Analysis of Factors Influencing Ring Spun Yarn Tenacities for a Long Staple Cotton

A family of yams from a particular Egyptian cotton was used to develop a method of determining the number of fibers broken, Part I, and the effective fiber length, Part II, acting in each yarn. The yarns were spun independently on a ring frame with wide ranges of yarn sizes and twist factors. The method of yam analysis was developed by evaluating the yarn data. Single-strand breaking tenacity was measured for each yarn. Fiber fineness was used to determine the number of fibers in each yarn after correcting for angle of twist. Yam tenacity was normalized first for total fibers and then for broken fibers in the yarn. Equations relating yarn twist to the normalized yarn tenacity data for different yarn sizes at a constant twist factor were determined for each twist factor. The shape of the family of curves of twist versus normalized yarn tenacity per broken fiber in the yarn permits an existing theory for determining the number of broken fibers in a yarn to be evaluated, as well as a comparison of experimental with theoretical yarn twist.