The extent to which the fiber tufts are opened has a direct effect on the service life of the card clothing – the better the opening degree, the longer the service life.

Parallel to the opening of fiber tufts, trash is eliminated at the same time. Different licker-in wires are used depending on fiber type and fiber denier. There are revolving flat cards with one lickerin-in and cards with three licker-ins.

The cylinder wire selection is crucial to the intensity of the carding, in addition to cylinder rotation and flats speed. Parameters such as front angle, PPSI (points per square inch) and the height of the cylinder wire play an important role.

The tooth shape of curved doffers, used for specific doffer wires, improves fiber transfer from cylinder to doffer and facilitates transfer of the web from the doffer to the stripping roller. Doffer wires with striations increase fiber cohesion, which is very important to the processing of synthetic fiber at high production speeds.

In recent years the production of synthetic man-made fibers, a trend leading to finer fibers, has accelerated. Groz-Beckert supports this trend with the high-performance doffer wire D40-30-52C CBF. The special geometry and high tooth density (520 PPSI) result in significantly better yarn quality with regard to yarn imperfections.

Revolving tops are available in different heights and with varying PPSI, selected in accordance with production level and spinning process.

Tops with high PPSI are recommended for fine ring-spun yarn; tops with low PPSI are primarily used for coarse ring-spun yarn and open-end yarn.

In the pre carding zone the raw material should be prepared in such a way that the load on the flats is limited. Large fiber tufts are opened into smaller fiber tufts by the stationary flats. In the post carding zone further carding takes place in which the fibers are again parallelized and individualized.

If cotton is being processed then the fiber of the stationary flats in the pre and post carding zone must be prepared in such a way that trash and dust can be removed by the mote knives.

Groz-Beckert also supplies stationary flat systems for carding, consisting of 2 to 22 stationary flats, depending on card type and model. Moreover, one or more extraction units can be connected to the system for trash removal.

The cleaning roller of the stripping roller prevents lapping of the stripping roller, while cleaning rollers for revolving tops remove the flat strips from the revolving tops. For good carding results and for keeping the card sliver clean, flat strips must be completely removed.