Seal formed of plastic layer having outwardly open depressions

Abstract

The seal or pattern between two machine parts has on one of the sealing gap-forming, facing surfaces (5) a plastic layer (1) with closely juxtaposed depressions (8) which have the form of partly cut off voids of an expanded plastic structure. They are formed by the removal of a plastic layer (3) expanded on the machine part, the layer thickness being so uniformly reduced that the voids (4) of the bottom void layer (4) adjacent to the base surface (5) of the machine part are open. This avoids the insulating action of the closed voids of an expanded plastic layer and the latter has a very limited weight, which avoids any risk of the layer being detached or separated due to centrifugal forces. Moreover, in simple manner, a honeycomb-like, open surface structure is obtained, so that there is a labyrinth effect in the sealing gap. In order to obtain minimum, sealing gaps by running in the open, honeycomb-like surface structure is particularly advantageous, because the solely linear contact which occurs ensures a rapid running in of the mating surface, which can be abrasively prepared. The seal or packing is particularly suitable for very rapidly rotating machine parts.