Multi-layered wood composite block, multi-layered wood veneer and method for producing the same

Description

[0001] The invention relates to a multi-layered wood composite block, a multi-layered wood veneer, and methods for producing them. Furthermore, the invention relates to the use of the multi-layered wood veneer as a decorative and / or cladding element, particularly in a vehicle interior, and to articles comprising the multi-layered wood veneer.

[0002] Multi-layered wood veneers, obtained from multi-layered wood composite blocks, are known.

[0003] DE 60 2005 001 689 T2 deals with a process for producing veneer. In this process, wooden blocks are sliced ​​into veneer with a thickness of approximately 0.65 mm after prolonged heating and soaking. Suitable adhesives mentioned include, among others, moisture-curing, thermal polyurethane adhesives.

[0004] The process for producing refined wood veneers set out in DE 1 086 425 B can optionally include slicing or rotary peeling of a multi-layered, glued block of wood to produce individual veneers.

[0005] EP 2 310 196 B1 describes a multi-layered block of wood, veneers obtainable from it, and methods for their production.

[0006] DE 10 2017 113 764 B4 discloses a method for producing a wood veneer and a veneer block, as well as a method for producing a molded part. The veneer blocks are produced using an adhesive and then sliced ​​into veneers.

[0007] DE 10 2015 009 012 B3 discloses a method for producing a veneer, wherein the method comprises separating veneer sheets using a veneer knife machine.

[0008] For economic reasons, wood veneers are preferably produced using knives. This method is material-efficient and yields veneers with a thickness between 0.3 and 4 mm. However, the wood or veneer blocks must be heated and soaked in water for an extended period to prepare them for slicing. Since this pretreatment involves changes in temperature and humidity, which lead to deformation, particularly expansion, of the individual wood layers within the veneer block, the achievable precision of sliced ​​veneers is limited. Furthermore, this type of pretreatment only allows for limited bonding of different materials, or the resulting bond often lacks the desired properties.In particular, adhesives suitable for bonding different materials such as wood, metals, and plastics, while also exhibiting sufficient resistance to moisture and / or heat during soaking or steaming, are not yet commercially available. Furthermore, pretreatment can result in color changes in the wood. Finally, both sliced ​​and round-peeled veneers are prone to cracking. Generally, veneers can only be sliced ​​up to a certain hardness of the wood or wood (composite) block used; ironwood, in particular, meaning various tropical woods, cannot be sliced ​​into veneers but can only be processed by sawing.

[0009] Multi-layered sawn veneers are also a known technique. Sawing wood (composite) blocks into veneers is the most traditional method. One disadvantage of sawing is the comparatively large material loss, which depends, among other things, on the thickness of the saw blade used. Overall, sawing is considerably more labor-intensive. However, sawn veneers retain their color and are largely crack-free, as they do not necessarily need to be moistened / steamed and then dried again, but can be sawn directly dry. Sawn veneers can generally be produced with a thickness of 1 mm or more and are mainly used for high-quality and heavily stressed workpieces, e.g., in furniture making or for floor coverings.

[0010] The present invention is based on the objective of providing a multi-layered wood composite block suitable as a starting material for the production of a high-precision veneer with a veneer thickness in the range of 0.2 to 4.0 mm. A further objective of the invention is to provide a high-precision, multi-layered wood veneer that can be used for decorative and / or cladding elements.

[0011] The present problem is solved by the wood composite block according to claim 1, the multilayer wood veneers according to claim 6, the methods according to claims 10 and 12, the use according to claim 14, and by articles according to claim 15.

[0012] A first aspect of the invention relates to a multi-layered wood composite block comprising a plurality of superimposed layers of wood, and at least one adhesive layer, wherein at least one adhesive layer is arranged between successive layers of wood, and wherein the at least one adhesive layer, in the cured state, has a hardness of at least 70 Shore A, determined according to DIN EN ISO 868, and / or a hardness of at least 20 Shore D, determined according to DIN EN ISO 868, wherein the wood composite block has a wood moisture content of less than or equal to 15%.

[0013] Advantageous features and further training options are specified in the respective dependent requirements.

[0014] The multi-layered wood composite block according to the invention can be machined using saws or knives, as the wood composite block possesses advantageous properties. Preferably, the multi-layered wood composite block according to the invention can be machined using saws or knives in the dry state, and even more preferably using saws in the dry state. If the cured adhesive layers of the wood composite block are too soft, sawing is no longer possible because the adhesive layers smear and / or the sawn veneers do not retain their shape. However, if the adhesive layers are too hard, sawing is no longer possible and / or the wear on the tools used is enormous. Specifically, the adhesive layers, in the cured state, have a hardness of at least 70 Shore A and / or a hardness of at least 20 Shore D, preferably at least 75 Shore A and / or at least 24 Shore D, and more preferably at least 80 Shore A and / or at least 27 Shore D.

[0015] Preferably, the hardness of the adhesive layers, in the cured state, is less than or equal to 60 Shore D.

[0016] Preferably, the hardness of the adhesive layers, in the cured state, is less than or equal to 100 Shore A.

[0017] The measurement of hardness, Shore A and Shore D, is carried out according to DIN EN ISO 868.

[0018] Unlike veneer production using knives, sawing eliminates the need for pretreatment of the wood composite blocks. This means that temperature and / or humidity fluctuations are avoided, preventing warping and / or discoloration of the blocks. As a result, sawn veneers can be produced with greater precision. Furthermore, the nature of the wood composite structure and the sawing process allow for designs that were previously impossible with other methods.

[0019] In principle, all adhesives suitable for gluing wood are suitable for implementing the present invention. Since fluctuations in humidity, or swelling and / or warping of the wood, should be avoided, water- and solvent-free adhesives are preferred.

[0020] Preferably, at least one adhesive layer is produced using water- and solvent-free adhesives. Any residual amounts of water and / or solvents present are either non-removable residues or, for example, water introduced through atmospheric humidity.

[0021] Another important factor is the adhesive properties of the adhesives. The surface properties, such as polarity and structure, of different materials—that is, different types of wood, but also other materials that may be incorporated as intermediate layers into the multi-layered wood composite block or multi-layered wood veneer—can differ significantly. Therefore, a crucial criterion for selecting suitable adhesives is that they exhibit sufficient adhesion to all materials used.

[0022] Suitable adhesives include polyurethanes (PUR), epoxy resins, silane-modified polymers, and two-component adhesives such as PVAc copolymer with isocyanate. Hot melt adhesives based on polyurethane prepolymers and epoxy resins are particularly suitable.

[0023] Particularly preferred are moisture-curing hot melt adhesives based on polyurethane prepolymers, which have a processing temperature of 100 - 140 °C, and / or which, before curing, have a viscosity of 5000 to 20000 mPas, preferably 5000 to 16000 mPas, more preferably 8000 to 16000 mPas at 130°C (Brookfield DV-II+ Thermosel, spindle 29), and / or which, before curing, have a density of 1.0 to 1.5 g / cm³, preferably 1.0 to 1.3 g / cm³, more preferably 1.1 to 1.3 g / cm³.

[0024] According to a preferred embodiment, the wood composite block comprises a plurality of adhesive layers. The presence of multiple adhesive layers opens up additional design possibilities, since each adhesive layer also forms a line element within the wood composite block. Furthermore, the influence of the adhesive's properties—such as its hardness—on the machinability of the wood composite block increases with an increasing number of adhesive layers.

[0025] If the wood composite block comprises a number of different layers, these can be arranged in different ways; specific arrangements of the individual layers contained in the wood composite block can be seen in the attached figures.

[0026] Basically, the adhesive layers serve to bond one layer of wood to another layer of wood.

[0027] According to another preferred embodiment, the wood composite block has a) a total carbon emission (TVOC - Total Volatile Organic Compounds) of less than or equal to 50 µg carbon / g determined according to VDA 277, and / or b) a content of volatile organic compounds (VOC - Volatile Organic Compounds) of less than or equal to 100 mg / kg and semi-volatile organic compounds (FOG - Fogging or also SVOC - Semi-Volatile Organic Compounds) of less than or equal to 250 mg / kg determined according to VDA 278, and / or c) a formaldehyde emission value of less than or equal to 3 mg / kg determined according to VDA 275, on.

[0028] The aforementioned emission values ​​TVOC, VOC, FOG and the formaldehyde emission value of the wood composite block according to the invention can also be zero, independently of each other.

[0029] Experts distinguish between volatile organic compounds (VOCs), highly volatile organic compounds (VVOCs), and semi-volatile organic compounds (SVOCs). The sum of the concentrations of all volatile organic compounds yields the TVOC value (Total Volatile Organic Compounds).

[0030] The term VOC encompasses volatile organic compounds with a boiling point range of 50-100°C to 250-260°C. FOG and / or SVOC refer to organic compounds with a boiling point range of 240 to 400°C that may form a precipitate (lubricating film).

[0031] A wood composite block that meets the aforementioned criteria regarding emission tests according to VDA 275, 277 and / or 278 exhibits low toxicity. Such a wood composite block is therefore suitable for a wide variety of applications, particularly in interior spaces. For example, the wood composite block is suitable for the production of decorative and / or cladding elements, especially for vehicle interiors.

[0032] Preferably, the wood composite block has a) a total carbon emission (TVOC) of less than or equal to 50 µg carbon / g determined according to VDA 277, and b) a volatile organic compound (VOC) content of less than or equal to 100 mg / kg and semi-volatile organic compounds (FOG) content of less than or equal to 250 mg / kg determined according to VDA 278; or a) a total carbon emission (TVOC) of less than or equal to 50 µg carbon / g determined according to VDA 277, and c) a formaldehyde emission value of less than or equal to 3 mg / kg determined according to VDA 275; or b) a volatile organic compound (VOC) content of less than or equal to 100 mg / kg and semi-volatile organic compounds (FOG) content of less than or equal to 250 mg / kg determined according to VDA 278, and c) a formaldehyde emission value of less than or equal to 3 mg / kg determined according to VDA 275; on.

[0033] Preferably, the wood composite block according to the invention has a) a total carbon emission (TVOC) of less than or equal to 50 µg carbon / g determined in accordance with VDA 277, and b) a content of volatile organic compounds (VOCs) of less than or equal to 100 mg / kg and semi-volatile organic compounds (FOCs) of less than or equal to 250 mg / kg determined in accordance with VDA 278, and c) a formaldehyde emission value of less than or equal to 3 mg / kg determined in accordance with VDA 275, on.

[0034] According to a further preferred embodiment, the at least one adhesive layer can be colored and / or is temperature-resistant up to 180°C, preferably 190°C, more preferably 200°C and even more preferably 220°C.

[0035] Colorable adhesive layers allow for the suppression of potential yellowing and / or prevent the penetration of light. For example, in the case of adhesive layers colored with a black pigment, any yellowing effects are no longer visible. Furthermore, colorable adhesive layers offer additional design possibilities, as an adhesive layer always forms a linear element within the wood composite block.

[0036] The temperature resistance of the adhesive layers prevents yellowing effects, as – even with significant natural fluctuations in ambient temperature – no or only very small amounts of decomposition products are present in the adhesive layers. Temperature resistance here encompasses not only the decomposition of the adhesive layers but also their dimensional stability; that is, an adhesive layer resistant up to 180°C neither softens (melts) nor undergoes thermal decomposition. Adhesive layers resistant up to 180°C open up additional possibilities with regard to processing methods.

[0037] Preferably, the at least one adhesive layer is colorable and temperature-resistant up to 180°C, preferably 190°C, more preferably 200°C and even more preferably 220°C, so that a potential impairment of the optics due to yellowing is prevented.

[0038] According to a further preferred embodiment, the wood composite block comprises at least one intermediate layer, wherein the at least one intermediate layer is arranged between two wood layers.

[0039] The use of intermediate layers opens up additional design possibilities, as each intermediate layer also forms a linear element within the wood composite block. Furthermore, the intermediate layers can influence the processing properties of the wood composite block.

[0040] Preferably, the at least one intermediate layer consists of metal, textile, plastic, leather, non-woven fabric, stone, felt, pressed paper, mineral material, medium-density fiberboard (MDF), or combinations thereof.

[0041] Suitable pressed papers include, for example, the products of the company Richlite (USA).

[0042] Within the wood composite block according to the invention, the at least one intermediate layer can be arranged between two wood layers in such a way that the intermediate layer is connected to a first wood layer by a first adhesive layer and to a second wood layer by a second adhesive layer, i.e., the intermediate layer is embedded in an adhesive layer that connects two wood layers together.

[0043] According to a preferred embodiment, the wood composite block according to the invention contains a plurality of intermediate layers. If the wood composite block comprises a plurality of intermediate layers, these can be arranged in different ways. For example, several intermediate layers can be arranged between a first and a second wood layer. Possible arrangement variants of the individual layers contained in the wood composite block are shown in the attached figures.

[0044] The thickness of a layer can be the same across its entire area. However, the thickness of a layer can also vary; for example, a layer can have a rectangular, wedge-shaped, round, or curved cross-section. In principle, the shape and thickness of the individual layers are freely selectable, depending, for example, on the desired design.

[0045] This applies to both the wood layers contained in the wood veneer, as well as to the adhesive layers and the - optional - intermediate layers.

[0046] The wood composite block has a wood moisture content of ≤ 15%, preferably between 6 and 15%. The wood moisture content is measured using a commercially available measuring device (Gann Hydromette, H35-M20), which determines the wood moisture content based on electrical resistance (DIN EN 13183-2:2002-07 with DIN EN 13183-2 Amendment 1: 2003-12).

[0047] Alternatively, the wood moisture content can also be determined by means of an oven-drying test (DIN EN 13183-1:2002-07 with DIN EN 13183-1 Amendment 1: 2003-12).

[0048] Another aspect of the invention relates to a multi-layered wood veneer comprising: a plurality of superimposed wood layers, and at least one adhesive layer, wherein the at least one adhesive layer is arranged between successive wood layers, and wherein the at least one adhesive layer, in the cured state, has a hardness of at least 70 Shore A, determined according to DIN EN ISO 868, and / or a hardness of at least 20 Shore D, determined according to DIN EN ISO 868.

[0049] Preferably, the adhesive layers, in the cured state, have a hardness of at least 75 Shore A and / or at least 24 Shore D, more preferably at least 80 Shore A and / or at least 27 Shore D.

[0050] Preferably, the hardness of the adhesive layers, in the cured state, is less than or equal to 60 Shore D.

[0051] Preferably, the hardness of the adhesive layers, in the cured state, is less than or equal to 100 Shore A.

[0052] The measurement of hardness, Shore A and / or Shore D, is carried out according to DIN EN ISO 868.

[0053] The technical effects correlating with the hardness of the adhesive layers - as described for the wood composite block according to the invention - are also valid with regard to the multilayer wood veneer.

[0054] According to a preferred embodiment, the multi-layered wood veneer according to the invention has a thickness between 0.2 and 4.0 mm, preferably between 0.3 and 1.5 mm, more preferably between 0.5 and 1.0 mm and even more preferably between 0.6 and 0.9 mm.

[0055] With veneer thicknesses of 1.5 mm or less, multi-layered wood veneers are still sufficiently flexible to be bent into shape, for example, for applications as decorative and / or cladding elements, especially for vehicle interiors. At the same time, material consumption is relatively low for veneers with a thickness of 1.5 mm or less.

[0056] The wood veneer according to the invention is preferably manufactured with high precision, i.e. it has a thickness tolerance of less than or equal to 0.25 mm, preferably less than or equal to 0.20 mm and more preferably less than or equal to 0.15 mm.

[0057] According to a preferred embodiment, the wood veneer comprises a plurality of adhesive layers.

[0058] According to another preferred embodiment, the wood veneer has a) a total carbon emission (TVOC - Total Volatile Organic Compounds) of less than or equal to 50 µg carbon / g determined according to VDA 277, and / or b) a content of volatile organic compounds (VOC - Volatile Organic Compounds) of less than or equal to 100 mg / kg and semi-volatile organic compounds (FOG - Fogging or also SVOC - Semi-Volatile Organic Compounds) of less than or equal to 250 mg / kg determined according to VDA 278, and / or c) a formaldehyde emission value of less than or equal to 3 mg / kg determined according to VDA 275, on.

[0059] The aforementioned emission values, TVOC, VOC, FOG and the formaldehyde emission value of the wood veneer according to the invention, can also be zero, independently of each other.

[0060] Preferably, the wood veneer exhibits a) a total carbon emission (TVOC) of less than or equal to 50 µg carbon / g determined according to VDA 277, and b) a volatile organic compound (VOC) content of less than or equal to 100 mg / kg and semi-volatile organic compounds (FOG) content of less than or equal to 250 mg / kg determined according to VDA 278; or a) a total carbon emission (TVOC) of less than or equal to 50 µg carbon / g determined according to VDA 277, and c) a formaldehyde emission value of less than or equal to 3 mg / kg determined according to VDA 275; or b) a volatile organic compound (VOC) content of less than or equal to 100 mg / kg and semi-volatile organic compounds (FOG) content of less than or equal to 250 mg / kg determined according to VDA 278, and c) a formaldehyde emission value of less than or equal to 3 mg / kg determined according to VDA 275; on.

[0061] Preferably, the wood veneer according to the invention has a) a total carbon emission (TVOC) of less than or equal to 50 µg carbon / g determined in accordance with VDA 277, and b) a content of volatile organic compounds (VOCs) of less than or equal to 100 mg / kg and semi-volatile organic compounds (FOCs) of less than or equal to 250 mg / kg determined in accordance with VDA 278, and c) a formaldehyde emission value of less than or equal to 3 mg / kg determined in accordance with VDA 275, on.

[0062] According to a further preferred embodiment, the at least one adhesive layer can be colored and / or is temperature-resistant up to 180°C, preferably 190°C, more preferably 200°C and even more preferably 220°C, so that a potential impairment of the optics due to yellowing is prevented.

[0063] According to a further preferred embodiment, the wood veneer comprises at least one intermediate layer, wherein the at least one intermediate layer is arranged between two wood layers.

[0064] Preferably, the at least one intermediate layer consists of metal, textile, plastic, leather, non-woven fabric, stone, felt, pressed paper, mineral material, medium-density fiberboard (MDF), or combinations thereof.

[0065] Suitable pressed papers include, for example, the products of the company Richlite (USA).

[0066] According to another preferred embodiment, the wood veneer according to the invention contains a plurality of intermediate layers.

[0067] Within the wood veneer according to the invention, the at least one intermediate layer can be arranged between two wood layers in such a way that the intermediate layer is connected to a first wood layer by a first adhesive layer and to a second wood layer by a second adhesive layer, i.e., the intermediate layer is embedded in an adhesive layer that connects two wood layers together.

[0068] If the wood veneer comprises multiple layers, these can be arranged in various ways. For example, several layers can be placed between a first and a second layer of wood. Possible arrangements of the individual layers contained in the wood veneer are shown in the attached figures.

[0069] The thickness of a layer can be the same across its entire area. However, the thickness of a layer can also vary; for example, a layer can have a rectangular, wedge-shaped, round, or curved cross-section. In principle, the shape and thickness of the individual layers are freely selectable, depending, for example, on the desired design.

[0070] This applies to both the wood layers contained in the wood veneer, as well as to the adhesive layers and the - optional - intermediate layers.

[0071] Preferably, the multi-layered wood veneer according to the invention is a sawn veneer.

[0072] The wood veneer has a wood moisture content of less than or equal to 15%, preferably between 6 and 15%.

[0073] The wood moisture content is measured using a commercially available measuring device (Gann Hydromette, H35-M20), which determines the wood moisture content based on electrical resistance (DIN EN 13183-2:2002-07 with DIN EN 13183-2 Amendment 1: 2003-12). Alternatively, the wood moisture content can also be determined by oven drying (DIN EN 13183-1:2002-07 with DIN EN 13183-1 Amendment 1: 2003-12).

[0074] The technical effects corresponding to the above-mentioned preferred embodiments - as described for the wood composite block according to the invention - are also valid with regard to the multilayer wood veneer.

[0075] Another aspect of the invention relates to a method for producing a multilayer wood composite block according to the invention as defined in claims 1 to 5, comprising the steps of: a) Providing a plurality of dry wood layers; b) Dry gluing the dry wood layers together.

[0076] Because the wood layers are dry and dry-glued during the inventive process for producing the multi-layered wood composite block, deformation and / or discoloration of the wood layers caused by moisture can be avoided.

[0077] Preferably, the cut, dry wood layers and / or cut intermediate layers are calibrated before dry gluing and / or the hardened wood composite block is calibrated after dry gluing.

[0078] Even more preferably, both the cut, dry wood layers and / or cut intermediate layers are calibrated before dry gluing, as well as the hardened wood composite block after dry gluing.

[0079] The above information regarding the wood composite block according to the invention also applies accordingly to the method for producing the multi-layered wood composite block.

[0080] According to a preferred embodiment, the individual layers of wood are stacked on top of or next to each other with the aid of a matrix, the matrix being designed in such a way as to prevent the layers of wood from slipping.

[0081] Using a matrix prevents the wood layers from slipping during gluing, thus ensuring the desired precision.

[0082] Another aspect of the invention relates to a method for producing a multi-layered wood veneer according to the invention, comprising separating a multi-layered wood composite block according to one of claims 1 to 6 to produce multi-layered wood veneers.

[0083] Preferably, the wood composite block is sawn into multi-layered wood veneer.

[0084] Sawing veneers, unlike slicing, does not require pretreatment such as soaking and / or steaming of the wood composite block. Consequently, the wood composite block is not exposed to temperature and / or humidity fluctuations that could lead to deformation and / or discoloration of the composite block or the individual veneer sheets. Because thermal pretreatment of the multilayered wood composite block is not necessary, the selection of suitable adhesives is less limited than with the conventional slicing process. This expanded selection also allows the use of adhesives that exhibit particularly advantageous bonding properties with respect to different materials, i.e., not only wood but also the materials used as intermediate layers. Thus, the inventive method offers greater design flexibility with regard to possible material combinations and correspondingly accessible designs.

[0085] Furthermore, sawing offers the advantage of avoiding cracking and allowing a wider range of materials to be used in the production of multi-layered veneers; very hard materials such as ironwood, i.e. various tropical woods, metals and hard plastics, can be sawn, but not sliced.

[0086] The wood composite block is sawn to create multi-layered wood veneers, preferably using a band saw, for example a horizontal band saw.

[0087] According to a further development of the invention, the wood composite block is separated at an angle of 0° to 180° to the cutting surfaces of the wood layers, in particular at an angle between 45° and 135° to the cutting surfaces of the wood layers. Particularly preferably, the wood composite block is separated perpendicular to the cutting surface of the wood layers.

[0088] The wood composite block according to the invention remains dry throughout the entire processing process; that is, neither a water- or solvent-based adhesive is used, nor is the wood composite block moistened or steamed.

[0089] To ensure the precision of the finished multi-layered wood veneers, it is essential to always pay attention to the moisture content of the wood composite block or the individual components.

[0090] The wood composite block has a wood moisture content of less than or equal to 20%, preferably less than or equal to 18%, more preferably less than or equal to 15%, and even more preferably between 6 and 15%.

[0091] The wood moisture content is measured using a commercially available measuring device (Gann Hydromette, H35-M20), which determines the wood moisture content based on electrical resistance (DIN EN 13183-2:2002-07 with DIN EN 13183-2 Amendment 1: 2003-12).

[0092] Alternatively, the wood moisture content can also be determined by means of an oven-drying test (DIN EN 13183-1:2002-07 with DIN EN 13183-1 Amendment 1: 2003-12).

[0093] The multi-layered wood composite block is separated into multi-layered wood veneers with a thickness in the range of 0.2 and 4.0 mm, preferably between 0.3 and 1.5 mm, more preferably between 0.5 and 1.0 mm and more preferably between 0.6 and 0.9 mm by sawing or slicing, preferably by sawing or slicing in the dry state, and even more preferably by sawing in the dry state, wherein the thickness of the multi-layered wood veneer has a tolerance of less than or equal to 0.25 mm, more preferably less than or equal to 0.20 mm and more preferably less than or equal to 0.15 mm.

[0094] The above information on the wood veneer according to the invention also applies accordingly to the process for producing the multi-layered wood veneer.

[0095] Another aspect of the invention relates to a multi-layered wood veneer obtainable by the method according to claims 10 to 12.

[0096] The technical effects or advantages of such a wood veneer according to the invention are analogous to those described for the process and the preceding wood veneer.

[0097] Another aspect of the invention relates to the use of a multi-layered wood veneer according to one of claims 6 to 9 or 15 as a decorative and / or cladding element.

[0098] The wood veneer according to the invention can also be used as a decorative and / or cladding element in furniture construction, interior design, in everyday objects such as mobile phones and corresponding protective cases, but also in the field of textile and leather goods.

[0099] The multi-layered wood veneer according to the invention is preferably used as a decorative and / or cladding element in a vehicle interior.

[0100] Compared to the prior art, the use of a multi-layered wood veneer according to the invention, as described above, opens up new possibilities. This is due, on the one hand, to the fact that the veneers are significantly more flexible than conventional sawn veneers due to their thinness, and on the other hand, to the fact that the accessible designs can be reproduced with exceptional precision. In addition, the type of wood composite structure and the inventive method for producing the veneers, in particular the method for dry sawing, allow the use of materials in versions and thicknesses that are not suitable for veneer production using knives. Consequently, the present invention expands the design possibilities in veneer production and makes new designs accessible that cannot be produced with existing technical means.

[0101] Another aspect of the invention relates to an article comprising a multilayered

[0102] Wood veneer according to one of claims 6 to 9 or 15.

[0103] The advantages over the state of the art correspond to those described in connection with the use of wood veneer.

[0104] The invention is explained in more detail below with reference to exemplary embodiments and the accompanying schematic drawings. Further advantages of the invention will become apparent from the following description of preferred embodiments, which, however, are in no way to be understood as limiting. All embodiments of the invention can be combined with one another within the scope of the invention. Fig. 1 schematic representation of a multi-layered wood composite block according to the invention; Fig. 2 schematic representation of a multi-layered wood veneer according to the invention; Fig. 3a - 3d Schematic representation of various layer arrangements in wood composite blocks or veneers according to the invention.

[0105] Figur 1 Figure 1 shows a wood composite block according to the invention. The illustrated wood composite block comprises a plurality of wood layers (1), a plurality of adhesive layers (2), and an (optional) intermediate layer (3). Each of the layers (1), (2), and (3) has a thickness (d), wherein (d) can be selected independently of the thickness (d) of the other layers, both for each layer type (1), (2), and (3) and for each individual layer (1a), (1b), (1c).

[0106] Between two layers of wood (1), only an adhesive layer (2) can be provided, through which the layers of wood (1) are bonded together. This adhesive layer (2) then forms a visible line element in the finished multi-layered wood veneer. Optionally, the adhesive layer (2) can be colored to allow for further design alternatives.

[0107] Fig. 2 Figure 1 schematically shows a wood veneer according to the invention. The wood veneer shown comprises a plurality of wood layers (1) with a thickness (d), a plurality of adhesive layers (2) with a thickness (d), and an (optional) intermediate layer (3) with a thickness (d), wherein the thickness (d) for each of the individual wood layers (1), adhesive layers (2) and intermediate layer(s) (3) can be selected independently from the plurality of layers.

[0108] The wood veneer has a thickness (s) in the range of 0.2 to 4.0 mm, preferably between 0.3 and 1.5 mm, more preferably between 0.5 and 1.0 mm and even more preferably between 0.6 and 0.9 mm; wherein the thickness of the multilayer wood veneer has a tolerance of less than or equal to 0.25 mm, more preferably less than or equal to 0.20 mm and more preferably less than or equal to 0.15 mm.

[0109] Fig. 3a - 3d The figures schematically show various possible arrangements of the wood layers (1), adhesive layers (2) and intermediate layers (3) in wood composite blocks or veneers according to the invention.

[0110] Fig. 3a The simplest variant according to the invention is shown, comprising a plurality, here two, of superimposed wood layers (1) and at least one adhesive layer (2), wherein the at least one adhesive layer (2) is arranged between successive wood layers (1).

[0111] Fig. 3b Figure 1 shows a variant according to the invention, comprising a plurality of superimposed wood layers (1) and a plurality of adhesive layers (2), wherein each of the adhesive layers (2) is arranged between two successive wood layers (1).

[0112] Fig. 3c Figure 1 shows a variant of the invention comprising a plurality of superimposed wood layers (1), a plurality of adhesive layers (2), and an intermediate layer (3) which is inserted between two wood layers (1) such that it is connected to the wood layers (1) via two adhesive layers (2). In other words, the intermediate layer (3) is embedded in an adhesive layer (2) that connects two wood layers (1) to each other. The intermediate layer (3) forms a linear element in the multilayered wood veneer.

[0113] Fig. 3d Figure 1 shows a variant of the invention comprising a plurality of superimposed wood layers (1), a plurality of adhesive layers (2), and a plurality of intermediate layers (3). As shown in the figure, an intermediate layer (3) can be embedded in an adhesive layer (2) that bonds two wood layers (1) together. Alternatively, several intermediate layers (3) can be embedded in an adhesive layer (2) that bonds two wood layers (1) together. The number and thickness (d) of the layers (1), (2), and (3) in a wood composite block or veneer according to the invention are freely selectable. Bezugszeichenliste

[0114] (1) : Wood layer (2) : Adhesive layer (3) : Intermediate layer (d) : Layer thickness (s) : Thickness (x) : Width (y) : Height (z) : Depth

Claims

1. A multi-layer wood composite block comprising - a plurality of superimposed wood layers; and - at least one adhesive layer, wherein the at least one adhesive layer is arranged between successive wood layers, and wherein the at least one adhesive layer, in the cured state, has a hardness of at least 70 Shore A, determined in accordance with DIN EN ISO 868, and / or a hardness of at least 20 Shore D, determined in accordance with DIN EN ISO 868; wherein the wood composite block has a wood moisture of less than or equal to 15%.

2. The multi-layer wood composite block according to claim 1, wherein the wood composite block comprises a plurality of adhesive layers.

3. The multi-layer wood composite block according to claim 1 or 2, wherein the wood composite block a) has a total carbon emission (TVOC) of less than or equal to 50 µg carbon / g determined in accordance with VDA 277; and / or (b) has a volatile hydrocarbon (VOC) content of less than or equal to 100 mg / kg and less volatile hydrocarbons (FOG) of less than or equal to 250 mg / kg determined in accordance with VDA 278; and / or c) a formaldehyde emission value of less than or equal to 3 mg / kg determined in accordance with VDA 275.

4. The multi-layer wood composite block according to any preceding claim, wherein the at least one adhesive layer can be colored; and / or wherein the at least one adhesive layer is temperature-resistant up to 180°C; and / or wherein the adhesive layer is produced with water-free and solvent-free adhesives; and / or wherein the wood composite block comprises at least one intermediate layer, and wherein the at least one intermediate layer is arranged between two wood layers.

5. The multi-layer wood composite block according to any preceding claim, wherein the wood composite block can be processed in the dry state by means of sawing or cutting, preferably can be processed in the dry state by means of sawing; and / or wherein the wood layers are dry wood layers; and / or wherein the wood composite block has a wood moisture between 6 and 15%.

6. A multi-layer wood veneer, comprising - a plurality of superimposed wood layers; and - at least one adhesive layer, wherein the at least one adhesive layer is arranged between successive wood layers, and wherein the at least one adhesive layer, in the cured state, has a hardness of at least 70 Shore A, determined in accordance with DIN EN ISO 868, and / or a hardness of at least 20 Shore D, determined in accordance with DIN EN ISO 868; wherein the wood veneer has a wood moisture of less than or equal to 15%.

7. The multi-layer wood veneer according to claim 6, wherein the multi-layer wood veneer has a thickness between 0.2 and 4.0 mm, preferably between 0.3 and 1.5 mm, more preferably between 0.5 and 1.0 mm and even more preferably between 0.6 and 0.9 mm; and / or wherein the wood veneer has a thickness tolerance of less than or equal to 0.25 mm, preferably less than or equal to 0.20 mm and more preferably less than or equal to 0.15 mm; and / or wherein the wood veneer comprises a plurality of adhesive layers; and / or wherein the wood veneer is a sawn veneer; and / or wherein the wood veneer has a wood moisture between 6 and 15%.

8. The multi-layer wood veneer according to any one of claims 6 or 7, wherein the wood veneer a) has a total carbon emission (TVOC) of less than or equal to 50 µg carbon / g determined in accordance with VDA 277; and / or (b) has a volatile hydrocarbon (VOC) content of less than or equal to 100 mg / kg and of less volatile hydrocarbons (FOG) of less than or equal to 250 mg / kg determined in accordance with VDA 278; and / or c) has a formaldehyde emission value of less than or equal to 3 mg / kg determined in accordance with VDA 275.

9. The multi-layer wood veneer according to any one of claims 6 to 8, wherein the at least one adhesive layer can be colored; and / or wherein the at least one adhesive layer is temperature-resistant up to 180°C; and / or wherein the wood veneer comprises at least one intermediate layer, and wherein the at least one intermediate layer is arranged between two wood layers.

10. A method for producing a multi-layer wood composite block according to any one of claims 1 to 5, comprising the steps of: a) providing a plurality of dry wood layers; b) dry gluing of the dry wood layers to each other.

11. A method for producing a multi-layer wood veneer comprising separating a multi-layer wood composite block according to any one of claims 1 to 5 into multi-layer wood veneers.

12. The method for producing a multi-layer wood veneer according to claim 11, wherein the wood composite block is sawn or sliced, preferably sawn, into multi-layer wood veneer; and / or wherein the processing, in particular the separation of the multi-layer wood composite block, takes place in the dry state.

13. A multi-layer wood veneer obtainable by the method for producing a multi-layer wood veneer according to any one of claims 11 or 12.

14. Use of a multi-layer wood veneer according to any one of claims 6 to 9 or 13 as a decorative and / or paneling element, preferably as a decorative and / or paneling element in a vehicle interior.

15. An article comprising a multi-layer wood veneer according to any one of claims 6 to 9 or 13.