Abstract

Roller hardness of drafting unit in ring spinning frame is very important for controlling the draft and quality of yarn. This research work deals with the impact of cot roller shore hardness on the quality of cotton carded yarn. The five samples were prepared by using the combination of three different cot roller shore hardness (650, 750 and 830) in ring frame. At first, yarn samples of 30Ne were produced by varying front roller cot hardness with constant back roller hardness. Secondly, yarn samples of 30Ne were produced by varying back roller cot hardness with constant front roller hardness. The test results of the samples were carried out. The trends of the obtained results were analyzed. The results showed that softer cots at front line significantly reduced mass variation and hairiness of yarn. On the other hand, harder cots at back line significantly reduced mass variation, imperfection level as well as yarn strength. Among these combinations, 650 at front line and 830 at back line were better for producing good quality yarn. This study will help the spinners of Bangladesh to select the appropriate cot roller with optimum shore hardness of front and back line at the drafting system in a ring spinning frame to get the required quality of the cotton carded yarn.

Keywords: Cot roller; Shore hardness; Durometer; Count Strength Product (CSP); Reiss kilometer (Rkm)s