Decorative panel and method for manufacturing decorative panel

Abstract

The present invention relates to a decorative panel, in particular a floor, ceiling, or wall panel, and a method for manufacturing such a decorative panel. The panel according to the present invention comprises at least one foam layer having an upper side and a lower side, and at least one decorative solid layer attached directly or indirectly to the upper side of the foam layer, wherein both the foam layer and the decorative solid layer are wood-based materials. The present invention also relates to a floor covering made up of a plurality of such panels.

Description

[Technical Field]

[0001] The present invention relates to a decorative panel, in particular a floor panel, ceiling panel, or wall panel. The present invention also relates to a decorative covering, in particular a decorative floor covering, decorative ceiling covering, or decorative wall covering, comprising a plurality of such decorative panels. Furthermore, the present invention also relates to a method for manufacturing a decorative panel, in particular a floor panel, ceiling panel, or wall panel. [Background technology]

[0002] Decorative floor panels typically consist of multi-layered decorative panels, which can be bonded to a subfloor or interconnected by incorporating interlocking features such as tongue and grooves into the panels. The layers used in the panels are typically synthetic polymers, such as polyvinyl chloride (PVC) and polyurethane (PU)-based layers. Each layer typically has its own function and purpose, such as providing panel strength, desired resilience and / or stiffness, improved sound damping properties, thermal stability, desired indentation properties, an attractive aesthetic appearance, and improved recyclability. Traditional flooring materials, such as MDF / HDF, which have been used for decorative panels for decades, are increasingly being replaced with synthetic polymers to further improve the overall panel properties. However, a topic of growing concern with synthetic polymer materials is the migration of harmful volatile and semi-volatile substances, such as plasticizers, added to these synthetic polymer materials. Polyurethane-based materials also present recyclability challenges. Polyurethane generates toxic fumes when incinerated, and physical and chemical recycling presents technical and economic challenges. Therefore, there is a need to replace the synthetic polymers currently used in decorative panels with more natural materials, especially wood, without compromising the panel properties that can be achieved with synthetic polymers such as PVC and PU. Summary of the Invention [Problem to be solved by the invention]

[0003] A primary goal of the present invention is to provide a wood-based decorative panel that can replace synthetic polymer-based decorative panels without compromising panel properties.

[0004] It is a second object of the present invention to provide an improved wood-based decorative panel.

[0005] It is a third object of the present invention to provide an improved wood-based decorative panel having improved properties over conventional MDF / HDF-based decorative panels. [Means for solving the problem]

[0006] At least one of these goals can be achieved by providing a decorative panel, in particular a floor panel, ceiling panel, wall panel or furniture panel, comprising at least one solid layer having an upper part and a lower part, the solid layer being at least partially made from densified wood, and at least one foam layer attached directly or indirectly to the solid layer, the foam layer being at least partially made from wood foam, the decorative panel having a decorative top surface.

[0007] The use of a combination of a foam layer, including wood foam, and a solid layer, including compressed wood, has several advantages: both wood-based layers have unique properties that are superior to comparable synthetic polymer layers, and the combination of both layers offers additional properties not found in traditional MDF / HDF or synthetic polymer-based floor panels.

[0008] First, the advantages of wood foam include its high fire resistance, excellent sound-damping or sound-insulating properties, and good thermal insulation, while remaining entirely wood-based. Furthermore, wood foam's low density makes it a very lightweight material. Experiments have also confirmed that it has excellent moisture resistance and little bending or warping when immersed in water. These properties of wood foam make it particularly suitable as an insulating and / or sound-insulating layer for floor and wall coverings. Because wood foam is based solely on wood without mixing wood fibers with synthetic polymers such as PVC, PU, ​​synthetic resins, or synthetic adhesives, it does not qualify as a composite material and differs from wood polymer composites (WPCs). The structure of wood foam can be partially attributed to the natural chemical bonding between wood fibers, which can be initiated by hydrogen peroxide added during the manufacturing process. However, these chemical forces alone are insufficient to achieve sufficient mechanical strength. Therefore, the wood foam in the foam layer is preferably composed of (naturally) chemically bonded wood fibers. The second factor underlying the structure of wood foam is the physical anchoring and intertwining between the wood fibers (strands). For example, untreated wood fibers have a very smooth surface, but the fibers need to be roughened to allow anchoring. This can be achieved, for example, by grinding the substrate with a wood fiber-roughening scouring machine, roughening the surfaces of the wood fibers until they no longer slide against each other. The natural chemical interlocking of the roughened wood fibers allows for wood foams with relatively high mechanical strength that can be produced without the use of adhesives. Wood foams usually have a substantially open-pore structure. Due to the rigid structure of the wood foam, such a foam layer can be a (substantially) rigid layer. The foam layer is preferably a waterproof layer. Both hardwoods and softwoods, as well as other lignocelluloses, are suitable raw materials for producing wood foams.

[0009] With respect to solid layers containing densified wood, the use of such material layers has several (other) advantages. Densified wood significantly improves the mechanical properties of wood. Densified wood can be obtained by engineering processes, one example of which is shown below. Technically, it is possible to compress wood to 20% of its original thickness, thereby achieving so-called complete densification. Densification within the meaning of the present invention usually means compression to at least 50%, preferably at least 40%, and more preferably at least 30% of its original thickness. To obtain such densified wood, natural wood is first boiled in a solution of NaOH / Na2SO3 to obtain more porous and flexible wood. The wood is then compressed perpendicular to the direction of growth at a temperature of at least 100°C. This process usually partially removes hemicellulose and lignin (the harder component of wood), which are the glue that connects wood cells. Complete removal of these may result in a poor-quality material, suggesting that lignin is still necessary to bind the wood. However, the cellulose in the wood remains intact, and hydrogen bonds between closely spaced cellulose nanofibers enhance the strength of the densified wood. Therefore, the densified wood of the solid layer is preferably composed of chemically treated and compressed wood. Preferably, the densified wood of the solid layer contains less than 20% by weight, more preferably less than 10% by weight, of hemicellulose and / or less than 30% by weight, more preferably less than 15% by weight, of lignin. The densified wood obtained by this process is a fairly stable type that is not affected by humidity conditions and is therefore suitable for use in floor and wall or ceiling construction. It is also useful for construction purposes due to its excellent mechanical properties and relatively light weight. Densified wood is also suitable as a solid layer due to its relatively high scratch resistance. Instead of the term "densified wood," the term "compressed wood" can also be used. Densified wood can be radially and / or tangentially compressed wood. Preferably, the consolidated wood of the solid layer is at least partially composed of hardwood such as alder, balsa, beech, hickory, mahogany, maple, oak, teak, walnut, oak, and / or poplar.The hardwood used to make the solid layer is preferably obtained from angiosperms (or flowering plants) that are not monocotyledonous. Typically, the densified wood has waterproof properties. Therefore, the solid layer is preferably a waterproof layer.

[0010] In addition to the advantages of the foam layer according to the present invention and the solid layer according to the present invention, the use of both layers in a panel according to the present invention has several technical advantages. Because both the foam layer and the solid layer are relatively light, this combination results in a relatively lightweight panel suitable for application in several construction fields. Due to the relatively high flexibility of the material, it can be used as a curved or shaped wall panel or, for example, a ceiling panel. Furthermore, the panel can also be used as an exterior wall cladding material, since its light weight and high density reduce the load on the wall. This simplifies installation, potentially eliminating the need for traditional screw and / or nail connections, allowing alternative connection systems to be used. However, nailing and / or screwing of the panels according to the present invention is possible. Furthermore, the material combination used is also suitable for sawing and gluing, for example.

[0011] Furthermore, this panel contains natural materials in both the foam and solid layers, making it environmentally friendly. The materials used offer several advantages over conventional natural materials. Wood foam has a relatively high breathability, allowing trapped moisture to escape in a controlled manner. Poor breathability is a common problem with conventional woods, such as cedar or other softwoods, which can lead to wood rot. The solid layer containing compacted wood can provide protection for the wood foam layer. The panels of the present invention are contemplated for both indoor and outdoor use, and for use in both dry and damp areas of the home (e.g., bathrooms). The foam layer containing wood foam allows for a uniform surface level. This is particularly beneficial when used for flooring, as it can eliminate the need for an additional subfloor layer. The wood foam in the foam layer can also be configured to provide the necessary sound and / or thermal insulation, making the latter a viable option. Therefore, the panels of the present invention are considered to replace conventional floor, wall, or ceiling panels with separate insulating (polyurethane) layers. The panels of the present invention have a long expected lifespan, but if they need to be removed, they are rather easy to recycle because they are entirely wood-based. Furthermore, they offer a competitively priced alternative to polyurethane-based products, especially for environmentally and health-conscious consumers.

[0012] In further possible embodiments, it is envisaged that at least one foam layer is made substantially entirely of wood foam, and at least one solid layer is made substantially entirely of densified wood.

[0013] In a preferred embodiment of the panel, the solid layer comprises a first panel edge including a first interlocking profile, a second panel edge including a second interlocking profile designed for interlocking engagement with the first interlocking profile of an adjacent panel, preferably in both the horizontal and vertical directions, a third panel edge including a third interlocking profile, and a fourth panel edge including a fourth interlocking profile designed for interlocking engagement with the third interlocking profile of an adjacent panel, preferably in both the horizontal and vertical directions. In another possible embodiment, the foam layer could comprise a first panel edge including a first interlocking profile, a second panel edge including a second interlocking profile designed for interlocking engagement with the first interlocking profile of an adjacent panel, preferably in both the horizontal and vertical directions, a third panel edge including a third interlocking profile, and a fourth panel edge including a fourth interlocking profile designed for interlocking engagement with the third interlocking profile of an adjacent panel, preferably in both the horizontal and vertical directions. The panels, and in particular the solid layer, including the connecting profiles make it easier to build floor, wall or ceiling coverings of multiple panels according to the invention. Due to the relatively high density of the solid layer, it is possible to provide the interconnecting profiles on the side edges of the solid layer. It is further conceivable that the interconnecting profiles are provided on the foam layer or on an assembly (laminate) of at least one solid layer with at least one foam layer. Non-limiting examples of possible interconnecting profiles are described below. For example, it is conceivable that the solid layer is provided with complementary connecting means, such as a tongue and groove joint. However, it is also possible that the interconnecting means are embodied as described below.

[0014] In a panel according to the present invention, the interconnecting interlocking contours may include first and second interlocking contours at respective first and second side edges of the pair of side edges, respectively. Here, the first connecting contour comprises: ·Upturned tongue; at least one upward flank spaced apart from the upward tongue; an upward groove formed between the upward tongue and the upward flank, the upward groove adapted to receive at least a portion of a downward tongue of a second connecting profile of another identical panel; and at least one first locking element, preferably provided on the far side of the upward tongue facing away from the upward flank; wherein the second coupling configuration is First downward tongue; at least one first downward flank spaced apart from the downward tongue; a first downward groove formed between the downward tongue and the downward flank, the downward groove adapted to receive at least a portion of an upward tongue of a first connecting profile of another identical panel; and at least one second locking element adapted to cooperate with a first locking element of another identical panel, said second locking element preferably being provided on said downward flank; Equipped with.

[0015] Furthermore, in the panel according to the present invention, the panel may comprise at least one third connecting contour and at least one fourth connecting contour disposed at the third panel edge and the fourth panel edge, respectively, and the third connecting contour may comprise: a lateral tongue extending in a direction substantially parallel to the upper side of the panel; at least one second downward flank spaced apart from the lateral tongue; and a second downward groove formed between the lateral tongue and the second downward flank; wherein the fourth connecting configuration is a third groove configured to receive at least a portion of a lateral tongue of a third connecting profile of the second identical panel, the third groove being defined by an upper lip and a lower lip, the lower lip comprising an upwardly directed locking element; Equipped with wherein the third connecting contour and the fourth connecting contour are configured such that the third connecting contour and the fourth connecting contour of two identical panels can be connected to each other by a pivoting movement, whereby at least a portion of the lateral tongue of the first panel is inserted into the third groove of the other identical panel, and wherein at least a portion of the upward locking element of the other panel is inserted into the second downward groove of the first panel.

[0016] Preferably, the solid layer has a top surface area that exceeds the top surface of the foam layer. Alternatively, the solid layer may be attached to the foam layer at an offset position. Both options typically make it easier to profile one or more edges of the solid layer and to interconnect panels during installation.

[0017] Typically, at least one foam layer has a density of 40 kg / m 3 ~300kg / m 3 The mechanical strength of the wood foam varies depending on the density of the wood foam. The higher the density, the closer the fibers are to each other, and the stronger the entanglement anchorages of the wood itself. Therefore, the higher the density, the higher the mechanical strength. For example, at least one foam layer may have a density of 40 kg / m 3 ~100kg / m 3 , or 100 kg / m 3 ~200kg / m 3 , or 200 kg / m 3 ~300kg / m 3 It is thought to have a density of

[0018] As already indicated above, in a preferred embodiment of the panel according to the invention, at least one foam layer is (substantially) free of resins, adhesives, and / or binders, in particular added binders. Such an embodiment is advantageous, since health concerns due to emissions from any of such additives can be eliminated. The foam layer is preferably also (substantially) free of any other (chemical) synthetic additives, such as one or more synthetic polymers. It is also conceivable that the foam layer is composed only of wood foam, in particular wood fibers and / or wood strands. It is also advantageous that such a panel is (substantially) free of resins, binders, and / or adhesives.

[0019] An embodiment is conceivable in which at least one foam layer and at least one solid layer are fused together. In this way, the use of adhesives and / or binders and / or connecting materials can be omitted. Because the foam layer and the solid layer both comprise wood-based materials, the layers can be fused together. Fusing the core layer and the solid layer usually results in a strong and rigid connection between the layers. It can also significantly reduce delamination changes. However, it is still conceivable that the solid layer is glued to the foam layer.

[0020] The panel may include multiple foam layers, each comprising wood foam. In such an embodiment, each foam layer may have a different density. Providing a panel including multiple foam layers, each comprising wood foam, may be beneficial because material properties such as stiffness can be relatively easily tailored. The multiple foam layers may be bonded to one another, for example, via a fusion process. The advantage is that the use of adhesives can be avoided. In a further possible embodiment, the panel may include at least one intermediate layer encapsulated between at least two foam layers, preferably comprising densified wood. This configuration allows for the construction of a lightweight panel that has the aforementioned damping and isolation properties but also has a (substantially) rigid spine for added torsional stiffness and rigidity. It is particularly beneficial if the intermediate layer comprises densified wood, which allows for the provision of an interlocking profile. Thus, the panel may be considered a layered panel including at least two foam layers enclosing an intermediate layer, with the upper side of the top layer attached to the solid layer. Both the solid layer and the intermediate layer may comprise densified wood. For this embodiment, preferably, the intermediate layer comprises an interlocking profile, which may be any of the described examples of interlocking profiles according to the present invention, and may be substantially similar to a solid layer according to the present invention.

[0021] Preferably, at least one foam layer has a thickness of 2 to 30 mm, preferably 5 to 20 mm, more preferably 5 to 15 mm. It has been experimentally found that foam layers according to the present invention having such thicknesses can provide sufficient stability for such panels. The thickness of the foam layer can be selected depending on the desired application and desired material properties. A relatively thick foam layer can, for example, provide improved insulating properties.

[0022] Typically, the solid layer has a strength of at least 800 kg / m 3 , preferably at least 900 kg / m 3 , more preferably at least 1000 kg / m 3The density of the solid layer is typically substantially higher than the density of the at least one foam layer. Optionally, the solid layer has a thickness of 1 to 7 mm, preferably 2 to 5 mm.

[0023] It is contemplated that at least one foam layer may comprise a wood foam made from a single type of wood. The advantage of using a wood foam made from a single type of wood is that it may be less expensive to manufacture. It is also possible that multiple types of wood may be used to manufacture the wood foam. As already indicated above, the wood foam may be made from, for example, softwood or hardwood, or a combination of both. Non-limiting examples of types of wood that may be used to manufacture wood foam for use in the foam layer include beech and / or pine.

[0024] In a preferred embodiment, at least one solid layer is applied directly or indirectly onto at least one foam layer. Preferably, the decorative upper surface of the panel is at least partially formed by the solid layer. A protective coating, such as an oil-based coating, may be applied to protect the solid layer. It is also conceivable to apply an oil-based coating to the solid layer. Applying an oil-based coating to the solid layer can improve the dimensional stability of the solid layer. Densified wood can weaken or swell slightly under extremely high humidity conditions, such as about 95% humidity. An oil-based coating can prevent this swelling and provide a protective coating for the solid layer.

[0025] It is also envisioned that at least one foam layer is attached directly or indirectly onto at least one solid layer.

[0026] It may be preferable for the panel to comprise a decorative top substrate attached directly or indirectly to the solid layer and / or the foam layer, the decorative top substrate constituting the decorative upper surface of the panel. The top substrate may consist of a single layer or multiple layers. Preferably, the top substrate comprises at least one printed layer and / or at least one protective (top) layer covering the printed layer, if applied. The presence of the printed and / or protective layer can protect the panel, particularly the solid layer, from scratches and / or damage that may occur from environmental factors such as ultraviolet light, moisture, and / or abrasion. It is also conceivable that an oil-based coating is applied to the solid wood layer before applying the at least one printed and / or protective layer. The printed layer may be formed by a decoratively printed film, which is applied to the solid layer and / or the foam layer. The printed layer may also be formed by at least one ink layer applied directly onto the solid layer, the top surface of the foam layer, or onto a primer layer applied onto the solid layer and / or the foam layer.

[0027] In another possible embodiment, the panel may include at least one backing layer attached to the underside of the foam layer. The backing layer may provide stability and / or protection to the panel, for example. The backing layer may include, for example, a porous natural layer, particularly porous cellulose. The use of a porous cellulose backing layer allows moisture to evaporate from the wood-foam-containing foam layer during the manufacturing process, while allowing the (semi-)porous backing layer to come into contact with the subfloor, which is advantageous when combined with underfloor heating. The presence of such a porous backing layer may allow for greater absorption of convective heat radiation to the wood-foam-containing foam layer. Alternatively, other natural fiber materials may be applied as the backing layer, including, but not limited to, nonwoven structures based on PLA. However, the backing layer may also be a non-porous natural layer, preferably a non-porous water vapor barrier layer. A possible, non-limiting example of such a layer is non-porous cellulose. A non-porous backing layer can prevent moisture from entering the wood foam-containing foam layer for areas with relatively high levels of humidity (e.g., bathrooms). Both the porous and non-porous backing materials will need to be heat-resistant or crystalline, preferably made from bio-based materials, to withstand the dry conditions used in manufacturing wood foam-containing foam layers.

[0028] Furthermore, the at least one foam layer may contain at least one mineral material, particularly concrete. The use of at least one mineral material as a filler in the foam layer may reduce the water absorption of the foam layer. For example, 5 to 15 wt. % of the mineral material may be applied to the foam layer. Wood foam is susceptible to water absorption, which is undesirable because it may encourage fungal attack. The use of at least one mineral material, especially in the amounts described above, may significantly reduce the water absorption of the wood foam. The use of at least one mineral material in the foam layer may also result in a higher density of the foam layer. It is also conceivable that at least one hydrophobic additive, such as a silane and / or wax, may be applied instead of the mineral material. However, the hydrophobic additive may adversely affect the strength of the foam layer.

[0029] Preferably, each layer of the panel is a (substantially) waterproof layer. Preferably, the decorative panel is a waterproof panel. Preferably, the decorative panel is a thermally stable (heat resistant) panel.

[0030] In a preferred embodiment of the decorative panel according to the invention, said panel does not comprise a solid layer based on compacted wood. In another preferred embodiment of the decorative panel according to the invention, said panel does not comprise a foam layer based on wood foam.

[0031] Preferably, at least one panel layer, particularly at least one solid layer and / or at least one foam layer, contains and / or is coated with at least one antimicrobial agent. The incorporated antimicrobial agent(s) inhibit the growth of bacteria, fungi, microorganisms, and other pathogens or non-pathogens and typically migrate to the tile surface over time, thereby establishing a concentration gradient that inhibits microbial growth upon contact with the tile surface. Preferably, the antimicrobial agent is selected from (i) organic or organometallic antimicrobials, such as halogenated phenyl ethers, halogenated salicylanilides, sesquiterpene alcohols, halogenated carbanilides, bisphenol compounds, general phenols, formaldehyde, quaternary ammonium compounds, pyridine derivatives, and hexachlorophene, and / or (ii) inorganic antimicrobials, including silver, zinc, or copper, in a glass or ceramic matrix. The antimicrobial agent also preferably includes 2,4,4'-trichloro-2'-hydroxydiphenyl ether. The antimicrobial agent may also be a chemical selected from the group consisting of triclosan, orthophenylphenol, diiodomethyl p-tolylsulfone, zinc pyrithione, sodium pyrithione, azoles such as propiconazole, poly(hexamethylene biguanide) hydrochloride, 3,4,4' trichlorocarbanilide, barium monohydrate, and silver, copper, or zinc in zeolite or amorphous glass powder. It is conceivable, and even practical, to mix at least one antimicrobial agent with the wood foam (or precursor wood pulp suspension) during the production of the foam layer.

[0032] The present invention further relates to a decorative covering, in particular a decorative floor covering, a decorative ceiling covering or a decorative wall covering, comprising a plurality of decorative panels according to the invention, in particular a plurality of interconnected decorative panels according to the invention. As indicated above, due to the relatively high flexibility of the layer, the covering can be applied in a curved or shaped configuration.

[0033] The present invention further relates to a method for producing a decorative panel, in particular a floor, ceiling or wall panel, preferably a decorative panel according to the invention, said method comprising the following steps: providing at least one foam layer including an upper portion and a lower portion, the foam layer comprising wood foam; and providing at least one decorative solid layer comprising densified wood; attaching the solid layer to the upper side of the foam layer; Includes:

[0034] It is contemplated that the solid layer is attached to the upper side of the foam layer by welding, also known as heat sealing, typically by melting at least a portion of the boundary zone (interface) between the solid layer and the foam layer. The method may further include machining the panel edges of the solid layer so that a first panel edge includes a first interlocking contour, a second panel edge includes a second interlocking contour, preferably designed for interlocking engagement with the first interlocking contour of an adjacent panel in both horizontal and vertical directions, a third panel edge includes a third interlocking contour, and a fourth panel edge includes a fourth interlocking contour, preferably designed for interlocking engagement with the third interlocking contour of an adjacent panel in both horizontal and vertical directions. The method may also further include applying at least one printed layer and / or at least one protective layer to the upper side of the solid layer and / or applying at least one backing layer to the lower side of the foam layer. Non-limiting examples of such layers are described above.

[0035] Ordinal numbers used in this document, such as "first," "second," and "third," are used for identification purposes only. For example, the use of the expressions "third locking element" and "second locking element" does not necessarily require the coexistence of a "first locking element." The decorative panels according to the present invention may also be called decorative tiles. "Complementary" interlocking profiles mean that the interlocking profiles can cooperate with each other. However, for this purpose, it is not necessary that the complementary interlocking profiles have complementary shapes. "Vertical" locking refers to locking in a direction perpendicular to the plane of the panels. "Horizontal" locking refers to locking in a direction perpendicular to the respective interlocking edges of the two panels and parallel to or coincident with the plane defined by the panels.

[0036] The invention will now be explained on the basis of non-limiting exemplary embodiments shown in the following drawings. [Brief explanation of the drawings]

[0037] [Figure 1a] 1 is a cross-sectional view of a decorative panel 100 according to the present invention. [Figure 1b] 1 is a cross-sectional view of a decorative panel 100 according to the present invention. [Figure 2a] 1A to 1C are diagrams showing examples of possible embodiments of decorative panels 200a to 200c according to the present invention. [Figure 2b] 1A to 1C are diagrams showing examples of possible embodiments of decorative panels 200a to 200c according to the present invention. [Figure 2c] 1A to 1C are diagrams showing examples of possible embodiments of decorative panels 200a to 200c according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0038] 1a and 1b are cross-sectional views of a decorative panel 100 according to the present invention. The panel 100 comprises a foam layer 101, including an upper portion 101a and a lower portion 101b, and a decorative solid layer 102. The decorative solid layer 102 is attached to the upper portion 101a of the foam layer 101. The foam layer 101 comprises wood foam, which has a substantially open-pore structure. The decorative solid layer comprises compressed wood. Optionally, the panel 100 may comprise a printed layer 140 and / or at least one protective layer 140. It is also contemplated that the panel 100 may comprise a backing layer 150 attached to the lower portion of the foam layer 101. In the illustrated embodiment, the solid layer 102 optionally comprises interlocking interlocking profiles 103, 104, 105, and 106.

[0039] FIG. 1a shows possible shapes of complementary first and second edges 107, 108 of the solid layer 102. The first edge 107 includes a lateral tongue 109 that is integrally connected to the solid layer 102. The front region of the lateral tongue 109 includes a rounded bottom surface. The outer end of the rounded bottom surface is adjacent to a sloped locking surface. The opposite end of the rounded bottom surface is adjacent to a bearing surface 110 that forms part of the rear region of the lateral tongue 109. The second edge 108 of the solid layer 102 includes an upper lip 112 and a lower lip 113 that define a recess 114. Both lips are integrally connected to the solid layer 102. The recess 114 has a shape complementary to the shape of the lateral tongue 109. More specifically, the upper surface of the rear region of the lower lip 113 has a complimentary rounded shape configured to cooperate with the rounded front regions of the lateral tongues 109, and the front regions of the lower lip 113 include upwardly projecting shoulders configured to cooperate with the bearing surfaces of the lateral tongues 109. The lower surface of the upper lip 112 is sloped to correspond to the locking surfaces of the lateral tongues 109. Insertion of the lateral tongues 109 of a tile 100 into the recesses 114 locks them with the first edge 107 and the second edge 108 of the adjacent tile 100, where the tile 100 is initially held in a sloped position. After insertion of the lateral tongues 109 into the recesses 114, the tiles 100 to be joined are pivoted (angled) downward about an axis parallel to the first edge 107 until both tiles 100 are positioned in the same (generally horizontal) plane, the locking surfaces of the lateral tongues 109 engage the locking surfaces of the upper lip 112, and at least the bottom front is substantially form-fitted and received in the recess 114, with the bearing surfaces supported by the shoulder. By locking at the first edge 107 and the second edge 108, the connected tiles 100 are locked both horizontally and vertically. The angling-down locking principle of the first and second edges 107, 108 is a relatively easy locking principle that facilitates interconnection of tiles at these edges 107, 108.

[0040] 1b shows possible shapes of complementary third and fourth edges 117 and 118. The third edge 117 comprises an upward tongue 119, an upward flank 120, and an upward groove 121 formed between the upward tongue 119 and the upward flank 120. The upward tongue 119 is connected to the solid layer 102 by a bridge 123, preferably with some elasticity. The side of the upward tongue 119 facing the upward flank 120 extends in the direction of a normal N1 to the upper side of the solid layer 102. Thus, the tangent R1 and the normal N1 to the upper side of the solid layer 102 are directed toward each other (convergent orientation), and the angle enclosed by R1 and N1 is preferably between 0 and 10 degrees in this exemplary embodiment. Due to the convergent orientation of the upward flank 120 and the side of the upward tongue 119 facing toward the upward flank 120, the upward groove becomes a closed groove that is accessible to a complementary counterpart only by deformation of the upward tongue 119 and / or the bridge 123. Another side of the upward tongue 119 facing toward the upward flank 120 forms an alignment edge that allows for easy connection to an adjacent tile 100. The lower portion of the upward flank 120 is oriented obliquely, while the upper portion of the upward flank 120 is shown as being substantially vertical and forms a stop surface for the fourth edge 118. An additional connection element, in particular an additional bulge 123, is provided between the inclined portion 120 and the substantially vertical portion of the upward flank. The lower wall portion of the upward groove 121 is oriented substantially horizontally in this exemplary embodiment. The fourth edge 118 is substantially complementary to the third edge 117. The fourth edge 118 comprises a downward tongue 125, a downward flank 126, and a downward groove 127 formed between the downward tongue 125 and the downward flank 126. The side of the downward tongue 125 facing the downward flank 126 is in the direction of a normal N2 to the underside of the solid layer 102. This means that a tangent R2 to the side of the downward tongue 125 and a normal to the underside of the solid layer 102 converge to each other, where the angle enclosed by R2 and N2 is preferably between 0 and 10 degrees in this exemplary embodiment. More preferably, the slope of R1 is the same as the slope of R2, and therefore R1 and R2 are preferably parallel.Due to the convergent orientation of the downward flank 126 and the side of the downward tongue 125 facing towards it, the downward groove 127 becomes a closed groove that is accessible to the upward tongue 119 of an adjacent tile 100 only by deformation of the downward tongue 125 and / or bridge, so that the entrance of the downward groove can be (temporarily) widened. The inclined surface of the downward tongue 125 also functions as an alignment edge to further facilitate the connection between two tiles 100. Another side facing away from the downward flank 126 is substantially vertical in shape and comprises a small cavity 128 configured to cooperate with the additional bulge 124 of another tile 100. The downward flank 126 is oriented substantially vertically and comprises a recess 129 adapted to receive the outward bulge 130 of the upward tongue 119 (of the adjacent tile).

[0041] 2a-2c show examples of possible embodiments of decorative panels 200a-200c according to the present invention. Each figure shows a cross section of a panel 200a-200b. FIG. 2a shows a decorative panel 200a according to the present invention, which comprises a foam layer containing wood foam and a solid decorative layer 202 attached to the upper side of the foam layer. The solid decorative layer 202 comprises compressed wood. The layers 201, 202 can be connected to each other by fusion bonding. In a preferred embodiment, the solid layer 202 comprises interlocking profiles. However, it is also conceivable that the foam layer 201 comprises interlocking profiles (not shown) that connect the layers to each other. FIG. 2b shows a decorative panel 200b according to the present invention, which comprises multiple foam layers 201a, 201b. Each foam layer 201a, 201b comprises wood foam. In the illustrated embodiment, the upper foam layer 201a has a higher density than the lower foam layer 201b. Figure 2c shows a decorative panel 200c comprising a solid layer 202 and an intermediate layer 260 sandwiched between two foam layers 201c, 201d. The intermediate layer 260 comprises compressed wood and may include interconnecting interlocking profiles (not shown).

[0042] The inventive concepts described above are illustrated by several exemplary embodiments. It is understood that when a particular inventive concept is applied, the other details of the examples described above may not be applied. Those skilled in the art will understand that many inventive concepts can be combined to arrive at a specific application, so it is not necessary to detail examples of all possible combinations of the inventive concepts described above.

[0043] It will be clear that the invention is not limited to the embodiments shown and described herein, but is capable of many modifications within the scope of the appended claims which will be apparent to those skilled in the art.

[0044] As used in this patent publication, the verb "comprises" and its conjugations are understood to mean not only "comprises," but also the phrases "contains," "consists essentially of," and "formed by," and their conjugations. Furthermore, when a material characteristic such as "rigidity" or "waterproof" is mentioned, this means that the material characteristic is at least predominantly present in the material under discussion and is present to a greater extent than the opposite material characteristic. Thus, each material characteristic can actually be understood to be the recited material characteristic preceded by the adverb "substantially," e.g., "substantially rigidity" or "substantially waterproof." The same applies to embodiments referring to material compositions, particularly when the phrase "free" is used. This latter phrase can actually be understood as "substantially free," since traces or other minor amounts of the negatively recited component may still be present in the recited composition.

Claims

1. A decorative panel comprising: at least one solid layer including an upper portion and a lower portion, the solid layer being made at least in part from densified wood; and at least one foam layer attached directly or indirectly to the solid layer, the foam layer being at least partially made from wood foam; wherein the decorative panel has a decorative upper surface; A panel, wherein the panel comprises a plurality of foam layers, wherein each foam layer comprises wood foam.

2. The panel a first panel edge including a first interlocking profile and a second panel edge including a second interlocking profile designed to interlockingly engage the first interlocking profile of an adjacent panel; and / or 10. The panel of claim 1, comprising a third panel edge including a third interlocking contour, and a fourth panel edge including a fourth interlocking contour designed to interlockingly engage the third interlocking contour of an adjacent panel.

3. The panel of claim 2 , wherein the first connecting contour, the second connecting contour, the third connecting contour, and the fourth connecting contour are all at least partially disposed in the solid layer.

4. At least one foam layer has a strength of 40 kg / m ３ ~300 kg / m ３ 4. The panel according to claim 1, having a density between 0.1 and 0.

2.

5. 5. The panel of any one of claims 1 to 4, wherein the wood foam of the foam layer is composed of chemically bonded wood fibers, wherein the wood fibers are further bonded by physical anchoring and entanglement of wood fibers and / or strands of wood fibers.

6. The panel of any one of claims 1 to 5, comprising at least one intermediate layer enclosed between at least two foam layers.

7. The panel according to any one of claims 1 to 6, wherein at least one foam layer has a thickness of from 2 to 30 mm.

8. The solid layer has a strength of at least 800 kg / m ３ 8. The panel according to claim 1, having a density of

9. A panel according to any one of claims 1 to 8, wherein the solid layer has a thickness of from 1 to 10 mm.

10. 10. The panel of any one of claims 1 to 9, wherein the densified wood of the solid layer is comprised of chemically treated and compressed wood.

11. 11. The panel of claim 1, wherein the densified wood of the solid layer contains less than 10% by weight of hemicellulose and / or less than 15% by weight of lignin.

12. 12. The panel of any one of claims 1 to 11, wherein at least one foam layer and at least one solid layer are glued together.

13. 13. A panel according to any one of claims 1 to 12, wherein the decorative top surface of the panel is at least partially formed by the solid layer.

14. 14. The panel of claim 1, wherein the panel comprises a decorative top substrate attached directly or indirectly to the solid layer and / or the foam layer, the decorative top substrate comprising at least one printed layer and at least one protective layer covering the printed layer, and constituting the decorative top surface of the panel.

15. 15. The panel of any one of claims 1 to 14, wherein each layer of the panel is a waterproof layer.

16. 16. The panel of any one of claims 1 to 15, wherein at least one layer of the panel comprises and / or is coated with at least one antimicrobial agent.

17. A decorative cover comprising a plurality of decorative panels according to any one of claims 1 to 16.

18. 17. A method for producing a decorative panel according to any one of claims 1 to 16, comprising the steps of: a) providing at least one foam layer including an upper portion and a lower portion, the foam layer comprising wood foam; and b) providing at least one decorative solid layer comprising densified wood; c) applying the solid layer to the upper or lower side of the foam layer.

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