Yarn Shape in Twisting Part of Disc Friction False Twister

Abstract

The disc friction false-twisting machine has an established processing process that enables it to process different types of yarns. However, its optimum processing condition is unclear, and basic data for designing a processing machine is scarce. The number of discs, disc shape, and disc material are empirically set, as the twisting mechanism is yet to be clarified. The mechanism of twisting and untwisting helps understand the relationship between yarn quality and twisting form. In addition, it is possible to optimize design, reduce cost, and improve processing efficiency in developing a processing machine. This study will examine twisting and untwisting of the disc to obtain basic data on the disc friction false-twisting machine. The picture of the yarn shape on the disc in the twisting part was collected as data. When the yarn is twisted, the apparent yarn thickness decreases and the twisting angle increases and when it is untwisted, the apparent yarn thickness increases and the twisting angle decreases. Based on these characteristics, the apparent thread thickness and twist angle as the yarn shape were measured, which showed that the twisting and untwisting position on the disc were switched. These results also showed that untwisting started in the middle of the twisting part while the yarn slipped on the disc. Therefore, it is possible to calculate the number of optimum discs required for the twisting part.