One of the tasks of the drawframe is dust removal. Release of dust occurs almost exclusively in the drafting arrangement and this should be totally enclosed so that dust does not pass into the surrounding atmosphere. The dust-laden air must be extracted by suction (as shown in Fig. 10 for the Rieter machine). Each roller of the arrangement has an associated cleaning device (scraping bar and suction tube) so that fly and fibers tending to adhere to the rollers can also be carried away. In addition, on the Rieter drawframe the scraping bars are lifted from the top rollers intermittently. Trash collections therefore pass into the dust removal system. The air extracted is passed via tubes directly to filters within the machine and then into the exhaust ducts of the air-conditioning system or directly into those ducts. Filters within the machine are cleaned manually or by a wiper. This latter arrangement has the advantage not only of easier handling but also of constant suction pressure, resulting in constant cleaning efficiency.