Mechanism of generation of drafting waves during spinning and the way to eliminate it

The generating mechanism of the staple yarn′s drafting waves during roller drafting is analyzed.It is assumed that the generation of drafting waves during roller drafting is mainly ascribed to the fiber-to-fiber static friction coefficient is greater than the dynamic one.It is proposed that a high frequency undulating wave is imposed on the fiber strand in the drafting zone of roller system so that a high frequency and slight relative movement occurs between the fibers in the drafting zone,and the fiber-to-fiber friction is dominated by the dynamic friction rather than the static one,and thus the ″stick-slip″ motion will be eliminated.As a result,the fiber binding effect causing drafting waves can be significantly reduced.This hypothesis is verified by experiments,and it can be applied to the development of new spinning drafting devices.