Abstract
Factors affecting translation of strength from single yarn to doubled yarn and from multiple strand to fabric have been investigated with polyester, cotton, and polyester/cotton blends. The effect of intimacy of mixing and blend variation on these aspects was also investigated by comparing blends made at drawframe and ringframe.
The variability in strength and elongation is more marked with blends than in cotton, and hence the strength reduction with increase of specimen length and the losses from single strand to multiple strand are more prominent with the former. At the same time, strength improvements from doubling and from fabric assistance due to interiacement of threads are more pronounced in such material than in cotton. Between the two blends, the drawframe blend is superior to the ring frame blend in the single-yarn stage. After doubling, the difference in strength diminishes and even vanishes at the short specimen length. Once again, the drawframe blend is found to be superior to the ringframe blend in the multiple strand test, but the difference vanishes after the material is woven into a fabric.
The inferior strength in the ringframe blend in the single-yarn and multiple strand arises because of higher variability in this material, but this deficiency is made up by doubling and interlacement of threads, and as a result the ringframe blend becomes comparable to the drawframe blend in the doubled-yarn and fabric stage.