Studies on the short-term irregularity of spun yarn (Part 2.) Effect of the front top roller hardness on the short term irregularity

방적사의 단주기 불균제도에 관한 연구(제2보) -제2보 프론트 톱 로울러의 경도가 단주기불균제도에 미치는 영향-

The authors investigated the yarn irregularities caused by the different hardness of front top rollersi.e., 65$^{\circ}$ 70$^{\circ}$ 75$^{\circ}$ 80$^{\circ}$ 85$^{\circ}$at the ring spinning frame and the results were as the followings; 1. The irregularity of the spun yarn (U%) was linearly increased with the hardness of front top roller and this tendency was significant statisticall. 2. Short-term additional irregularity caused by the front top roller largely affected to the amount of total yarn irregularity at the rate of 45%~80%. 3. IPI Values (thin place and thick place) of spun yarn was increased as the hardness of roller was increased and the increasing rate of IPI Value was large at the low count yarn in which the percentage of short fibre content was large.