合体透气性的新方法,并对不同种类及排列的纤维集合体进行了透气性能对比与分析,实验证明:由于不同的纤维具有不同的形态结构特征,从而造成各种纤维集合体间具有不同的透气性能,并且受纤维排列形式的影响;气流流过集合体时不仅与空隙的多少有关,而且与空隙的形状、曲折程度、排列和孔径的分布有关.     

变异山羊绒纤维集合体的压缩性能

采用KES FB-AUTO-FB织物风格自动评价系统,测试分析了5种国内不同产区、不同羊种的山羊绒纤维集合体的压缩及回复性能,并将几种山羊绒的压缩性能进行了对比评价,得出纤维集合体的压缩量越大,纤维的抗弯刚度越小,即纤维越柔软,同时,山羊绒纤维集合体压缩回复率越高,则纤维集合体的蓬松性越好.而且在压缩的各个时期,随着密度变化,单根纤维和纤维集合体的主导作用也在变化,而这些变化可对变异山羊绒压缩性能建立最新数据及评价提供参考.     

仿毛纤维集合体压缩弹性试验方法的研究

一、前言 纤维集合体的压缩弹性体现了其特有的力学性质,它与纤维、条子或最终产品的手感、柔软性、弹性等风格有关,并且对服用性能产生直接的影响。目前测试纤维集合体压缩弹性的方法有多种,最常用的是在规定的压头、负荷下,分别测定在轻、重两种负荷下纤维集合体的高度,计算其压缩率和压缩弹性回复率等参数;也有同属于这一原理,而以计算硬度的方法来表征压缩弹性的;另外还有采用重锤落下的方式,使其落在纤维集合体上,观察纤维集合体的情     

服装絮填材料保暖性能的研究

研究了羊毛、腈纶、木棉及鹅绒4种随机排列絮填纤维集合体的保暖性能,对比了4种集合体的保暖性能与透气性能之间的关系,并分析了纤维形态结构及集合体的体积密度对集合体保暖性能的影响。提出通过控制集合体的体积密度,使其包含较多的静止空气是提高纤维集合体保暖性能最主要的方法。     

基于X射线断层扫描的纤维集合体结构研究

研究棉纤维集合体受压后的微观结构变化。采用X射线计算机断层扫描技术,从堆砌密度、孔隙结构和分形维数3个方面,对棉纤维集合体压缩前后的微观结构及其变化规律进行了系统的研究和表征。结果表明:随机任意排列的棉纤维集合体在压缩过程中,堆砌密度增大,且沿受力方向略有波动;压缩后总孔隙率降低,但闭孔隙率和闭孔半径增大;压缩后棉纤维集合体的分形维数增大。认为:分形维数是描述复杂结构的有效手段,纤维集合体分形维数与堆砌密度之间存在高度的线性相关性。     

基于三维编织模型的棉纤维集合体压缩过程有限元建模与仿真

为分析棉纤维集合体在压缩过程中纤维受力情况来提高棉花压缩打包的质量,结合三维编织复合材料的细观几何建模思想,将具有相同圆形截面的棉纤维束按照三维四向编织复合材料的纤维分布进行排列,构建新的棉纤维集合体模型。将该模型应用于棉纤维集合体压缩过程分析,研究了棉纤维集合体压应力与相对密度的变化关系及棉纤维应力变化情况,分析了回潮率对棉纤维集合体压应力的影响。结果表明:随回潮率的升高,棉纤维集合体应力呈现先降低后升高的趋势,当回潮率位于8.8%~12.3%之间时,棉纤维应力最小;仿真结果与试验结果相符,说明该棉纤维集合体模型具有合理性。     

纤维排列方向对热线法导热系数测试的影响

针对纤维的特点,设计试样制备方法,在热线法中测量纤维在不同排列方向时的导热系数。采用最小二乘法处理数据,分析纤维排列方向对导热系数的影响。结果表明,随着纤维排列方向的变化,纤维集合体的导热系数产生一定的线性变化,且不同纤维的变化幅度不同。     

木棉/低熔点纤维成絮复合浮力材料的研发

木棉纤维集合体作为浮力材料具有许多优点。但如长时间使用或在存放条件下会由于纤维间的滑移而被压缩，影响浮力性能。文章通过试验分析指出利用低熔点纤维把木棉固结成絮，不仅可改善木棉纤维集合体的浮力，且比木棉，三维卷曲中空涤纶混配集合体具有更好的耐压缩性能，能提供更大的浮力倍数。     

羊毛纤维集合体的分形结构与其保暖性的关系

针对羊毛纤维集合体结构特征往往难以得到有效表征这一问题,将分形的概念引入羊毛纤维集合体的结构表征,利用计盒维数的方法,计算了5种不同质量的羊毛纤维集合体的分形维数,同时采用平板式保温仪测定了羊毛纤维集合体的保暖性能;随后定量关联了羊毛纤维集合体的分形维数与其基本结构参数和保暖性指标之间的关系。结果表明:利用分形维数来表征纤维集合体的结构特征是可行的,随羊毛纤维质量和体积分数的增大,集合体的分形维数增大,这说明集合体中的纤维结构更杂乱;随分形维数增大,集合体的克罗值和保温率增大,而传热系数减小,即纤维集合体的保暖性增强。     

Fractal approach to structure and thermal property of down fiber assembly

Down fiber assembly is a heterogeneous and hierarchical system whose structure can be hardly characterized. At the meantime, its thermal property is valuable for usage, it would guide design if the correlation between thermal performance and structure can be understood. In this paper, fractal approach was introduced to characterize the microstructure of down fiber assembly. Fractal dimensions of fiber assemblies are calculated by box-counting method and are found to be positively correlated with basic structural parameters such as fiber mass and volume fraction. Meanwhile, the results indicate that increasing fractal dimension will lead to an enhancement of thermal insulation performance.     

Study on compressional energy contribution into total energy of pile deformation in cut-pile carpet

Compression behavior is one of the most important properties of the carpets. In this study, a new theoretical model has been presented in which total energy of pile deformation in cut-pile carpet including bending energy of pile deformation, frictional loose energy due to sliding pile yarns, and compressional energy due to piles jamming at the end of pile deformation process has been calculated. Then, derived equations have been solved by computer software and calculated theoretical values have been compared with experiment. Results show that compressional energy has no remarkable contribution into total energy of pile deformation. Also, difference between theoretical results and experiment is not large, and presented theory can well predict compression behavior of the cut-pile carpet. Meanwhile, new proposed model could not improve previous presented theory.     

An investigation into the effect of fabric structure on the compressional properties of woven fabrics

Lateral compression is one of the most important mechanical aspects of fabrics, which reflects their handle. Fabric compressional features depend on the compressional characteristics of constituent yarns and the fabric structure. In order to consider the effect of fabric structural parameters on its compressional properties, woven fabrics with five different weave patterns (plain, hopsack 2/2, twill 2/2, twill 3/1, warp rib 2/2) were produced with three different nominal weft densities (12, 15, 18 cm^?1). The compressional properties of produced fabrics were evaluated at different pressure values using a conventional fabric thickness tester. It was observed that increasing the weft density leads to decrease in the dissipated compression energy as well as the compressibility of the fabric, while the thickness recovery of the fabric increases. Moreover, the plain woven fabric exhibited the lowest dissipated compression energy and compressibility, while the highest thickness recovery. Besides, at the low pressure level, the fabrics with the lower weft densities demonstrate the higher thickness. By increase in the pressure level, the fabric thickness decreases by decreasing the weft density.     

玉石纤维的形态结构及物理机械性能研究

对新型凉爽保健纤维——玉石纤维的形态结构、物理机械性能进行了分析研究。结果表明,玉石纤维呈现蜂窝状微孔结构;回潮率相比于涤纶有很大程度的提高;干湿态玉石纤维的拉伸断裂强度、初始模量、钩结强度以及打结强度均随着拉伸速度的增加而提高;当拉伸速度增加到一定值后,强度和初始模量趋向稳定,不再提高;玉石纤维的湿态强度和初始模量均高于相应的干态强度和初始模量。     

Study on thermal resistance of multilayered fabrics under different compressional loads

In this work, the thermal resistance of multilayered fabric ensembles meant for cold weather conditions were studied under different compressional loads. An instrument has been developed to study the thermal resistance of fabrics under different compressional loads. The instrument consists of a test plate, guard plates and a bottom plate. The test plate and guard plates were assembled together as a single entity, which can be moved up and down with a screw shaft. A load cell was connected to the plate assembly to apply the required compressional load on the fabric specimen. Thermal resistance of multilayered fabrics was studied in the developed instrument under different loading conditions. Single-jersey knitted fabric, needle punched fabric and polytetraflouroethylene (PTFE) coated fabrics were used in the inner, middle and outer layer, respectively. Twenty different multilayered fabric ensembles with the same inner and outer layers were studied. The middle layers, i.e. needle punched nonwoven fabrics, were produced from polyester hollow fibres, with varying linear density of fibre, mass per unit area and punch density. The thermal resistance of multilayered fabrics obtained from the developed instrument was compared with the thermal resistance of instruments, namely sweating guarded hot plate (SGHP) and Alambeta. Regression equations were developed and the contour plots were drawn to analyse the effect of the fibre, fabric and process parameters. ANOVAs were conducted to find the significance of the compressional load, linear density of fibre, mass per unit area and punch density on the thermal resistance of fabrics. It was found that the thermal resistance obtained from the instrument follows the same trend as that of thermal resistance obtained from SGHP and Alambeta. Mass per unit area was found to have significant effect on the thermal resistance of multilayered fabrics under different compressional loads. The effect of punch density decreases with the increase in compressional load on the thermal resistance of multilayered fabrics. The thermal conductivity of multilayered fabrics was observed to increase with the increase in the compressional load.     

鹅、鸭绒纤维形态结构差异及对保暖性能的影响

利用电子和光学显微镜对鹅、鸭绒纤维形态结构进行观察,定量阐述了鹅、鸭绒纤维绒核结构、绒枝结构、绒小枝及节点结构的差异,在此基础上对鹅、鸭绒纤维保暖性进行测试,分析了结构差异对纤维保暖性的影响.与鸭绒纤维相比,鹅绒纤维绒朵较大,绒核较小,绒枝长而粗,绒小枝长而细且分布较密,绒小枝上节点小而多且分布均匀,这使得鹅绒纤维具有...