Effect of Delivery Speed on the Lateral Deformation of Sliver in Roller Drafting Zone

Abstract

Recently, the high speed machines appeared in the spinning process and the delivery speed of the drawing machine, for example, reached 400-500m/min. It is considered that the drafting behaviour at high speeds is quite different from that of conventional low speeds. The drafting force tester that is usually used to evaluate the drafting behaviour can not apply at high speed region because the inertia and the vibration of the detecting part become large as the speed increases. In previous paper, it is reported that the lateral deformation of sliver in the roller drafting zone (LD) is one of the important expressions to show the roller drafting behaviour.
In this paper, LD was measured for the delivery speeds of the roller drafting machine and the effects of the delivery speed on LD were discussed. As the delivery speed increases, the mean of LD increases. The coefficient of variation of LD also increases reaching the delivery speed 100m/min. At low delivery speed, LD shows the strong periodicity, but the periodicity decreases rapidly when the delivery speed increases. The wave length of LD is approximately constant irrespective of the delivery speed. The results show the same tendency as the output sliver irregularity for the delivery speeds. It is clear that the drafting behaviour becomes worse, while the periodicity becomes weaker when the delivery speed increases.