Thesis Details

Thesis Title: The effect of card mat weight, openness, and tension draft on sliver and yarn quality
Thesis Author: Jeffery Frye
Abstract: Yarn quality is a critical factor in any textile operation. The impact that yarn quality can have on a textile operation is made evident by the research conducted at the Institute of Textile Technology that proves significantly better yarn at weaving will significantly improve weaving efficiency and save a notable amount of money. Researchers have concluded that the carding process has a direct influences on yarn quality. This thesis further analyzed what effect carding has on card sliver and ring spun yarn. The focus of this thesis is on the card mat and how making simple adjustments to the card mat can affect sliver and yarn qUality. According to publications conducted at the Institute of Textile Technology, card mat weight, card mat openness, and card mat tension draft vary widely throughout the textile industry. Therefore, this thesis research attempts to determine the optimal condition for the card mat. The results of this thesis are intended to aid yarn manufacturers in determining what levels of card mat variables are needed to attain the highest level of sliver and yarn qUality. To accomplish this research, a total of thirty-six conditions was processed into ring spun yarn. All processing and testing took place at the Institute of Textile Technology in Charlottesville, Virginia. The conditions consisted of three levels of card mat weight (11 oz/yd, 16 oz/yd, 20 oz/yd), two levels of card mat openness (low - 112 0.1., high - 135 0.1.), and three levels of card mat tension draft (1.23, 1.47, 1.60). Each condition was processed once with card autolevelling and once with without card autolevelling to determine the effects of the variables without the possibility of any special cause variation generated by the autoleveller. For this research, cotton stock from the West Texas growing region was carded and used to spin 20/1 Ne ring spun yarn. The thirty-six carded conditions were tested extensively. Each sliver condition was tested for trash content, Uster mass variation (normal and inert), fiber alignment, neps, short fiber content, sliver weight variation, and slubs as measured by the Sliver Analyzer. All thirty-six yarn conditions were tested and ranked according to the Institute of Textile Technology's Monthly Yarn Quality and Calibration Program (MQC). Considering experimental limitations, and with respect to the objectives of this thesis, the following conclusions were derived: 1. The card mat weights, selected for this research, did not have an overall effect on yarn quality. 2. High card mat openness (135 0.1.) compared to low openness (112 0.1.) increases card sliver quality and yarn qUality. 3. The combined effect of card mat openness and card mat tension draft was determined to have significant effects on yarn qUality. The combination of high card mat openness (135 0.1.) and high card mat tension draft (1.60) decreases yarn quality; however, at low card mat openness (112 0.1.) the use of high card mat tension draft will increase yarn quality. 4. This research indicated that mid-term autolevellers must be calibrated according to the level of card mat fiber openness. If the card autoleveller is not optimized to the level of fiber openness improper sliver correction occurs and negatively affects yarn qUality. 5. The best yarn quality, in this research, was produced with the combination of high card mat openness, 1.47 card mat tension draft, and 20 oz/yd mat weight.