Abstract: Particle boards having at least one surface made of a resin impregnated paper web are provided during their production with a surface structure due to the fact that a glass sphere blasted surface structure is provided for in the pressing surface of a double band press.

Abstract: Particle boards having at least one surface made of a resin impregnated paper web are provided during their production with a surface structure due to the fact that a glass sphere blasted surface structure is provided for in the pressing surface of a double band press.

Abstract: A continuously operating press is described in which endless bands are moved with constant speed around an upper and a lower press platten and a lubricant film is formed between the confronting press platten surfaces and the respectively associated endless band. The fluid which serves for the build up of the lubricant film is kept in this arrangement under a predeterminable hydrodynamic pressure in at least one press zone at the input side of the press, while a calibration zone is provided at the output side of the press in which the lubricant stands substantially only under static pressure.

Abstract: A method and an apparatus for the continuous manufacture of particle board from a mat of cellulose based material in the form of particles, fibers or the like, together with at least one heat hardenable binder, features a high frequency heating station 4 disposed between a scattering station 2 and a finishing press 9. The mat 3 scattered in the scattering station 2 is continuously fed on an endless conveyor band 1 through a working gap defined between upper and lower electrode plates 5 and 6 of a high frequency capacitive heating arrangement in the high frequency heating station 4. A recirculating cover band 7 contacts the upper surface of the mat and the mat is moved with full-area contact between the upper and lower electrode plates 5 and 6, i.e. without any form of air gap. Several variants are described, in particular the upper and lower electrode plates 5 and 6 can be constructed to compress the mat to a certain degree. In the FIG.

Abstract: Particleboard is manufactured by scattering an endless mat of chip and binder material on a series of overlapped mat carriers 17 moving on a forming conveyor 2 beneath a scattering station 1. A cut-off saw 5 is then used to separate the endless mat into mat sections 18 each of which is mounted on a respective mat carrier 17. The overlap between the mat carriers is eliminated and the laden mat carriers are removed from the forming conveyor 2 by an accelerating conveyor 6 which simultaneously operates as an intermediate store and a feed unit for a single storey press 8 arranged immediately after the accelerating conveyor 6. The accelerating conveyor 6 introduces the laden mat carrier into the inlet to the press from where it is transported into the press by internal transport devices of the press. After the mat section has been pressed to form a particleboard a pair of driven rollers 9 extract the mat carrier from the press and feed it towards a separating wedge 10.

Abstract: An arrangement for processing ligno-cellulose containing particles for the manufacture of wood-product plates. These have layers of oriented chips, and a chipper comminutes raw material. The fine material and dust are separated by a sifting device, and the sifted chips are provided with binder material by a gluing device. The chipper produces more chips of as great a length as possible than are required for forming of at least one cover layer of a mat. Behind the chipper, there are provided a wet-chip bunker and a dryer. The sifter separates the chips, obtained after removal of the fine material and the dust, into two fractions. The chip composition of one of these fractions, during the processing time, constantly contains chips which are as long as possible and which are more than that required for forming the mat layer. The other fraction has shorter chips obtained during chipping, and both fractions are present each in at least one bunker.

Abstract: A heated platten press for the manufacture of particle board features a pair of heatable press plattens 1 and 2 which are located between relatively movable press beams. The platten 1 is constructed as a rigid platten to define a flat reference surface for one side of the board to be pressed and is constructed so that it does not deflect either mechanically or thermally during operation of the press. The second press platten 2 is constructed to be elastically deflectable and is supported on a plurality of individual piston-in-cylinder arrangements 4 forming an array of adjacent substantially contiguous support fields which are substantially uniformly distributed over the whole area of the compensation platten. In operation a board is pressed and the deviation in thickness of the board from the nominal thickness is measured at points corresponding to the positions of the piston-in-cylinder arrangements within the array.

Abstract: Poorly conducting substances, such as chips of cellulose material containing a heat hardenable binder, are heated by passing them between the plates of an operational capacitor supplied with energy from a high frequency generator. An adjustable auxiliary capacitor is connected in parallel with the operational capacitor and is adjusted to match the capacity of the output circuit to the generator with changing conditions of the poorly conducting substances. Coarse initial control is effected by adjusting the separation of the plates of the operational capacitor. The apparatus is especially useful for making chip boards and the like in which a precompressed mass of chips is passed between the plates of the operational capacitor sandwiched between two endless belts.

Abstract: Particleboard made from particles in the form of chips or fibers or the like is made by distributing a mass of chip material onto an endless belt conveyer system. The mass of material is subsequently passed to a precompressor, a high frequency preheating device, a further press and a finishing press. The unheated further press serves to reduce the thickness of the material to substantially that of the finished board prior to its consolidation by temperature and pressure in the finishing press. A further endless belt contacts the surface of the material and runs through the precompressor, the high frequency heating device and the further press and serves to counteract any tendency of the chip material to expand after leaving the precompressor. This endless belt additionally yields a number of other significant advantages, in particular a reduction of loss of heat from the material prior to reaching the finishing press.

Abstract: A high frequency industrial generator, especially suitable for supplying power to a device for heating an electric poorly conducting substance such as a fleece of a cellulose material, comprises two hollow concentrically disposed conductors each of square section and supporting respective electrode plates of an associated capacitor. All the plates are vertically disposed and lie at right angles to the walls of the respective conductors. In the middle of the electric plates there is situated a triode electron tube electrically connected to the plates to form an oscillating circuit. The anode potential and cooling water supply for the electron tube is located within a field free space inside the internal conductor. One set of electrode plates can be adjusted relative to the other to adjust the frequency and the arrangement ensures only low electrical losses are incurred.

Abstract: A bottom-belt bunker which receives and delivers particles for the manufacture of fiberboards, chipboards, or the like, and containing cellulose, is disposed upstream of a glue applicator or a front of a forming station. A centrally located feed opening is associated with a drivable auger disposed transverse to the longitudinal extension of the bunker. The auger has a pair of opposed helical blades or flights. A shoveling slide having an adjustable stroke is disposed beneath the auger and partially encompasses the same, the length of the slide being smaller than half the width of the bunker and/or half the length of the auger. Terminal positions of the reciprocating slide are disposed at a spacing from the side of the bunker and the average moving speed of the slide is approximately half that of the velocity of the helical blades of the auger.

Abstract: A gluing machine for gluing lignocellulose-containing particles such as fibers, shavings, dust, and the like, for the production of pressed wood plates, in which a housing has, at one end, an intake for material to be glued. At the other end of the housing there is an outlet for glued material. A stirring mechanism having mixing tools rotating with a shaft, is centered in the housing. Glue supply nozzles are also provided. The mixing tools are in the form of rods which run parallel to the stirring mechanism shaft, and they are supported on their ends on this shaft. The rods carry spaced cross surfaces, and are relatively close to the housing interior wall. At least some of the cross surfaces are inclined relative to the longitudinal axes of the rod with either the stirring mechanism shaft inclined from the horizontal in the direction towards the outlet downward, or with the horizontal stirring mechanism shaft.

Abstract: An apparatus for metering particles containing lignocellulose employs a measuring and control unit. This unit compensates volumetric fluctuations in the bulk density of particles in a metering tank moving at constant speed, through the use of radioactive detection.

Abstract: The temperature distribution through the thickness of a layer of particulate matter formed by air screening and by compressing in a press for forming a particle board therefrom is made more nearly uniform by heating the air stream or air streams used for the air screening of the particulate matter.

Abstract: Process and apparatus for the production of chipboards, fiberboards, or like panels from a mixed material, the components of which have specific gravities that differ relatively greatly from one another. In one preferred embodiment, the components are fed separately from one another to the bottom belt of a mixing bin to form a plurality of thin layers. The mixing bin is arranged upstream of a fine-metering device, which in turn, meters the mixed material for feeding into a press. Another preferred embodiment feeds the mixture components to the bottom belt mixing bin together, while depositing the mixture material in obliquely oriented layers in superimposed strata so that the angle of each layer is smaller with respect to the horizontal than the natural angle of repose of the individual mixer components.

Abstract: An apparatus for forming a layer from a mixture of particles having variable particle sizes and including throwing rolls for casting the particulate mixture onto a flat support is further provided with a blower arranged to reverse the direction of horizontal movement of the particles as they fall onto the support by means of air flow.

Abstract: Apparatus for the continuous production of chipboard, fibreboard or like panels, comprising a tensioned endless steel belt guided over a plurality of rollers and partially around a heated revolvable press drum such that said rollers press the belt against said drum, sprinkler apparatus disposed over a portion of the belt which extends horizontally before said drum in the direction of movement of the belt such that material to form said panels sprinkled onto said portion of the belt is pressed between the belt and the drum to form a web of material, wherein at least one of said plurality of rollers has over its width a convexly ground surface, whereby panels produced on the apparatus can have substantially uniform thickness and weight.