Fibre migration in compact spun yarns: Part Ⅱ - Mechanical compact yarn

摘要

Fibre migration of ring and mechanical compact spun combed cotton yarns (40s Ne) has been studied using the tracer fibre technique. It is observed that the migration parameters for compact yarn made from Mechanical Compacting System (MCS)-positive nip are 10-15 % lower than that of the ring yarn and similar to that of pneumatic compact yarn of the same count. However, only a marginal reduction (2-6%) is observed in migration parameter for compact yarn made from MCS-semi-positive nip as compared to ring yarn and it is not significant. Significantly lower degree of migration is observed in mechanical compact yarn spun from MCS-positive nip than in ring yarn due to the significant reduction in size of the spinning triangle in the system and its consequence in the tension gradient. In the case of MCS-semi-positive nip, the base of the spinning triangle remaining the same, its altitude increase causes slight reduction in tension gradient, resulting in marginal change in migration parameters. Yarn diameter of mechanical compact yarn from MCS-positive nip system is found to be significantly lower than that of ring yarn and similar to pneumatic compact yarn, which contributes to increase in strength by 10-15%. The yarn from MCS-semi-positive nip system has shown a marginal reduction in yarn diameter and hence the increase in strength is marginal (3-5%).