A study on fiber motion in the drafting zone and hook removal

Abstract

In this study, the hook removal of four types of hooks during the drafting process has been investigated, and the theory of fiber straightening was further improved by analyzing the relationship between fiber length, fiber straightness, draft ratio, and the fiber accelerated point. Simultaneously, a time domain model was used to simulate the dynamic drafting process based on the straightening analysis, which provided an approach to capture the dynamic motion of different types of fibers and hook removal in the drafting zone. The model is validated by a previous study and experimental work, with the result that the output fiber straightness is both in a good agreement with those calculated by classical theories and experimental data. The straightening effect of the drafting process on four types of hooks under the same drafting conditions is compared. It is shown that the drafting effect on different types of hooked fibers is varied, with the clumped fiber removed preferentially followed by both end hooks or the trailing hook, whereas the leading hook is the most difficult to remove.