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.

Abstract: The invention relates to a process and apparatus for applying liquid, pasty or foamy substances to both sides of webs of material. To prevent any adverse effect on the web of material or the applied substances, application is performed by means of a pair of S-rolls 7,11 at a looping angle just enough for the application, the web of material being guided substantially straight. The two applicator rolls 7,11 are disposed as close as possible to one another immmediately upstream of the drier inlet 1. At least one of the applicator rolls 11 can be moved out of the operating position, to enable the web of material to be drawn in unimpeded.