Studies on the short-term irregularity of spun yarn (Part 1) Efect of the front top roller eccentricity on the short term irregularity

방적사의 단주기 불균제도에 관한 연구(제1보) -프런트 톱 로울러의 편심이 단주기불균제도에 미치는 영향-

Effect of the eccentric front top roller on the short term irregularity of three spun yarns, carded 30's combed 83's and polyester/ cotton blended 45's was studied, and the results of it were as the followings; 1. Effect of the eccentricity of front top roller on the irregularity of the spun yarn was significant and the irregularity produced was linearly increased with the level of eccentricity. 2. Maximum allowable eccentricity of front top roller for the tested yarns should be less than 2/100mm to avoid irregularity caused from the eccentricity. 3. Added irregularity (CVE) produced only from the eccentricity was expressed with the following empirical equations; CD30 : CVE=105(D-1)α·e/d-0.3 CD30 : CVE=73(D-1)α·e/d+1.8 P/C45 : CVE=63(D-1)α·e/d+2.0 where D : draft ratio e : eccentricity (1/100mm) d : diameter of top roller (mm) d' : diameter of bottom roller (mm) α : 2d'/d+d' 4. Irrequalarity caused from the eccentric front top roller had periodicity and most of their length of period were the same as the circumference of the roller and some of them were the half of it. 5. Single strand strength of spun yarn was decreased, as the eccentricity was increased and the rate of it had the maximum value on the carded yarn 30's.