Thesis Details

Thesis Title: Evaluation of the High-Draft Retrofit for Ring Spinning of 100% cotton and 50/50 Polyester/cotton Yarns at Different Draft Levels
Thesis Author: John Parrish
Abstract: Two major functions performed by high-draft retrofits for short staple ring spinning include: superior control over short fibers and parallelization of the fiber bundle. The high-draft retrofit investigated in this thesis is an apron device which was sUbstituted for the top front roll of the drafting system. The brushing action and short fiber control performed by the apron enabled the fiber bundle to be drafted more evenly. Resulting yarns possessed improved quality when compared to yarns produced on the same equipment without the retrofit. In pursuit of high quality yarns, an additional advantage of a high-draft retrofit would be the easy installation of the retrofit to existing spinning frames at a substantially lower cost than replacing machines with newer equipment. During this thesis work, the development of the high-draft retrofit for short staple was based on the long staple version manufactured by Monsanto. Various counts of yarn were spun from 100% cotton; 50/50 polyester/cotton, coarse and fine roving with and without the retrofit in order to determine quality changes in yarns as a result of the device. The tensor pin angle was found to vary the amount of control and brushing action of the apron on the fiber bundle moving through the drafting zone. Four roving constuctions were spun on a conventional Casablancas drafting system as well as the retrofitted system. The retrofit was tested three times, each with a different tensor pin angle. Evaluation of the yarns produced from the different systems was based on Adjusted Break Factor of skeins, Single End Strength, Single End Elongation, Uster CV%, Uster Imperfections, Shirley Hairiness, Appearance, and ends down rate in spinning. Based on the results of this thesis research, the following general results were noted: 1. The best yarns were produced from retrofitted systems with tensors set at the 0 and 45 degree. 2. Significant quality improvements included: Adjusted Break Factor increased 8 percent Uster CV% decreased 2.5 points Uster Thin Places showed a 75 percent reduction Uster Thick Places decreased 45 percent Uster Neps decreased 25 percent Single End Tenacity increased by 1.0 gram/tex Ends down rate dropped 50 percent 3. Retrofitted yarn hairiness increased 20-25 percent over conventionally spun yarns.