Cleaning Action of Cotton Card Equipped with Metallic Card Clothing Part 1 Comparative Spinning Tests of the Cards Equipped with Metallic Card Clothing and Wire Fillet Clothing

In using metallic card clothing for cotton processing, the most important step to be taken is to reduce impurities-neps and other imperfection-in the sliver and, therefore, in the yarn. A number of comparative spinning tests has been made of two types of card: (a) MC, equipped with several tooth angle combinations of metallic card clothing on the cylinder and on the doffer; (b) FC, equipped with an ordinary wire fillet clothing. The behavior of impurities has been minutely analyzed in each case. The impurities discharged into various parts of a card have been classified into four kinds by their structures and into six classes by their sizes. It has been concluded from the tests that neps are always fewer in a sliver on MC than in a sliver on FC, because there is a smaller deposit of fibers on MC's cylinder and flats and, therefore, there is less nep formation. It has been concluded also that the other kinds of impurities in a sliver on MC can also be made fewer than in a sliver on FC if the tooth angle combination is properly adjusted. The proper adjustment is to make the tooth angle large on the cylinder and small on the doffer. This reduces the fiber density on the cylinder surface, improves the impurity-removing ability of the flats, and lessens the impurities in the sliver. These results have been confirmed again by the fact that yarns spun from an MC-processed slivers get a better rating for neps and other imperfections in an appearance test. Since there is no appreciable difference in the quality of the yarn except in the impurities, metallic clothing can be very profitably used for cotton spinning also.