Dye Non-Uniformity in Textured Yarn Fabrics-A Diagnostic Approach

Abstract

<span style="font-size:11.0pt;line-height:115%; font-family:" calibri","sans-serif";mso-ascii-theme-font:minor-latin;mso-fareast-font-family:="" calibri;mso-fareast-theme-font:minor-latin;mso-hansi-theme-font:minor-latin;="" mso-bidi-font-family:timesnewromanpsmt;mso-ansi-language:en-us;mso-fareast-language:="" en-us;mso-bidi-language:ar-sa"="">Three possible causes of non-uniform dyeing of textured yarns, namely defective texturing, post-texturing twist variations and pirn winding tension variation in fabric manufacture, were explored. During texturing, the most common sources of faults cause non-uniform/uniform tension variations along the thread line which are subsequently reflected in crimp contraction force (CCF) variation. A Dynafil assessment of CCF variation has been found to be an effective way of detecting potential non-uniform dyeing behavior of textured yarns. In the absence of such sophisticated instruments, faults can also be predicted from simple tests on denier and yarn elongation. A variation of 4% and above in denier brings about non-uniform dyed fabrics in the case of twisted textured yarns. The residual elongation or boiling-water shrinkage is effective in segregating yarns with potential for non-uniform dyeing. The defective textured yarns are much more sensitive to pirn winding tension as compared to the normal textured yarns. In normal yarns, a pirn winding tension variation of about 18 g and above causes dye non-uniformity, whereas in defective yarns, even a variation as little as 4 g brings about weft bars.</span>