Single facer for corrugated board

Claim 1

A single facer for corrugated board of the kind comprising an upper corrugating roll (1) having flutes extending over its outer peripheral surface. a lower corrugating roll (2) having meshing flutes and a fixed pressure member (10a) disposed lose to said lower corrugating roll to provide a stationary, contoured pressure surface (14) in conformity with the rotational surface of the outer peripheral extent of said lower corrugating roll, said surface having a length, in the direction of the circumference of the lower corrugating roll, greater than the distance between two adjacent flutes of said lower corrugating roll; characterised in that for use in conjunction with the fixed pressure member, an endless belt (12) is provided, the belt being arranged such that one run thereof is inserted between the pressure surface of said pressure member and a liner web (5) fed between the lower corrugating roll and said pressure member, in that said run of the endless belt is driven (13) in the same direction and substantially at the same peripheral rotational speed as said lower corrugating roll during pressing together and pasting of said liner web and a corrugated web (6) carried on the lower corrugating roll, and in that the pressing force, which is exerted solely by said fixed presure member, is transmitted by the endless belt so that friction forces, which would otherwise occur between said liner web and said stationary pressure surface, are significantly reduced.