VORRICHTUNG UND VERFAHREN ZUM AUFTRAGEN EINES FLÜSSIGEN ODER PASTÖSEN AUFTRAGSMEDIUMS AUF EINE LAUFENDE MATERIALBAHN, INSBESONDERE AUS PAPIER ODER KARTON

摘要

The apparatus to coat a surface of a moving web, with a liquid or paste coating medium, has a unit (122,122') to generate or deliver a fluid and especially steam which is next to and after the application point (S) or doctor in the direction of web (116) travel. The generated (122,122') fluid is directed at the coating application point (S) from an outlet opening (124a) near the applicator (110) and aligned at the application point (S). The walls defining the fluid outlet opening give the emerging fluid a jet stream flow action, and preferably taper together in the fluid flow direction. The fluid generating and/or delivery is from a back pressure unit. A trap (126) is at the side of the web (116) away from the fluid delivery unit, to catch surplus coating medium droplets or particles (N) which have not bonded to the web (116) at the application point (S). A cooling unit (134) is at the catch surface (128) of the trap (126), such as with cooling ribs and/or cooling coils and/or a heat exchanger. A unit (136) to deliver a flushing fluid is at the droplet/particle catch surface (128). A suction system (135), is at the side of the web (116) away from the fluid delivery unit, to extract floating coating medium droplets or particles (N) from the atmosphere following the application point (S). Where the web (116) is coated on both sides, a fluid generating/delivery unit (122,122') is on both sides of the web. They are arranged in rows across the web (116) width, each with an independent control to set their fluid delivery rates by time units. An Independent claim is included for a web coating process, where the coating medium (120,120') is applied (118,118') to the surfaces of application rollers (112,112'), which transfer it as a coating layer (120a,120a') to the web surfaces. The gap between the application rollers and the web forms a medium sump, to be picked up by the web through its precipitation. The applied coating is smoothed and/or dosed by a doctor after the application point (S). After the application and doctor points, a fluid is sprayed at the coated web, prefer as steam. Preferred Features: The fluid spray is aligned towards the coating application point (S), so that any loose coating droplets or particles are forced into the web surface. Floating droplets or particles are caught in a trap (126) and extracted from the atmosphere by suction (135).