Ryu, Woon-Young;Chang, Chul-Sik;Lee, Joung-Ryul;Huh, Kyu
8
Effects of the top roller weighting, tensor opening, and drafting speed on the added irregularity (short term, long term and total), yarn evenness (U%) and other properties of three spun yarns, carded 30's, combed 38's, and polyester/cotton blended 45's were studied, and the results were as the followings; 1. Short term added irregularity, total added irregularity, and U% were minimum at 16-12-14 (kg) of top roller weighting (front-middle-back) for carded yarn 30's and 13-12-13 (kg) for combed yarn 38's and P/C blended yarn 45's. Maximum lea C.S.P. was obtained at 16-12-14 (kg) of top roller weighting for all experimented yarns. Imperfections for P/C blended yarn 45's were minimum at 13-12-13 (kg) of top roller weighting. 2. Short term added irregularity, total added irregularity, and U% were minimum at 3.0∼3.5mm of tensor opening for carded yarn 30's, and 2.5mm for combed yarn 38's and P/C blended yarn 45's. Maximum lea C.S.P. was obtained at 3.5mm for carded yarn 30's, 2.5mm for combed yarn 38's and 3.0mm for P/C blended yarn 45's. Imperfections were increased with the increase of tensor opening for all experimented yarns. 3. Short term added irregularity, total added irregularity, and U% were increased linearly with the increase of drafting speed for combed yarn 38's and P/C blended yarn 45's, but not for carded yarn 30's. Maximum lea C.S.P. was obtained at the spindle speed of 8,000 r.p.m. for carded yarn 30's and combed yarn 38's, 10,000 r.p.m. for P/C blended yarn 45's. Single yarn breaking extension was decreased with the increase of drafting speed.