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Abstract:
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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.
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