carding machine[′kärd·iŋ mə′shēn]
a machine for carding fiber materials for the production of textiles; one of the primary machines used in spinning. A distinction is made between carding machines proper and combing machines. In the former, tangled fibers are separated and fine, cohesive contaminants and defective fibers are removed by passing the fiber between the working members of a machine, which are covered by regular or metallic card clothing.
Two types of carding machines are used, depending on the material being processed and the type of production: machines with flats (for cotton and short chemical fibers) and machines with roller cards (for wool, bast fibers, and long chemical fibers). Various methods of feeding material to the machine are used to obtain a carded product of uniform thickness. Cotton is fed to flats in a layer of uniform thickness—a lap prepared by an openingscutching machine. Roller-card machines are fed by a weighing device that periodically weighs out equal portions of the fiber material.
The primary working members of a carding machine with flats are a taker-in, a cylinder, a doffer roller, and flats. Flats are narrow plates of a spiked belt arranged above the cylinder and covering approximately half of the cylinder’s surface. The lap proceeds from the feed plate to the taker-in, which is covered with teeth. The taker-in performs a preliminary carding of the fibers and removes contaminants and defects. The fibers are then fed to the cylinder, which is covered with a serrated or spiked belt. The primary carding process takes place between the cylinder and the flats; short fibers and contaminants adhere to the flats and are removed. The carded fibers are taken from the cylinder by the doffer roller, from which they are removed by a comb in the form of a thin web. After passing through a special funnel, the layer of fibers is transformed into a relatively dense, thin sliver which is deposited in a cylindrical container. Special carding machines with two cylinders are used to prepare sliver for spindleless spinning; such machines ensure higher quality carding.
The principal working members of a roller-card machine are the taker-in, the cylinder, from three to six pairs of worker rollers and stripper rollers set around the cylinder in pairs, a fancy roll, and a doffer roller. The taker-in separates large clumps of fiber material into smaller ones and prepares the material for the primary carding process between the cylinder and the worker rollers. Clumps and individual fibers that remain on the worker rollers after being processed against the cylinder are returned to the cylinder by the doffer roller. The rapidly revolving fancy roll has spikes that fit in the spaces between the spikes of the cylinder, thereby extracting the fibers from the surface of the cylinder. The fibers are then fed to the doffer roller, where they are arranged in a denser layer and made uniform in thickness and composition. The carded material from the doffer roller is removed by a comb, which makes a rapid vibratory motion.
Further improvements in carding machines are aimed at increasing efficiency and productivity by improving the precision of machine manufacture, increasing the speed of the working members, and equipping the machines with stronger preliminary carding units, compression rollers, and other devices.
REFERENCESTruevtsev, N. I., N. N. Truevtsev, and M. S. Genzer. Tekhnologiia i oborudovanie tekstil’nogo proizvodstva. Moscow, 1975.
V. V. ZHOKHOVSKII