Modifications to drafting system for improvement in yarn quality

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:="" "times="" new="" roman";mso-fareast-theme-font:minor-fareast;mso-hansi-theme-font:="" minor-latin;mso-bidi-font-family:calibri;mso-bidi-theme-font:minor-latin;="" mso-ansi-language:en-us;mso-fareast-language:en-us;mso-bidi-language:ar-sa"="">The benefits arising from certain modifications in ring frame drafting system to yarn quality and spinning performance have been discussed. Nose bar was modified by introducing a depression in its height for a portion of the width on the front side. Different levels of depression were tried. The modification has been found to give about 14-45% reduction in yarn imperfections, the reduction being more prominent with short staple cottons. The studies extended to mills also confirm the reduction in yarn imperfections. Besides, some reduction in end breakage rate in ring frame and winding has been observed with modified nose bar. Lowering the nose bar height also reduces imperfections, but the order of improvement thus obtained is lower than that obtained by using modified nose bar. Modified nose bar brings down the imperfections with all the apron spacers. Use of soft cots of 65° shore hardness at the front in combination with modified nose bar brings down the yarn imperfections by 35-55% and U% by 1-1.5 units. Offsetting of back top roller also shows a marginal reduction in imperfections provided that the optimum back zone setting and break drafts are used.</span>