Analysis of spinning process using the Taguchi method. Part I: Effect of spinning process variables on fibre orientation and tenacities of sliver and roving

Abstract

The effect of drafts at different stages of spinning process on fibre orientation and tenacities of sliver and roving has been studied by using Taguchi method and analysis of variance. Among all the fibre orientation parameters analysed the ‘coefficient of relative fibre parallelization (K _rp)’ influenced the maximum with change in process variables. Further, the equation used for calculation of K _rp was critically analyzed and modified for a better explanation of fibre orientation. The fibre orientation in sliver and roving was also studied in terms of a new index of measurement of fibre straightness along the length. Increase in lap hank and card draft increases proportion of curved fibre ends (ρ) and decreases K _rpm in card and breaker sliver. However, the improvement in K _rpm is seen to be higher in finisher sliver and roving produced by finer lap hank and higher card draft in subsequent processes. Increase in lap hank, card draft and draft/doublings decrease the FSI in slivers. The lower speed frame draft tends to decrease fibre straightening index (FSI) of roving. Further, a combination of K _rpm, ρ and FSI values is seen to decide the strength of slivers.

Keywords:

• Analysis of variance
• card draft
• draft/doublings
• fibre parallelization
• fibre relaxation
• hooks
• regression model
• Taguchi method
• tenacity