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.

Abstract: A belt press has horizontally extending and vertically spaced upper and lower plates defining a horizontally extending gap, vertically spaced upper and lower upstream drums rotatable about respective horizontal drum rotation axes at the upstream press end, and vertically spaced upper and lower downstream drums rotatable about respective horizontal drum rotation axes at the downstream press end. Each of the downstream drums is supported for at least limited pivoting about a vertical axis generally intersecting the respective drum rotation axis. Upper and lower endless belts spanned over the respective upper and lower drums each have a working stretch lying between the plates and a return stretch.

Abstract: A press for making pressed board has a plurality of longitudinally spaced rigid frames supporting a lower press plate extending longitudinally through the frames and having an upwardly directed upper surface and a downwardly directed lower surface. A layer of insulation upwardly directly engages the lower press plate and downwardly directly engages the press frames so that the lower press plate is supported via the insulation layer directly on the frames. An upper press plate extending longitudinally above the lower plate through the frames has a lower surface defining with the lower press plate a longitudinally through going press gap and a plurality of vertically effective hydraulic actuators are carried on the frames above the upper plate. A layer of insulation upwardly directly engages the actuators and downwardly directly engages the upper press plate so that the upper press plate is supported via the respective insulation layer directly on the actuators.

Abstract: A fiber or chip board is made by first forming a mixture of a binder and particles having a relatively low moisture content that is substantially less than a relatively high moisture content that a finished board should have. This mixture is deposited as a mat on a movable substrate so that the mat is substantially at ambient temperature and has the relatively low moisture content. Then the mat is preheated with steam to raise its temperature and to increase its moisture content to the predetermined relatively high moisture content. The thus preheated mat, whose moisture content has been corrected, is then simultaneously heated and compressed to form it into a board.

Abstract: A press for the continuous production of pressedboard utilizes a pair of steel pressing belts running over respective surfaces of a platen defined by gaps into which steel rollers are fed. The rollers which have diameters of less than 20 mm are fed with a spacing which corresponds substantially to the thickness of the belts and have diameters equal to substantially ten times this thickness.

Abstract: A platen press has upper and lower platens each provided with at least one rigidifying beam. A group of hydraulic cylinders spaced about over one of the platens serves to urge the two platens together in a pressing direction to compress a workpiece--plywood, fiber mat, chipboard, or the like--between the platens. During pressing the platens and their rigidifying beams bend somewhat. This bending is measured by an apparatus which comprises a flexible strand, holders at the ends of the one beam for gripping the ends of the strand and holding same straight and under tension, and sensors fixed on the one beam at a location between the ends of the one beam for measuring the displacement of the strand relative to the beam at the location during pressing. This sensor lies wholly out of physical contact with the strand.