Wood material board and method for the production thereof

Abstract

The present invention relates to a wood-based panel with inorganic-based particles and a method for its production.

Description

[0001] The present invention relates to the technical field of wood-based materials.

[0002] In particular, the present invention relates to a wood-based panel with inorganic-based particles, which is suitable for use as a construction panel.

[0003] Furthermore, the present invention relates to the use of a wood-based panel as a construction panel, in particular for drywall construction and for interior construction.

[0004] Finally, the present invention relates to a method for producing a wood-based panel.

[0005] Wood-based panels, such as particleboard, OSB, or fiberboard, have been used extensively in interior design and furniture construction for several decades. Wood-based panels are less stable than solid wood. However, due to their structure—that is, the result of shredding the solid wood and reassembling the wood particles—they exhibit better insulating properties than solid wood and do not swell in the presence of moisture. The properties of wood, which depend on the grain direction, as well as the swelling and shrinkage behavior of the wood in damp or dry conditions, are compensated for in the wood-based panel by the shredding and reassembling.

[0006] In addition, wood-based panels can be equipped with various properties and combined with additional, decorative, layers. For example, there are fungicide-resistant or moisture-resistant panels, as well as versatile decorative panels for furniture construction.

[0007] Depending on the type, wood-based panels are used in drywall construction for the construction of interior or exterior walls, as column, beam, ceiling, and sloping roof cladding, or as dry screeds and floors. Depending on the panel properties and construction, wood-based panels are used for non-load-bearing, stiffening, or load-bearing components.

[0008] The use of engineered wood panels is also advantageous in furniture construction for a variety of reasons. Solid wood in the form of solid wood is not suitable for all applications due to the possibility of warping or cracking. Furthermore, furniture made from engineered wood is generally significantly less expensive than solid wood furniture.

[0009] In addition, wood-based materials and their processing into wood-based panels also represent a form of economical wood processing, since a significant portion of the panels consists of waste or by-products from wood processing in the form of wood chips or fibers, which otherwise can hardly be used economically.

[0010] In addition to a wood-based material, such as wood chips or fibers, a binding agent, traditionally known as glue, is required for the production of wood-based panels. In simple terms, the production of a wood-based panel involves several steps. First, the wood-based material, for example in the form of chips, is prepared using a chipper and grinder. For the gluing or mixing of the binding agent and subsequent pressing, the wood-based material must have a required target moisture content, which usually requires a drying step. The drying process depends on the parameters of the wood species, chip size, bulk density, and initial moisture content.

[0011] After drying, the wood-based material is mechanically screened. This screening allows the wood-based material to be glued or mixed with the binder according to its intended use. Gluing involves the following process steps: preparing the binder or glue solution, dosing the wood-based material, applying the binder, and mixing the wood-based material and binder.

[0012] After the wood-based material is mixed with the binder, i.e., glued, the mixture is spread onto a fleece or mat. This is then pressed into panels under pressure and high temperatures. Old presses were designed as single- or multi-opening presses, while modern systems operate continuously. After pressing, the panels are finally conditioned (stored for a week to equalize the moisture and heat in the panel), trimmed, and sanded.

[0013] Due to their outstanding properties, wood-based panels are also used in a wide variety of construction applications, particularly in drywall construction and interior design. One disadvantage of wood-based panels compared to plasterboard, which is particularly widely used in drywall construction and interior design, is that the binding agent used makes them difficult to coat with inorganic materials such as plaster. This material incompatibility limits the use of wood-based panels, even though wood-based panels can be processed more easily and quickly in frame or stud construction without additional stiffening elements due to their often higher flexural strength compared to plasterboard. Furthermore, wood-based panels do not require double or triple sheathing to achieve a sufficiently high load-bearing capacity of a wall.

[0014] There have already been attempts in the state of the art to replace some of the wood chips or fibers in wood-based panels with inorganic fillers in order to save wood.

[0015] EP 2 944 621 B9 describes a wood fibre board which comprises 50 to 99.0 parts by weight of wood fibres of various classifications and 1 to 50 parts by weight of a calcium carbonate-containing material as well as 0.5 to 20 parts by weight of a binder and optionally a wax.

[0016] Furthermore, EP 3 606 711 B1 discloses a method for producing a wood-based decorative panel, for the production of which a base body made of a wood-based material is provided with a coating compound which, in addition to a binder, comprises an inorganic filler.

[0017] However, the incorporation of inorganic fillers into wood-based materials has the serious disadvantage that a homogeneous distribution of the fillers throughout the wood-based material, particularly in the glue, is virtually impossible. Typically, agglomerates form, which negatively impact the properties of the wood-based panels. To ensure better distribution of the fillers throughout the wood-based material, dispersions of inorganic fillers are occasionally added to the wood-based material during the production of the wood-based panels. However, this does not lead to the necessary homogeneous distribution of the fillers, so that the resulting wood-based panels exhibit different properties in certain areas. Furthermore, the aggregates cause problems during the final processing of the wood-based panels, particularly during sawing.This repeatedly leads to the wood material tearing out, which puts strain on the tools and thus leads to faster wear, especially of saws and saw blades.

[0018] The state of the art therefore still lacks a wood-based panel that is ideally suited for interior construction or drywall construction and that can be easily coated with inorganic coatings, particularly plasters. Furthermore, the state of the art still lacks a wood-based panel that has a high proportion of inorganic fillers and yet can be processed, especially assembled, like a conventional wood-based panel.

[0019] The present invention is therefore based on the object of eliminating, or at least mitigating, the aforementioned disadvantages associated with the prior art.

[0020] In particular, it is an object of the present invention to provide a wood-based panel which is excellently suited for interior construction or drywall construction and which can be coated with inorganic materials.

[0021] A further object of the present invention is to provide a wood-based panel with inorganic fillers, which can be processed and finished like conventional wood-based panels.

[0022] Furthermore, an object of the present invention is to provide a wood-based panel with a wide range of applications under economically favorable conditions.

[0023] The above-mentioned object is achieved according to a first aspect of the present invention by a wood-based panel according to claim 1; further advantageous embodiments of the wood-based panel according to the invention are the subject of the relevant subclaims.

[0024] A further subject matter of the present invention according to a second aspect of the present invention is the use of a wood-based panel according to claim 13.

[0025] Yet another subject matter of the present invention according to a third aspect of the present invention is a method for producing a wood-based panel according to claim 14; further advantageous embodiments of this aspect of the invention are the subject matter of the relevant subclaims.

[0026] It goes without saying that special features, characteristics, configurations and embodiments as well as advantages or the like which are explained below only with regard to one aspect of the invention in order to avoid unnecessary repetition, naturally apply accordingly with regard to the other aspects of the invention without this requiring express mention.

[0027] In addition, all values or parameters or the like mentioned below can generally be determined using standardized or explicitly specified determination methods or using determination methods that are familiar to a person skilled in the art.

[0028] Furthermore, it goes without saying that all percentages based on weight or quantity are selected by the person skilled in the art in such a way that the total amounts to 100%.

[0029] Having said that, the present invention will be described in more detail below.

[0030] Subject of the present invention - according to a first Aspect of the present invention is thus a wood-based panel, wherein the wood-based panel contains inorganic-based particles in amounts of at least 5% by weight, based on the wood-based panel.

[0031] The wood-based panel preferably contains inorganic-based particles in amounts of at least 10 wt.%, in particular at least 15 wt.%, preferably at least 20 wt.%, based on the wood-based panel.

[0032] The wood-based panel according to the invention is thus preferably a hybrid panel which combines the advantages of wood-based panels, namely in particular easy processing as well as high rigidity and mechanical strength with low dead weight, with the advantages of mineral panels for interior and dry construction, in particular plasterboard, namely simple coating and plastering with in particular inorganic materials.

[0033] Due to the high content of inorganic or inorganic-based materials in the wood-based panel according to the invention, the properties, in particular the surface properties of the wood-based panel are approximated to those of inorganic materials, so that they can be easily combined with other inorganic materials, in particular plaster systems.

[0034] In addition, the wood-based panel according to the invention is significantly lighter than purely inorganic-based panels made of, for example, metal, glass or gypsum and can therefore be easily processed.

[0035] The wood-based panel according to the invention is characterized by a very homogeneous distribution of the inorganic-based particles, which in particular also enables very stress-free processing and finishing, ie when sawing or finishing the wood-based panels on the construction site or during the manufacturing process, the tools, in particular saw blades, are not subjected to greater stress than when finishing or cutting wood-based panels without filler.

[0036] Furthermore, the wood-based panel according to the invention has improved fire resistance compared to pure wood-based panels, but the panel continues to be a wood-based panel with the advantages described above.

[0037] In contrast to the classic use of fillers, which are not intended to change the properties of a material, the wood-based panel according to the invention comprises large amounts of inorganic-based particles in order to specifically influence and adjust the properties, in particular surface properties, of the wood-based panel.

[0038] For the purposes of the present invention, an inorganic-based particle is understood to mean a particle that consists predominantly of inorganic materials. Preferably, the inorganic-based particles are inorganic particles, i.e., particles made of an inorganic material.

[0039] In the context of the present invention, it has proven useful if the wood-based panel comprises the inorganically based particles in amounts of 5 to 50 wt.%, in particular 5 to 40 wt.%, preferably 5 to 35 wt.%, more preferably 5 to 30 wt.%, particularly preferably 10 to 30 wt.%, very particularly preferably 15 to 30 wt.%, particularly preferably 20 to 30 wt.%, based on the wood-based panel.

[0040] As far as the material of the inorganic-based particles is concerned, this can be selected from a wide variety of materials. However, within the scope of the present invention, it has proven useful if the material of the inorganic-based particles is selected from the group consisting of loam, clay, chalk, calcium carbonate, gypsum, calcium silicate, silicon dioxide, silicas, and mixtures thereof. In this context, it has proven useful if the material of the inorganic-based particles is selected from the group consisting of loam, gypsum, calcium silicate, silicon dioxide, silicas, and mixtures thereof. Particularly good results are obtained if the material of the inorganic particles is selected from the group consisting of loam, gypsum, and mixtures thereof. Within the scope of the present invention, it is very particularly preferred if the material of the inorganic-based particles is gypsum.

[0041] In the context of the present invention, it is usually provided that the inorganically based particles have a particle size distribution D90 in the range from 1 to 300 µm, in particular 5 to 250 µm, preferably 10 to 200 µm, more preferably 20 to 150 µm, particularly preferably 50 to 120 µm.

[0042] The inorganic-based particles are therefore preferably incorporated into the wood-based panel in the form of a powder, in particular a fine powder.

[0043] Furthermore, it can also be provided that the inorganic-based particles have a particle size distribution D50 in the range from 1 to 50 µm, preferably 2 to 40 µm, preferably 3 to 30 µm.

[0044] The corresponding particle sizes and particle size distributions can be determined using methods based on sieve analysis, laser scattering, or the like. The respective determination methods are well known to the person skilled in the art, so no further explanation is required in this regard.

[0045] According to the invention, a wood-based material is understood to be a material made of lignocellulosic or wood-containing material, in particular wood chips or wood fibers, which are bonded together by a binding agent. Examples of lignocellulosic materials include straw, flax, hemp, or bagasse. The lignocellulosic material is advantageously a wood-containing material, such as roundwood, industrial wood (sawmill and planing residues), waste wood, drilled and residual wood, as well as small- and thinning wood, or a comparable wood-containing material.

[0046] Within the scope of the present invention, it can be provided that the wood-based panel according to the invention contains a single lignocellulose- or wood-containing material or a mixture of different lignocellulose- or wood-containing materials.

[0047] In addition, the wood-based panel may also have one or more layers. The individual layers may consist of the same or different wood materials, i.e., they may differ in type, composition, and content of lignocellulose or wood-containing material, binders, inorganic-based particles, and possibly additives.

[0048] As far as the composition of the wood-based panel is concerned with regard to the lignocellulose- or wood-containing material used in the wood-based panel, it has proven to be advantageous if the lignocellulose- or wood-containing material is selected from lignocellulose- or wood-containing chips and / or fibers, in particular selected from the group of hardwoods, softwoods, waste wood, straw, bast, flax, hemp, bagasse, bamboo, plant meal, waste paper, waste cardboard, waste carton and mixtures thereof, in particular hardwoods, softwoods, waste wood and mixtures thereof.

[0049] The lignocellulosic or wood-containing material preferably comes from sources where the wood-based material is a by-product or waste product. Therefore, the lignocellulosic or wood-containing material is preferably wood or wood-containing material selected from the group of roundwood, industrial wood, sawmill wood, wood residues, waste wood, construction timber, residual wood, small-sized wood, thinning wood, and mixtures thereof, in particular industrial wood, waste wood, residual wood, and mixtures thereof. This ensures efficient value creation and conserves wood from primary sources, which is considered advantageous from an environmental and sustainability perspective.

[0050] According to a preferred embodiment of the present invention, it is provided that the wood-based panel comprises wood particles and / or wood fibers.

[0051] With regard to the particle size of the lignocellulosic or wood-containing material, in particular the particle size of the wood chips or wood fibers, it has proven advantageous if the particle size varies within the range of 0.5 to 200 mm. Wood chips preferably have a size in a range of 0.5 to 15 mm, and wood fibers a size in a range of 1 to 6 mm. Likewise, it is also possible within the scope of the present invention to use coarse chips. Here, it has proven advantageous if the coarse chips have a size in a range of 100 mm to 200 mm in terms of length, 10 to 50 mm in terms of width, and 0.6 to 1.5 mm in terms of the thickness of the coarse chip.

[0052] Within the scope of the present invention, it is preferably provided that the wood-based panel comprises the lignocellulose- or wood-containing material, in particular the wood particles and / or wood fibers, in amounts of at least 50 wt.%, in particular at least 60 wt.%, preferably at least 65 wt.%, preferably at least 70 wt.%, particularly preferably at least 80 wt.%, based on the wood-based panel.

[0053] As already explained above, the wood-based panel according to the invention is, despite the high proportion of inorganic-based particles which change the surface properties of the wood-based panel, a wood-based panel which still has the advantages of a filler-free wood-based panel, namely high flexural strength, low moisture swelling, low shrinkage and a low bulk density.

[0054] Within the scope of the present invention, it can further be provided that the wood-based panel comprises the lignocellulose- or wood-containing material, in particular the wood particles and / or the wood fibers, in amounts of up to 95% by weight, in particular up to 93% by weight, preferably up to 90% by weight, based on the wood-based panel.

[0055] Furthermore, according to a preferred embodiment of the present invention, it is further provided that the wood-based panel comprises the lignocellulose- or wood-containing material, in particular the wood particles and / or wood fibers, in amounts of 50 to 95 wt.%, in particular 60 to 95 wt.%, preferably 65 to 93 wt.%, preferably 70 to 93 wt.%, particularly preferably 80 to 90 wt.%, based on the wood-based panel.

[0056] Within the scope of the present invention, it is usually provided that the wood-based panel comprises at least one binder, in particular at least one organic binder.

[0057] In the context of the present invention, a binder is understood to be a composition with a binding effect. The binding effect of the binder is usually based on a main component that can create or promote chemical bonds at the phase boundary with particles or trigger or increase effects such as adsorption and adhesion or friction. In this sense, the binder is intended to bond different substances, in this case lignocellulose-containing materials and inorganic particles, together by absorbing, accumulating, holding together, cross-linking or bonding these substances. In addition to the main component, a binder often also contains auxiliary substances or additives, such as pH adjusters, defoamers, stabilizers or the like, as well as optionally a solvent.

[0058] In the context of the present invention, it has proven useful if the binder is selected from the group consisting of polymeric diphenylmethane diisocyanate (PDMI), urea-formaldehyde resins (UF), phenol-formaldehyde resins (PF), resorcinol-formaldehyde resins, phenol-resorcinol-formaldehyde resins, melamine-formaldehyde resins (MF), melamine-urea-formaldehyde resins (MUF), urea-melamine-phenol-formaldehyde resins (UMPF), biogenic binders, and mixtures thereof. In the context of the present invention, a biogenic binder is understood to mean a binder that has at least one component of biological origin. The biogenic binder is preferably selected from lignin-based binders, starch-based binders, protein-based binders, and mixtures thereof.

[0059] In the context of the present invention, it is therefore preferred if the binder is selected from the group of diphenylmethane diisocyanate (PDMI), urea-formaldehyde resins (UF), phenol-formaldehyde resins (PF), resorcinol-formaldehyde resins, phenol-resorcinol-formaldehyde resins, melamine-formaldehyde resins (MF), melamine-urea-formaldehyde resins (MUF), urea-melamine-phenol-formaldehyde resins (UMPF), lignin-based binders, starch-based binders, protein-based binders and mixtures thereof.

[0060] According to a preferred embodiment of the present invention, the binder is selected from the group consisting of polymeric diphenylmethane diisocyanate (PDMI), biogenic binders, and mixtures thereof. Furthermore, it is preferred within the scope of the present invention if the binder is selected from the group consisting of polymeric diphenylmethane diisocyanate (PDMI), lignin-based binders, starch-based binders, protein-based binders, and mixtures thereof. Particularly good results are obtained within the scope of the present invention if the binder is polymeric diphenylmethane diisocyanate (PDMI).

[0061] In the context of the present invention, it is preferred if the binder is formaldehyde-free.

[0062] As far as the amount of binder in the wood-based panel is concerned, this can naturally vary widely.

[0063] Within the scope of the present invention, it can be provided in particular that the wood-based panel comprises the binder in amounts of up to 25% by weight, in particular up to 20% by weight, preferably up to 15% by weight, preferably up to 10% by weight, based on the wood-based panel.

[0064] Likewise, it can be provided that the wood-based panel contains the binder in amounts of 0.1 to 25 wt.%, in particular 0.5 to 20 wt.%, preferably 1 to 15 wt.%, more preferably 2 to 10 wt.%, based on the wood-based panel.

[0065] According to a preferred embodiment of the present invention, the wood-based panel (a) a lignocellulose- or wood-containing material, in particular wood chips and / or wood fibers, in particular in amounts of 50 to 95 wt.%, (b) at least one binder, in particular in amounts of 0.1 to 25 wt.%, and (c) inorganic-based particles, in particular in amounts of 5 to 50 wt.%, in each case based on the wood-based panel.

[0066] For this particular and preferred embodiment of the present invention, all of the aforementioned features, advantages and special features apply accordingly.

[0067] Furthermore, within the scope of the present invention, it can be provided that the wood-based panel comprises at least one additive. If the wood-based panel comprises an additive, the additive is typically selected from the group of dyes, dispersants, biocides, flame retardants, hardeners, and mixtures thereof.

[0068] If the wood-based panel comprises at least one additive, it has proven advantageous if the wood-based panel comprises the additive in amounts of at most 5% by weight, in particular at most 4% by weight, preferably at most 3% by weight, preferably at most 2% by weight, very particularly preferably at most 1% by weight, based on the wood-based panel.

[0069] Likewise, it can be provided that the wood-based panel contains the additive in amounts of 0.1 to 5 wt.%, in particular 0.1 to 4 wt.%, preferably 0.2 to 3 wt.%, more preferably 0.2 to 2 wt.%, particularly preferably 0.3 to 1 wt.%, based on the wood-based panel.

[0070] According to a further preferred embodiment of the present invention, it can be provided that the wood-based panel (a) a lignocellulose- or wood-containing material, in particular wood chips and / or wood fibers, in particular in amounts of 50 to 95 wt.%, (b) at least one binder, in particular in amounts of 0.1 to 25 wt.%, (c) inorganic-based particles, in particular in amounts of 5 to 50 wt.%, and (d) optionally at least one additive, in particular in amounts of 0.1 to 5 wt.%, each in relation to the wood-based panel.

[0071] Within the scope of the present invention, it is usually provided that the wood-based panel is a fiberboard or a chipboard.

[0072] Particularly good results are obtained within the scope of the present invention when the wood-based panel is a wood chipboard, also called wood particle board, or a wood fiber board.

[0073] According to a preferred embodiment of the present invention, the wood-based panel is selected from the group of particleboards (flat-pressed boards), extruded boards, coarse-grained particleboards (OSB), strip-laminated chipboards (LSL), medium-density fiberboards (MDF), high-density fiberboards (HDF), and ultra-light fiberboards (ULF). Preferably, the wood-based panel is selected from particleboards, in particular flat-pressed boards, and medium-density fiberboards (MDF).

[0074] Furthermore, within the scope of the present invention, it can further be provided that the wood-based panel has a bulk density in the range of 400 to 1,000 kg / m 3 , in particular 450 to 950 kg / m 3 , preferably 500 to 900 kg / m 3 , determined according to EN 323:1993. The wood-based panel according to the invention is thus relatively light and can be used without difficulty as a construction panel for interior and dry construction.

[0075] If the wood-based panel according to the invention is a particle board, it has proven advantageous if the wood-based panel has a bulk density in the range from 400 to 1,000 kg / m 3< , in particular 500 to 900 kg / m 3< , preferably 600 to 900 kg / m 3< , determined according to EN 323:1993.

[0076] If the wood-based panel is a wood fibre board, in particular MDF board, it has proven to be suitable if the wood-based panel has a bulk density in the range of 400 to 1,000 kg / m 3< , in particular 450 to 950 kg / m 3< , preferably 500 to 900 kg / m 3< , determined according to EN 323:1993.

[0077] Within the scope of the present invention, it is furthermore customary for the wood-based panel to have a flexural strength in the range of 10 to 40 N / mm 2 , in particular 12 to 35 N / mm 2 , preferably 13 to 30 N / mm 2 , more preferably 15 to 30 N / mm 2 , determined in accordance with EN 310:1993. The wood-based panel according to the invention thus has flexural strengths that are significantly superior to conventional mineral-based panels for drywall or interior construction. The wood-based panel according to the invention can therefore be installed in a simple frame or stud construction without the need for additional stiffening elements, such as C-profiles.

[0078] The wood-based panel according to the invention typically has a length in the range of 2 to 3 m and a width in the range of 0.5 to 1.5 m. The thickness of the wood-based panel typically varies in the range of 1 to 10 cm, preferably 2 to 5 cm, and more preferably 2 to 3 cm. Due to the low density, the wood-based panel according to the invention can be processed by one or a maximum of two people, like conventional construction panels.

[0079] According to a preferred embodiment of the present invention, the wood-based panel has a maximum moisture swelling of 10%, in particular 8%, preferably 6%, preferably 5%, particularly preferably less than 5%, determined according to DIN EN 317:1993 (Particleboards and fiberboards; Determination of thickness swelling after water storage). Due to the low moisture swelling, the wood-based panel according to the invention can be used without problems as a construction panel, as it is dimensionally stable and neither swells nor shrinks with fluctuating ambient humidity.

[0080] Furthermore, within the scope of the present invention, it is preferably provided that the wood-based panel has the fire resistance class B-s1-d0 according to EN 13823 (test method for SBI (Single Burning Item)).

[0081] According to a further embodiment of the present invention, the wood-based panel is laminated on at least one side, preferably laminated with paper. Furthermore, it can also be provided that the wood-based panel is laminated on both sides, preferably laminated with paper on both sides.

[0082] A lamination, in particular paper lamination, is typically used in the present invention only when the wood-based panel according to the invention is a particle board. Paper lamination can generally be omitted for fiberboard.

[0083] The single figure shows a preferred process sequence for producing a wood-based panel according to the invention in the form of a fiberboard.

[0084] Another object of the present invention - according to a second Aspect of the present invention is the use of a previously mentioned wood-based panel according to the invention as a construction panel, in particular as a construction panel for interior construction or drywall construction.

[0085] As already described above, the wood-based panel according to the invention is excellently suited for interior construction or drywall construction, as it is highly dimensionally stable and compatible with inorganic materials and can, for example, be plastered without any problems.

[0086] For further details on this aspect of the invention, reference can be made to the above statements on the wood-based panel according to the invention, which apply correspondingly with regard to the use according to the invention.

[0087] Yet another object of the present invention - according to a third Aspect of the present invention is a method for producing a wood-based panel, in particular as described above, wherein (a) firstly a lignocellulosic or wood-containing material, in particular in particulate form, preferably wood fibres and / or wood chips, is provided, and (b) subsequently the lignocellulosic or wood-containing material, in particular the wood chips and / or wood fibres, is admixed, in particular mixed, with a binder and inorganic-based particles, wherein the inorganic-based particles, in particular in powder form, are added to the lignocellulosic or wood-containing material in amounts of at least 5% by weight, based on the resulting wood-based panel, before, during or after admixing with the organic binder, or wherein the inorganic-based particles are added to the organic binder, in particular in powder form, in amounts of at least 5% by weight, based on the resulting wood-based panel, and the mixture is then added to the lignocellulosic or wood-containing material.

[0088] According to a preferred embodiment of the present invention, the method according to the invention is carried out in such a way that (a) firstly a lignocellulose- or wood-containing material, in particular in particulate form, preferably wood fibres and / or wood chips, is provided, and (b) subsequently the lignocellulose- or wood-containing material, in particular the wood chips and / or wood fibres, is admixed, in particular mixed, with a binder, wherein inorganic-based particles, in particular in powder form, are added to the binder or to the lignocellulose- or wood-containing material provided with an organic binder in amounts of at least 5% by weight, based on the resulting wood-based panel.

[0089] Within the scope of the present invention, it is preferably provided that the inorganically based particles are added to the lignocellulose- or wood-containing material provided with an organic binder, in particular the wood chips and / or wood fibers, in particular in fine distribution and / or with mixing, or that the lignocellulose- or wood-containing material, in particular the wood chips and / or wood fibers, is mixed together with the binder and the inorganically based particles.

[0090] It is particularly preferred within the scope of the invention if (a) firstly a lignocellulose- or wood-containing material, in particular in particulate form, preferably wood fibres and / or wood chips, is provided, and (b) subsequently the lignocellulose- or wood-containing material, in particular the wood chips and / or wood fibres, is admixed, in particular mixed, with a binder, wherein inorganic-based particles, in particular in powder form, are added to the lignocellulose- or wood-containing material provided with the organic binder in amounts of at least 5% by weight, based on the resulting wood-based panel.

[0091] Adding the inorganic-based particles to the lignocellulosic or wood-containing material, especially wood chips and / or wood fibers, provided with the organic binder is particularly preferred in the production of fiberboards, preferably MDF boards. This prevents the formation of aggregates of the inorganic-based particles, even in the very fine (wood) fibers, and the surfaces of the wood fibers mixed or wetted with the binder are very evenly coated with inorganic particles, thus achieving a very homogeneous distribution of the inorganic-based particles in the wood-based panel, especially the wood fiberboard.

[0092] If, within the scope of the present invention, the wood-based panel is a wood fiber board, it has proven useful if the process for producing the wood-based panel comprises the following process steps: (a) Providing wood fibers, (b) subsequently mixing the wood fibers with a binder, in particular an organic binder, in particular with intensive mixing, (c) mixing the wood fibers provided with a binder with inorganic-based particles, in particular with powdered inorganic-based particles, in finely divided form with mixing, in amounts of at least 5 wt.%, based on the resulting wood fiber board, and (d) subsequently processing the wood fibers provided with a binder and inorganic-based particles to form a wood fiber board.

[0093] Within the scope of the present invention, it can be provided, in particular, that the wood fibers are mixed, in particular mixed, with a binder, in particular an organic binder, before or after a drying process in process step (b). This means that the wood fibers can be mixed with a binder, in particular an organic binder, in process step (b) before or after they are subjected to a drying process.

[0094] Within the scope of the present invention, it is further possible for the wood fibers to be mixed with the binder by means of blowline gluing or dry gluing.

[0095] During blowline gluing, the still-moist wood fibers from the refiner are mixed with the organic binder in a blowline, ensuring a highly homogeneous distribution of the organic binder over the wood fibers. The inorganic-based particles are then injected into the blowline in a finely distributed manner, ensuring they adhere to the glue surface.

[0096] In dry gluing, the wood fibers are first dried, and then the binder is applied, particularly by spraying, onto the dried fibers while agitating the material. After the binder is applied, the wood fibers, which have been mixed with the organic binder, are mixed with the inorganic-based particles, preferably by spraying or spraying.

[0097] In the context of the present invention, blowline gluing is preferred.

[0098] Typically, the mixing of the wood fibers with the inorganic-based particles is followed by a drying process. The drying process is preferably performed after both blowline gluing and dry gluing to adjust the moisture content of the wood fibers to optimal values for further processing.

[0099] Furthermore, it may be provided that the fibers are screened, i.e. classified according to their sizes.

[0100] Usually, after adding the organic binder, gluing, adding the inorganic-based particles and drying, the fibers are screened in order to provide optimal fiber compositions for the wood-based panels.

[0101] Further processing of the fibers into a wood-based panel is usually done by hot pressing. For this purpose, the fibers, preferably previously screened if necessary, are first scattered into a mat. The mat is then pre-pressed, preferably using a cold press. Finally, hot pressing is performed, usually at temperatures in the range of 150 to 230 °C and at a pressure of 2 to 3 MPa. Pressing can be performed in single- or multi-opening presses, but continuous presses are preferred, as these allow for higher throughput.

[0102] Usually, a finishing process step follows, namely trimming and cutting the wood-based panels to cut them to the correct size.

[0103] As already explained above, the method according to the invention can also be used to produce a wood chip material.

[0104] According to a preferred embodiment of the present invention, the method according to the invention is thus a method for producing a wood chip material, wherein wood chips and a binder, preferably an organic binder, are homogeneously mixed with inorganic-based particles, in particular in powder form, in amounts of at least 5 wt.%, and the wood chips provided with the organic binder and the inorganic particles are then further processed to form a wood material, in particular a wood chipboard.

[0105] Further processing into wood-based panels is usually carried out by hot pressing.

[0106] To process the wood chips containing an organic binder and inorganic particles into a wood chip material, the wood chips containing an organic binder and inorganic particles are scattered into fleeces and the fleeces are then pressed into a wood chip material.

[0107] For further details on this aspect of the invention, reference can be made to the above statements on the other aspects of the present invention, which apply correspondingly with regard to the method according to the invention.

[0108] The subject matter of the present invention is explained below with reference to the figures in an exemplary and non-limiting manner.

[0109] The figure shows a preferred method 1 according to the invention for producing a wood fiber board 15.

[0110] The process shown in the figure for producing a wood fiber board 15 begins with the starting material wood 12 and ends with a wood fiber board 15.

[0111] In a first process step of comminution 2, lignocellulosic material, preferably wood-containing material, preferably wood 12, is comminuted. Straw, flax, hemp, or bagasse, among others, can be used as lignocellulosic material; however, a wood-containing material, in particular wood 12, is advantageously used. The wood 12 can be selected from any suitable wood-containing materials. Typically, the wood 12 is selected from roundwood (logs), industrial wood (sawmill and planing residues), waste wood, drilled and residual wood, as well as small- and thinning wood, or comparable wood-containing materials.

[0112] Large pieces of wood, especially round wood, are usually debarked and preferably chopped into wood chips in disc chippers or drum chippers.

[0113] The shredded wood 12, in particular the wood chips, are then generally cleaned in a cleaning process step 3, in particular by means of dry cleaning and / or wet cleaning, in order to free them from impurities.

[0114] Subsequently, the shredded and cleaned wood 12 is preferably subjected to a hydrothermal treatment 4 process step, in particular at temperatures of up to 100°C and a pressure of 8 to 10 bar. This softens the middle lamellae of the wood cells, which promotes subsequent fiberization.

[0115] Subsequently, the wood 12, in particular the wood chips, is subjected to a process step of defibration 5. The defibration 5 is usually carried out in a refiner, in which the shredded and softened pieces of wood are defibrated between two grooved grinding discs.

[0116] The fibers are then typically conveyed, in particular blown out, from the refiner via a blowline under pressure. In the blowline, the wood fibers are preferably subjected to a mixing process step 6. In this process, the wood fibers are first mixed with an organic binder 13 in a first mixing process step 6, in particular by injecting the binder 13 into the blowline. The turbulence in the blowline ensures that the wood fibers are evenly wetted with the organic binder.The binder is preferably selected from the group of diphenylmethane diisocyanate (PDMI), urea-formaldehyde resins (UF), phenol-formaldehyde resins (PF), resorcinol-formaldehyde resins, phenol-resorcinol-formaldehyde resins, melamine-formaldehyde resins (MF), melamine-urea-formaldehyde resins (MUF), urea-melamine-phenol-formaldehyde resins (UMPF), lignin-based binders, starch-based binders, protein-based binders and mixtures thereof.

[0117] Subsequently, in a second mixing process step 6, preferably still in the blow line, inorganic-based particles 14 are added to the wood fibers provided with the binder 13, preferably by spraying them in a finely distributed manner. As a result, the surfaces of the wood fibers provided with the organic binder 13 are uniformly coated with inorganic-based particles 14.

[0118] The material of the inorganic-based particles 14 is preferably selected from the group consisting of loam, clay, chalk, calcium carbonate, gypsum, calcium silicate, silicon dioxide, silica, and mixtures thereof. In this context, it has proven advantageous if the material of the inorganic-based particles 14 is selected from the group consisting of loam, gypsum, calcium silicate, silicon dioxide, silica, and mixtures thereof. Particularly good results are obtained if the material of the inorganic particles 14 is selected from the group consisting of loam, gypsum, and mixtures thereof. Within the scope of the present invention, it is very particularly preferred if the material of the inorganic-based particles 14 is gypsum.

[0119] Preferably, the inorganic-based particles 14 have a particle size distribution D90 in the range from 1 to 300 µm, in particular 5 to 250 µm, preferably 10 to 200 µm, more preferably 20 to 150 µm, particularly preferably 50 to 120 µm.

[0120] Likewise, it can be provided that the inorganic-based particles 14 have a particle size distribution D50 in the range from 1 to 50 µm, preferably 2 to 40 µm, preferably 3 to 30 µm.

[0121] The wood fibers mixed with an organic binder 13 and inorganic-based particles 14 are then usually subjected to a drying process step 7, whereby a targeted residual moisture content, usually between 9 and 11%, of the wood fibers is set.

[0122] The dried wood fibers can then preferably be subjected to a screening process step 8, in which they are classified. By selectively mixing wood fibers of different sizes, an optimal composition of the wood fiber material is always achieved.

[0123] As an alternative to mixing the moist wood fibers with the binder and the inorganic-based particles 14, in particular in a blowline, it is also possible to first dry the wood fibers and then mix them with the binder 13 and the inorganic-based particles 14. This is preferably done in an analogous manner, i.e., the wood fibers are preferably first mixed with the organic binder 13 and then the wood fibers mixed with the organic binder 13 are mixed with the inorganic-based particles 14.

[0124] After screening 8 of the wood fibers, the fibers are further processed into wood fiberboard 15. For this purpose, the fibers are usually scattered into a mat in a scattering process step 9 and the mat is smoothed if necessary.

[0125] After spreading 9, the mat is typically subjected to a pressing process step 10. Preferably, the mat is first cold pre-pressed. Pre-pressing is followed by hot pressing, preferably in a continuously operating press or in a single- or multi-opening press. The temperatures during hot pressing are between 150 and 230 °C, and the pressure is 2 to 3 MPa.

[0126] After pressing, the wood-based materials are usually subjected to a finishing process step 11, in which the wood-based materials are particularly trimmed and cut and, if necessary, laminated. List of reference symbols:

[0127] 1 Proceedings 9 Spread 2 Shredding 10 Press 3 Clean 11 Final editing 4 hydrothermal treatment 12 Wood 5 shredding 13 binder 6 Mix 14 inorganic-based particles 7 Dry 15 wood fiberboard 8 Views

Claims

1. Wood-based panel characterized by that the wood-based panel contains inorganic-based particles in amounts of at least 5% by weight, based on the wood-based panel.

2. Wood-based panel according to claim 1, characterized in that the wood-based panel comprises the inorganically based particles in amounts of 5 to 50 wt.%, in particular 5 to 40 wt.%, preferably 5 to 35 wt.%, more preferably 5 to 30 wt.%, particularly preferably 10 to 30 wt.%, very particularly preferably 15 to 30 wt.%, particularly preferably 20 to 30 wt.%, based on the wood-based panel.

3. Wood-based panel according to claim 1 or 2, characterized in that the inorganic-based particles are selected from the group of loam, clay, chalk, calcium carbonate, gypsum, calcium silicate, silicon dioxide, silicic acids and mixtures thereof.

4. Wood-based panel according to claim 3, characterized in thatthe inorganic-based particles are selected from the group of clay, gypsum and their mixtures, preferably gypsum.

5. Wood-based panel according to one of the preceding claims, characterized in that the wood-based panel comprises lignocellulose-containing materials, in particular wood-containing materials, preferably wood particles and / or wood fibers.

6. Wood-based panel according to claim 5, characterized in that the wood-based panel comprises the lignocellulose-containing material, in particular the wood particles and / or wood fibers, in amounts of at least 50% by weight, in particular at least 60% by weight, preferably at least 65% by weight, preferably at least 70% by weight, particularly preferably at least 80% by weight, based on the wood-based panel.

7. Wood-based panel according to one of the preceding claims, characterized in that the wood-based panel comprises at least one binder, in particular at least one organic binder.

8. Wood-based panel according to claim 7, characterized in that the wood-based panel contains the binder in amounts of up to 25% by weight, in particular up to 20% by weight, preferably up to 15% by weight, more preferably up to 10% by weight, based on the wood-based panel.

9. Wood-based panel according to one of the preceding claims, characterized in that the wood-based panel is a fiberboard or a chipboard.

10. Wood-based panel according to one of the preceding claims, characterized in that the wood-based panel is a wood-chip board or a wood-fibre board.

11. Wood-based panel according to one of the preceding claims, characterized in that the wood-based panel has a bulk density in the range of 400 to 1,000 kg / m 3 , especially 450 to 950 kg / m 3 , preferably 500 to 900 kg / m 3 , determined according to EN 323:1993.

12. Wood-based panel according to one of the preceding claims, characterized in thatthe wood-based panel is laminated on at least one side, preferably with a paper backing.

13. Use of a wood-based panel according to one of claims 1 to 12 as a construction panel, in particular as a construction panel for interior fittings.

14. A method for producing a wood-based panel, in particular according to one of claims 1 to 12, characterized by that(a) firstly a lignocellulose-containing material, in particular in particulate form, preferably wood fibres and / or wood chips, is provided, and (b) subsequently the lignocellulose-containing material, in particular the wood chips and / or wood fibres, is admixed, in particular mixed, with a binder and inorganically based particles, wherein the inorganic-based particles, in particular in powder form, are added to the lignocellulose-containing material in amounts of at least 5% by weight, based on the resulting wood-based panel, before, during or after the admixture with the organic binder or wherein the inorganic-based particles are added to the organic binder, in particular in powder form, in amounts of at least 5% by weight, based on the resulting wood-based panel, and the mixture is then added to the lignocellulose-containing material.

15. Method according to claim 14, characterized in that(a) firstly a lignocellulose-containing material, in particular in particulate form, preferably wood fibres and / or wood chips, is provided, and (b) subsequently the lignocellulose-containing material, in particular the wood chips and / or wood fibres, is admixed, in particular mixed, with a binder, wherein inorganic-based particles, in particular in powder form, are added to the binder or to the lignocellulose-containing material provided with an organic binder in amounts of at least 5% by weight, based on the resulting wood-based panel.

16. Method according to claim 14 or 15, in particular for producing a wood fibre board, characterized in thatthe process comprises the following process steps: (a) providing wood fibers, (b) subsequently adding a binder, in particular an organic binder, to the wood fibers, in particular with intensive mixing, (c) adding inorganic-based particles, in particular powdered inorganic-based particles, in finely divided form to the wood fibers provided with a binder, with mixing, in amounts of at least 5% by weight, based on the resulting wood fiber board, and (d) subsequently processing the wood fibers provided with a binder and inorganic-based particles to form a wood fiber board.

17. A method according to claim 14 or 15, in particular for producing a wood chip material, wherein wood chips and a binder, preferably an organic binder, are homogeneously mixed with inorganic-based particles, in particular in powder form, in amounts of at least 5% by weight, and the wood chips provided with the organic binder and the inorganic particles are then further processed to form a wood material, in particular a wood chipboard.

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