LIGHTWEIGHT PANELS

Description

[0001] The invention relates to a method for manufacturing a lightweight panel according to claim 1.

[0002] Lightweight panels made from particle-based materials, wood-based panels, or combinations thereof are widely available. In particular, three-layer sandwich panels with two face sheets and a core that is lighter than the face sheets are already used in many applications, such as furniture manufacturing, vehicle construction, and similar sectors. A key principle of multi-layered lightweight panels is to make the core layer as light as possible compared to the face sheets. For this purpose, the core layer is often made of a different material than the face sheets. Furthermore, hollow structures, such as honeycomb, are common in the core layer. A widespread type of lightweight panel thus also includes face sheets made of wood-based panels, such as fiberboard or particleboard, and a honeycomb core layer, which may be made of paper, for example.

[0003] Another lightweight panel is disclosed, for example, in DE 20 2010 005 900 U1, which proposes producing two sub-panels made of particulate material. These sub-panels have a flat outer surface for conventional use and an inner surface opposite the outer surface with support structures, which are bonded to a base plate. The structures have a considerable height relative to the overall height of the sub-panel, so that when the sub-panel is bonded to the base plate, cavities are created in the center of the panel, thus significantly reducing the weight of the overall panel compared to a conventional solid panel.

[0004] WO 2015 / 104009 A1 describes a method for improving the density profile of a wood-based panel, comprising the steps of pre-pressing, hot pressing and hardening, wherein during the hot pressing step a geometric pattern is imprinted into both surfaces of the wood-based panel, wherein the geometric pattern on one surface is shifted relative to the geometric pattern on the opposite surface.

[0005] WO 2018 / 115278 (A1) describes a device for forming monolithic pressed wood pallets with increased load-bearing capacity, comprising: - storage means with a chamber for collecting a mixture, in which a first conveyor belt is housed for feeding a uniform layer of mixture to the outlet (104), wherein the first belt is wound around at least a first motorized roller and is carried along by it at the feeding speed; - pressing means (106) which are provided with a lower molded part and an upper molded part, between which a receptacle for forming a pallet is provided; - a second conveyor belt which is arranged between the storage means and pressing means.The device includes means for modulating at least one of the feed rates, the feed rate and the translation rate, in order to adjust the amount of mixture loaded / unloaded onto / from the upper section of the second belt along the mat.

[0006] US 2018 / 021977 A1 describes a fiberboard made of lignocellulosic fibers, in particular wood fibers, and a binder to provide a fiberboard that makes it possible to combine high stability on the one hand and a comparatively low weight on the other, and which can nevertheless be produced with low financial expenditure.

[0007] To produce the support structures, DE 20 2010 005 900 U1 proposes that a press plate with raised sections, or in the case of a continuous press, a corresponding roller with raised sections, creates depressions in the material mat during pressing, thereby generating the support structures. However, it has been found that pressing in support structures can lead to significant inaccuracies in the support structure height, making it problematic to connect the support structure to a material plate or a second partial plate.

[0008] As an alternative to pressing, the subsequent milling of support structures into the finished pressed mat is revealed. This allows for very precise control of the support structure height and thus the height of the panel center. However, subsequent milling is very labor-intensive and costly.

[0009] The invention is based on the objective of proposing a method for manufacturing lightweight panels, with which partial panels with support structures can be produced simply and cost-effectively.

[0010] The invention solves the problem by means of a method having the features of claim 1. Advantageous further developments of the invention are specified in the dependent claims.

[0011] The inventive method for producing a coated lightweight panel comprises the following steps: Producing a pressable mat that can be pressed into a partial plate by arranging adhesive particles on a first press mold, pressing the mat into the partial plate with support structures on a plate surface in a press, joining, in particular bonding, the support structures to a material plate, wherein the press mold includes recesses for producing support structures on a surface of the partial plate and, during the production of the mat, a portion of the particles is introduced into the recesses; wherein, after the application of the particles, they are additionally wiped, swept in or brushed in and / or transported into the recesses by means of air currents.

[0012] Surprisingly, by incorporating some of the scattered particles into the recesses of the press mold, it is possible to produce very uniform heights of the support structures. This means that the free ends of the generated support structures lie almost entirely in the same plane, which is advantageous for a secure and simple bond with the material sheet.

[0013] Furthermore, the production of the support structures takes place together with the pressing process of the pressable mat into a panel, here a partial panel of the lightweight panel, hereinafter also called lightweight panel half-shell, which makes the production effort significantly lower and more cost-effective compared to the also very precise milling of support structures, but the support structures are of the same quality.

[0014] Pressed mats are commonly used in the production of particleboard or fiberboard. In their dry production, chips or fibers bonded with an adhesive are spread or thrown onto a press plate / belt. The resulting mat of chips or fibers is then fed into a press, where the loosely layered chips or fibers are compressed under pressure and, if necessary, heat. During this process, the air is expelled from the spaces between the chips and fibers, the mat is compressed to its final thickness, and the adhesive sets, bonding the chips or fibers together. Adhesives commonly used in wood-based panel production, such as those based on urea resin, melamine resin, and / or phenolic resin, can be employed.

[0015] In the context of the invention, "particles" refers in particular to organic particles, e.g., from renewable raw materials such as woody plants, i.e., for example, wood fibers, wood chips, or wood strands. Besides particles based on woody plants, particles from annual plants, bamboo particles, grass particles, or more generally, cellulose-based particles, which can also be in the form of chips or fibers, are also considered organic particles. Expanded materials such as popcorn can also be used as organic particles. Furthermore, plastic particles and / or metal particles, or mixtures of organic particles, plastic particles, and / or metal particles, can also be used.

[0016] Standard presses from the wood-based materials industry are used. Depending on the process, these can be intermittent or continuous presses, for example, a calender press such as a Mende calender. Accordingly, a first press form can be a press plate for an intermittent press, a press belt for a continuous press, a press die for insertion into a press, or a roller for a calender press.

[0017] The first press mold has indentations. The shape of the indentations corresponds to the later shape of the support structures. The indentations are thus designed as negative molds of the support structures. In contrast to known embossing plates, which are designed for imprinting surface structures into a surface coating, the first press mold is intended for direct contact with the particles. Since the support structures ultimately form the center of the later lightweight panel, and the thickness of the later lightweight panel is significantly influenced by the height of the support structures (from the base of the structure to the free end), the structures in the first press mold are considerably larger than those in known embossing plates. The finished support structures preferably protrude at least 2 mm, in particular at least 2 mm to 15 mm, preferably at least 2 mm to 30 mm, and most preferably at least 2 mm to 45 mm from the base of the structures.Correspondingly, the indentations in the first pressing mold are formed.

[0018] Should lightweight panels require a certain thickness, the support structures can, of course, be made even thicker. Particularly preferably, in the case of a fully pressed pressed mat (partial panel), the ratio between the height of the support structures (from the base of the support structures to the free end of the support structures) and the thickness of the top layer (outer surface to the base of the support structures) is at least 1:1, preferably at least 1.5:1, particularly preferably at least 2:1, and advantageously at least between 1:1 and 1:4, and particularly advantageously at least between 1:1 and 1:10. The top layers preferably have a thickness of at least 2 mm, more preferably at least 2.5 mm, particularly preferably at least 3 mm, and advantageously at least between 3 mm and 10 mm.

[0019] The formation of support structures at exact heights from 2 mm to 45 mm, or of support structures with an even greater height, is made possible in particular by the fact that the structures are not pressed into a pressing mat from above, but are first filled with the particles before the pressing mat is pressed.

[0020] In addition to the common plane, which, apart from minor production deviations, is formed by all free ends of the support structures, the support structures are preferably also of largely the same height (free end to base of structure).

[0021] The support structures can be formed in various ways. They can be designed as individual projections distributed across the surface, with, for example, a cylindrical, pyramidal, or frustoconical (vertical) cross-section. Alternatively, the structures can be designed as ribs, either individually or interconnected. Another preferred embodiment provides for individual projections connected by corresponding ribs. Ultimately, the projections (support structures) form at least a portion of the inner surface of a sub-plate.

[0022] A particularly preferred embodiment provides for the raised areas to be generated in a grid with a spacing of 32 mm. That is, the central longitudinal axes of the raised areas, which are perpendicular to the surface of the panel, are preferably arranged at right angles to each other and spaced 32 mm apart. In the case of raised areas designed as ribs, the ribs preferably have a spacing of 32 mm, and are preferably arranged parallel and / or orthogonally to each other. This allows, in particular, the production of universally applicable panels for furniture construction. For continuous production of the individual panels, support structures extending in the production direction are suitable, e.g., ribs extending in the direction of the press. Such ribs advantageously also have a constant cross-section to further simplify production.

[0023] The application and placement of the particles into the depressions is carried out either separately or together with the production of the grit mat. That is, either in a first pass, only the particles for creating the support structures are placed on the first press mold and into the depressions, and in a second pass, further particles are arranged to create the next layer of grit mat (which, for example, also forms the outer top layer).

[0024] Alternatively, the particles for the depressions and for the additional layer of grit mat covering them can be arranged together. In this case, some of the applied particles penetrate the depressions and fill them. The portion of the particles that does not penetrate the depressions forms a grit mat layer covering them. This layer, in turn, forms the top layer of the sub-plate when compressed. The surface of this layer forms an outer surface opposite the first pressing mold, which, during compression, rests against a second pressing mold. The particles resting against the first pressing mold form the inner surface of the sub-plate.

[0025] The production of the spreading mat, i.e. the application of the particles penetrating the depressions and the particles arranged above the depressions, is carried out by a conventional spreading device or throwing device.

[0026] To increase the filling level of the depressions, a vibration motion can be applied, for example, to a first press mold designed as a press plate, in order to increase the bulk density in the depressions. According to the invention, after the particles have been applied, they are additionally wiped, swept in, or brushed in and / or transported into the depressions by air currents. This is particularly relevant in a two-stage spreading and / or throwing process, in which the particles are first introduced into the depressions in a first pass.

[0027] In addition, further compaction processes can be carried out. For example, the particles in the depressions can be pre-compacted using compressed air, a roller or multiple rollers, or a press. The roller or multiple rollers, or alternatively a press die, used to compact the particles in the support structures can be adapted to the support structures and have corresponding ridges adapted to the depressions. The ridges can also be smaller than those in the depressions of the first press die to achieve compaction without crushing the particles. This is particularly important when using multiple rollers / press dies.It is possible to create these structures with varying heights (raised areas adapted to the depressions in the first press mold) and, after each compaction process, to transfer new particles into the recesses with a roller / press mold and then compact them with a roller / press mold that has a lower height than the previous one. This allows for the production of particularly stable support structures with precise height and a high particle density.

[0028] Naturally, the application of the particles into the depressions, or—as already mentioned—the creation of the entire spreading mat, can also be carried out in several partial passes. For example, after a support structure check to determine whether the particles present in the depressions have a sufficient spreading density to ensure the stability of the resulting support structures, additional particles can be applied. A support structure check and / or an inspection of the entire spreading mat can, of course, also be performed after the entire spreading mat has been produced.

[0029] Regardless of the manufacturing of the support structures, the lightweight panels known from DE 20 2010 005 900 U1 also have the problem that the support structures cannot withstand the necessary high pressing pressures in the range of, for example, 30 kg / cm² to 60 kg / cm² for coating the panel with a synthetic resin-based decorative coating, as known from the wood-based materials sector and implemented, for example, in the form of an HPL, CPL, DPL coating, a melamine resin direct coating or a similar coating, so that only limited coatings in the form of coatings that can be applied at least largely without pressure, for example, lacquer coatings, can be carried out here.

[0030] To provide a suitable lightweight panel with an HPL, CPL, DPL coating, or a similar coating applied by means of pressing, a further development of the invention provides for the application of a surface coating to the outer surface of the grit mat opposite the first pressing mold. The application of the surface coating can take place before the grit mat is pressed in the press to form the partial panel.

[0031] In this context, surface coating refers to coatings applied to and bonded to a surface using pressure and heat. This includes, in particular, decorative and / or protective coatings. Such surface coatings are primarily synthetic resin coatings. Examples include the aforementioned HPL, DPL, or CPL coatings, where resin-impregnated papers, such as decorative paper and / or overlay papers, are bonded to the surface of wood-based materials, in this case, the grit mat. A direct melamine resin coating can also be used as a surface coating.

[0032] The spreading material mat basically forms two main surfaces. Firstly, the inner surface, which is formed, among other things, by the supporting structures, and secondly, the outer surface, which is formed by the particles that are opposite the first pressing form and, during pressing, come into contact with a second pressing form.

[0033] This means that the grit mat is pressed between the first and second dies in a known manner. Depending on the specific process, the second die can be designed either as a press plate in an intermittent press or as a press belt in a continuous press. The second die can be unstructured, resulting in a flat, smooth surface on the outer surface of the pressed grit mat or coating. Alternatively, it can incorporate a structure, particularly on the outer surface of the coating. Here, "structure" refers not to supporting structures, but rather to a 3D texture matching a color scheme, with slight depressions and raised areas on the surface, typically less than 1 mm in diameter. These textures can also be synchronized with the color scheme (e.g., synchronized pores).

[0034] According to a further development of the invention, the pressed material mat is pre-compacted before pressing. In this process, the loosely layered particles are pushed together in the press to force out a high proportion of air from the spaces between the particles. However, after pre-compaction, the pressed material mat has not yet reached its final thickness. Furthermore, the adhesive on the particles has not yet fully cured. This pre-compaction significantly improves the pressing quality of the resulting sheet, as it prevents, for example, cracking during the pressing of the pressed material mat to form the sheet.

[0035] In principle, it is possible to apply the surface coating to the outer surface of the pressed material mat, i.e., to the loosely layered particles, before pre-compaction and to carry out the pressing process of the sub-plate together with the surface coating. For example, pre-compaction and then final compaction, i.e., the actual main pressing process, can be carried out simultaneously with the surface coating.

[0036] It is particularly advantageous for the pressed material mat to be pre-compacted before the surface coating is applied. This allows for a particularly high surface quality of the coating, as the surface of the spreading material mat is already largely flat after pre-compaction. In other words, the surface coating is applied to a largely flat surface of the spreading material mat. In particular, pre-compaction before applying the surface coating also prevents particles from penetrating the coating or from being punctured during the pressing process.

[0037] According to a further development of the invention, it is provided that the material mat is completely compressed into a partial plate simultaneously with the pressing of the surface coating. As already mentioned above, this can be done either starting from the uncompacted material mat or from a pre-compacted material mat. In any case, the material mat, regardless of whether it is pre-compacted or not, rests on the first press mold during the pressing process in which the surface coating is pressed together with the material mat and the material mat is simultaneously compressed into the partial plate. This also means that the support structures formed or to be formed by the particles remain in the recesses of the first press mold.

[0038] Alternatively, according to a further development of the invention, the pressed material mat is fully compressed, i.e., into a partial plate, before the surface coating is applied. The surface coating is then placed onto the fully compressed partial plate, and in a second pressing operation, the surface coating is pressed onto the outer surface of the compressed pressed material mat (also called a partial plate). However, the fully compressed material mat still rests on the first pressing mold, and the now completed support structures are located in the recesses of the first pressing mold.

[0039] According to a further development of the invention, the fully pressed mat (partial plate) is removed from the first press mold and placed back onto the first press mold for arranging and pressing the surface coating, i.e., inserted into the recesses with the support structures. This makes it possible, for example, to pre-produce partial plates and apply the surface coating individually, e.g., according to requirements and order volume.

[0040] During the pressing of the coating, particularly the resin-based coating, water can be produced as a byproduct. Due to the particularly thin layer of the top layer over the support structure, which is, for example, only 2.5 mm thick, any water that may be produced cannot be completely absorbed by the pressed material mat, i.e., by the particles. To reduce or completely prevent the risk of resulting pressing errors, a further development of the invention provides that a vacuum is applied to the pressed material mat during pressing, and any moisture produced during the curing of the coating is extracted.

[0041] The vacuum is applied starting from the first mold. For this purpose, the first mold can advantageously have micro-perforations, which are connected, for example, to a suitable suction device. Micro-perforations are understood to be, in particular, small holes with a diameter between 0.3 mm and 0.6 mm. The holes can advantageously be arranged in a grid of 3 mm x 3 mm to 5 mm x 5 mm to generate a uniform vacuum.

[0042] Another problem when removing the pressed mat, partial plate, or coated partial plate from the first mold can arise from the adhesion of the support structures to the mold's recesses. To facilitate removal, and also to prevent damage to the support structures, for example, pressurization is preferably applied to the first mold to remove the finished mat and / or partial plate. This pressurization is achieved, for example, through the micro-perforation of the first mold as described above, so that the connected suction device is also designed to expel, for example, air.

[0043] To further reduce the weight of the resulting lightweight panel, a further development of the invention provides that a layer of coarse particles is arranged to produce the pressed material mat. These coarse particles are placed, in particular, into the recesses of the first pressing mold, and then fine particles with a smaller volume compared to the coarse particles are arranged on top of them. This makes it possible, for example, to largely imitate the known three-layer structure of particleboard and to obtain outer surfaces with a high proportion of fine particles, which are preferred according to common surface treatments in the wood-based materials industry.

[0044] To produce a lightweight panel, a material panel is connected to the support structures of the sub-panel according to the invention. The material panel can, for example, be designed as a solid panel and made of known materials such as chips, fibers, or other materials. For instance, conventional particleboard, fiberboard such as HDF, MDF, or similar materials can be used. Material panels made of other base materials, such as metal, plastic, composite products, or similar materials, or even material panels already designed as lightweight panels, can also be used. However, the material panel is particularly preferably designed as a second sub-panel with support structures and optionally a corresponding surface coating, wherein the support structures, and especially the free ends of the support structures of the two sub-panels, are connected to each other, particularly by bonding.The resulting lightweight panels have two outer, opposing cover layers with surfaces that can be designed according to familiar solid wood-based panels (especially particleboard, fiberboard, OSB panels) and either consist of the respective particle material or are already surface-coated and have a middle core consisting of two glued support structures.

[0045] Preferably, the sub-panels are bonded together in such a way that numerous cavities are created between the support structures, thereby significantly reducing the overall weight of the lightweight panel. For this purpose, for example, the outer ends of the support structures can be connected. That is, the second sub-panel preferably has the same support structures and / or can be designed to be mirror-symmetrical to the first sub-panel, so that the respective free ends of the support structures can be connected. In particular, two sub-panels are bonded together whose support structures have the previously described 32 mm grid.

[0046] The sub-plate(s) are typically designed as flat, plate-shaped components. Because two components (sub-plate to sub-plate or sub-plate to material plate) are bonded together to create a finished product (plate), it is particularly easy and advantageous to bond sub-plates or sub-plates and material plates together to form an arc-shaped component. For this purpose, the sub-plates and / or material plates can either already have an arc shape when they are bonded together, or they can be bent during the bonding process.

[0047] Depending on the design of the support structures, a network of cavities can be created within the core of the slab, which can be used, for example, to install pipes or similar components. Advantageously, the support structures are designed as individual, separate elevations.

[0048] According to an alternative embodiment of the invention, the spaces between the support structures are filled, at least partially, with a lightweight material, in particular a foam, thereby significantly improving the stability of the lightweight panel, for example, under compressive forces perpendicular to the surface plane of the lightweight panel. Furthermore, cut edges can be more easily coated with edge material.

[0049] A lightweight material is understood to be, in particular, a material that has a lower density than the potentially organic particles. The lightweight material can either be introduced into the cavities subsequently, i.e., after the support structures have been bonded to a material plate, or, according to a further development of the invention, it is used to bond the partial plate to the material plate, in particular to a second partial plate. Foams, in particular, can be used as lightweight materials.

[0050] Furthermore, a lightweight panel with a sub-panel is disclosed, which has an inner surface with support structures, wherein the support structures are connected, in particular bonded, to a material panel, wherein an outer surface of the sub-panel opposite the inner surface of the sub-panel is provided with a surface coating which was cured by means of pressure and heat and simultaneously bonded to the outer surface.

[0051] Surface coatings are understood to be, in particular, resin-based surface coatings such as HPL, CPL, or DPL, which cure under the influence of heat and pressure and simultaneously bond to the surface of the sub-panel. These surface coatings are those that have been pressed onto the surface of the sub-panel with a pressure typical for resin coatings, e.g., in the range of 30–60 kg / cm², and a temperature of 100–200 °C. Surface coatings that are applied to the outer surface using a cold bonding process and at least largely without pressure are not part of the invention.

[0052] Furthermore, a press mold for pressing a mat of particles into a partial plate is disclosed, wherein the press mold (also called first press mold) has recesses for receiving particles and when pressing with the press mold a support structure of pressed particles is created on a surface of the partial plate.

[0053] Particularly preferably, the press mold also features micro-perforations designed to create a vacuum on the pressing mat resting on the mold and / or to blow air onto the pressing mat to facilitate its removal. A suction and / or blowing device can thus be connected to the press mold. This device can extract air and its components, such as moisture from the pressing mat or moisture generated during the curing of a synthetic resin surface coating on the pressing mat, through the micro-perforations. Alternatively, it can blow air (or a gaseous medium) against the compressed pressing mat, for example, to facilitate its removal from the press mold.

[0054] Furthermore, a method for manufacturing partial panels for a lightweight panel is disclosed.

[0055] The process comprises the following steps: creating a first pressing mat that can be pressed into a partial plate by arranging glued particles on a substrate, arranging a pressing die on the first pressing mat, creating a second pressing mat that can be pressed into a partial plate by arranging glued particles on the pressing die, pressing the pressing mats in a press to form two partial plates, wherein the pressing die includes recesses on two opposite die sides, some of the particles are placed in the recesses, and support structures made of pressed particles are created on each of the sides (surfaces) of the partial plates adjacent to the die sides as the partial plates are pressed.

[0056] The press die largely corresponds to the aforementioned press form, but differs in that it is not designed as a press plate or press strip of the press, but as a central die positioned between two mats of material to be pressed. It enables the simultaneous production of two partial panels with support structures for manufacturing lightweight panels.

[0057] The substrate can be, for example, a pressed sheet or pressed strip and preferably has a flat and unstructured surface. The support structures are, as described above, raised areas that extend, for example, from a top layer of the sub-plate.

[0058] For a further description of the features, reference is made to the previous explanations on the method for manufacturing a lightweight panel, to the explanations on the lightweight panel and the press mold, and to the following explanations.

[0059] To improve the introduction of the particles into the recesses of the press die, a further development of the invention provides that the press die is vibrated after being arranged on the first pressing mat and / or after the creation of the second pressing mat, so that the particles of the first pressing mat and / or the second pressing mat penetrate into the adjacent recesses of the press die.

[0060] The generation of vibrations can occur in one operation, i.e., after the application of the particles of the second pressing mat, or in two operations, i.e., both after the positioning of the pressing die on the first pressing mat and also during the positioning and / or after the creation of the second pressing mat. To generate the vibrations, the pressing die is moved, in particular, in the direction of its plane (XY direction), causing the particles of the first pressing mat to pile up into the recesses and the particles of the second pressing mat to slide into the recesses.

[0061] According to a further development of the invention, the outer surfaces of the partial panels opposite the support structures are coated, with the press die being arranged between the partial panels during the coating process. The arrangement of the partial panels in the press die mechanically stabilizes them, allowing the sandwich of partial panels and press die to be further processed in the same way as conventional solid wood-based panels. For example, the sandwich of partial panels and centrally arranged press die can be treated with a liquid surface coating applied to the outer surfaces. It is also possible to coat the outer surfaces with web-shaped or sheet-shaped coating materials, such as films or resin-impregnated substrates like paper, which are cured under pressure and heat in a press.For coating, the sandwich panels produced in the press can be used directly without first removing the individual panels from the press dies. Alternatively, it is also possible to first remove the individual panels from the press dies, for example, to machine them, and then reinsert them into the press dies for subsequent surface coating. During the pressing process, the outer surfaces are typically oriented towards the respective press belts or press plates and thus face the support structures of the respective individual panel. The outer surfaces are usually flat and unstructured.

[0062] In addition to the option of a simple surface coating, the sandwich, consisting of partial panels and a press die, can be treated like a conventional solid wood-based panel. The sandwich can be removed from the press in the usual way and cooled, for example, in a star turner. The produced sandwich, or the sandwich strand (in continuous production), can also be cut into smaller components, while the sandwich structure remains intact. Either the press die is cut open along with the components, or the cuts are made between two press dies. Furthermore, processing the outer surface opposite the support structures, such as cleaning or sanding, is particularly easy with the partial panels already present in the press die.

[0063] Alternatively or additionally to coating the outer surfaces after pressing, direct coating can also be carried out during pressing. According to a further development of the invention, the first pressing mat is produced on a first surface coating, and a second surface coating is applied to the second pressing mat. During pressing, both surface coatings are bonded to the outer surfaces of the resulting partial plates opposite the support structures. Sheet-shaped or web-shaped surface coatings are primarily used for direct coating. In particular, resin-impregnated carrier systems, such as resin-impregnated papers or films, are used. Resin-impregnated surface coatings are applied during the application of the first pressing mat or...When placed on the second pressing mat, the resin is usually pre-dried but not yet fully cured. Therefore, the pressing pressure and heat applied when pressing the sub-sheets simultaneously cure the resin in the carrier system completely. Accordingly, the first and second surface coatings are generally similar, although they may differ, for example, in the case of a decorative pattern.

[0064] Especially when using organic particles, such as wood particles like fibers or chips, and due to the adhesive applied to the particles, high amounts of moisture are generated during pressing, which must escape in the form of water vapor. To prevent steam bursting during pressing as much as possible, a further development of the invention provides that the water vapor generated during pressing the first and second mats is passed through the pressing die. The water vapor is thus conducted from the first mat to the second mat and vice versa. This results in an advantageously uniform distribution of the water vapor over the entire pressed material (mats or partial sheets and pressing die).Since moisture is introduced into the pressed material during simultaneous direct coating using a resin-impregnated carrier system, passing through the water vapor is particularly advantageous during direct coating.

[0065] To facilitate the passage of water vapor, the die is made, for example, of a porous material. The pores must be sufficiently small to prevent particle penetration and must be present in sufficient number to allow for rapid and uniform distribution of the water vapor. Preferably, a die with manufactured microperforations is used. In particular, the microperforations are located in all sections of the die, i.e., both in areas with depressions and in the normal sections of the die without depressions.

[0066] According to a further development of the invention, a negative pressure is applied to the press die, particularly for drawing in particles and / or extracting water vapor during pressing, and / or a positive pressure is applied to the press die for easy removal of the partial plates from the press die. For this further development, the press die is permeable to a gas, particularly air, so that the negative or positive pressure can act on the partial plates. The press die can, for example, be micro-perforated. Furthermore, the press die can, for example, have corresponding channels that transmit the negative or positive pressure to the die faces or to the support-structured surface (inner surfaces) of the partial plates. These channels can, for example, be connected to and optionally complement the micro-perforations.

[0067] Overpressure refers to gas pressure, such as air pressure, that is higher than atmospheric pressure. Similarly, underpressure refers to gas pressure that is lower than atmospheric pressure. Overpressure and underpressure are specifically defined as pressures of 1.25 bar and above, or 0.75 bar and below.

[0068] The use of negative pressure can, for example, improve the insertion of particles into the recesses. For this purpose, the recesses have corresponding micro-perforations, allowing the particles to be drawn into the recesses by the negative pressure. The negative pressure can be applied, for example, after the production of the second partial plate, or even during the generation of vibrations in the press die.

[0069] Furthermore, the negative pressure can be used to improve the removal of water vapor generated during pressing. The water vapor is drawn out of the press die through the microperforations and, for example, other channels by means of the negative pressure.

[0070] The indentations in the die can cause difficulties when removing the partial plates from the press die, for example, due to adhesive forces. The overpressure acting on the partial plates, however, makes them particularly easy to remove from the press die.

[0071] To ensure that the partial plates produced with a press die are as similar as possible, it is necessary to position the press die precisely between the two partial plates and to guarantee that the press die remains in its position during pressing. According to a further development of the invention, the press die is therefore positioned between the two mats of material to be pressed by means of roller, slider, or chain guides and / or the press die is supported on at least one pressing surface of the press. The roller, slider, or chain guides are designed, for example, to position the press die between the two mats of material to be pressed, optionally also to vibrate them, and / or to hold them in position during the pressing of the partial plates.In particular, for positioning the press die during pressing, an alternative or additional support device can be provided to support the press dies on the press plates / press strips of the press.

[0072] To create a lightweight panel from the manufactured sub-panels, a further development of the invention provides that a finished sub-panel is connected to another material panel, in particular another sub-panel, at its support structures to form a lightweight panel. This means that each of the sub-panels can be connected to another sub-panel, whereby in this case the respective support structures should be designed to correspond to each other so that the two sub-panels can be connected to each other at their respective support structures. It is also possible to connect each of the sub-panels to another material panel, for example, a solid panel such as a wood-based panel, fiberboard, or particleboard, so that the support structures of the sub-panel are connected to a surface of the respective material panel.Connecting the support structures to a material sheet refers specifically to bonding the support structures to the respective surface of the material sheet or to the support structures of a second sub-sheet. To connect the support structures of at least one sub-sheet, it is necessary to first remove it from the die. The sub-sheet may already be coated, for example, directly coated.

[0073] As an alternative to removing and connecting the partial plate with a material plate, the two partial plates produced with a press die can also be joined directly during pressing. According to a further development of the invention, the recesses extend through the press die, and the particles of the first pressing mat placed in the recesses come into contact with the particles of the second pressing mat and / or the particles of the second pressing mat placed in the recesses come into contact with the particles of the first pressing mat and are joined together during pressing.

[0074] This process creates two partial plates that are firmly bonded together during pressing and cannot be separated without damage. This means that the press die cannot simply be removed, but remains, for example, sandwiched between the two partial plates.

[0075] In this embodiment, the depressions are to be understood as holes or openings through the die, which are large enough in cross-section to allow the particles to pass through. Accordingly, vapor-permeable microperforations in the die, for example, are not to be understood as holes or openings.

[0076] In addition to leaving the press die between the partial plates, this embodiment would also allow for the removal of the press die between the two partial plates using an alternative method. For example, with a suitable design, the press die could subsequently be disassembled or reduced in size / minced so that it can be removed from between the partial plates.

[0077] Particularly when a press die remains between the sub-panels, it is advantageous for the press die to have a lower density than the sub-panels, thus ensuring the production of a lightweight panel. A pressure-resistant foam film or a pressure-resistant bubble wrap film can therefore be used as the press die, which is especially preferred. Furthermore, a pressure-resistant foam film or a pressure-resistant bubble wrap film can be designed such that it can be removed from between two firmly bonded sub-panels by dissolving or reducing its size, as described in the two alternative methods outlined above. Of course, pressure-resistant foam films or pressure-resistant bubble wrap films can also be used as press dies when producing unbonded sub-panels.

[0078] The pressure-resistant foam film, regardless of whether it is designed with standard or through-holes, is preferably manufactured inline; that is, the indentations are created directly in the foam film during the manufacturing process of the sub-sheets. For this purpose, a suitable embossing and / or die-cutting device, such as a roller, can be used. For example, the foam film can be supplied as a roll or sheet, then provided with indentations or perforations using the appropriate embossing or die-cutting roller, and finally applied directly to the first pressing mat during the sub-sheet manufacturing process. Of course, pre-prepared foam films or bubble wrap sheets designed as press dies can also be used.

[0079] Furthermore, a press die for producing partial panels for lightweight panels is disclosed, with two opposing die sides for arranging a pressable mat made of glued particles, wherein each die side has recesses for receiving the glued particles and the recesses are designed to form support structures from the glued particles.

[0080] The press die is thus designed as a central die positioned between two pressing mats. It has two opposing surfaces (die sides) with recesses extending from one die side, particularly towards the opposite die side. Each surface preferably forms a plane, but without any protrusions projecting above the plane. The press die can, for example, be milled from a workpiece such as a plate. The press die is made of a pressure-resistant material. It can, for example, be made of a metal or a suitably pressure-resistant plastic. The embossing die can also be made of, for example, a pressure-resistant foam or a pressure-resistant bubble wrap. The height (depth) of the recesses is, for example...5 mm to 9 mm starting from the plane surface of the press die.

[0081] In the following, with regard to the characteristics of the press die or the recesses, reference is again expressly made to the aforementioned explanations concerning the press die, the descriptions of the press mold and the recesses in the press mold.

[0082] As already explained in the process description, a large amount of moisture is generated during pressing, especially when using organic particles and the adhesive employed, which must escape in the form of water vapor. Accordingly, a further development of the invention provides that the pressing die is designed to be vapor-permeable between the opposing die sides. This ensures that the generated water vapor can distribute evenly over the material being pressed, i.e., over both partial plates / mats and the pressing die, thus preventing steam bursts during pressing. To achieve the necessary permeability of the pressing die, it can be made of suitable (e.g., porous) plastics, pressure-resistant foams, or similar materials. The pressing die can also be made of synthetic resin or be designed as a sandwich product.Resin-impregnated carrier systems can be used, in particular, for the production of the press die. The press die preferably features microperforations for the passage of water vapor between the opposing die faces. The microperforations are designed to connect the two die faces. The perforation holes are sized large enough to allow a sufficient amount of water vapor to pass through, yet small enough to prevent the penetration of particles, especially fibers or chips.

[0083] One method for manufacturing the lightweight panels involves joining the individual sub-panels together using their respective support structures. However, this requires that the support structures of the two sub-panels to be joined are arranged in the same position. Accordingly, the press die is preferably designed such that the recesses on a first die side correspond to the recesses on a second die side opposite the first, allowing two sub-panels produced with the press die to be joined at their respective support structures.

[0084] For this purpose, the recesses on the first matrix side are preferably arranged in a mirror-symmetrical manner to the recesses on the second matrix side. Of course, if the recesses are arranged symmetrically on one of the matrix sides, the second matrix side can be identical to the first matrix side.

[0085] For press dies whose total thickness is greater than the sum of the deepest recesses on each of the two die sides, the arrangement of the die sides relative to each other is irrelevant. Here, for example, the recesses of the first die side can be arranged exactly opposite the recesses in the second die side. Particularly in press dies whose total thickness is less than the sum of the deepest recesses of the first die side and the deepest recesses of the second die side, a further development of the invention provides that corresponding recesses on the second die side are offset along an X-axis and / or Y-axis relative to the recesses on the first die side, so that corresponding recesses in the second die side extend into areas of the first die side where no recesses are arranged.

[0086] This means that the recesses on the first and second sides of the die are not aligned on opposite sides, but rather that the recesses on one side of the die are offset along the longitudinal and / or transverse axis (XY axes) of the press die. However, the relative arrangement of the recesses on the first side of the die still corresponds to the relative arrangement of the recesses on the second side.

[0087] For particularly easy further processing of the individual sub-sheets, a further development of the invention provides that the press die comprises two separate press shells, each press shell having one of the die sides and the press shells being arranged against each other on the surfaces opposite the die sides. The two press shells are detachably connected to each other, so that after pressing the mats, the two press shells can be separated, leaving each sub-sheet with a press shell for further processing. The design of the press die with two press shells also significantly simplifies its manufacture. For example, if one die side is damaged, only the corresponding press shell needs to be replaced instead of having to remake the entire press die.In addition, the demolding of the partial plates from the die sides is also significantly simplified.

[0088] According to a further development of the invention, each press tray has a microperforation extending from the respective die side into the press tray, wherein at least one of the press trays comprises a channel which, at least in the assembled state of the press trays, is in contact with the microperforation of the two die sides and enables the application of a vacuum to the die sides for the purpose of drawing water vapor from the pressing mats and / or for drawing particles into the recesses and / or applying a pressure medium to the die sides for easier removal of the partial plates from the press trays.

[0089] The press shells also significantly simplify the production of a press die designed for applying a vacuum or overpressure. The channel (or channel system) connecting the microperforations can be incorporated into one or both press shells. The channel is preferably, and at least partially, incorporated into the side of the press shell opposite the die side containing the recesses.

[0090] Although some aspects have been described in connection with one of the devices or one of the methods, it is understood that these aspects also constitute a description of the further method or devices, and vice versa. Aspects described in connection with the devices can also be understood as process steps of the first and / or second method. Similarly, aspects described in connection with or as a process step also constitute a description of a corresponding block, detail, or feature of a corresponding device.

[0091] The invention is further explained using several exemplary embodiments: These show Figure 1 schematically shows, in a flowchart, the individual process steps for producing a partial panel and a lightweight panel from a partial panel and a material panel; Figures 2a to 2c schematically show cross-sections of press dies of different thicknesses with partial panels; Figure 3 schematically shows, in a cross-section, two partial panels assembled to form a lightweight panel from the Figures 2a to 2c Figure 4a schematically shows a first matrix side with indentations in one view; Figure 4b schematically shows a second matrix side with indentations corresponding to the indentations of the first matrix side. Figure 4a corresponding depressions; Figure 4 schematically shows the two matrix sides in one view. Figure 4a and Figure 4barranged one above the other, with a second matrix side offset from the first matrix side by an X-axis and a Y-axis; Figure 5a schematically shows a first matrix side with indentations in one view; Figure 5b schematically shows a second matrix side with indentations corresponding to the indentations of the first matrix side. Figure 5a corresponding depressions; Figure 5 shows a schematic view of the two matrix sides. Figure 5a and Figure 5b arranged one above the other, with a second matrix side that is offset from the first matrix side by an X-axis and a Y-axis.

[0092] In the first step, the particles, in this case wood chips, or alternatively, for example, wood fibers, are provided. Optionally, a distinction can be made between particles for the supporting structures and particles for the top layer, with the particles for the top layer having, for example, a smaller volume than the particles for the supporting structures.

[0093] In a second step, the particles are coated with an adhesive and, if necessary, other additives such as wax. This is done in equipment commonly used in wood-based panel production.

[0094] In a further process step 3, the first press mold is prepared. For this purpose, it can be cleaned beforehand or coated with suitable release agents. After the adhesive is applied, the particles are applied to the first press mold (step 4), in this case using a standard spreading head. This is done in two passes. In one pass, coarse particles are first sprinkled onto the press mold and into the cavities. To increase the bulk density, the particles on the press mold are then wiped into the cavities again using a brush roller (step 5). Subsequently, the particles in the cavities are pre-compacted with compressed air (step 6), although both steps are optional.Pre-compaction can be carried out, for example, using one or more rollers, preferably with raised areas on their surface that are aligned with the depressions of the first press die. This allows the particles to be compacted or pressed directly into the depressions. If an optional control test reveals that the depressions are not sufficiently filled with particles, more coarse particles can be applied, wiped in, and pre-compacted if necessary.

[0095] After the depressions are filled, the top layer is spread in a further pass using another spreading device (step 8). The top layer can consist entirely of fine particles, i.e., particles that have a smaller volume than the coarse particles. Alternatively, the top layer can also have several layers, so that, for example, another layer of coarse particles borders directly on the depressions, and only an outer layer consists of fine particles. When fibers are used as particles, the particles for the depressions and the particles for the top layer are often identical.

[0096] The pressed material mat, consisting of loosely layered particles, is then pre-compacted in a press under pressure (step 9). A surface coating is applied to the pre-compacted mat, which remains on the first press die (step 10). This surface coating consists of a decorative paper with a colored print and an overlay layer positioned above it. The overlay layer is also made of overlay paper. Both the decorative paper and the overlay paper are impregnated with synthetic resin, in this case, melamine resin. The overlay is optional and is used particularly for surfaces subjected to very high stress. Alternatively, only the resin-impregnated decorative paper can be used.

[0097] The resulting package, consisting of pre-compacted pressed material mat and melamine resin-impregnated surface coating films, is fed into the press and compressed under heat and pressure (step 11). This process further compacts the pressed material mat to its final thickness, bonds the particles together through the curing of the adhesive, and bonds the surface coating to the outer surface of the granulate mat using the resin.

[0098] The finished, surface-coated partial plate is then removed from the press, taken out of the mold, cooled, and, if necessary, post-processed. This allows for tasks such as format cutting (step 12). To facilitate easy removal of the partial plate from the first mold, the first mold may have holes, such as micro-holes, to create a vacuum or even a negative pressure on the pressing mat and / or be designed to press the partial plate with compressed air to simplify removal and protect the support structures.

[0099] To manufacture the lightweight panel, the surface-coated sub-panel and a material panel (e.g., a second surface-coated sub-panel) are prepared (step 13). Adhesive is then applied to the outer ends of the support structures and / or to the material panel (step 14). Various adhesives, particularly those that cure without pressure, can be used. Here, PVAC adhesive is applied. The sub-panel and the material panel are then placed with their inner surfaces facing each other (step 15) and bonded together to form a lightweight panel (step 16). The necessary pressure can be generated by the weight of the material panel or the sub-panel. Alternatively, bonding can be carried out, for example, in a press under slight pressure that the support structures can withstand. After the lightweight panel is finished, it can be further processed, e.g., cut to size (step 17).

[0100] The Figures 2a to 2c Figure 1 shows press dies 1 of different thicknesses. On the first die side 2a, an upper partial plate 3a is arranged, while on the second die side 2b, opposite the first die side 2a, a lower partial plate 3b is present.

[0101] Both the upper matrix side 2a and the lower matrix side 2b have recesses 4 in which support structures 5 made of the material of the sub-plates 3a, 3b are formed. The recesses 4 are arranged in a regular grid pattern (indicated here by auxiliary lines H), resulting in an average spacing of 32 mm between the recesses 4. The sub-plates 3a, 3b are made of fiberboard, but could also consist of, for example, other organic particles bonded together. The recesses 4 of the first matrix side 2a correspond to the recesses 4 of the second matrix side 2b, so that the sub-plates 3a, 3b produced on the two matrix sides 2a, 2b can be joined to each other at their respective support structures 5.

[0102] At the in Figure 2aIn the illustrated press die 1, the recesses 4 of the first die side 2a extend into a region 6 of the second die side 2b in which no recesses 4 are arranged. Conversely, the recesses 4 of the second die side 2a also extend into a region 6 of the first die side 2a in which no recesses 4 are present. The illustrated press die 1 has a thickness of approximately 2.5 mm. The two sub-plates 3a, 3b have a total thickness of 8 mm from the outer surface 7 to the outer end 8 of the support structure 5, whereby the top layer region 9 is 2.5 mm thick and the recesses 4 rising from the top layer region 9 are accordingly 5.5 mm thick up to their outer end 8.

[0103] At the in Figure 2b The arrangement of the recess 4 relative to the press die 1 shown is as follows: Figure 2aidentical. Due to their greater thickness of approximately 19.5 mm, the respective recesses 4 of one matrix side 2a, 2b are only opposite areas 6 of the other matrix side 2a, 2b in which no recesses 4 are arranged, but they do not extend into these areas 6.

[0104] During the Figure 2c The formation and shaping of the recesses 4 and the arrangement of the recesses 4 on each die side 2a, 2b of the depicted press die 1 are identical to those shown in the Figures 2a and 2b Press dies shown 1. In contrast to those shown in the Figures 2a and 2b However, in the press dies 1 shown, the first die side 2a is not offset around the X-axis and Y-axis relative to the second die side 2b, but the recesses 4 of each die side 2a, 2b are arranged congruently on opposite die sides 2a, 2b of the press die 1.

[0105] The dimensions of the various designs differ from the... Figures 2a and 2b compared to the embodiment Figure 2c exclusively in the case of the press die 1, while the dimensions of the partial plates 3a, 3b are identical to the dimensions of the partial plates 3a, 3b from the embodiment shown Figures 2a and 2b are.

[0106] Figure 3 shows the two in the Figures 2a to 2c The illustrated partial panels 3a and 3b are connected to each other at their respective support structures 5, here bonded together, to form a lightweight panel 10. Between the bonded support structures 5, which extend as projections from the surface layer areas 9, cavities 11 are formed, resulting in a particularly low density of the lightweight panel 10. The total thickness of the lightweight panel 10 is 16 mm.

[0107] The Figures 4a and 4b Figures 2a and 2b show the first and second sides of a press die 1 with indentations 4. Figure 4aThe depicted depressions 4 extend from the plane of representation towards the viewer, while the ones in Figure 4bThe depicted depressions 4 extend away from the viewer. The depressions 4 form a regular grid pattern with squares consisting of nodes 12 and webs 13, and a dome-shaped node 12 located in the center of each square. It is clearly recognizable that at least the nodes 12 of the depressions 4 on the first matrix side 2a are arranged symmetrically to the nodes 12 of the depressions 4 on the second matrix side 2b. The respective nodes 12 are arranged in a 32 mm grid (shown here by guidelines H) on each matrix side 2a, 2b. The nodes 12 (i.e., parts of the depression 4) of the first matrix side 2a correspond to the nodes 12 of the second matrix side 2b. h, for each individual node 12 of the first matrix side 2a, 2b there is a corresponding node 12 on the second matrix side 2b.In addition, a plurality of the webs 13 of the first matrix side 2a are formed corresponding to a plurality of the webs 13 of the second matrix side 2b, so that partial plates 3a, 3b, which are produced with an embossing matrix 1 having these two matrix sides 2a, 2b, can be connected to each other at all node points 12 and a plurality of webs 13.

[0108] Figure 4c schematically shows the two in Figure 4a and Figure 4b The matrix faces 2a and 2b are shown superimposed, with only the recesses 4, the outer edges K, and the auxiliary lines H being shown for clarity. The second matrix face 2b (Figure 3b) is shown superimposed on the first matrix face 2a. The two matrix faces 2a and 2b are offset by half a node distance in both the X-axis and Y-axis directions.

[0109] The in the Figures 5a to 5c The matrix pages 2a and 2b shown differ from those in Figure 4a to Figure 4c The matrix faces 2a and 2b shown are defined by the grid pattern formed by the indentations 4. While the matrix faces shown in the Figures 4a to 4c The depicted depressions 4 largely form squares of webs 13 with nodes 12 and a dome-shaped node 12 arranged in the middle of each square, are those in the Figures 5a to 5c The depicted depressions 4 are designed as separate, dumbbell-shaped depressions 4, each having a rib 13 with external nodes 12. Here too, the depressions 4 of the first matrix side 2a are arranged in a mirror-symmetrical manner relative to the depressions 4 of the second matrix side 2b; that is, here too, the depressions 4 of the first matrix side 2a correspond to the depressions 4 of the second matrix side 2b. As can be seen from the Figure 5cAs can be seen, the second matrix side 2b is offset from the first matrix side 2a by a distance X in both the X-axis and Y-axis directions. Here too, distance X corresponds to half the distance between two nodes 12 of a depression 4, both in the X-axis and Y-axis directions.

[0110] All in the Figures 2a to 5a The press dies 1 shown also have a micro-perforation (not shown) which creates a vapor permeability of the press die 1.

[0111] As explained, the ones in the Figures 2a 5c The depicted depressions 4 and, accordingly, the resulting support structures 5 are arranged according to a regular grid (shown as guide lines H). In the exemplary embodiments of the Figures 2a to 5cThe grid spacing between the nodes is 12, i.e., also between the intersecting grid lines (auxiliary line H) is 32 mm. However, other grid configurations are also possible, e.g., different grid patterns and / or different grid spacings, or even an irregular arrangement of the recesses 4 on the matrix sides 2a, 2b. In this case, the recesses 4 on the opposite matrix sides 2a, 2b are designed to correspond to and, if necessary, offset from each other, so that at least a large proportion of the correspondingly produced support structures 5 of the sub-plates 3a, 3b are arranged correspondingly to each other and thus connectable. Reference symbol list

[0112] 1. Press die 2a. First die side 2b. Second die side 3a. Partial plate 3b. Partial plate 4. Recesses 5. Support structures 6. Area 7. Outer surface 8. Outer end of the support structure 9. Top layer area 10. Lightweight panel 11. Cavities 12. Junction 13. Web Guidelines KK edges

Claims

1. Method for manufacturing a lightweight panel (10) comprising the following steps: - creating a pressing-material mat that can be pressed into a partial plate (3a, 3b) by arranging glued particles on a first pressing mold, - pressing the pressing-material mat in a press to form the partial plate (3a, 3b) with support structures (5) on one side of the plate; - connecting, in particular bonding, the support structures (5) to a material plate, wherein - the pressing mold comprises recesses (4) for creating support structures (5) on a surface of the partial plate (3a, 3b) and during the production of the pressing-material mat, a portion of the particles is introduced into the recesses (4); wherein after the application of the particles, they are additionally wiped, swept in or brushed in and / or conveyed into the recesses via air currents.

2. Method according to at least claim 1, characterised in that the fully pressed pressing-material mat has a ratio between the height of the support structures (5), starting from a support structure base to a free end of the support structures, and the thickness of the top layer, starting from an outer surface of the partial plate to the free end of the support structures, of at least 1:1, preferably at least 1.5:1, particularly preferably at least 2:1, and advantageously at least between 1:1 and 4:1.

3. Method according to at least one of the preceding claims, characterised in that a surface coating is arranged on an outer surface of the spreading mat opposite the first pressing mold.

4. Method according to claim 3, characterised in that a vacuum is applied to the pressing-material mat during the pressing of the coating and in particular moisture produced during the curing of the coating is extracted.

5. Method according to at least one of the preceding claims, characterised in that a second partial plate (3a, 3b) is used as material plate, wherein the two partial plates (3a, 3b) are each connected to each other with their support structures (5).

6. Method according to at least one of the preceding claims, characterised in that when the support structures (5) are bonded, cavities (11) remain in the area of the support structures (5).

7. Method according to at least one of the preceding claims, characterised in that spaces between the support structures (5) are filled with a lightweight material, in particular a foam.

8. Method according to claim 1, wherein the partial plates (3a, 3b) for the lightweight panel are produced by the following steps: - creating a first pressing-material mat that can be pressed into a partial plate (3a, 3b) by arranging glued particles on a substrate, - arranging a pressing die (1) on the first pressing-material mat, - creating a second pressing-material mat that can be pressed into a partial plate (3a, 3b) by arranging glued particles on the pressing die (1), - pressing the pressing-material mats in a press to form two partial plates (3a, 3b), characterised in that - the pressing die (1) comprises recesses (4) on two opposite die sides (2a, 2b), - a portion of the particles is introduced into the recesses (4), and - by pressing the partial plates (3a, 3b), support structures (5) made of pressed particles are created on each of the surfaces of the partial plates (3a, 3b) adjacent to the die sides (2a, 2b).

9. Method according to claim 8, characterised in that the pressing die (1) is set into vibration after being arranged on the first pressing-material mat and / or after the second pressing-material mat has been produced, so that the particles of the first pressing-material mat and / or the second pressing-material mat penetrate into the adjacent recesses (4) of the pressing die (1).

10. Method according to claim 8 or claim 9, characterised in that the outer surfaces of the partial plate (3a, 3b) opposite the support structures (5) are coated, wherein the pressing die (1) is arranged between the partial plates (3a, 3b) during coating.

11. Method according to one of claims 8 to 10, characterised in that - the first pressing-material mat is produced on a first surface coating and - a second surface coating is arranged on the second pressing-material mat, - wherein both surface coatings are bonded to the sides of the resulting partial plates (3a, 3b) opposite the support structures (5) during pressing of the pressing-material mats.