Influence of Selected Gin-and Mill-Cleaning Treatments on Cotton-Dust Levels, Spinning Performance, and Yarn Quality

Three gin-cleaning levels consisting of minimum, normal, and elaborate amounts of machinery were compared. Mill cleaning consisted of two levels of cleaning before a single stage of carding and one level of cleaning in combination with double carding. Increased gin cleaning lowered foreign-matter contents of cotton at the feeder apron but had no effect on ginning rate. The normal and elaborate treatments produced lower foreign-matter contents in ginned lint and cottonseed than did the minimum treatment. Each increase in gin-cleaning level raised the classer's grade of about one-half of the test lots but had little effect on staple length or micronaire reading. Fiber-length measurements were affected slightly by gin-cleaning treatments, but fiber strength was not affected by any of the experimental treatments. There was no significant difference in processing waste between the normal and elaborate treatments, but the minimum treatment produced about 20 percent more waste than the other two treatments. Each increase in mill-cleaning level increased processing waste. Cardroom dust levels decreased with increased gin cleaning, but the difference between minimum and normal gin cleaning was not statistically significant. The elaborate treatment reduced cardroom dust levels about 16 percent when compared with the normal treatment. Increased mill cleaning before carding had no significant effect on cardroom dust levels, but the dust level during the second stage of carding was 50 percent lower than during the first stage. Ends down during ring spinning increased significantly with each increase in gin cleaning, and the mill-cleaning treatment with double carding produced a higher number of ends down than did the treatments with single carding. Rotor residue decreased about 25 to 30 percent with each increase in gin cleaning. There was no significant difference in rotor deposits between the mill-cleaning treatments with single carding, but the treatment with double carding was very effective in reducing these deposits. Open-end and ring-spun yarns from the minimum gin-cleaning treatment were stronger and more uniform than yarns from the other two treatments. However, there was little difference among gin-cleaning treatments in yarn appearance and single-strand strength. Yarn quality was affected only slightly by mill-cleaning levels. For ring-spun yarns, the double-carding treatment produced a slightly higher yarn appearance index and fewer neps than the other mill treatments; for the open-end yarns, it produced more neps than the other mill treatments. There was little difference in bale loan value between the minimum and normal gin-cleaning treatments, but the elaborate treatment lowered bale values by excessively reducing bale weights during seed-cotton cleaning. These data should be useful to researchers, textile-mill operators, and others in the cotton industry for developing improved methods of reducing dust levels in ginned lint.