Effects of Pin Drafting on Irregularities of Sliver Made from Fine Denier Fibers

Abstract

To improve the quality of spun yarn made from fine denier fibers, the technique of pin drafting is examined and discussed. Slivers made from four levels of fiber fineness are drafted with an experimental pin drafting system by changing the draft ratio. Deviations between indices of irregularities I corresponding to output and input slivers are calculated to evaluate the performance of the drafting process. Deviations of the gill sliver decrease with decreasing fiber denier. This phenomenon can be explained by the larger number of fibers contacting the pins of the gill fallers and the greater interfiber cohesive force with decreasing fiber denier. Irregularities of sliver from fine denier fibers are effectively negated by an appropriate pin drafting system.