Abstract: A process for making a composite wood panel, fiberboard or the like comprises putting a mat to be pressed between the press platens of a press, compressing the mat with heated press platens in a first compression step without feeding in steam until a density of at least 50% of that of the product panel is reached, preferably 70 to 85%, in a second compression step feeding steam with a pressure of between 1 to 3 bar through both press platens and compressing further until from 10 to 40% of the compression occuring in the first compression step (this is taken as 100%) is attained, in a third compression step interrupting the steam feed, the density attained in the second step being maintained, and subsequently compressing with a pressure of steam which is greater than the steam pressure used in the second compression step.

Abstract: Particulate mats are transported from the downstream end of an upstream conveyor normally moving continuously in a longitudinal transport direction at a predetermined relatively slow speed to a press downstream in the direction from the upstream conveyor that receives the mats and presses them into hard panels by supporting the mats between the upstream conveyor and the press on a downstream conveyor having an upstream end spaced downstream from the downstream end and a downstream end at the press and an intermediate conveyor extending between the upstream end of the downstream conveyor and the downstream end of the upstream conveyor and having a length in the direction at least equal to that of each of the mats in the direction. A carriage supporting the downstream end of the upstream conveyor, the intermediate conveyor, and the upstream end of the downstream conveyor is reciprocated in the direction at a frequency related to mat size and speed.

Abstract: A particleboard press for converting a thick mat into a thin panel has a frame, an upper beam and a lower beam carried on the frame and vertically confronting each another, respective upper and lower platens carried on the beams and vertically confronting each other, and respective upper and lower belts having stretches engaged under and over the upper and lower platens, respectively. The belts are synchronously driven so as to advance a mat in a transport direction through the press between the platens. One of the beams is vertically displaceable on the frame relative to the other beam and its platen has relative to the direction a downstream calibration portion and an upstream compression portion at least limitedly vertically displaceable relative to the one beam and the downstream calibration portion.

Abstract: A belt-type press for making particleboard has a longitudinal row of transverse frames through which pass upper and lower longitudinally extending press beams extending along and carried on the row of frames flanking respective heated press platens in turn flanking stretches of respective upper and lower belts driven to move a mat of particles to be pressed along the path in a transport direction. The upper beam is pressed down by a plurality of substantially identical hydraulic actuators to compress the mat between the belts with a relatively high pressure in an upstream compression region of the press and with a relatively low pressure in a downstream compression region of the press. The upper platen and beam have a downstream calibration portion and an upstream compression portion, the latter being elastically deflectable upward relative.

Abstract: A continuously operable belt-type press comprises two endless upper and lower press belts forming a pressing gap in a pressing region, an upper and lower platen, a drive mechanism and a press framework. In the pressing region two rod containers are positioned from which a plurality of rolling rods are fed with spacing from each other, these rolling rods being guided above the upper press belt and below the lower press belt by rod circulating mechanisms each comprising two synchronized first chains each guided over at least one sprocket and first chain drive wheel. In the entrance region of the pressing gap and of the upper and lower platens second chains are positioned over a second chain guide wheel. On the chain rollers of the second chains rolling rods are guided between the first chains and act similar to roller bearings.

Abstract: A continuously operable belt-type press for making particleboard, fiberboard and the like pressedboard products comprises an endless upper press belt circulated over at least one upper belt guide roller, a corresponding endless lower press belt circulated over at least one lower belt guide roller, these press belts forming a pressing gap in a pressing region, and a press framework having a lower and upper platen as well as a drive mechanism. The rod circulating mechanisms each comprise two first chains each guided over at least one sprocket and at least one first chain drive wheel with support bolts for connection of the rolling rods, chain link members with chain bolts therein, outer running rollers mounted on the chain bolts, and guide rails for the running rollers.

Abstract: An apparatus for pressing and steam curing a wood-particle mat to produce a wood-particle board includes a pair of pressing belts which are arranged above each other at a distance to define a gap therebetween within which the wood-particle mat is conveyed and shaped. Along its passage through the pressing belts, the wood-particle mat is first moved along a compression zone in which the gap is gradually reduced and then passes along a sizing zone. Cooperating with the pressing is a steam injection unit which includes a steam supply channel system and a steam discharge channel system. Both channel systems border on the pressing gap and are provided with nozzle bores extending towards the gap. Via the supply channel system, steam is injected along the compression zone in direction of the wood-particle mat while the discharge channel system which extends at least along a downstream section of the sizing zone is provided to collect and eventually to discharge steam.

Abstract: A spindle press in which a lubricant is displaced by relative movement of the threaded spindle and the ram displaced thereby, at least on a return stroke of the ram effected by a fluid operated jack. According to the invention, the press is provided with a control piston which blocks the lubricant flow as the ram approaches a deadpoint position at the end of its return stroke so as to enable the lubricant trapped between the spindle and the ram to damp the end of the return stroke.

Abstract: A press for compacting comminuted material in the manufacture of pressedboard comprising a pair of steel pressing bands which are backed up in the pressing zone by roller bodies on endless chains carried through this zone between respective press platens and the bands. The chains have links which are folded into a zigzag configuration as they enter the zone and are drawn out into an extended configuration outside the zone.

Abstract: A central station of a belt-type particleboard press, serving to compact a prepressed mat of wood particles and binder prior to its conversion into particleboard in a final station, comprises a multiplicity of mutually identical frame elements with aligned windows traversed by a pair of platens bracketing upper and lower stretches of two conveyor belts between them, these belt stretches entraining the mat along a horizontal path. The frame elements form supports spaced along the path, each support consisting of one or more such elements and carrying a group of hydraulic rams acting upon the upper platen to place the mat under a pressure which peaks in an upstream zone, decreases in an intermediate zone and levels off in a downstream zone of its path.

Abstract: A press comprises a drum having a heated outer surface and rotatable about an axis and at least one endless belt radially juxtaposed with a portion of the outer drum surface and consisting mainly of an elastically deformable matrix and a plurality of parallel, twisted, and generally annular multifilament cords axially spaced from one another and formed of yarns of an aromatic polyamide imbedded in the matrix. The belt is tensioned and thereby urged radially toward the drum-surface portion. Thus the belt and the drum-surface portion form an angularly extending pressing region. A web to be compressed is fed tangentially to one end of the pressing region and is withdrawn it from the other end thereof. A drive rotates the drum and thereby displaces the web and the belt angularly along the portion so that the web is compressed against and heated by the drum. The cords according to this invention are formed as cables.

Abstract: A mat-forming installation for the production of pressedboard comprises a grate conveyor whose bars are carried by chains on opposite sides of the conveyor and define gaps at spaced-apart locations into which the headpiece (entraining beam) of a press underlay can fit. The headpiece is connected by a two-joint piano hinge structure to the underlay onto which the fibrous or particulate material is deposited to form the mat, the layer or mat being entrained into the piece on the underlay.

Abstract: An apparatus for forming a mat of comminuted material for the production of pressed board comprises a conveyor belt forming a transport path and a receiving surface for the mat and a plurality of spreading machines spaced apart along the band for depositing respective layers of comminuted material on the surface to form the mat. Each of the spreading machines has a feeder for feeding the comminuted material to a roller grate for depositing the comminuted material in a respective layer with longitudinal orientation of the comminuted material in the direction of movement of the belt. At least one of the machines is provided with a transverse orienter between the roller grate and the belt for imparting a transverse orientation to the comminuted material deposited on the belt. The orienter is shiftable between a position wherein it is interposed between the roller grate of the belt and a position in which it is offset from the interposed position.

Abstract: An apparatus for applying, without folds or trapped air pockets, a metal foil to an underlying plate of board comprises a pair of parallel elongate suction wedges juxtaposable to the plate and reciprocatable parallel thereto a vertically reciprocatable bar for clamping the foil to the plate along a line extending between the suction wedges and parallel thereto. The wedges are each provided with a multiplicity of apertures in a linear array along the vertex of the wedge and a textile web extending from the respective wedge parallel to the plate for supporting the foil during a withdrawal stroke of the wedge.

Abstract: An apparatus for feeding mats to a press, e.g. for the production of particleboard or the like, comprises a feed conveyor with a discharge nose which lies in a plane tangent to the plane of a receiving conveyor entraining the mat into the press. Between the pick-up side of the receiving conveyor and the discharge end of the feed conveyor, this plane is tangent to a drum whereby press underlays are positioned beneath each mat with a head bar disposed ahead of the leading edge of the mat. According to the invention, the surface of the conveyor is provided with recesses to receive each bar so that the latter lies at least in part inwardly of the circumference or periphery of the drum while an underlay sheet lies along a drum surface which progressively merges with the circumference from this recess, i.e. is progressively asymptotic. When the recess is fixed, it can have a flank ahead of the bar against which the bar is positioned.

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 pressed-board plant having a multi-level press for the pressing of mats of comminuted or fiber material, with or without added binder, to form pressed board, for the lamination of finishing layers to substrates and wherever multi-level presses are applicable, has a multi-level emptying rack adapted to receive the pressed articles on respective press underlays (press trays or sheets). According to the invention, a storage rack for the press underlays is provided with the levels of the storage rack spaced at levels substantially corresponding to those of the press platens in the open condition of the press and from which the underlays are introduced into the press. The storage levels are interspaced with the levels of the emptying rack.

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.

Abstract: This invention relates to improvements of installations for the handling of molds associated with a transfer type press.This installation is characterized in that at each level of the transfer type press (1) and on either side of the latter, there are displacement and guiding (4a, 4b, 4c, 4d) channels for molds (2,3) which are removed from the press (1) for the stripping and loading operations at different distances from that press, which leads to a sufficient separation between the molds.This is applicable to the curing of flat objects.

Abstract: A mat-forming apparatus, especially for the production of particle board, comprises a conveyor grate disposed above a layer-carrying surface, e.g. a conveyor, and below a feeder for scattering the particles onto the surface through the travelling grate. According to the invention, the lower pass of the conveyor grate is displaceable in the same direction as the receiving conveyor and is inclined upwardly away from the receiving conveyor in the direction of displacement thereof at an acute angle, this lower pass forming an inclined plane.