Study On The Abrasion Resistance And The Model Of Sized Yarns

With the increase of the speed and weft-insertion rates of looms, as well as the development of high-grade, high-quality fabrics such as the fine count and high-density, higher and higher demands are put forward to the warps'weavability. In weaving, sized yarns are subjected to not only the tension but also various friction. In normal circumstances, the maximums of the tension and the elongation of the warps suffered in weaving are less than the actual breaking strength and breaking elongation. The abrasion resistance of warps is more important for their weavability. In this thesis, the internal factors that affecting the abrasion resistance of sized yarns are set out to study the abrasion resistance of original yarns, sized yarns and size films. Results show that the abrasion resistance of sized yarn is highly correlated with not only the breaking stress and the breaking elongation of original yarns, but also with those of the sized yarns; similarly, the abrasion resistance of size films depends on both their breaking strength and their breaking elongation. In view of these, the tensile properties of grey yarns, size films and sized yarns can be used to evaluate the sized yarns'abrasion resistance indirectly. Then, the sized yarn structure model is established by observing the cross-section of sized yarns using Keyence digital microscope. On the basis of circular cross-section, the size penetration and encapsulation are characterized by three concentric rings: the outmost ring is the sized film, the intermediate is the bonding body of fibers and sizes, the innermost is the fibers that sizes fail to reach. Thus the relationship between the structural parameters and the fineness, penetration and encapsulation of sized yarn are established. Based on the studies above, the prediction models of breaking stress and breaking elongation are explored primarily. The strength and elongation properties of yarns, the force of adhesion, the penetration and the encapsulation of sizes to yarns are included in the model. Proving trials show that the prediction of breaking stress of sized yarn is acceptable, but the prediction of the breaking elongation demands further work. At last, some suggestions are put forward for the further research according to the experiences and deficiency in this study.