Wet paper or card coating unit

摘要

The coating medium (24) comes into contact with the web of material in the wrapped-around region (u). The coating unit (20) is located on the side of the web which faces away from the roller. It slides against the sieve belt (14, 16) or alternatively clears it. A stripper (26), preferably immediately after the coater removes excess. A smoother further levels the coating and as required, also removes excess. The smoother has a scraper. The coating may be fed over the surface by a roller. The coater is in sliding contact with the roller surface or clears it. In one part of the wrapped region (U), there is a zone (28) of reduced pressure. Coating leaves the coating chamber (22) under a pressure of 300 Pa - 10 kPa, preferably 500 Pa - 5 kPa. Residence time is 1-10 ms. The coater is constructed to dose the coating medium. It is a fine jet nozzle system. The web of material is held between two sieve belts (14, 16). Roller radius is 200 - 1200 mm. The solids content of the web is 5% - 50%, preferably 8% - 17%. The solids content of the coating medium (24) is 5% - 50% , preferably 10% - 30%.