Abstract: An apparatus for comminuting a stack of wood boards to produce wood strands. A stack feeder feeds the stack of wood boards to a chipper chamber on a longitudinally displaceable carriage moving transverse to the direction of feed of the stack and having a blade ring for comminuting the end of the stack. The chamber is reduced in full volume with replaceable and removable filler bodies.

Abstract: An apparatus for continuously produced pressed board has a structuring belt in the form of a metal wire screen which is fed with a respectively endless steel belt and the wood-based mat passing through a continuous press whose heated upper and lower press platens have the belts guided therealong via rollers displaceable along closed paths. The wire mesh configuration of the structuring belt is continuously impressed into the pressed board strand which is produced.

Abstract: In order to preheat a particle mat having upper and lower faces and edges to a predetermined desired temperature for pressing into a pressed board air is conditioned to a temperature below 100.degree. C. and a moisture content together imparting to the conditioned air a dew point generally equal to the desired temperature. This conditioned air is simultaneously introduced from above and below at the same rate into the respective faces of the mat to produce in the mat a pair of horizontal and vertically approaching fronts at which moisture condenses out of the conditioned air. Introduction of the conditioned air into the mat is ended when condensed moisture and the conditioned air are forced out of the edges of the mat.

Abstract: A particle mat for pressing into a pressed board is heated by concurrently passing through the mat treatment air coming from an air-conditioning system and having a predetermined moisture content and dew point, heating the treatment air passing through the mat to a temperature which is greater by a dew-point differential than the dew point of the treatment air, and controlling the volume rate of flow of the treatment air and the moisture content of the treatment air such that the mat is preheated to a predetermined temperature while liquid in the treatment air is allowed to condense in the mat to at most a maximum liquid content.