Arrangement for impregnating webs of porous material

Abstract

In known pressure impregnating devices there is a chamber, which continuously narrows in the transport direction, between a cylinder around which the web to be impregnated loops, and the inner wall of a trough containing the impregnating agent. The impregnating agent is supplied to the chamber under high pressure, which is further increased in the chamber by dynamic effects. Sealing problems arise at the inlet and outlet slits as well as at the front faces because of the high pressure. Disruptions in the operation can be created by fluff coming loose from the paper web as well as by impregnating agent penetrating between the sliding faces. The new device is intended to remedy these disadvantages, and is provided with the seals have alternating narrow gaps and wide grooves in the form of a labyrinth seal. The grooves are have drain openings for the impregnating agent flowing through.

Dependencies are inferred from the claim text.