The Effect of the Winding Process on Yarn Structure

الملخص

It is often claimed that the quality of the yarn is improved as a result of winding. This is based on the assumption that during winding thick, thin and weak places are eliminated.
Although the use of a clearer and slub-catcher devices in the winding machine result in the elimination of these undesirable places, most of the tensioning and clearing devices impart a frictional drag on the yarn and have the effect of a rubbing or scraping action on the yarn. Such actions will change the yarn surface structure.
In this paper the properties studied were the yarn hairiness, regularity and tenacity. Carded cotton ring-spun and open-end spun yarns were used. By rewinding the same yarn from each type several times, and measuring those properties, after each rewinding process, it was found that there were significant changes in the yarn hairiness, regularity and tenacity. The changes were more significant for the ring-spun yarn This could be explained as follows; after rewinding, the separation of the yarn from the package surface can only be achieved by the breaking of this mechanical interlocking. Therefore, some fibres will be removed from the yarn body thus resulting in some changes in the yarn structure. The results also showed that the direction of unwinding has an effect on the yarn structure.
It was inferred from the results obtained that during the winding process there was a mechanical interlocking action between the protruding fibres on the yarn surface. This interlocking is mainly caused by the rolling action of the yarn during winding, effected by the grooved drum, and the rolling of the incremental length of yarn at the unwinding point, owing to the drag between the withdrawn moving yarn and the supply package surface.