Curtain-coating unit for coating a moving paper, cardboard or other fiber web with fluid to pasty coating medium in the form of one or more layered curtain, comprises a curtain coating head arranged over the fiber material web

摘要

The curtain-coating unit comprises a curtain coating head (3) arranged over fiber material web (2) and formed as sliding layer nozzle, curtain slot nozzle or as twin-nozzle, and a lateral curtain holder mounted on the curtain coating head. One or more layered curtain (7) reduces the gravity following on the surface of the fiber material web. Edge strips (9) are arranged on both sides. The single or multi-layered curtain is guidable over its falling path between a cutting edge (6) and the surface of the fiber material web at its lateral edges. The curtain-coating unit comprises a curtain coating head (3) arranged over fiber material web (2) and formed as sliding layer nozzle, curtain slot nozzle or as twin-nozzle, and a lateral curtain holder mounted on the curtain coating head. One or more layered curtain (7) reduces the gravity following on the surface of the fiber material web. Edge strips (9) are arranged on both sides. The single or multi-layered curtain is guidable over its falling path between a cutting edge (6) and the surface of the fiber material web at its lateral edges. The edge strips are adjustable to each other in width direction of the curtain for adjusting a curtain and/or coating width. The edge strip connects itself directly to the cutting edge and has a distance of 0-0.1 mm for the cutting edge. The edge strips are adjustable during the coating process and are subjectable and/or wettable with auxiliary fluid at its interior side to produce a fluid film. A collecting element is equipped that is arranged at the external side of the edge strip at its upper area and receives coating medium, which dose not arrive on the fiber material web. A suction device is equipped per edge strip that takes away the concentrated or mixed coating medium from the lower area of the edge strip or from its external side and at the same time stabilizes the falling curtain directly before its application on the fiber material web. Water is used as the auxiliary fluid and is mixed with chemical additives such as surfactants and thickener. Nozzles or pores are incorporated for discharging the auxiliary fluid into the edge strips. Double walled collecting element is formed as container that comprises a leaned base area that is leaned in a direction turned away the edge strip. The collecting element is adapted at the desired length of the coating width, is subjected with a cooling fluid and has 50-500 mm length. An independent claim is included for a method for coating a moving paper, cardboard or other fiber web with fluid to pasty coating medium.