METHOD AND DEIVCE FOR PRODUCING A COMPOSITE WOOD BOARD

Abstract

The disclosure relates to a method for producing a wood material panel with at least one layer with an inhomogeneous density profile, including the steps: scattering a multitude of wood particles to produce a particulate cake, pressing the particulate cake to form a layer of the wood material panel, and scattering different pre-determined quantities of wood particles in at least two areas within the particulate cake.

Claims

1. A method for producing a wood material panel, comprising: (a) scattering a multitude of wood particles to produce a particulate cake, wherein at least one adhesive is applied to at least some of the wood particles prior to and/or during scattering, (b) pressing the particulate cake under high pressure and at a high temperature to form a wood material panel, and (c) introducing different quantities of at least one additive at different positions within the particulate cake during the scattering of the wood particles.

2. The method according to claim 1, wherein the at least one additive contains at least one adhesive, at least one fire-retardant substance, at least one biocidal substance, at least one substance for preventing the swelling of wood, at least one foamer and/or at least one substance that alters a visual and/or haptic and/or physical property of the wood material panel.

3. The method according to claim 1, wherein the different additives and/or different quantities of various additives are introduced at different positions within the particulate cake.

4. The method according to claim 1, wherein a quantity of wood particles, which are scattered to form the particulate cake, is varied depending on their anticipated position in the particulate cake.

5. The method according to claim 4, wherein the quantity of the scattered wood particles and the type and/or quantity of the additives introduced is selected in such a way that the wood material panel has a homogeneous bulk density.

6. A device for conducting a method according to claim 1 which comprises an introduction device and an electric control system, which is configured to control the introduction device such that different quantities of the at least one additive are introduced at different positions within the particulate cake during the scattering of the wood particles.

7. The device according to claim 6, wherein the electrical control system has an electronic data processing device that is configured to access information saved in an electronic memory and, based on this information, to control the introduction device.

8. The device according to claim 6, wherein the introduction device comprises at least one scattering head with at least one scattering nozzle for scattering the wood particles and at least one scattering head for scattering the at least one additive.

9. The device according to claim 8, wherein the at least one scattering head comprises at least two different additive nozzles for scattering different additives.

10. The method according to claim 2, wherein the physical property of the wood material panel is its electrical conductivity or thermal conductivity.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0018] In the following, an example of an embodiment of the present invention will be explained in more detail by way of the attached figures: They show:

[0019] FIG. 1 shows the schematic depiction of a device for conducting a method, and

[0020] FIG. 2 shows the schematic depiction of a wood material panel.

DETAILED DESCRIPTION

[0021] FIG. 1 depicts a device for producing a wood material panel. First of all, wood 2 is provided, which is comminuted in a comminutor 4 to produce woodchips. These are then washed in a washing device 6 and subsequently boiled in a pressure tank; this is followed by fiber maceration in a refiner 8. After the refiner, glue is added in a gluing device 10, thereby producing glued wood particles. These are dried in a drying device 12 and subsequently subjected to a quality check in a separator. The glued wood particles are then fed into an introduction device 16, which in the example of an embodiment shown features several scattering heads 18, of which three are depicted. Here, only the left-hand scattering head 18 is depicted by solid lines. The remaining heads are depicted with dashed lines so as to indicate that they are optional. The various scattering heads 18 are used to scatter different additives, thereby introducing them into the scattered particulate cake. An additional scattering head, not depicted here, is available for scattering the wood particles. The dashed lines 20 of different lengths serve to show that different additives are scattered from different scatter heads 18. Alternatively to the embodiment depicted, it is also possible to use different scattering heads 18 to first mix the scatter particles with the additives and then to apply them via an aggregate scattering head, not depicted in FIG. 1. This ensures that the required additives and materials are present in a mixed form at the respective positions in the wood material panel to be produced. This prevents layers from forming.

[0022] The particulate cake which is scattered in this manner then reaches a pre-compactor 22 before being pressed in a hot press 24 to form a wood material panel.

[0023] FIG. 2 shows a schematic sectional view through a wood material panel 26. A first additive 28 can be clearly seen, which is depicted in the form of small circles and which may be, for instance, glass beads or expanded clay; said additive is distributed almost homogeneously in one plane between an upper side 32 and a lower side 34. This allows, for instance, the bulk density of the wood material panel 26 to be reduced in this area, thereby saving on weight. A second additive 30, which is depicted in the form of dashes, is arranged in the shape of rods in the wood material panel 26. This may be an additive which increases or reduces the electrical conductivity and/or thermal conductivity of the panel, for example, which creates certain transport routes for heat and/or an electrical charge.