the production processes used to make yarn from cotton fibers. Synthetic fibers may also be processed by cotton spinning, both mixed with natural fibers and alone, which makes it possible to widen the assortment of cotton fabrics available and improve their appearance and quality. Three systems of spinning are used, depending on the requirements of the yarn and the length, weight-to-length ratio, and other properties of the cotton fiber: card, card and comb, and condenser spinning.
Card spinning is used to produce yarn of average weight-to-length ratio from medium-fine cotton fiber. The system uses only the carding process. The raw material is first fed to openingscutching units; from there the cotton in the form of a loosened mass, sometimes pressed into a lap, or roll, is delivered to a flat card. Here, the layer of fibers is formed into sliver, which is doubled and stretched on the two rollers of a drawing frame to achieve an even thickness and straighten out the fibers. The sliver is then fed to roving frames, where it is thinned by being drawn out, twisted, and, in the form of roving, wound onto bobbins, which are then passed to ring frames. When pneumatic spinning frames are used, the sliver is fed directly to the spinning frames from the drawing frames.
Card and comb spinning is usually used to produce the finest yarn or yarn of average weight-to-length ratio but of higher quality from medium-fine and fine cotton fiber. The fibers are combed on a flat card and then on a combing machine, where adhering contaminants are removed and a significant number of short fibers are separated from the contaminants. The combing machines are usually fed laps produced by sliver lap machines. The need for additional transfers to prepare the sliver for combing makes card and comb spinning more expensive than card spinning. After carding, the combed sliver is made more uniform on several rollers of drawing frames and then processed into roving and yarn.
Condenser spinning is used to produce thick yarn from low grades of cotton and from cotton waste. The yarn obtained is thicker, looser, fluffier, and less uniform than yarn produced by card spinning. The raw material is worked by beaters and openers, then blended and loosened some more on a picker. The picked material is fed to a carding machine, which usually includes two roller cards. The cotton is separated lengthwise into narrow slivers and rolled into roving on the roving carriage of the second card of the carding machine; the roving is then fed to the spinning frame.
Promising lines of development in cotton spinning include the use of spindleless spinning frames, the combining of equipment into single units, and the construction of automatic production lines.
REFERENCEPriadenie khlopka i khimicheskikh volokon, parts 1–2. Moscow, 1973–74.
V. V. ZHOKHOVSKII