Wood-based board, in particular particle board, and method of manufacturing the wood-based board, in particular particle board

Abstract

The invention relates to a wood-based board (1) and a method of its manufacturing using wood-based board waste, in particular from particle boards. The wood-based board (1) is a prism and comprises interconnected layers, including a core (2), the core (2) comprising at least two interconnected layers of half-planks (4) made of a wood-based material. A single half-plank (4) is cut from wood-based board waste, and it has at least one surface (4B) comprising the wood-based material. The half-planks (4) forming the core are glued together by surfaces (4B) comprising the wood-based material, and the core (2) comprises a plurality of interconnected half-planks glued together by surfaces (4B) comprising the wood-based material and edge-joined together, whereby the glued half-planks (4) in the core (2) are arranged at an angle ranging from 0 to 90 degrees with respect to a selected pair of parallel sides of the board. In the manufacturing method, wood-based board waste is cut into planks in the shape of a prism, and subsequently the planks produced in this manner are cut along the plane of symmetry to produce half-planks (4). The half-planks (4) made of wood-based board waste having the same width are glued together by the surfaces (4B) comprising the wood-based material to produce a construction plank (6), and the construction planks (6) are face-glued together to form a lath (7). The lath is cut into segments which are glued together by side walls, forming a wood-based board (1) core (2) in the shape of a rectangular cuboid.

Description

[0001] Wood-based board, in particular particle board, and method of manufacturing the woodbased board, in particular particle board

[0002] Technical field

[0003] The object of the invention is a wood-based board, in particular particle board, and a method of manufacturing the wood-based board, in particular particle board. The solution is found useful in various industries, and primarily in the furniture industry as a method of processing wood-based board waste, in particular particle boards, providing the possibility to remanufacture a valuable product in the form of a wood-based board.

[0004] Prior art

[0005] From prior art there are known wooden planks and boards comprising wooden planks which are glued together. For example, US3888061A discloses a laminated floor panel, also comprising a laminated core. During manufacturing of this floor panel a semi-finished plank composed of four battens which are laterally glued together. The semi-finished plank can also be a continuous band of battens in arbitrary lengths glued together transversely and longitudinally. One of the battens forming the semi-finished plank is a batten made of hardwood. The semi-finished plank is cut into transverse sections, every second section being square, and the intermediate sections having shorter length. The sections obtained are so disposed that every second section, in the present case each square section, has battens extending transversely of the longitudinal direction of the laminated board to be made, whereas the remaining sections have battens extending in the same direction as the direction of the laminated floor board to be manufactured. The sections have edge fillets made of hardwood and of a softer timber material. In order to prepare the final core, the material is split into several portions, each successive one being turned by 180 degrees and joined with the previous portion. The battens in both core portions are mutually connected and have the fibre directions essentially oriented at right angles with respect to each other in the laminated floor panel structure. This results in obtaining an efficient interlock counteracting shape distortion due, for example, to the effect of moisture. The core of the laminated floor panel has a wearing parquet layer comprising longitudinally and transversely extending staves, which are respectively oriented in relation to the upper surface of the core portion, so that also in this respect a substantial interlock will be obtained between the staves of the wearing layer and the battens of the core portion. In order to enable the joining of the laminated panels, a groove has been cut into the core part, and the opposite end edge of the plank is provided with a tongue. Therefore, the laminated floor panels are joined together using the tongue and groove method.

[0006] US2006275574A1 in turn discloses solid structural wood products comprising oriented fibres and a method of manufacturing the same. The disclosed method of manufacture comprises edge-gluing wood boards together to form an edge-glued panel, followed by cutting the edge-glued panel at an oblique angle to form a plurality of laths. The panel is cut at an angle of 0 to 90 degrees, preferably between 30 and 60 degrees. Once the laths have been formed, a first lath is re-oriented relative to a second lath such that the wood fibre orientation of the first lath relative to the second lath is misaligned. This is followed by face-gluing or edgegluing the first and second lath together to form a wood product, for example a board. A single board may comprise more than two panels, which are also glued together.

[0007] Wood-based particle boards are commonly known, inter alia from the offers of manufacturers and from practical use. Such wood-based boards are made of pressed wood particles, whose binder is resin, and they are usually covered with a decorative material. Structures of this type of boards do not have oriented wood fibres which are present in solid wood. Wood fibres in wood particles are ruptured during the fragmentation process. In most commercially available products, wood particles of a larger size are present inside the board and they are less compressed, while the wood particles of smaller size and higher compression occur near the planes of the board that are covered with a decorative material. Usually, the decorative material of such furniture boards is decorative paper cured by melamine resin, which is commonly called a melamine finishing.

[0008] From prior art, there is also known the use of recycled wood or wood waste, which had previously been thermally treated, to manufacture oriented strand boards. Such a solution is disclosed in EP3648937B1, in which recycled wood flakes that have been obtained by flaking of recycled wood are used in a core layer of an oriented strand board. Such an oriented strand board comprises at least three layers: an upper surface layer comprising oriented strands bonded to one another by means of a binder, a core comprising wood flakes which have been obtained by flaking of recycled wood and are bonded to one another by means of a binder, a lower surface layer comprising oriented strands bonded to one another by means of a binder. The flakes in the board core have a smaller number average mean length than the flakes in the upper and lower surface layers. In order to enable its use in the core of an oriented strand board, recycled wood or wood waste must first be subjected to processing, in particular with the use of such devices as flaking devices with knife rings, woodchippers or crushers. Wood waste, in particular in the form of furniture, requires prior fragmentation before successive processing operations in order to be used in the core of an oriented strand board.

[0009] The purpose of the invention is to solve the technical problem involving the limited abilities of reusing wood-based board waste, or processing thereof requiring high energy expenditure. The purpose of the invention is also to reduce the scale of thermal treatment of wood-based board waste. The purpose of the invention is also to limit the generation of production waste while increasing the utilisation of wood particles and wood powder generated during typical production processes, involving in particular the cutting, milling and grinding of wood or wood-based materials. The purpose of the invention is also to provide alternative -construction of a wood-based board while providing improved mechanical properties, such as flexural strength, at the same time with minor consumption of electrical energy.

[0010] The essence of the invention

[0011] The invention relates to a wood-based board, in particular a particle board, being a prism and comprising an interconnected layers, including a core, whereby the core comprises an interconnected half-planks made of a wood-based material, characterised in that the core comprises at least two layers of interconnected half-planks made of a wood-based material, whereby a single half-plank is cut from wood-based board waste and has at least one surface comprising the wood-based material, whereby the half-planks forming the core are glued together by surfaces containing the wood-based material, and the core comprises a plurality of interconnected half-planks glued together by surfaces comprising the wood-based material and edge-joined together. The glued half-planks in the core are arranged at an angle ranging from 0 to 90 degrees with respect to a selected pair of parallel sides of the board. Throughout the present specification, wood-based board waste is to be understood as production and post-consumer waste comprising wood-based boards or fragments thereof of various sizes, and originating in particular from the furniture industry, in the form of furniture waste, old or worn out furniture and parts thereof.

[0012] It is preferable when the core has an outer finishing layers, whereby the finishing layers comprise a wood particle and wood powder blend layer.

[0013] It is also good when the half-planks have the shape of a rectangular cuboid with side walls, and at least one side wall of the half-planks are joined with each other by form-fit connection.

[0014] It is desirable when in the finishing layer on the wood particle and wood powder blend layer there is a layer of finishing materials selected from a group comprising varnishes, paints, wood stains, decorative papers, technical papers, stickers, wallpapers, films, continuous pressure laminates, high pressure laminates, plywoods, veneers, wooden facing boards.

[0015] It is also appropriate when the half-planks in the core are equal in width.

[0016] It is particularly good when the half-planks are cut from particle board waste.

[0017] The second invention relates to a method of manufacturing a wood-based board, in particular a particle board, in which the material forming the wood-based board is cut, and the resulting fragments are subsequently joined with each other to form a rectangular cuboid wood-based board . The essence of the method is in that:

[0018] - wood-based board waste comprising a wood-based material is cut into planks in the shape of a prism,

[0019] - the planks produced in this manner are cut along the plane of symmetry to produce halfplanks made of wood-based board waste having at least one surface containing a woodbased material,

[0020] - the half-planks made of wood-based board waste having the same width are glued together by the surfaces containing a wood-based material to produce a construction plank,

[0021] - the construction planks are face-glued together to form a lath, the single lath being formed of construction planks of the same width, - subsequently, the lath is cut at an angle of 1 to 90 degrees into segments having the shape of a parallelogram in a top view, with a dimension corresponding to at least the width or the length of the rectangular cuboid wood-based board,

[0022] - and the segments are glued together by side walls to form a prefabricated element of the wood-based board having the shape of a parallelogram in a top view,

[0023] - subsequently, a fragment of the prefabricated element of the wood-based board is cut off and joined with the remaining part of the prefabricated element of the wood-based board to form a core of the rectangular cuboid wood-based board.

[0024] It is preferable when the core of the wood-based board is coated with finishing layers, whereby the finishing layers preferably comprises a wood particle and wood powder mixture layer, which is formed by collecting wood particles and wood powder from the processes of cutting, routing or grinding the wood-based board waste, the half-planks, the construction planks, the laths and the prefabricated element of the wood-based board, and is subsequently used to prepare the finishing layers.

[0025] It is good when the half-planks made of wood-based board waste are glued together with a longitudinal or transverse offset of the ends of the glued half-planks, of preferably at least 5 mm.

[0026] It is appropriate when, prior to face-gluing, the construction planks or segments are routed on surfaces intended for gluing to increase the gluing area.

[0027] It is desirable when, before gluing together the half-planks made of wood-based board waste, a surface-planning operation is performed on their surface containing the woodbased material and intended for gluing.

[0028] It is equally preferable when the core of the rectangular cuboid wood-based board is ground before being coated with the finishing layers.

[0029] It is justified when the wood particle and wood powder mixture is blended with a binder and applied on the surfaces of the core.

[0030] It is good when particle board furniture waste comprising outer decorative surfaces is selected as the wood-based board waste. Preferably, laths of various widths are shaped and cut into segments, and segments of various widths are used to form the prefabricated element of the wood-based board.

[0031] Advantages of the solution

[0032] The invention allows for the use of wood-based board waste, which currently ends up in landfills or is thermally treated, to manufacture a wood-based board. The wood-based board and its manufacturing method may use most of the wood-based board waste, regardless of its coating type or its quality and strength. A new wood-based board may be produced with the use of raw particle boards and those with finishing layers, such as melamine-faced particle boards, particle boards coated with HPL - (high pressure laminate), boards coated with CPL (continuous pressure laminate), particle boards coated with veneer, laminated and raw MDF (medium-density fibreboard) boards , compact boards or OSB (oriented strand board) boards . A plank may be cut from any type of wood-based board waste, subsequently forming a half-plank, which constitutes a base material for the production of a new woodbased board. The wood-based boards produced on the basis of the method of manufacturing a wood-based board have standard thickness, which is 18 mm in Poland or 19 mm in many other countries. Wood-based boards of any thickness may also be produced according to the method, among which, apart from the 18 / 19 mm thickness, the following values of thickness are the most common in the furniture industry: 16 mm, 25 mm, 28 mm. Therefore, the woodbased board complies with commercial standards, and it may be used next to the commercially available wood-based boards.

[0033] The applied method of manufacturing a wood-based board from waste materials allows for producing a wood-based board of any size, and it allows for avoiding the cutting of standard sheets of wood-based boards to a size required by a final recipient, which generates much waste. The entire method of production is designed so that the only waste generated in the production process of wood-based boards is wood powder and wood particles, which are used as a raw material for the finishing layers of the wood-based board.

[0034] Moreover, a wood-based board made of wood-based board waste has increased mechanical strength; according to tests, the measured deflection of wood-based board core corresponded to half of the deflection of the core of a standard, new wood-based board. The core of a wood-based board does not use any additional reinforcing materials which could hinder or even prevent the processing of such boards. For example, when manufacturing furniture and during its assembly, such a board may be easily cut and subjected to any typical operations, like for example joining with further wood-based boards, or drilling holes for hinges.

[0035] By cutting the planks made of wood-based board waste in a plane of symmetry between their outer surfaces, two identical half-planks made of wood-based board waste are produced with the same dimensions and structure. In this operation, planks made of wood-based board waste are cut in a layer in which there are thick, loosely compressed wood particles. A fraction of material very often having the lowest density is removed at the width of the saw which is used. Therefore, layers used in further steps of processing wood-based board waste comprise fine, heavily compressed wood particles, and the outer surfaces of woodbased board waste, which are the most responsible for the strength of the wood-based boards. The half-plank used in further steps of production is formed after cutting the plank made of wood-based board waste. Depending on the utilised waste, on one side of such a half-plank made of wood-based board waste there is a visible outer surface of the plank, with the board core on the other, so that in the case of a particle board, a glued wood particle is visible. In the case of wood-based board waste, in numerous cases the outer surface of the plank would comprise old outer finishing layers forming the decorative coating of the utilised wood-based board waste. A half-plank made of wood-based waste would always comprise at least one surface made of wood-based materials. The cutting operation itself is very easy to perform.

[0036] Good strength of the board and its flexural strength result from the maximum exploitation of the strongest layers of wood-based board waste comprising heavily compressed wood particles. Due to this, the wood-based board is characterised by homogenised mechanical properties over the length and width of the board. The longitudinal and transverse offset of the ends of the half-planks glued with each other also contributes to an increase in strength.

[0037] Due to the use of a wood particle and wood powder blend layer for finishing the wood-based board, it is possible to retrieve waste from the preceding steps of cutting, routing or grinding. This is particularly good when the wood particle and wood powder mixture is blended with a binder suitably selected in terms of the expected physical and mechanical properties of the final product, and usually based on a polyvinyl acetate-based adhesive. After applying the wood particle and wood powder blend onto the outer surfaces of the board, it should be levelled and compressed, usually by pressing, but these operations pose no difficulties.

[0038] The use of form-fit connections and gluing between the individual half-planks, construction planks, segments, achieved in particular by routing the respective walls, allows for the achievement of a permanent and secure connection.

[0039] The use of planks of equal width in the wood-based board and in the manufacturing method streamlines the processes of processing wood-based board waste and acquiring a raw material forming the wood-based board. To this end, it is especially good to use wood-based board waste from particle boards, which are very often used in commercially available furniture.

[0040] Due to the surface-planning of the half-planks containing a wood-based material and intended for gluing, even before the gluing operations, any irregularities resulting from cutting errors are eliminated. The cutting surface is smoothened, and the thickness of the fragments of wood-based board waste is evened out.

[0041] Grinding the core of the wood-based board before coating it with the finishing layers allows for the elimination of irregularities and an increase in roughness, and thus for developing its outer surfaces and an improvement in the adhesive properties of the core of the wood-based board.

[0042] Another benefit achieved due to the use of wood-based board waste is extension of the life cycle of the utilised materials. The method of manufacturing a wood-based board and the wood-based board produced with this method comply with the assumptions of circular economy and contribute to a reduction in the amount of wood-based board waste.

[0043] The invention is presented in embodiments and in the drawing, which presents in: fig. 1— a cross-section of the core of a wood-based board; fig. 2 and fig. 3— cross-sections of parts of the wood-based board; fig. 4— a cross-section of a half-plank made of a wood-based material; fig. 5— the core of the wood-based board in a top view; fig. 6A and fig. 6B— longitudinal sections of a construction plank; fig. 7A and fig. 7B— longitudinal sections of a part of a lath; fig. 7C and fig. 7D— a top view of a part of a lath; fig. 8A and fig. 8B— the successive steps of forming a wood-based board in a top view.

[0044] Detailed description of the invention

[0045] First embodiment

[0046] A wood-based board 1 has the shape of a rectangular cuboid and comprises interconnected layers. In the first embodiment, the wood-based board 1 has a distinguishable core 2 comprising layers. Such a wood-based board 1 is formed by the core 2 and does not have decorative coatings 3, thus forming a raw wood-based board, for example intended to produce concealed elements of furniture.

[0047] The core 2 comprises two interconnected layers 2A of a wood-based material glued together, originating from wood-based board waste. The layers 2A of the core 2 comprise half-planks 4 made of the wood-based material. A single half-plank 4 (fig. 4) is cut from wood-based board waste, and it has a first surface 4A containing outer decorative melamine surfaces, and a second surface 4B containing the wood-based material. The half-plank 4 has been cut from a particle board with a melamine decorative coating, but the half-planks 4 may also originate from other waste of any kind from wood-based boards, in particular those commonly used in the furniture industry, meaning HPL boards (high pressure laminate), laminated and raw MDF boards (medium-density fibreboard), compact boards, OSB boards (oriented strand board), or raw particle boards.

[0048] The half-planks 4 have the shape of a prism with side walls, and they are glued by form-fit connection on their front and side walls in order to achieve higher strength of the glued connection. The width of the half-planks 4 in the wood-based board 1 is constant, and it is within a range of 30 mm to 500 mm. In this embodiment, the width of the half-planks was 50 mm. The length W of the half-planks 4 in a given wood-based board in the shape of a rectangular cuboid is varied, and it results from the dimensions of the wood-based board waste. Therefore, the length of the half-planks 4 generally depends on the size of wood- based board waste. The length of the half-planks 4 is within a range of 100 mm to 2800 mm, the half-planks most preferably have a length of 1200 mm. The half-planks 4 were produced as a result of cutting wood-based board waste, and their thickness is adjusted so that once glued together and coated with finishing layers, the half-planks 4 would form a wood-based board 1 which is 18 mm thick.

[0049] The half-planks 4 forming the core 2 of the wood-based board 1 are glued together by the second surfaces 4B, as well as by their side and front walls. Each of the layers 2A of the core 2 comprises a plurality of interconnected by sides half-planks 4. The half-planks 4 in each of the layers are arranged at an angle of 45 degrees with respect to a selected pair of parallel sides of the rectangular cuboid wood-based board. Therefore, the core 2 has a plurality of half-planks 4 glued together by the second surfaces 4B and edge-joined with each other.

[0050] The half-planks 4 are glued with the use of adhesives suitably selected in terms of the expected physical and mechanical properties of the rectangular cuboid wood-based board. The most commonly used adhesives include those based on polyvinyl acetate: PVa or PVaC, polyurethane adhesives, or ecological adhesives, for example based on casein, lignin or starch. The present embodiment used a polyvinyl acetate-based adhesive PVaC.

[0051] The core 2 in the production process was milled on both sides in order to eliminate irregularities and increase surface roughness. The core 2 formed in this manner, which does not have finishing coatings 3, constitutes a raw wood-based board 1. In other embodiments, a raw wood-based board 1 may be covered with a decorative layer 3 in the form of a paper layer intended to level the surface of the wood-based board 1.

[0052] The wood-based board 1 was produced by completing the procedure described below.

[0053] Wood-based board waste comprising a wood-based material and outer decorative surfaces has been cut into planks of equal width. In this embodiment, particle boards with outer melamine decorative surfaces were cut into planks. The planks had an equal width of 50 mm, and a maximum length of 1200 mm. The length of the plank depends mostly on the dimensions of wood-based board waste. The planks cut from wood-based board waste have the shape of a prism. The planks produced in this manner were cut in the plane of symmetry between the outer decorative surfaces of the plank, and the resulting half-planks 4 made of wood-based board waste have a first surface 4A comprising outer decorative surfaces of the waste, and a second surface 4B comprising a wood-based material. In this manner, a fragment of a middle part comprising thick, loosely compressed wood particles was cut out from the wood-based board waste, and two identical half-planks 4 were made from a single plank.

[0054] In the next step, the half-planks 4 were processed. The second surfaces 4B of the halfplanks 4 comprising the wood-based material were subjected to surface- planning. This operation resulted in the elimination of any irregularities caused by cutting errors and possible differences in the thickness of the wood-based board waste. The second surfaces 4B were smoothened, and the thickness of the half-planks 4 was equalised. Once the second surfaces 4B were planned, the half-planks 4 were mechanically cleaned in order to eliminate the remains of wood powders and wood particles by means of a system of brushes. The halfplanks 4 were produced as a result of cutting the planks, are therefore they are free of dirt, for example they are free of grease marks. Therefore, before the gluing process, there is no need for chemical cleaning, defatting or the performance of other operations intended to clean the wood-based board waste and prepare it for gluing.

[0055] The half-planks 4 made of wood-based board waste were glued together by the second surfaces 4B, resulting in a construction plank 6 (fig. 4A). The gluing process was executed in accordance with the methods known from prior art, in accordance with the specifications of the adhesives used, and according to the expected results. In the case of PVaC-based adhesives, they are usually applied onto both glued surfaces, while PUR adhesives are most commonly applied onto one glued surface. The adhesive was applied onto the second surfaces 4B of the half-planks by means of a roller or a cylinder, which at the moment of contacting the second surface 4B of the half-plank 4 transferred an adhesive film from the roller or cylinder onto the half-plank 4. Once the half-planks 4 have been glued, they are usually pressed for 3 to 6 minutes. The details of the gluing process are selected depending on the specification of the adhesive, ambient temperature, ambient humidity and the technologies used. The gluing process may be shortened by supplying heat to the glued elements, using microwaves or ultrasounds. Full setting of the adhesive takes place after 24 hours, but the process allows for the use of the construction planks upon prior pressing. The construction plank 6 produced after the gluing process has a homogeneous inner surface after gluing, but a gluing line is visible therein.

[0056] During gluing, the ends of the half-planks 4 made of wood-based board waste may also be moved longitudinally or transversely with respect to each other by at least 5 mm. This results in producing a construction plank 6 (fig. 6B), in which the gluing surfaces do not overlap and are offset with respect to each other. The construction planks 6 have two longer side walls and two shorter side walls; the shorter side walls are developed in order to achieve better mechanical properties during their subsequent gluing. In this embodiment, the side walls of the half-planks 4 were milled in order to increase the glued areas.

[0057] In the next step, construction planks 6 of the same width, in this embodiment 50 mm, are face-glued together to form a lath 7 (fig. 7B). Further construction planks 6 may be glued to the prepared lath 7, forming an endless product. Adhesives known from prior art are also used to face-glue the construction planks 6. In this embodiment, the same adhesive as the one used when gluing the half-planks 4 made of wood-based board waste was used to faceglue the construction planks 6. Due to the developed surfaces of the shorter side walls, the adhesive was applied with the use of a roller or a cylinder having a surface corresponding to the developed surface of the construction planks 6. Alternatively, nozzles dispensing adhesive strips by means of pressure can be used to this end. After the application of the adhesive onto the construction planks 6, they were pressed against each other until the adhesive set to an extent allowing further processing of the resulting lath 7.

[0058] Depending on the construction plank 6 used, the edges of the planks 4 in the lath 7, and subsequently in the wood-based board 1, may overlap (fig. 7A), or they may be offset with respect to each other (fig. 7B).

[0059] As described earlier, the construction planks 6 are formed as a result of cutting the planks into half-planks 4 and the subsequent gluing. Therefore, the construction planks 6 forming the lath 7 may have front surfaces which were cut at various angles, in particular at an angle of 90° and at acute angles. The construction planks 6 for forming a lath 7 are face-glued together, and face-gluing may be achieved at various angles (fig. 7C- fig. 7D).

[0060] Subsequently, the lath 7 produced in this manner was cut at an angle of 45 degrees, resulting in segments having the shape of a parallelogram in a top view. One of the dimensions of the resulting segments corresponds to the width or length of the wood-based board 1 being produced. The cutting of the laths at an angle of 45 degrees allows for maximum utilisation of the wood-based board waste, and limits the waste to a minimum when producing a rectangular cuboid wood-based board. In this embodiment, the lath 7 was cut into segments maintaining a width of 50 mm, meaning a width corresponding to the width of the planks cut from the wood-based board waste. The length of the cut segments was 2070 mm, and it corresponded to the width of a standard laminated wood-based board. The segments were edge-glued together so as to achieve a board length of 2800 mm. To this end, segments with a width of 50 mm and a length H corresponding to the width of the ultimately formed board— 2070 mm— were glued together resulting in a prefabricated element 8 of the woodbased board having the shape of a parallelogram in a top view.

[0061] In this embodiment, segments originating from the same lath with a width of 50 mm were glued together. A wood-based board may also be produced with the use of segments having various widths, for example with widths of 50 mm and 100 mm, and glued together resulting in a prefabricated element 8 of the wood-based board. Segments in the shape of a parallelogram have shorter front walls and longer side walls. The surface of the longer side walls is developed to achieve better mechanical properties when joining them with each other. In this embodiment, the side walls of the segments were milled in order to increase the glued areas. As mentioned, after edge-gluing, the resulting prefabricated element 8 of the wood-based board had the shape of a parallelogram in a top view. The gluing of the segments was accomplished like in the previous operations, including inter alia the pressing of the glued segments.

[0062] Subsequently, a fragment of the prefabricated element 8 of the wood-based board was cut off. The cut off fragment 8A had a triangular shape in a top view, and it was cut off from the prefabricated element 8 of the wood-based board along the height of the parallelogram, and subsequently, after reversing, it was glued to the edge of the prefabricated element 8 of the wood-based board, so that the core 2 of the rectangular cuboid wood-based board 1 was formed.

[0063] The core 2 of the wood-based board 1 produced in this manner was ground on both sides in order to eliminate irregularities and increase the roughness of the surfaces which constitute the first surfaces 4A of the half-planks 4. The product made in this manner constitutes the core of the wood-based board 1 which is:

[0064] - 2800 mm long,

[0065] - 2070 mm wide, - 16 mm thick.

[0066] The core 2 of the wood-based board 1 produced using the method described above was subjected to a measurement of deflection. Loads were centrally applied over a length of 245 mm to the core 2 of the wood-based board 1 placed on supports with a spacing of 1000 mm. The deflection of the core 2 of the wood-based board 1 was measured in its central point. The width of the tested sample of the core 2 of the wood-based board 1 was 300 mm. The deflection was measured for samples of the core 2 of the wood-based board 1 and, as a reference sample, the core of a standard wood-based board in the form of a raw particle board of identical thickness as the core 2 of the wood-based board. In order to obtain identical thickness of the samples, the raw particle board had been milled in advance. The results of deflection the core of the raw particle board and the samples of the core 2 of the wood-based board 1 are presented in the following table in mm.

[0067] As presented in the table above, the samples of the core 2 of the wood-based board 1 are characterised by smaller deflection compared to the core of standard particle board, which indicates increased strength of the core 2 of the wood-based board 1. Six samples of the core 2 of the wood-based board 1 were tested for each load. For each series, the reduction in deflection compared to the core of the particle board was calculated as a percentage. For the core 2 of the wood-based board 1, the bending is lower by approximately 50% compared to the core of the particle board, which translates to a strength of about two times more compared to the core of the standard particle board.

[0068] The wood-based board manufactured with the above presented method may be used to produce furniture. Due to the improved strength properties of the board core, the woodbased board will make a perfect structural element of furniture bodies.

[0069] Second embodiment

[0070] A wood-based board 1 has the shape of a rectangular cuboid and comprises interconnected layers. The wood-based board 1 has a distinguishable core 2 and decorative coatings 3. The core 2 is identical as in the first embodiment, and it comprises two layers 2A of a wood-based material glued together, originating from wood-based board waste. The layers 2A of the core 2 comprise half-planks 4 made of the wood-based material. A single half-plank 4 is cut from wood-based board waste, and it has a first surface 4A comprising outer decorative melamine surfaces, and a second surface 4B comprising the wood-based material. The halfplank 4 has been cut from a particle board with a melamine decorative coating.

[0071] In this embodiment, the width of a plank cut from wood-based board waste was 300 mm.

[0072] In this embodiment, the half-planks 4 were glued using a biodegradable starch-based adhesive. The core 2 in the production process was ground on both sides in order to eliminate irregularities and increase surface roughness. A wood particle and wood powder blend 5 layer is present on the surface of the core 2, meaning on the first surfaces 4A of the half- planks 4. This blend comprises a mixture of wood particles and wood powder retrieved from the previous board production steps, blended with a binder adjusted to the expected physical and mechanical properties of the rectangular cuboid wood-based board , and compliant with expectations regarding the appearance of the final product. The wood particle and wood powder blend 5 layer forms a new finishing layer, and it has been applied onto the first surfaces 4A of the half-planks 4, meaning on the decorative coating of wood-based board waste. The binder of the wood particle and wood powder blend 5 is usually a starch-based adhesive. In this embodiment, a layer of varnish was applied on the wood particle and wood powder blend 5 layer.

[0073] The wood-based board 1 was produced by following the method described in the first embodiment, except the wood-based board waste comprising a wood-based material and outer decorative surfaces was cut into planks of an equal width of 300 mm. In this embodiment, particle boards with outer melamine decorative surfaces were cut into planks. In addition, the lath 7 produced in the successive steps was cut at an angle of 25 degrees, resulting in segments having the shape of a parallelogram in a top view.

[0074] The core 2 of the wood-based board 1 produced according to the method presented in the first embodiment and while taking into account the above differences was ground on both sides in order to eliminate irregularities and increase the roughness of the surface which constitutes the first surfaces 4A of the half-planks 4. A first finishing layer in the form of a wood particle and wood powder blend 5 layer was applied onto the surface of the core 2 of the wood-based board 1 prepared in this manner. The wood particle and wood powder blend 5 comprises a blend of sawdust and wood powder retrieved from earlier cutting and grinding stages joined by a binder selected suitably in terms of the expected physical and mechanical properties of the rectangular cuboid wood-based board. In this embodiment, the binder was a starch-based adhesive. Dyes, catalysts, antifoams or cellulose fibres are used as an additive to the binder. Following the application of the wood particle and wood powder blend layer, it was compressed by pressing.

[0075] Following the process of compressing the wood particle and wood powder blend, the surface of the core 2 of the wood-based board 1 was ground in order to achieve a smooth surface. The degree of grinding should depend on the final finishing layer, which requires various degrees of surface roughness for varnishing or lamination. In this embodiment, the degree of grinding was adjusted to subsequent coating with varnish. The process of applying the first finishing layer was performed analogically for the second surface of the core of the rectangular cuboid wood-based board. In the final step, the core 2 of the wood-based board 1 was covered with a final finishing layer adjusted to the customer's expectations. In this embodiment, a layer of varnish was used as the final finishing layer.

[0076] The wood-based board 1 produced in this manner was:

[0077] - 2800 mm long,

[0078] - 2070 mm wide,

[0079] - 18 mm thick.

[0080] The preceding cutting of planks made of wood-based board waste resulted in the possibility to apply a finishing layer comprising a wood particle and wood powder blend onto a first surface 4A comprising outer decorative surfaces of the waste-based wood-based board, which completely covered the decorative surfaces of the waste-based board. This coverage did not increase the thickness of the wood-based board 1, which meets the standards encountered inter alia in the furniture industry.

[0081] Third embodiment

[0082] The wood-based board 1 in a third embodiment has a structure analogical to the second embodiment, except the wood-based board waste was raw MDF boards (medium-density fibreboard). The wood-based board 1 was also produced according to the method presented in the second embodiment.

[0083] In this embodiment, planks of various widths were cut from wood-based board waste, including widths of 100 mm, 150 mm and 300 mm. According to the steps presented in the previous embodiments, laths 7 with widths of 100 mm, 150 mm and 300 mm were formed from these planks.

[0084] The resulting laths 7 were cut at an angle of 75 degrees, resulting in segments having the shape of a parallelogram in a top view. One of the dimensions of the resulting segments correspond to the width or length of the wood-based board 1 being produced. The length of the cut segments was 2070 mm, and it corresponds to the width of a standard laminated MDF board. The segments were edge-glued together so as to achieve a board length of 2800 mm. To this end, segments with a width of 100 mm, 150 mm and 300 mm, and a length of 2070 mm, were glued together resulting in a prefabricated element 8 of the wood-based board having the shape of a parallelogram in a top view. A PVa-based adhesive was used in all steps of manufacturing the wood-based board 1.

[0085] In this embodiment, a longitudinal offset of the edges of half-planks 4 by 50 mm with respect to each other, and a transverse offset of the edges of the half-planks 4 by 15 mm with respect to each other were used in the earlier step of gluing construction planks 6 from the halfplanks 4. This resulted in achieving increased strength in the place of connecting.

[0086] The core 2 of the wood-based board 1 produced according to the method presented in the first embodiment and while taking into account the above differences was ground on both sides in order to eliminate irregularities and increase the roughness of the surface which constitutes the first surfaces 4A of the half-planks 4. A first finishing layer in the form of a wood particle and wood powder mixture layer was applied onto the surface of the woodbased board 1 core 2 prepared in this manner. The wood particle and wood powder blend comprises a blend of sawdust and wood powder retrieved from the preceding cutting and grinding steps, blended by a polyvinyl acetate-based adhesive PVa.

[0087] Following the process of compressing the wood particle and wood powder blend, the surface of the core 2 of the wood-based board 1 was ground in order to achieve a smooth surface. The degree of grinding was adjusted to the subsequent coating of the wood-based board 1 core with a film. The wood-based board 1 core 2 was covered with a final finishing layer in the form of a film adjusted to the customer's expectations.

Claims

Claims1. A wood-based board, in particular a particle board, being a prism and comprising an interconnected layers, including a core (2), whereby the core (2) comprises an interconnected half-planks (4) made of a wood-based material, characterised in that the core comprises at least two layers of interconnected half-planks (4) made of a wood-based material, whereby a single half-plank (4) is cut from wood-based board waste and has at least one surface (4B) comprising the wood-based material, whereby the interconnected half-planks (4) forming the core are glued together by surfaces (4B) containing the wood-based material, and the core (2) comprises a plurality of interconnected half-planks glued together by surfaces (4B) comprising the wood-based material and edge-joined together, whereby the glued half-planks (4) in the core (2) are arranged at an angle ranging from 0 to 90 degrees with respect to a selected pair of parallel sides of the board.

2. The wood-based board according to claim 1, characterised in that the core (2) has an outer finishing layers (3), whereby the finishing layers comprising a wood particle and wood powder blend (5) layer.

3. The wood-based board according to claim 1 or 2, characterised in that halfplanks (4) have the shape of a rectangular cuboid with side walls, and at least one side wall of the half-planks (4) are joined with each other by form-fit connection.

4. The wood-based board according to any of the claims from 1 to 3, characterised in that in the finishing layer (3) on the wood particle and wood powder blend layer (5) there is a layer of finishing materials selected from a group comprising varnishes, paints, wood stains, decorative papers, technical papers, stickers, wallpapers, films, continuous pressure laminates, high pressure laminates, plywoods, veneers, wooden facing boards.

5. The wood-based board according to any of the claims from 1 to 4, characterised in that the half-planks (4) in the core (2) are equal in width.

6. The wood-based board according to any of the claims from 1 to 5, characterised in that the half-planks (4) are cut from particle board waste.

7. A method of manufacturing a wood-based board, in particular a particle board, in which the material forming the wood-based board is cut, and the resulting fragments are subsequently joined with each other to form a rectangular cuboid wood-based board , characterised in that: a. a wood-based board waste comprising a wood-based material is cut into planks in the shape of a prism, b. the planks produced in this manner are cut along the plane of symmetry to produce half-planks (4) made of wood-based board waste, having at least one surface (4B) containing the wood-based material, c. the half-planks (4) made of wood-based board waste having the same width are glued together by the surfaces (4B) containing the wood-based material to produce a construction plank (6), d. the construction planks (6) are face-glued together to form a lath (7), the single lath (7) being formed of construction planks (6) of the same width, e. subsequently, the lath (7) is cut at an angle of 1 to 90 degrees into segments having the shape of a parallelogram in a top view, with a dimension corresponding to at least the width or the length of the rectangular cuboid wood-based board, f. and the segments are glued together by side walls to form a prefabricated element (8) of the wood-based board having the shape of a parallelogram in a top view, g. subsequently, a fragment of the prefabricated element (8) of the woodbased board is cut off and joined with the remaining part of the prefabricated element (8) of the wood-based board to form a core (2) of the rectangular cuboid wood-based board (1).

8. The method of manufacturing a wood-based board according to claim 7, characterised in that the core (2) of the wood-based board is coated with finishing layers (3), whereby the finishing layers (3) preferably comprises a wood particle and wood powder blend (5) layer, which is formed by collecting wood particles and wood powder from the processes of cutting or grinding woodbased board waste, the half-planks (4), the construction planks (6), the laths (7)and the prefabricated element (8) of the wood-based board (1), and is subsequently used to prepare the finishing layers.

9. The method of manufacturing a wood-based board according to claim 7 or 8, characterised in that the half-planks (4) made of wood-based board waste are glued together with a longitudinal or transverse offset of the ends of the glued half-planks, of preferably at least 5 mm.

10. The method of manufacturing a wood-based board according to any of the claims from 7 to 9, characterised in that prior to face-gluing, the construction planks (6) or segments are milled on surfaces intended for gluing to increase the gluing area.

11. The method of manufacturing a wood-based board according to any of the claims from 7 to 10, characterised in that before gluing together the half-planks (4) made of wood-based board waste, a surface-planning operation is performed on their surface (4B) containing the wood-based material and intended for gluing.

12. The method of manufacturing a wood-based board according to any of the claims from 7 to 11, characterised in that the core (2) of the rectangular cuboid woodbased board (1) is ground before being coated with the finishing layers (3).

13. The method of manufacturing a wood-based board according to claim 12, characterised in that the wood particle and wood powder blend is blended with a binder and applied on the surfaces of the core (2).

14. The method of manufacturing a wood-based board according to any of the claims from 7 to 13, characterised in that particle board furniture waste comprising outer decorative surfaces is selected as the wood-based board waste.

15. The method of manufacturing a wood-based board according to any of the claims from 7 to 14, characterised in that laths (7) of various widths are shaped and cut into segments, and segments of various widths are used to form the prefabricated element (8) of the wood-based board.

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