Researched On Elasticity Of Woven Fabrics With And Without Spandex

Elastic fabric has superior wear ability and earns excellent rating among consumer. Also ithas a large share in textile. Based on20woven fabrics made of silk or imitated silk materials,which includes non-elastic and elastic woven fabrics, the elasticity of non-spandex and spandexwoven fabrics was analyzed in this thesis. Woven fabrics obtained elasticity by various methods.Besides, the wear abilities of the samples were also measured.First, multivariate statistical analysis was used to analyze the relationships of the fabricperformance indexes such as constant load elongation, static drape coefficient, bending rigidity,slow crease recovery angle. It makes clear that static drape coefficient and bending rigidity ofwoven fabric can be used to evaluate fabric’s softness. Fabric elongation and elastic recovery ratein the warp or weft direction can be used to respectively represent fabric elastic features in thewarp or weft direction. However, slow crease recovery angle should not be used to represent theelasticity of fabric.Second, the relationships between the fabric performance and its structure were alsoresearched. It figures out that the significant factor which affects fabric elasticity in the warp orweft direction is wrap or weft raw material respectively. Fabric weight is determined by lineardensity of warp and weft, warp and weft density, so fabric weight and thickness can be used toassess fabric softness.Third, woven fabric geometric model established by Peirce was improved by the fact thatyarns in the fabric can be elongated. Based on the geometric model of weft cross-section whoseweave is plain, the mathematical relation between elongation of fabric and elongation of yarn isderived. Meanwhile, the elongation of fabric is related to the parameters of fabric structure.Fourth, Quantitative relations between the elasticity of yarns and that of woven fabrics withor without spandex have been established based on the experiments. The conclusions are as follows. Elastic fabric with spandex has greater elasticity. The linear regression equation of25Nconstant load elongation of elastic fabrics with spandex on25cN constant load elongation of yarnsowns higher goodness of fit and larger slope. In another word, fabrics stretch with spandex hasgreater changes with the changes of yarns’ stretch. While elastic fabric without spandex is onlycomfortable for wearing. For example, modified polyester filament with elastic gives the fabricgood elasticity, textured polyester can improve the fabric’s elasticity and twisted silk can alsoimprove the elasticity of fabric. The linear regression equation of25N constant load elongation ofelastic fabrics without spandex on25cN constant load elongation of yarns owns also highergoodness of fit. But its slope is small. It is also said that the stretch of fabric without spandex hasslower changes with the changes of yarns’ stretch.Fifth, woven fabric is often classified by fabric weight and thickness. The thickness andweight usually affect fabric performance. The cluster analysis was used to divide the samples into2categories according to fabric weight and thickness. It is found that the lighter fabrics made ofsilk, polyester or modified elastic polyester has better softness. The heavier fabrics made of silkstill has better softness while the fabrics made of polyester and modified elastic polyester is notenough softness. In other word, in order to imitate silk fabric, the softness of the fabric made ofpolyester still needs to be further improved.