Characterization of neps in spinning processes

Abstract

Nep level and nep size distribution at different stages of cotton spinning has been studied with the help of Advanced Fibre Information System (AFIS). Importance of nep size, particularly for finer counts, and some of the ways and means of nep size reduction is brought out. The concept of critical nep size as enunciated by Zellweger Uster is made use of in the studies. Studies also highlight the fact that lower level of neps/g in card sliver does not necessarily mean lower level of neps in the yarn. The rate of change of cumulative nep size slows down, as per cent of total neps, from raw material stage to finisher drawing stage, except in blow room. At blow room, not only neps/g but their size also shows an increase. Card sliver hank and combing parameters such as feed/nip, cushion plate to half lap setting and top comb penetration have a

critical influence on the nep size in combed material.