Composite wood board and method for the production thereof

Abstract

The present invention relates to a composite wood board containing inorganics-based particles and to a method for the production thereof.

Description

[0001] Wood-based panel and process for its production

[0002] The present invention relates to the technical field of wood-based materials.

[0003] In particular, the present invention relates to a wood-based panel with inorganic-based particles, which is suitable for use as a construction panel.

[0004] 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.

[0005] Finally, the present invention relates to a method for producing a wood-based panel.

[0006] 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 the shredding of solid wood and the reassembly of 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 moisture or dryness, are compensated for in the wood-based panel by the shredding and reassembly.

[0007] In addition, wood-based panels can be equipped with various properties and combined with additional, for example, decorative, layers. For example, there are fungicide-resistant or moisture-resistant panels, as well as versatile decorative panels for furniture construction.

[0008] 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 screed and flooring. Depending on the panel properties and construction, wood-based panels are used for non-load-bearing, stiffening, or load-bearing components. Wood-based panels are also suitable for various reasons in furniture construction. Solid wood in the form of solid wood is not suitable for all applications due to the possibility of warping or cracking. Furniture made from wood-based materials is also 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 binding agent, i.e., glued, this 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 moisture and heat within the panel), trimmed, and sanded. Due to their outstanding properties, wood-based panels are also used in a variety of ways in construction, 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, due to their often higher flexural strength compared to plasterboard, can be processed more easily and quickly in frame or stud construction without additional stiffening elements. Furthermore, wood-based panels do not require double or triple sheathing to achieve a sufficiently high load-bearing capacity of a wall.

[0013] 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.

[0014] 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 as well as 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.

[0015] 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.

[0016] 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 on saws and saw blades.

[0017] 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.

[0018] The present invention is therefore based on the object of eliminating, or at least mitigating, the aforementioned disadvantages associated with the prior art.

[0019] 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.

[0020] 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.

[0021] Furthermore, an object of the present invention is to provide a wood-based panel with a wide range of applications under economically favorable conditions.

[0022] The aforementioned 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. A further subject 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.

[0023] 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.

[0024] It goes without saying that special features, characteristics, embodiments and forms of embodiment 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.

[0025] In addition, all values ​​or parameters or the like mentioned below can generally be determined using standardized or explicitly specified determination procedures or using determination methods that are familiar to a person skilled in the art.

[0026] 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%.

[0027] Having said that, the present invention will be described in more detail below.

[0028] The present invention—according to a first aspect of the present invention—thus provides a wood-based panel, wherein the wood-based panel contains inorganic-based particles in amounts of at least 5 wt.%, based on the wood-based panel. Preferably, the wood-based panel 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.

[0029] 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.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] 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.

[0034] 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.

[0035] For the purposes of the present invention, an inorganic-based particle is understood to mean a particle that consists predominantly of inorganic materials. The inorganic-based particles are preferably inorganic particles, i.e., particles made of an inorganic material.

[0036] In the context of the present invention, it has proven useful if the wood-based panel comprises the inorganic-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.

[0037] 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.

[0038] In the context of the present invention, it is usually provided that the inorganic-based particles have a particle size distribution D90 in the range from 1 to 300 pm, in particular 5 to 250 pm, preferably 10 to 200 pm, more preferably 20 to 150 pm, particularly preferably 50 to 120 pm.

[0039] The inorganic-based particles are thus preferably incorporated into the wood-based panel in the form of a powder, in particular a fine powder. Furthermore, it can also be provided that the inorganic-based particles have a particle size distribution D50 in the range of 1 to 50 pm, preferably 2 to 40 pm, and more preferably 3 to 30 pm.

[0040] 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.

[0041] 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, bonded together by a binding agent. Examples of lignocellulosic materials include straw, flax, hemp, and 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.

[0042] 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 also a mixture of different lignocellulose- or wood-containing materials.

[0043] 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.

[0044] 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.

[0045] 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.

[0046] According to a preferred embodiment of the present invention, it is provided that the wood-based panel comprises wood particles and / or wood fibers.

[0047] 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 useful if the particle size varies in the range from 0.5 to 200 mm. Wood chips preferably have a size in a range from 0.5 to 15 mm, and wood fibers a size in a range from 1 to 6 mm. Likewise, it is also possible within the scope of the present invention to use coarse chips. Here, it has proven useful if the coarse chips have a size in a range from 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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% by weight, in particular 60 to 95% by weight, preferably 65 to 93% by weight, preferably 70 to 93% by weight, particularly preferably 80 to 90% by weight, based on the wood-based panel.

[0052] 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.

[0053] 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 establish or promote chemical bonds at the phase boundary with particles or trigger or increase effects such as adsorption, adhesion, or friction. In this sense, the binder is intended to bond different substances—here, lignocellulose-containing materials and inorganic particles—to one another by absorbing, accumulating, holding together, crosslinking, or bonding these substances. In addition to the main component, a binder often also contains auxiliaries or additives, such as pH adjusters, defoamers, stabilizers, or the like, as well as optionally a solvent.

[0054] In the context of the present invention, it has proven useful if the binder is selected from the group 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.

[0055] 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.

[0056] 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).

[0057] In the context of the present invention, it is preferred if the binder is formaldehyde-free.

[0058] As far as the amount of binding agent in the wood-based panel is concerned, this can naturally vary widely.

[0059] Within the scope of the present invention, it can be provided, in particular, that the wood-based panel contains the binder in amounts of up to 25 wt.%, in particular up to 20 wt.%, preferably up to 15 wt.%, preferably up to 10 wt.%, based on the wood-based panel. 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.%, preferably 2 to 10 wt.%, based on the wood-based panel.

[0060] According to a preferred embodiment of the present invention, the wood-based panel

[0061] (a) a lignocellulose- or wood-containing material, in particular wood chips and / or wood fibres, in particular in amounts of 50 to 95% by weight,

[0062] (b) at least one binder, in particular in amounts of 0.1 to 25% by weight, and

[0063] (c) inorganic-based particles, in particular in amounts of 5 to 50 wt.%, in each case based on the wood-based panel.

[0064] For this particular and preferred embodiment of the present invention, all of the aforementioned features, advantages and special features apply accordingly.

[0065] Furthermore, within the scope of the present invention, it may 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.

[0066] 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, more preferably at most 2% by weight, very particularly preferably at most 1% by weight, based on the wood-based panel.

[0067] 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.%, preferably 0.2 to 2 wt.%, particularly preferably 0.3 to 1 wt.%, based on the wood-based panel. According to a further preferred embodiment of the present invention, it can be provided that the wood-based panel

[0068] (a) a lignocellulose- or wood-containing material, in particular wood chips and / or wood fibres, in particular in amounts of 50 to 95% by weight,

[0069] (b) at least one binder, in particular in amounts of 0.1 to 25% by weight,

[0070] (c) inorganic-based particles, in particular in amounts of 5 to 50 wt.%, and

[0071] (d) optionally comprises at least one additive, in particular in amounts of 0.1 to 5% by weight, in each case based on the wood-based panel.

[0072] In the context of the present invention, it is usually provided that the wood-based panel is a fiberboard or a chipboard.

[0073] 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.

[0074] 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 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).

[0075] Furthermore, within the scope of the present invention, it can be further provided 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. The wood-based panel according to the invention is thus relatively lightweight and can be easily used as a construction panel for interior and drywall construction. 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 of 400 to 1,000 kg / m 3 , especially 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, especially MDF board, it has proven to be effective if the wood-based panel has a 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.

[0077] Within the scope of the present invention, it is furthermore usually provided that the wood-based panel has a bending strength in the range of 10 to 40 N / mm 2 , especially 12 to 35 N / mm 2 , preferably 13 to 30 N / mm 2 , preferably 15 to 30 N / mm 2 , determined according to EN 310:1993. The wood-based panel according to the invention thus exhibits 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 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%, more preferably 5%, particularly preferably less than 5%, determined according to DIN EN 317:1993 (particleboards and fiberboards; determination of thickness swelling after storage in water). Due to the low moisture swelling, the wood-based panel according to the invention can be used without any problems as a construction panel, since it is dimensionally stable and neither swells nor shrinks with fluctuating ambient humidity. Furthermore, within the scope of the present invention, it is preferably provided that the wood-based panel has fire resistance class B-s1-d0 according to EN 13823 (test method for SBI (Single Burning Item)).

[0080] According to a further embodiment of the present invention, the wood-based panel is laminated on at least one side, preferably with a paper backing. Furthermore, the wood-based panel can also be laminated on both sides, preferably with paper backing on both sides.

[0081] A lamination, especially a paper lamination, is typically used in the present invention only if the wood-based panel according to the invention is a particle board. Paper lamination can generally be omitted for fiberboard.

[0082] The single figure shows a preferred process sequence for producing a wood-based panel according to the invention in the form of a fiberboard.

[0083] A further subject matter of the present invention - according to a second aspect of the present invention - is the use of an aforementioned wood-based panel according to the invention as a construction panel, in particular as a construction panel for interior construction or drywall construction.

[0084] 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.

[0085] 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.

[0086] Yet another subject matter of the present invention - according to a third aspect of the present invention - is a process for producing a wood-based panel, in particular as described above, wherein (a) firstly a lignocellulose- or wood-containing material, in particular in particulate form, preferably wood fibers and / or wood chips, is provided, and

[0087] (b) subsequently the lignocellulosic or wood-containing material, in particular the wood chips and / or wood fibers, 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

[0089] (a) firstly, a lignocellulose- or wood-containing material, in particular in particulate form, preferably wood fibres and / or wood chips, is provided, and

[0090] (b) subsequently, the lignocellulose- or wood-containing material, in particular the wood chips and / or wood fibers, 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.

[0091] Within the scope of the present invention, it is preferably provided that the inorganic-based particles are added to the lignocellulose- or wood-containing material, in particular the wood chips and / or wood fibers, provided with an organic binder, in particular in fine distribution and / or with thorough 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 inorganic-based particles. It is particularly preferred within the scope of the invention if

[0092] (a) firstly, a lignocellulose- or wood-containing material, in particular in particulate form, preferably wood fibres and / or wood chips, is provided, and

[0093] (b) subsequently, the lignocellulose- or wood-containing material, in particular the wood chips and / or wood fibers, 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.

[0094] 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.

[0095] If, in the context 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:

[0096] (a) Providing wood fibres,

[0097] (b) subsequently mixing the wood fibres with a binder, in particular an organic binder, in particular with intensive mixing,

[0098] (c) adding inorganic-based particles, in particular powdered inorganic-based particles, in finely divided form to the wood fibres provided with a binder, with thorough mixing, in amounts of at least 5% by weight, based on the resulting wood fibre board, and

[0099] (d) subsequent processing of the wood fibers provided with a binder and inorganic-based particles into a wood fiberboard. Within the scope of the present invention, it can be provided, in particular, that the wood fibers are mixed, in particular, 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.

[0100] 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.

[0101] During blowline gluing, the still-moist wood fibers coming 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 sprayed into the blowline in a finely distributed manner, ensuring they adhere to the glue surface.

[0102] In dry gluing, the wood fibers are first dried, and then the binder is applied, typically by spraying, to 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.

[0103] In the context of the present invention, blowline gluing is preferred.

[0104] Typically, the mixing of the wood fibers with the inorganic-based particles is followed by a drying process. The drying process is preferably carried out after both blowline gluing and dry gluing to adjust the moisture content of the wood fibers to optimal values ​​for further processing.

[0105] Furthermore, it may be provided that the fibers are screened, i.e., classified according to their size. Typically, after the organic binder has been added, the inorganic particles have been added, and the drying process has begun, the fibers are screened to ensure optimal fiber compositions for the wood-based panels.

[0106] Further processing of the fibers into a wood-based panel is typically done by hot pressing. For this, the fibers, which may have been previously screened, 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.

[0107] Usually, a finishing step follows, namely trimming and cutting the wood-based panels to cut them to the correct size.

[0108] As already explained above, the process according to the invention can also be used to produce a wood chip material.

[0109] According to a preferred embodiment of the present invention, the process according to the invention is thus a process 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.

[0110] Further processing into wood-based panels is usually carried out by hot pressing.

[0111] 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 nonwovens, and the nonwovens are then pressed into a wood chip material. For further details on this aspect of the invention, reference can be made to the above statements regarding the other aspects of the present invention, which apply correspondingly to the process according to the invention.

[0112] The subject matter of the present invention is explained below with reference to the figures in an exemplary and non-limiting manner.

[0113] The figure shows a preferred method 1 according to the invention for producing a wood fiber board 15.

[0114] 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.

[0115] In a first process step of comminution 2, lignocellulosic material, preferably wood-containing material, preferably wood 12, is comminuted. Straw, flax, hemp, or even 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 weak and thinning wood, or comparable wood-containing materials.

[0116] Large pieces of wood, especially round wood, are usually debarked and preferably chopped into wood chips in disc chippers or drum chippers.

[0117] 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.

[0118] Subsequently, the shredded and cleaned wood 12 is preferably subjected to a hydrothermal treatment step 4, particularly 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.

[0119] Subsequently, the wood 12, in particular the wood chips, is subjected to a process step of defibration 5. 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.

[0120] The fibers are then typically conveyed, in particular blown out, of 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.

[0121] 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.

[0122] 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.

[0123] The inorganic-based particles 14 preferably have a particle size distribution D90 in the range from 1 to 300 pm, in particular 5 to 250 pm, preferably 10 to 200 pm, more preferably 20 to 150 pm, particularly preferably 50 to 120 pm.

[0124] Likewise, it can be provided that the inorganic-based particles 14 have a particle size distribution D50 in the range from 1 to 50 pm, preferably 2 to 40 pm, preferably 3 to 30 pm.

[0125] 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.

[0126] 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.

[0127] 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, ie, 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.

[0128] After screening 8 of the wood fibers, the fibers are further processed into wood fiberboard 15. For this purpose, the fibers are typically scattered into a mat in a scattering process step 9, and the mat is smoothed if necessary. After scattering 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.

[0129] After pressing, the wood materials are usually subjected to a finishing process step 11, in which the wood materials are particularly trimmed and cut and, if necessary, laminated.

[0130] List of reference symbols:

[0131] 1 Procedure 9 Spreading

[0132] 2 crushing 10 pressing

[0133] 3 Cleaning 11 Finishing

[0134] 4 hydrothermal treatment 12 wood

[0135] 5 Defibrillation 13 Binders

[0136] 6 Mixing 14 inorganic based particles

[0137] 7 Drying 15 Fiberboard

[0138] 8 views

Claims

Patent claims: 1 . Wood-based panel, characterized in 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 that the inorganic-based particles are selected from the group of clay, gypsum and mixtures thereof, 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 comprises 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 chipboard or a wood fiberboard.

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 that the wood-based panel is laminated on at least one side, preferably laminated with paper.

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 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 lignocellulosic material, in particular the wood chips and / or wood fibers, 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 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 lignocellulosic 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 fibers, 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. A method according to claim 14 or 15, in particular for producing a wood fibre board, characterized in that the method comprises the following process steps: (a) Providing wood fibres, (b) subsequent mixing of the wood fibres with a binder, in particular an organic binder, in particular with intensive mixing, (c) adding inorganic-based particles, in particular powdered inorganic-based particles, in finely divided form to the wood fibres provided with a binder, with thorough mixing, in amounts of at least 5% by weight, based on the resulting wood fibre board, and (d) subsequent processing of the wood fibres containing a binder and inorganic-based particles into a wood fibre 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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