Abstract
This article deals with slub yarn which is manufactured on a spinning frame having a mechanism to speed up or slow down its roller speed from time to time. The authors theoretically discuss what happens to roller drafting when a roller speed is changed from time to time. They go on to clarify, on simple assumptions, that the formation of the slub portion occurs somewhat later than the change in the roller speed. The correlation among such factors as the size and length of slub portion, the staple fiber length of fed sliver, and the duration of speed-change in the roller has been experimentally computed. Various characteristics of the slub portion, such as the distribution of its twist, its quantitative distribution, its strength and elongation have been experimentally computed.
