Rieter

Dust removal

Index

Cotton contains very little dust before ginning, but working of the material on the machines causes dust. Even where dust is removed, new dust is being created through shattering of impurities and smashing and rubbing of fibers. Formerly, dust was of no great significance for the spinner, but now it poses a problem.

Firstly, increasingly strict laws have been passed regarding observation of specified dust-concentration limits in the air of blowing rooms, and secondly, many new spinning processes, especially OE rotor spinning react very sensitively to dust.

However, the removal of dust is not simple. Dust particles are very light and therefore float with the cotton in the air transport stream. Furthermore, the particles adhere quite strongly to the fibers. If they are to be eliminated, they must be rubbed off. The main elimination points for adhering dust, therefore, are those points in the process at which high fiber/metal friction or high fiber/fiber friction is produced. The former arises in the card, between the main cylinder and the flats, and the latter arises in drafting arrangements, mainly in the drawframe. Today the drawframe is a good dust removal machine owing to the suction extraction system around the drafting arrangement. Material leaving the drawframe contains only about 15% of the dust originally present or newly created  [4].

Dust that separates easily from the fibers is removed as far as possible in the blowroom. Various machinery manufacturers offer special dust-removing machines or equipment to be installed in the blowroom. These operate mostly with perforated surfaces together with suction. However, it must always be borne in mind that flocks resting on the perforated surface act as a filter, so that generally only the undersides can be cleaned.

It is also important that dust released during processing is sucked away immediately at the point of release.