Thesis Details


Thesis Title: The effect of fiber denier, spindle speed, ring type, treated balloon control rings and pigtail guides, and single-feed and double-feed roving on acrylic ring yarn properties
Thesis Author: Jennifer Holt
Abstract: Productivity of acrylic yarn manufacturing has been limited because of problems that occur with increased spinning speeds, such as increased yarn hairiness, yarn fusion points, and ends down. Increased yarn hairiness is caused by friction created between the yarn and metal components of the ring frame. High spinning speeds cause tension levels to exceed yarn tensile strength, resulting in a substantial increase in ends down. The decomposition of acrylic fibers at high temperatures leads to the formation of fused fiber ends. Spindle speeds of 100% acrylic short staple yarn typically do not exceed 13,500 rpm at present. The objectives of this research were to analyze the effects of increased ring spinning speeds on acrylic yarn properties and acrylic fabric appearance. Specifically, fiber denier was altered and different ring constructions and ring treatments were utilized, as well as single-feed and double-feed roving to improve spinning productivity. The results of this research indicate that spindle speed can be increased to at least 13,900 rpm without deteriorating yarn quality. A further increase to 14,700 rpm results in the rapid formation of fused and charred fibers. In comparison to 3.0-denier fiber, 1.7-denier fiber produces better quality yarn. The greater number of fibers per yam cross section with the 1.7-denier fiber contributes to the improved yam properties. The use of treated balloon control rings and pigtails results in a significant increase in yam single-end tenacity and single-end elongation and a decrease in yam hairiness, as compared to use of untreated components. In addition, double-creel roving produces superior yarn quality in comparison to all other variables.