Panel and a method for manufacturing a panel

Abstract

The present invention relates to a panel, comprising a composite layer, comprising a thermoplastic foamed substrate and a reinforcement framework and a decorative layer attached to at least one surface of the composite layer. The at least one core layer comprises a front surface and a back surface located on opposite sides, wherein the at least one reinforcement framework is embedded within at least one core layer such that at least part of an outer circumference of the at least one framework is located at 20% or less of the thickness of the at least one core layer seen from the front surface and / or back surface of at least one core layer, wherein the panel, and in particular the at least one core layer, comprises at least one coupling part for coupling with an adjacent panel.

Description

[0001] Panel and a method for manufacturing a panel

[0002] The present invention relates to a panel. The invention also related to a method for manufacturing a panel.

[0003] Construction and / or decorative panels generally used for the purpose of serving as panel in furniture, shelving, flooring, doors and building panels are typically woodbased, with chipboard, HDF, MDF, OSB, plywood and the like forming the core layer of the panel. However, these wood-based panels have several disadvantages. They are susceptible to moisture fluctuations and water, which may cause warping and delamination; they are generally anisotropic, with the material having distinct physical properties according to the axis it is measured, for example rigidity, expansion and / or swelling, which could provide disadvantageous when fastening means are provided; and they may have local deficiencies, such as cracks or knots, that may impact strength topically.

[0004] Thermolamination of panel’s composite layers, such as thermolamination of at least one decorative top layer to at least one core layer, may prove challenging due to the nature of said thermoplastics, including a low surface energy, thermal sensitivity, and lack of polar groups that may facilitate adhesion. The other drawback of existing composite panels includes low screw-holding strength and low load-bearing capacity which usually lead to addition of excessive layers, adding extra weight and cost, which is not desirable either for manufacturers or consumers. One well-known alternative to the above-mentioned panels, are composite panels comprising a thermoplastic polymer matrix mixed with natural fibers.

[0005] Known surface treatment methods enhancing adhesion can be divided into chemical, mechanical and thermal. Chemical or thermal surface treatment typically include irradiation, such as UV, excimer or chemical modification, chromic acid treatment, corona treatment, plasma treatment, polymer modification, or combination thereof. Some of these methods, however, might affect the core of thermoplastic polymer matrix inside the panel due to a long exposure on the surface. Therefore, some materials may react or become structurally compromised when exposed to certain types of surface modification. It is vital to assess the compatibility of the flooring material with the chosen surface modification method, which might appear costly and time consuming. Some forms of irradiation can also pose a risk for the machine operators. Mechanical treatments on the other hand, such as abrasion, scrubbing or grinding may potentially result in surface damage, especially if the material is delicate, and in consequence might lead to undesirable look or feel.

[0006] It is known in the prior art to use reinforcement layers and / or fillers to contribute to a thermoplastic composite panel’s strength. This is usually to add tensile or impact strength, dimensional stability and / or flexibility. One drawback of such reinforcing layers according to the prior art is that they rarely serve other purpose in the panel other than adding strength and reinforcing the whole structure.

[0007] Therefore, there is a need for an improved panel structure solving existing issues by keeping and / or reducing the weight of the panel, adding to the dimensional stability and load-bearing capacity, while also enhancing its surface properties in a cost-efficient way. The synergy of these properties is to be embodied by addition of at least one reinforcement framework. The object of the invention is to provide an improved lightweight, dimensionally stable panel, for use as a decorative element in furniture, shelving, flooring, doors, and building materials or at least to provide an alternative to the known panels.

[0008] The invention provides thereto a panel, comprising at least one core layer, in particular at least one composite core layer, comprising at least one thermoplastic foamed substrate, and at least one reinforcement framework, and at least one decorative layer attached to at least one surface of the core layer, wherein at least one core layer comprises a front surface and a back surface located on opposite sides, wherein at least one reinforcement framework is embedded within at least one core layer such that at least part of an outer circumference and / or outer surface of at least one reinforcement framework is located at 20% or less of the thickness of the core layer seen from the front surface of the at least one core layer and / or such that at least part of an outer circumference and / or outer surface of at least one reinforcement framework is located at 20% or less of the thickness of the core layer seen from the back surface of at least one core layer. Preferably at least part of the outer circumference and / or outer surface of at least one reinforcement framework is adjacent to the core layer surface but does not extend over the core layer’s thickness.

[0009] The panel according to the present invention addresses at least some of the aforementioned drawbacks and presents an alternative to the prior art by simultaneously exhibiting increased surface energy and enhanced load-bearing capacity by means of at least one embedded reinforcement framework into the core layer of the panel.

[0010] The panel according to the present invention benefits from at least one reinforcement framework. The reinforcement framework might be, but is not limited to a net, web, grid, mesh, wire, strips, cloths and / or combinations thereof. At least one reinforcement framework can be composed of materials at least partially embedded in the surface of at least one core layer. This reinforcement framework has better anchoring properties than the thermoplastic composite, and this is achieved without any surface treatment. It provides structural support, enhances anchoring properties, and improves overall mechanical properties of the thermoplastic foamed substrate. A non-limitative example of materials whereof at least part of at least one reinforcement framework can be made comprise fibrous materials such as fiberglass, polymer fibers or derived from polymer precursors such as aramic fibers, carbon fibers, polyamide fibers, polyaramide fibers, polypropylene fibers, polyester fibers such as polyethylene teraphthalate (PET), polyvinyl alcohol (PVOH), polyvinyl acetate (PVAc), PP, Polyamide, PET, PET-g, Polyethylene, acrylic fibers, PVC, rPVC; mineral fibers such as calcium carbonate, basalt fiber, talc, mica, wollastonite, tricalcium phosphate (TCP); organic / natural fibers such as jute, hemp, bamboo, flax, mycelium, wood flour and / or fibers including microfibrils, cotton or combination thereof. The fibers in the fibrous material can be coated or uncoated and non-limitative examples of non-fibrous materials comprising metals such as aluminium, steel including stainless and galvanized steel, brass, bronze and the like. It is imaginable that at least one reinforcement framework is formed by the non-connected particles, micro or and / or nanoparticles such as nanoclay including montmorillonite, carbon nanotubes and graphene, polymer microspheres dispersed within the thermoplastic matrix. This can also reinforce the material of the thermoplastic foamed substrate, improve mechanical properties, thermal stability and / or barrier properties of the panel. At least one reinforcement framework can be encapsulated within at least one core layer, and in particular within at least one thermoplastic foamed substrate. The at least one reinforcement framework can be encapsulated within at least one core layer, and in particular within at least one thermoplastic foamed substrate by the same material whereof said at least one thermoplastic foamed is made of. It is for example possible that an internal crust layer is formed around at least part of at least one reinforcement framework such that at least part of at least one reinforcement framework is encapsulated by said internal crust layer within at least one core layer, and in particular within at least one thermoplastic foamed substrate. In this embodiment, the co-action between the reinforcement framework and the thermoplastic foamed substrate can be further optimized. It is also possible that at least one core layer comprises at least one upper crust layer at the front surface and / or at least one lower crust layer a back surface. At least one reinforcement framework may be located at a distance from at least one upper crust layer and / or at least one lower crust layer. It is also imaginable that at least one internal crust layer overlaps with or is integrated into at least one upper crust layer and / or at least one lower crust layer.

[0011] The at least one reinforcement framework is preferably embedded within and / or provided onto the surface of the at least one substrate or core layer. The embedding embodiment, wherein the reinforcement framework is integrated within the foamed substrate during the extrusion process, is particularly advantageous for use as a building panel and provides outstanding strength to density ratios. This integration can occur through various methods disclosed in the present invention, such as placing the framework within the extrusion die or introducing it into the molten substrate stream. "Provided onto", conversely, refers to attaching the framework to the surface of the core layer, similarly according to any method according to the present invention. In this method, the framework is pre-fabricated and subsequently bonded to the substrate surface. This method is particularly advantageous for use as furniture panels. Both methods may further be combined for a particularly strong panel, such as for use as a load-bearing and / or structural building panel. In a possible embodiment the reinforcement framework is embedded into the panel during the foaming step of the uncured core layer, and in particular the thermoplastic foamed substrate thereof. The at least one reinforcement framework can be also embedded onto at least one surface of at least one core layer during the curing step. Possibly an internal crust present within the polymeric matrix of the thermoplastic foamed substrate around at least part of at least one reinforcement framework. It is conceivable that an internal crust is formed within the polymeric matrix of the thermoplastic foamed substrate around the reinforcement framework due to a change in the crystallinity gradient. The at least one internal crust might be formed around fibrous or non-fibrous structures in the reinforcement framework. The change in crystallinity gradient could be due to a phase transition from an amorphous stage to a crystalline state. The web-like bonding layer may serve as nucleation spot for crystallization. When the thermoplastic core cools down to the optimal crystallization temperature, and begins to crystallize, it may preferentially nucleate at or near the web-like structure bonding layer, where the temperature is lower than the rest of the (foaming) melt, melt strength is higher, and crystallization rates are as a result higher. This can lead to the formation of crystalline regions and / or higher density regions near the reinforcement framework, potentially resulting in regions of higher crystallinity and / or density. This unexpectedly reinforces the panel due to the additional support formed across the polymeric matrix.

[0012] To further elucidate the formation of two distinct crusts and / or regions of higher density, particularly on each surface of the panel, more particularly the top and bottom surfaces of the panel, one can consider the cooling process of the foamed substrate. During said cooling process, crystallization occurs preferentially at the cooler surfaces and / or around the embedded reinforcement framework. This stems from the fact that cooler regions and areas in contact with the framework provide ideal nucleation sites for crystal growth and / or reduced foaming agent degradation. Consequently, denser and / or more crystalline regions form at these locations, effectively creating "crusts" on the front and back surfaces of the core layer. These crusts exhibit a higher density compared to the less crystallized, more highly foamed inner region of the substrate. This results in a discrete density gradient across the core layer's thickness, enhancing its structural integrity.

[0013] It is additionally or alternatively also conceivable that at least one reinforcement framework is embedded onto at least one surface of the core layer by means of adhesives such as but not limited to polyurethane (PU), epoxy, acrylic, cyanoacrylate (CA), polyvinyl acetate (PVA) adhesives. The reinforcement framework can be also hot-pressed or punched into at least one surface of the semi-cured composite -layer. It is also possible that at least one reinforcement framework is embedded within and / or provided onto at least one core layer by means of at least one adhesive. At least one adhesive is for example chosen from the group of: polyurethane (PU), epoxy, acrylic, cyanoacrylate (CA) and / or polyvinyl acetate (PVA) adhesives.

[0014] Possibly, the at least one substrate has an acoustic impedance of at most 6MRayl, more preferably at most 5MRayl, most preferably at most 4MRayl. It is also conceivable that the at least one reinforcement framework comprises at least one reinforcing material having an acoustic impedance of at least 4 MRayl, more preferably at least 6MRayl, preferably at least 8MRayl. Incorporating at least one reinforcement framework or layer with a high acoustic impedance, such as aluminium, within the panel structure offers significant advantages in terms of sound insulation. The core layer, typically composed of a low-density thermoplastic foam, inherently possesses a low acoustic impedance (e.g., less than 4 MRayl for PVC). By strategically embedding and / or providing a layer of material with a significantly higher acoustic impedance (e.g., at least 4 MRayl, preferably at least 8 MRayl), the panel effectively creates internal reflective barriers for sound waves. These high-impedance layers impede the transmission of sound by reflecting a portion of the sound energy back towards the source and / or scattering incoming and / or outgoing sound waves. This reflection mechanism, coupled with the soundabsorbing properties of the low-impedance core comprising a plurality of cavities, significantly reduces the amount of sound energy that passes through the panel, enhancing its overall sound insulation performance.

[0015] To significantly enhance the panel's sound insulation capabilities, the panel according to the present invention strategically utilizes the interplay between a relatively low acoustic impedance foamed substrate and at least one reinforcement framework having a relatively high acoustic impedance. The at least partially foamed substrate, possibly composed of a low-density thermoplastic foam such as PVC, PET or PP, is preferably designed with an acoustic impedance of at most 6 MRayl, more preferably at most 5 MRayl, and most preferably at most 4 MRayl. This low impedance is primarily a result of the substrate's cellular structure and low density, which inherently reduces the transmission of sound waves by virtue of its many cavities. Conversely, the at least one reinforcement framework is preferably engineered to possess a significantly higher acoustic impedance, with a value of at least 4 MRayl, more preferably at least 6 MRayl, and preferably at least 8 MRayl. This high impedance can be achieved by incorporating materials such as aluminium or other dense materials that provide a strong acoustic reflective barrier.When sound waves encounter the panel, the low-impedance foamed substrate allows some initial transmission but also attenuates a significant portion of the acoustic energy due to the sound-absorbing properties of its cellular structure. Upon reaching the high-impedance reinforcement framework, a substantial portion of the remaining sound energy is reflected back into the foamed substrate. This reflection mechanism is beneficial for reducing sound transmission through the panel because it effectively creates an internal barrier for sound waves. The reflected sound waves are then further dissipated as they travel through the substrate and its many cavities, thus further reducing the overall sound energy that would otherwise pass through the panel.

[0016] In another embodiment the reinforcement framework is embedded within at least one core layer such that the surface energy of the at least one core layer is changed. The change in the surface energy aids to the adhesion of the at least one surface of the core layer to paint, ink, glue etc., providing unexpected improvement in bonding and stability of the panel. This prevents the peeling off the paint or ink or even delamination of the layers. In the preferred embodiment, panel comprises two reinforcement frameworks located on the upper and bottom surface of the core layer. In a particularly advantageous embodiment, at least two reinforcement frameworks are provided, on each of the two surfaces of the at least partially foamed substrate, particularly a low impedance substrate. This configuration creates multiple reflective interfaces, further enhancing the sound insulation performance of the panel. Each high-impedance layer will reflect sound waves, which are then attenuated by the foamed substrate as they travel back and forth between the reinforcement frameworks, significantly reducing the amount of sound that passes through the panel. The combination of these features results in a highly effective sound insulation system where the sound energy is continuously reflected and dissipated within the panel rather than being transmitted through it, making it suitable for various applications, including use as a building panel. The strategic placement of these reflective barriers, in combination with the sound-absorbing properties of the low impedance substrate, optimizes the panel's sound insulation performance.

[0017] In another embodiment, the presence of at least one reinforcement framework can alter the thermal conductivity of crystalline and / or semi-crystalline thermoplastic foamed substrate, as during the curing process, heat is applied to melt and shape the thermoplastic material. It is imaginable that the reinforcement framework can attribute to better heat conductivity, which can help distribute heat more evenly throughout the composite. This can affect the rate of crystallization in different regions.

[0018] In a preferred embodiment, at least one reinforcement framework does not extend over the thickness of the core layer. In one embodiment however, at least part of the front and / or back surface of the core layer can be formed by a reinforcement framework extending over the thickness of the core layer.

[0019] Advantageously, the strength of the panel is markedly increased by the presence of at least one reinforcement framework in the core layer. Several aspects of the panel can be measured. The American Society for Testing and Materials provides a standard test method, ASTM D 1037-96, for evaluating properties of wood-based fiber and particle panel materials. The tests included therein are the bending modulus of elasticity (MOE) and the modulus of rupture (MOR). Other useful tests included in ASTM D 1037-96 include the direct screw withdrawal test, the hardness test, the hardness modulus test, shear strength in the plane of the board, glue-line shear test, falling ball impact test. In the case if the panel is used as a part of a furniture product, test ANSI / KCMA A161.1 Kitchen Cabinet Furniture Testing may be particularly useful. The panel according to the invention can for example be a furniture panel and / or building panel. It is also possible that the panel is configured to be used as furniture panel and / or building panel.

[0020] Preferably the MOE of reinforcement framework is not measured alone but measured through the flexibility of the core layer according to ASTM-D 1037-96 and / or ASTM D7031 -11. If the core layer is made of a Wood Plastic Composite (WPG), the average MOE would range between 400 and 800 MPa, in particular between 500 and 700 MPa, such as 600 MPa, more preferably 700 MPa, and more preferably at least 800 MPa, more preferably at least 1000 MPa, and more preferably at least 1500 MPa if reinforcement framework would be present increasing the stiffness of the core. In one advantageous example the core layer together with an aluminium reinforcement framework can have an average MOE range between 3000 MPa to 10000 MPa, preferably at least 4000 MPa, more preferably at least 6000 MPa, more preferably at least 8000 MPa.

[0021] In one embodiment the panel according to the present invention may benefit from at least one core layer comprising at least one support structure aside from at least one reinforcement framework. The combination of at least one support structure together with at least one reinforcement framework according to the invention results in a relatively strong core layer. The core layer may benefit of at least part of at least one support structure extending over the thickness of at least one core layer, such that a strong and effective geometry is obtained. At least one support structure can thereby form a backbone construction of the panel. The support structure could also be referred to as backbone structure. Due to the use of at least one support structure which extends over the thickness of at least one core layer a relatively thin thermoplastic foamed substrate can be used. The orientation of at least part of the support structure provides rigidity to the thermoplastic foamed substrate. The panel according to the present invention in particular benefits of a good rigidity and strength.

[0022] Within the context of the present invention, the panel can be any panel suitable for decoration and / or construction. Hence, the panel can be a decorative panel and / or a structural panel. The panel according to the present invention can for example be configured for and / or suitable for use in furniture, shelving, doors but could also be decorative and non-decorative building panels, flooring, wall and / or ceiling panels. The panel can for example be a floor, wall or ceiling panel. Within the context of the present invention, when it is referred to a thermoplastic foamed substrate also a multicellular substrate could be meant.

[0023] A non-limiting example of a multicellular material is for example foamed material. The panel according to the present invention could thus comprise at least one at least partially foamed core layer. It is for example imaginable that the panel comprises a foamed thermoplastic core layer, for example foamed PVC, foamed PET, foamed PP, and / or foamed WPG, a foamed thermoset core layer, for example foamed TPU and / or PU foams, and / or a foamed inorganic core layer, for example comprising MgO, MgSO4, MgCI2, fiber cement and / or aluminosilicate. It is also imaginable that the panel comprises an organic core layer, for example comprising cork, mycelium or the like. The core layer is preferably a waterproof core layer. The panel is preferably a waterproof panel.

[0024] It is imaginable that at least part of the front surface and / or the back surface of the core layer is also formed by at least one reinforcement framework. It is also imaginable that at least part of at least one reinforcement framework extends over the entire thickness of the thermoplastic foamed substrate of at least one core layer. The panel and substrate can have several possible shapes. It is for example possible that the panel and / or the substrate are substantially plate-shaped. It is imaginable that the thickness of the core layer is substantially consistent over the entire core layer, and / or over the length of the core layer. In this case, it is beneficial if the height of at least part of the reinforcement framework substantially equals the thickness of the core layer. It is also imaginable that at least part of at least one reinforcement framework extends over at least the smallest thickness of at least one core layer. The core layer can have a variable thickness. It is for example imaginable that at least part of at least one support structure forms a connection or connecting bridge between the front surface of the core layer and the back surface of the core layer. It is imaginable that at least part of at least one support structure is positioned under an angle with respect to a plane defined by the front surface and / or back surface of the core layer. An embodiment is conceivable wherein at least part of at least one support structure is substantially perpendicular to a plane defined by the front surface and / or the back surface of at least one core layer. When it is referred to a front surface and a back surface, this could also be a first (side) and a second (side) surface. It is in particular referred to opposing sides of the panel. The panel according to the present invention can be applied in several orientations. Hence, the term front and back should not be interpreted as limiting. Instead of the wording front and back for example also upper and lower, first and second, primary and secondary could be used. The upper and lower side, or front and back side, are typically two opposite faces with largest surface area which serve as main decorative faces. The panel is for example substantially rectangular. However, the panel according to the present invention can have any convenient shape. It is for example imaginable that the panel is a cuboid or a hexahedron in particular comprising multiple faces.

[0025] The at least one core layer preferably may have a thickness of at least 3 mm. It is for example conceivable that at least one core layer has a thickness between 3 mm and 20 mm or between 5 and 16 mm, preferably between 6 mm and 8 mm or between 14 mm and 16 mm. Beneficial embodiments comprise a core layer having a thickness in the range of 2.5 to 4 mm or in the range of 3.5 to 5 mm. In case the panel comprises multiple core layers, it is also conceivable that said core layers vary in thickness. It is for example conceivable that the combination of core layers has a thickness between 3 and 12 mm. It is conceivable that the panel has multiple core layers, wherein at least one core layer has a thickness in the range of 0.5 to 1 mm and at least one further core layer has a thickness in the range of 1 to 3 mm. It is possible that a panel comprises at least three core layers adjacent to each other, wherein a central core layer is enclosed between an upper core layer and a lower core layer. It may be preferred that the upper core layer and / or the lower core layer have a larger thickness than the central core layer, or vice versa. At least one reinforcement framework can for example have a thickness which is substantially equal to the thickness of the core layer.

[0026] In one example of the present invention at least one reinforcement framework comprises a plurality of ribs. In a further preferred embodiment, at least one rib, and preferably at least two ribs, or more preferably each rib, extends over the thickness of at least one core layer. In this way, at least one rib or the plurality of ribs can form a reinforcing configuration within the core layer, and in particular within the thermoplastic foamed substrate. It is also imaginable that at least one reinforcement framework comprises a plurality of struts. When it is referred to a rib also a strut could be meant, or vice versa. In a preferred embodiment, at least one rib, preferably at least two ribs, and more preferably each rib, of at least one reinforcement framework extends over the entire thickness of the thermoplastic foamed substrate of at least one core layer. At least two ribs are preferably substantially parallel to each other. In this embodiment, a good strength can be achieved by the applied ribs. The parallel orientation of the ribs can contribute to a decent rigidity of the core layer, and of the panel as such. It is possible that at least two ribs, or the plurality of ribs extend substantially parallel throughout the entire thermoplastic foamed substrate. It is for example imaginable that at least two ribs are oriented substantially parallel to each other in a direction substantially perpendicular to a length direction of the panel. In case the panel is an extruded panel, it is imaginable that at least two ribs are oriented substantially parallel to each other in a direction substantially angled with respect to the extrusion direction. It is for example possible that at least two ribs are oriented substantially parallel to each other in a direction substantially perpendicular to the extrusion direction. Alternatively, and / or additionally, at least two ribs could define a triangle shape, for example wherein the legs of the triangle extend from the front surface to the back surface of the core layer, or vice versa. It is also imaginable that least two ribs are oriented substantially parallel to each other in a direction which equals length direction of the panel.

[0027] In a possible embodiment, at least two ribs of at least one reinforcement framework can be interconnected. Hence, it is imaginable that at least one reinforcement framework is formed by a plurality of substantially adjacent and / or parallel-oriented ribs which are interconnected. The ribs could form an interconnected network, thereby defining a reinforcement framework. It is also conceivable that at least two ribs are substantially isolated from each other. Hence, it is imaginable that at least one reinforcement framework is formed by a plurality of separate ribs. It is for example possible that a plurality of individual ribs together forms a reinforcement framework. It is also imaginable that the core layer comprises a plurality of reinforcement frameworks. The orientation and / or positioning of at least one reinforcement framework, and / or at least one rib and preferably the plurality of ribs, can contribute to the rigid characteristics of the core layer.

[0028] In a possible embodiment of a panel according to the present invention, the panel comprises at least two core layers. It is for example possible that the panel comprises at least two core layers, wherein each core layer comprises at least one thermoplastic foamed substrate and / or at least one reinforcement framework. It is then imaginable that a first reinforcement framework of a first core layer is arranged at an angle with respect to a second reinforcement framework of a second core layer. Each core layer can be any of the described embodiments of a core layer according to the present invention. The panel can for example comprise at least two stacked or coupled core layers, wherein said at least two layers comprise a plurality of ribs, in particular parallel ribs, wherein at least part of the ribs of a first core layer are arranged at an angle, and preferably substantially perpendicular, with respect to at least part of the ribs of a second core layer.

[0029] Preferably, at least part of the reinforcement framework is substantially rigid. In a further preferred embodiment, the reinforcement framework is a rigid support layer. It is also imaginable that the parts defining the reinforcement framework are not rigid as such, but that the orientation and / or positioning thereof results in the reinforcement framework having rigid characteristics. It is conceivable that at least part of the reinforcement framework forms a lattice structure.

[0030] In a preferred embodiment, at least one core layer is an extruded core layer. In some embodiments, the extruded substrate comprises at least two materials that are extruded simultaneously. The panel according to the present invention can also be an extruded panel. Extrusion is a preferred production method as it is relatively cost competitive and enables continuous bulk production.

[0031] The core layer can also be obtained via multi-extrusion. It is imaginable that the core layer, or the thermoplastic foamed substrate, comprises multiple materials. For example, at least one core layer can comprise an alternating sequence of materials. At least one core layer can for example comprise an alternating sequence of a first polymer material and a second polymer material, for example in a (-SPC-WPC-)*n configuration with n being an integer > 1.

[0032] In a possible embodiment, the panel according to the invention comprises at least two decorative layers. The at least two decorative layers are preferably provided at opposing sides of the panel. It is imaginable that a first decorative layer is attached to the front surface of the core layer and / or that a second decorative layer is attached to the back surface of the core layer. It is also imaginable that a further layer is present between at least one core layer and at least one decorative layer. A first decorative layer can be substantially identical to a second decorative layer. However, it is also conceivable that a first decorative layer differs from a second decorative layer. Any of the embodiments described for the decorative layer according to the present invention could be applied for the first and / or second decorative layer, if applied.

[0033] At least one core layer could comprise at least one side edge, and at least one decorative layer can be attached to at least one side edge. In such embodiment, the panel could for example be used for decorative purposes, and / or for furniture and / or the formation of a door. Typically, in a panel according to the present invention, the surface area defined by the front surface and / or the surface area defined by the back surface is larger than the surface area defined by at least one side edge. It is imaginable that at least one decorative layer completely surrounds core layer. It is possible at all side edges, including the front surface and back surface of the panel are provided with a decorative layer. A (rectangular) block shaped panel can for example have six sides provided with a decorative layer.

[0034] The panel according to the present invention, and in particular the core layer thereof could comprise sealed edges. The panel could for example comprise sealing strips or sealing layers, preferably applied via thermolamination. The sealing layer may be thermolaminated to the outer edges of the core layer. This prevents the collection of dirt or the uptake of moisture from the surroundings into the core layer. A separate sealing strip may be used. Such embodiment could provide for sealing of the thermoplastic foamed substrate through heat, allowing for stronger structural integrity at the edges, and for screws, fastening means, a click system and / or interlocking mechanism to be provided.

[0035] The panel, and in particular the at least one core layer, preferably comprises at least one coupling part for coupling with an adjacent panel. It s also possible that at least one coupling part comprise or is a groove or a tongue. It is also possible that the panel, and in particular the at least one core layer, comprises complementary coupling parts on opposing side edges of the panel. In a preferred embodiment, the panel comprising complementary coupling elements and / or coupling parts. It is for example imaginable that at least two side edges of the panel comprise complementary coupling elements. The coupling elements and / or coupling parts can for example be configured to provide a snap connection and / or click connection. The coupling parts of the panel may for example be interlocking coupling parts, which are preferably configured for providing both horizontal and vertical locking. Interlocking coupling parts are coupling parts that require elastic deformation, a click or a movement in multiple directions to couple or decouple the parts with or from each other. Any suitable interlocking coupling parts as known in the art could be applied. A non-limiting example is an embodiment wherein a first edge of said first pair of opposing edges comprises a first coupling part, and wherein a second edge of said first pair of opposing edges comprises a complementary second coupling part, said coupling parts allowing a plurality of panels to be mutually coupled; wherein the first coupling part comprises a sideward tongue extending in a direction substantially parallel to a plane defined by the panel, and wherein the second coupling part comprises a groove configured for accommodating at least a part of the sideward tongue of another panel, said groove being defined by an upper lip and a lower lip. It is imaginable that the coupling parts, or the click-assembly is thermoformed and / or milled.

[0036] A compression strength of the reinforcement framework may be higher than a compression strength of the thermoplastic foamed substrate, measured according to ASTM-D1037 in a direction from the front surface to the back surface of the core layer. Advantageously, the reinforcement framework as such increases the overall compression strength of the core layer and the panel as a whole. This results in a sturdier, more rigid panel, that is less likely to break under compressive forces.

[0037] Preferably, the at least one reinforcement framework and the thermoplastic foamed substrate comprise the same compounds and the density of the reinforcement framework is higher than the density of the thermoplastic foamed substrate. This allows the reinforcement framework and the thermoplastic foamed substrate to be bonded together without any adhesive, for example by thermolamination. The same compounds are herein defined as molecules being substantially the same. For example, both the reinforcement framework and the thermoplastic foamed substrate could be made of polyvinyl chloride. The density of the thermoplastic foamed substrate may nevertheless be lower than the density of the reinforcement framework because the thermoplastic foamed substrate may contain more cells and / or cell having a larger volume (i.e. having a larger cell size). Due to the increased density of the reinforcement framework relative to the thermoplastic foamed substrate, the reinforcement framework is stronger than the thermoplastic foamed substrate, enabling the reinforcement framework to support the entire core layer. In line therewith, an average cell volume of the thermoplastic foamed substrate is preferably larger than an average cell volume of the reinforcement framework. Optionally, the reinforcement framework may be substantially free of cells.

[0038] The reinforcement framework may comprise a thermoplastic polymer or a thermoset polymer. A thermoplastic polymer is preferred, as this enables heating of the thermoplastic polymer prior to extrusion, enabling a better control over the viscosity of the extruded material. A thermoset polymer is however also a possibility.

[0039] The at least one reinforcement framework may comprise at least one polymer selected from polyvinyl chloride (PVC), polystyrene (PS), polyethylene (PE), high- density polyethylene (HDPE), low-density polyethylene (LDPE), cross-linked polyethylene (XPE), polyurethane (PU), acrylonitrile butadiene styrene (ABS), polypropylene (PP), Polyethylene terephthalate (PET), thermoplastic starch (TPS), cross-linked polystyrene (XPS), styrene acrylonitrile (SAN), polyphenylene oxide (PPO), polylactic acid (PLA), phenolic resin, melamine resin, formaldehyde resin, or any combination thereof. Preferably, the thermoplastic foamed substrate and / or the reinforcement framework is at least partially biodegradable. Therefore, preferred polymers are biodegradable. It is imaginable that the thermoplastic foamed substrate comprises at least one bioplastic. It is also imaginable that the thermoplastic foamed substrate and / or the reinforcement framework is made of bioplastics. In a further embodiment, the reinforcement framework may comprise a thermoset resin and / or a reactive resin, such as a two-component reactive resin, a polyurethane (PUR) resin, a reactive PUR resin, and / or an acrylic resin. These resins, due to their liquid form before curing, would be able to penetrate at least part of the foamed structure of the thermoplastic foamed substrate, effectively impregnating the cellular structure. This impregnation would create a strong bond between the reinforcement framework and the substrate, enhancing the overall mechanical properties of the core layer. This resin could therefore be called an impregnating agent. In a particularly advantageous embodiment for applications where the panel is used as a building panel, such as a wall panel, ceiling panel, or substrate panel, the impregnating agent or resin comprises at least one fire retardant. This addition would impart fire-retardant properties to the core layer, improving the panel's safety profile without compromising its mechanical properties, making it particularly suitable for building applications where fire safety is a concern.

[0040] The polymer described above may also be a thermoplastic binder. The core layer preferably comprises at least one such thermoplastic binder. However, it is also conceivable that the core layer comprises additionally or alternatively at least one thermosetting binder. The use of at least one thermoplastic or thermosetting material in the core layer is conceived to impart flexibility characteristics to the panel when deemed necessary, for example when flexibility is required to achieve engagement of a locking mechanism.

[0041] The core layer and / or the reinforcement framework may comprise starch-based plastic, soybean-based plastic, cellulose-based plastic, lignin-based plastic, and / or natural fibers. The biodegradability of these plastics results in an environmentally friendly panel, as the panel can be biodegraded after its lifetime.

[0042] The core layer, may comprise at least one filler. The filler material can comprise organic or inorganic materials which includes but is not limited to cellulose materials, fibrous materials, kraft paper, saw dusts, wood dusts, wood fibers, long wood fibers, short wood fibers, sand, lime, volcanic ash, plants-based fibers such as mushroom fibers, cotton fibers, bamboo fibers, abaca fibers, pineapple fibers, magnesium compounds, magnesium oxide, magnesium carbonate, limestone, polymeric fibers, glass fibers, carbon-based fibers, polymeric pellets, or hollow microspheres or particles having size ranging from 1 to 1000 micrometers made of but is not limited to ceramics, glass, polymers, composites, or metals. Preferably, the core layer includes at least one filler selected from the group consisting of: minerals, preferably calcium carbonate; and pigments, modifiers, fibers, such as: glass fiber, wood, straw and / or hemp. The fibers can be loose fibers and / or interconnected fibers to form a woven or nonwoven layer. Preferably the core layer further includes at least one additional filler selected from the group consisting of steel, glass, polypropylene, wood, acrylic, alumina, curaua, carbon, cellulose, coconut, kevlar, Nylon, perlon, polyethylene, PVA, rock wool, viburnum and fique. This can further increase the strength of the panel itself and / or the water resistance and / or fire resistance of the panel. The core layer can be a wood plastic composite layer.

[0043] Preferably, the core layer has a discrete density gradient. It is preferred that the thermoplastic foamed substrate has a density that is relatively low compared to the average density of the core layer and also relatively homogenous. Preferably, the density of the reinforcement framework is relatively high compared to the average density of the core layer and also relatively homogenous. In particular, in the case where the thermoplastic foamed substrate and the reinforcement framework comprise the same compounds, and only differ by the volume and number of cells present, the gradient in density between the thermoplastic foamed substrate and the reinforcement framework is discrete. This ensures that the thermoplastic foamed substrate is very light, while the reinforcement framework is heavier and bears the vast majority of the load applied on the panel.

[0044] At least one core layer of the panel according to the invention is preferably at least partly foamed. Different degrees of foaming are conceivable within the scope of the present invention. It is preferred that the panel, and in particular at least one core layer, has an expansion percentage in the range of 5% to 50%. Non-limiting examples are an expansion percentage in the range of 15% to 35%, in particular in the range of 20% to 30%. However, it is also conceivable that the panel, and in particular at least one core layer, has an expansion percentage of at least 10%, in particular at least 20%, more in particular at least 30% and even more in particular at least 40%. The expansion percentage is in particular a measure for the rate of change of the volume of the panel, and in particular the core layer, compared to a non-foamed melt.

[0045] At least one core layer, and in particular at least one thermoplastic foamed substrate, may comprise at least one mineral filler preferably chosen from the group of: calcium carbonate (CaCO3), chalk, clay, calcium silicate (Si-Cal), dolomite, talc, magnesium oxide (MgO), magnesium chloride (MgCI or MOC cement), magnesium oxysulfate (MOS cement) and / or limestone. The use of at least one mineral material in the core layer is conceived to impart a sufficient rigidity thereby ensuring dimensional stability of the panel. It is for example conceivable that the mineral material comprises a magnesium-based mineral, such as but not limited to magnesium oxide (MgO), magnesium chloride (MgCI or MOC cement), magnesium oxysulfate (otherwise known as MOS cement). In case limestone is applied as mineral filler, it is beneficial if the mesh of limestone used is 325 mesh or 400 mesh. The core layer can for example comprise a composite material having a weight ratio of mineral filler to thermoplastic binder which is at least 3:1 . It is also conceivable that the composite material has a weight ratio of mineral filler to thermoplastic binder which is greater than 3.5:1 or in the range of 3:1 to 4:1. However, alternatively, it is also conceivable that the core layer comprises at least 30 wt% of at least one mineral filler, preferably at least 50% by weight, more preferably at least 60% by weight. The composite material could for example comprise at most 40% of said at least one thermoplastic binder, preferably at most 30% by weight, more preferably at most 25% by weight. It is conceivable that the ratio is smaller, such as 1 :1 , 1 .5:1 or 2:1 . The core layer can have a Vicat softening temperature of at least 80 degrees Celsius, preferably at least 85 degrees Celsius and / or and wherein the front surface of the panel and / or the back surface of the panel can have a Shore D hardness of at least 85. The use of at least one mineral material in the core layer is conceived to impart a sufficient rigidity, advantageously higher than 4000Mpa MOE and 22 Mpa MOR thereby ensuring dimensional stability and toughness of the panel. The use of at least one polymer in the core layer is conceived to impart flexibility characteristics to the panel when deemed necessary, or for example when flexibility is required to achieve engagement of a locking mechanism, if applied, advantageously lower than 9000Mpa and 36Nm MOR. The core layer according to the present invention is in particular configured and suitable for use in a thermo bonding process. The composite material of the core layer may for example comprise at least one additive configured to increase the Vicat softening temperature. At least one additive could for example comprise acrylonitrile styrene acrylate (ASA), acrylonitrile butadiene styrene (ABS), a thermoset system and / or an epoxy system. At least one additive can also be a Vicat modifier or referred to as Vicat modifier. In an alternative embodiment, it is possible that at least one polymer of the composite material is a thermosetting polymer.

[0046] To further enhance the mechanical properties and dimensional stability of the panel, the mineral content of the core layer, if applied, may comprise a strategic combination of talc and limestone. Hence, the core layer, and in particular at least one thermoplastic foamed substrate, may comprise talc and limestone. Talc has a platelet or elongated shape which tends to align during extrusion, leading to anisotropic strength with higher values in the extrusion direction. Limestone, having a more balanced 1 :1 width:length ratio, contributes to more isotropic strength properties. By incorporating a blend of talc and limestone, the panel can benefit from the enhanced strength in the extrusion direction provided by talc while mitigating the anisotropy through the addition of limestone. This combination allows for a more balanced strength profile across both the cross and machine directions, exceeding the performance of either filler alone and improving the overall structural integrity of the panel. This tailored strength profile, achievable through adjusting the talc and limestone ratio, is particularly advantageous in applications demanding specific load-bearing capacities. For instance, in substrate panels or ceiling panels, a higher strength in the machine direction, the direction the panels will be installed across trusses or joists, can be beneficial to withstand the building load. By optimising the talc content, the panel can provide enhanced durability and loadbearing capacity in the direction experiencing the primary forces, resulting in a longer lifespan and improved performance. Conversely, applications where a more balanced strength distribution is desired, such as wall panels or furniture components, can benefit from a higher limestone content to ensure consistent strength in all directions. This adaptability allows for the creation of panels specifically tailored to meet the unique mechanical demands of various applications. Several embodiments of talc to limestone ratios are conceivable. A ratio of the core layer of a panel according to invention can for example be 20:80 for Talc:Limestone. This ratio would favour limestone, resulting in a panel with more balanced strength properties in both the cross and machine directions. It would be suitable for applications where uniform strength is prioritised, such as wall panels or furniture components. Another ratio of the core layer of a panel according to invention can for example be 40:60 for Talc:Limestone: This blend would offer a compromise between the anisotropic strength of talc and the isotropic strength of limestone. It could be suitable for applications requiring moderate strength in both directions. Another possible ratio of the core layer of a panel according to invention can for example be 50:50 for Talc:Limestone: This balanced ratio might provide a good balance of strength properties. It could be investigated for general-purpose panels where a balance of cross and machine direction strength is desirable. Another possible ratio of the core layer of a panel according to invention can for example be 60:40 for Talc:Limestone: This ratio starts to favour the anisotropic properties of talc. The panel would likely exhibit increased strength in the extrusion direction, making it suitable for applications like subflooring where load bearing in a specific direction is important. Another possible ratio of the core layer of a panel according to invention can for example be 80:20 for Talc:Limestone: With a high talc content, this ratio would maximise the strength enhancement in the extrusion direction. This could be advantageous for applications demanding high loadbearing capacity in a specific direction, potentially allowing for thinner, lighter panels while maintaining strength, such as subfloors and / or ceiling panels.

[0047] In an embodiment, the thermoplastic foamed substrate and / or the reinforcement framework comprises a wood plastic composite (WPG). These wood plastic composites are aesthetically pleasing and as such, a decorative layer can be omitted.

[0048] The reinforcement framework may comprise a stone plastic composite (SPG) and / or a metal, such as aluminium. Like WPG, SPG is aesthetically pleasing as will, allowing the decorative layer to be omitted. Metals, such as aluminium provide extra stability to the reinforcement framework, while being relatively light weight, resulting in a strong but lightweight panel.

[0049] Advantageously, the core layer and / or the panel is substantially free of adhesive. In particular if the reinforcement framework and the thermoplastic foamed substrate comprise the same compound, there is no need to provide an adhesive layer between them. In addition, in this case extruded thermoplastic foamed plates can be adhered together via thermolamination soon after extrusion, instead of providing an adhesive. Adhesives often release harmful volatile organic compounds. As such, the lack of adhesives is a major advantage. In particular, panels may be connected via complementary coupling means, such as a tongue and groove, omitting use of adhesives even when panels are installed together to cover a surface larger than an individual panel.

[0050] The core layer may comprise at least one bio-based plasticizer, such as palm oil, epoxidized soybean oil, castor oil, succinic acid, citrates or any combination thereof. This allows the panel to be somewhat flexible, aiding in installing panels. In particular if the panels have complementary coupling means, the coupling means can be more flexible, resulting in facilitated coupling of the panels.

[0051] At least one decorative layer as applied in panel according to the present invention can for example comprise at least one support layer, for example at least one (highly) filled thermoplastic support layer thermolaminated with a thermoplastic decor layer, an optional wear layer and optionally finished with a UV coating. At least one decorative layer, and in particular at least one support layer, can comprise or consist of SPC, LVT, extruded, calendered or injection moulded thermoplastic.

[0052] At least one decorative layer, if applied, preferably comprises at least one support layer, at least one decor layer and / or at least one protective layer. It is conceivable that at least one decor layer is attached to the core layer, if applied. It is also conceivable that the decor layer is a print layer. It is also conceivable that at least one decorative layer is a print layer, in particular a digital print layer. The decor layer may also form integral part of a support layer. In a beneficial embodiment of the panel, at least part of the upper surface of the support layer is provided with at least one decorative pattern or decorative image. It is for example possible that such decorative image or pattern is provided via printing, for example via digital and / or inkjet printing. It is also possible that at least one decorative pattern is formed by relief provided in the upper surface of the support layer or panel. It is also conceivable that the decor layer or decorative layer is a separate layer, for example a high-pressure laminate (HPL), a veneer layer, a directly laminated paper layer, and / or a ceramic tile. In a preferred embodiment, at least one decorative layer comprises a thermoplastic film or a ply of cellulose. It is for example possible that the decor layer comprises a plurality of impregnated layers containing lignocellulose but also a wood veneer, a thermoplastic layer, a stone veneer, a veneer layer or the like and / or a combination of said materials. The veneer layer is preferably selected from the group comprising of wood veneer, cork veneer, bamboo veneer, and the like. Other materials such as ceramic tiles or porcelain, a real stone veneer, a rubber veneer, a decorative plastic or vinyl, linoleum, and laminated decorative thermoplastic material in the form of foil or film. It is imaginable that the support layer of at least one decorative layer is connected to the support structure of at least one core layer. At least one decorative layer can comprise at least one thermoplastic material. For example, at least one support layer of at least one decorative layer can comprise at least one thermoplastic material. The thermoplastic material can be PP, PET, RPET, PVC, PLA, PE, HDPE, LDPE, XPE, or a bioplastic such as thermoplastic starch (TPS) and the like. The design of the decorative layer can for example be chosen from a design database which includes digitally processed designs, traditional patterns, pictures or image files, customized digital artworks, randomized image pattern, abstract art, wood-patterned images, ceramic or concrete style images, or user-defined patterns. The designs can be printed or reproduced using laser printers, inkjet printers, or any other digital printing means including the conventional printing methods. Various types of inks can also be used to suit the design needs of the decor layer. Preferably, the ink used during the printing method comprises properties such as but is not limited to waterproofness, lightfastness, acid-free, metallic, glossy, sheen, shimmering, or deep black, among others. It is desirable that the decorative layer is visually exposed by the coating layer being a substantially transparent coating layer. The decor layer may comprise a pattern, wherein the pattern is printed via digital printing, inkjet printing, rotogravure printing machine, electronic line shaft (ELS) rotogravure printing machine, automatic plastic printing machine, offset printing, flexography, or rotary printing press. The thickness of the decorative layer is preferably in the range of 0.05 mm and 0.10 mm, for example substantially 0.07 mm. In a preferred embodiment, the decorative layer comprises at least one decor layer and / or at least one wear layer. The wear layer could for example be scratch resistant layer. The decorative layer could possibly comprise a wear layer or finishing layer, for example with a thermosetting varnish or lacquer such as polyurethane, PUR, or a melamine-based resin. In a preferred embodiment, the decorative layer comprises at least one substantially transparent wear layer or finishing layer. The wear layer may comprise one or more transparent layers of a thermoplastic or thermosetting resin. Non-limiting examples of thermoplastic or thermosetting materials which could be used are polyvinyl chloride (PVC), polystyrene (PS), polyethylene (PE), polyurethane (PU), acrylonitrile butadiene styrene (ABS), polypropylene (PP), Polyethylene terephthalate (PET), phenolic and / or melamine or formaldehyde resins. Said wear layer may also be in a liquid or paste-like form made of a thermosetting resin such as but not limited to phenolic and / or melamine or formaldehyde resins. The wear layer may comprise or may be substantially composed of an inherently scratch-resistant thermosetting resin impregnating a carrier layer such as paper or lignocellulose. An advantage of this latter embodiment is that the urea-formaldehyde also acts a relatively scratchresistant wear layer. Typically, a preferred thickness of the wear layer structure in the panel of the invention is in the range of 0.1 to 2.0 mm, more preferably between 0.15 mm to 1 mm and most preferably between 0.2 mm to 0.8 mm. At least one support layer can have a thickness in the range of 0.2-2mm, preferably 0.5-1 ,5mm. Such embodiment will provide sufficient body to the panel surface for screw strength and / or the screw pullout strength. At least one support layer of at least one decorative layer is preferably substantially rigid. A rigid support layer can provide rigidity and strength to the panel. The rigidity, or MOE, of at least one support layer can for example be larger than 2000 Mpa, preferably larger than 4000 Mpa, more preferably larger than 6000 Mpa according to EN 310 or a mandrel test >100mm according to ISO 24344.

[0053] The decorative top layer, and in particular the support layer thereof, could optionally comprise at least one filler. The filler material of the decorative layer, or the support layer thereof can comprise organic or inorganic materials which includes but is not limited to cellulose materials, fibrous materials, kraft paper, saw dusts, wood dusts, wood fibers, long wood fibers, short wood fibers, sand, lime, volcanic ash, plants- based fibers such as mushroom fibers, cotton fibers, bamboo fibers, abaca fibers, pineapple fibers, magnesium compounds, magnesium oxide, magnesium carbonate, limestone, polymeric fibers, glass fibers, carbon-based fibers, polymeric pellets, or hollow microspheres or particles having size ranging from 1 to 1000 micrometers made of but is not limited to ceramics, glass, polymers, composites, or metals. Preferably, the decorative layer, or the support layer, includes at least one filler selected from the group consisting of: minerals, preferably calcium carbonate; and pigments, modifiers, fibers, such as: glass fiber, wood, straw and / or hemp. The fibers can be loose fibers and / or interconnected fibers to form a woven or nonwoven layer. Preferably the decorative layer further includes at least one additional filler selected from the group consisting of steel, glass, polypropylene, wood, acrylic, alumina, curaua, carbon, cellulose, coconut, kevlar, Nylon, perlon, polyethylene, PVA, rock wool, viburnum and fique. This can further increase the strength of the panel itself and / or the water resistance and / or fire resistance of the panel. To enhance the panel's fire resistance, the thermoplastic foamed substrate of the core layer may further comprise at least one fire retardant. Suitable fire retardants include, but are not limited to, aluminium trihydrate (ATH), magnesium dihydroxide (MDH), halogenated compounds, phosphorus-based compounds, nitrogen-based compounds, or expandable graphite. The selection and concentration of the fire retardant can be tailored to achieve the desired level of fire resistance according to industry standards and regulations. This addition would impart fire-retardant properties to the core, improving the panel's safety profile without compromising its mechanical properties. At least one fire retardant may also be provided to at least one adhesive and / or resin. In one particularly advantageous embodiment, said at least fire retardant may be present in the at least one adhesive and / or resin comprised in said at least one reinforcement framework.

[0054] In a preferred embodiment, the wear layer or finishing layer can comprise at least one coating layer. For example, the at least one coating layer may comprise a protective coating layer that is at least partially transparent or translucent. In a preferred embodiment, the at least one coating layer can for example be a polyurethane coating, an acrylic coating, and / or an epoxy polyol coating. Such coating can for example be an ultraviolet (UV) or electron beam (EB) curable coating. It is further conceivable that the coating layer comprises a thermoset resin and a photoinitiator cross-linked by a UV, excimer or electron beam curing process.

[0055] It is further conceivable that at least one decorative layer includes a tactile texture, preferably of at least 0.1 mm depth, most preferably at least 0.3mm depth. Such tactile texture may provide an enhanced visual effect. The enhanced visual effect could also be referred to as embossing. In a possible embodiment of the invention, a texture or embossing can be provided during the production process by means of rotary or plate imprinting. It is possible that at least one wear layer, if applied, is embossed with a surface texture design. The texture design can be any design desired, such as the natural texture found in wood, stone and the like. The tactile structure, if applied, may for example have an irregular tactile texture. It is also conceivable that only part of at least one decorative layer is provided with a tactile texture. In another possible embodiment, both the upper surface of the decorative layer and the surface of a chamfer, which may be applied, can include a tactile texture, preferably of at least 0.1 mm dept. Especially when the decorative layer is produced via a lamination process, a single press machine can be used which makes it cost efficient to use a press plate with matching embossing for each decorative pattern in order to obtain a relief pattern on the top surface of the panel that matches the decorative pattern.

[0056] At least one decorative layer may further comprise at least one resin impregnated ply of paper comprising at least one antibacterial agent, preferably zinc oxide (ZnO) and / or silver nanoparticles or the like. It is also conceivable that the resin composition with which at least one ply of paper is impregnated comprises at least one antibacterial agent, preferably metal oxides such as titanium dioxide (TiO2), zinc oxide (ZnO), or isothiazolinone, zinc pyrithione, thiabendazole, and / or silver nanoparticles. The presence of at least one antibacterial agent can be beneficial in case it desired to apply the floor panel or floor covering made of such panel for business, industries or areas where a high hygiene standard is present. In case a wear layer or overlay is applied, it is also conceivable that the antibacterial agent is present in the wear layer or overlay. The antibacterial agent may form integral part of the decorative layer. A panel comprising a decorative layer which comprises at least one antibacterial agent typically provide a much better protection against bacteria, fungus, parasites and / or viruses compared to panels which are covered with an antibacterial agent.

[0057] It is beneficial if at least one decorative layer and at least one core layer are bonded via the provision of heat and / or pressure. At least one decorative layer and at least one core layer can for example be bonded via thermo bonding and / or thermolamination. It is beneficial to apply thermo bonding as for the use of an intermediate adhesive layer between the decorative layer and the core layer can be omitted. The use of the core layer and decorative layer according to the present invention allow the application of a thermo bonding process.

[0058] The invention also related to a method for manufacturing a panel, in particular a panel according to the present invention, comprising the following steps: a) extruding at least one mixture comprising at least one expandable thermoplastic material, such that at least one thermoplastic foamed substrate is formed; b) embedding at least one reinforcement framework within the thermoplastic foamed substrate such that a reinforced core layer is obtained; c) optionally cooling at least part of the core layer; d) adhering at least one decorative layer to at least one surface of the at least one core layer and preferably adhering at least two decorative layer to opposing sides of the panels, in particular to opposing surfaces of the core layer.

[0059] The method provides for a panel having all the advantages as disclosed hereinabove.

[0060] Preferably, step a) and step b) are performed substantially simultaneously. Advantageously, the extruded mixture is still at elevated temperature. This allows easier embedding of the reinforcement framework within the thermoplastic foamed substrate and may create an advantageous density and / or crystallinity reinforcing framework within the melt due to differentials in temperature and / or melt strength

[0061] The adhering in step d) may be a thermolamination step. As such, no separate adhesive is required.

[0062] The mixture may comprise at least one expansion agent, in particular supercritical CO2. This allows for effective foaming the mixture to obtain the thermoplastic foamed substrate of the panel.

[0063] The invention will be further elucidated based on the following non-limitative clauses.

[0064] 1. Panel, comprising:

[0065] - at least one core layer, in particular at least one composite core layer, comprising:

[0066] • at least one thermoplastic foamed substrate; and

[0067] • at least one reinforcement framework; and

[0068] - at least one decorative layer attached to at least one surface of the core layer; wherein at least one core layer comprises a front surface and a back surface located on opposite sides, wherein at least one reinforcement framework is embedded within at least one core layer such that at least part of an outer circumference of at least one framework is located at 20% or less of the thickness of the core layer seen from the front surface and / or back surface of at least one core layer.

[0069] 2. Panel according to clause 1 , wherein at least one reinforcement framework is encapsulated within at least one core layer, and in particular within at least one thermoplastic foamed substrate.

[0070] 3. Panel according to any of the previous clauses, wherein an internal crust layer is formed around at least part of at least one reinforcement framework such that at least part of at least one reinforcement framework is encapsulated by said internal crust layer within at least one core layer, and in particular within at least one thermoplastic foamed substrate.

[0071] 4. Panel according to any of the previous clauses, wherein at least one core layer comprises at least one upper crust layer at the front surface and / or at least one lower crust layer at a back surface.

[0072] 5. Panel according to clause 4, wherein at least one reinforcement framework is located at a distance from at least one upper crust layer and / or at least one lower crust layer.

[0073] 6. Panel according to any of the previous clauses, wherein the at least part of the outer circumference of at least one reinforcement framework is located 10% or less of the thickness of the core layer seen from the front surface and / or back surface of at least one core layer.

[0074] 7. Panel according to any of the previous clauses, wherein at least part of the outer circumference of at least one reinforcement framework is substantially parallel to the front surface and / or back surface of at least one core layer.

[0075] 8. Panel according to any of the previous clauses, wherein at least part of at least one reinforcement framework extends over the thickness of at least one core layer and in particular over the thickness of at least one thermoplastic foamed substrate.

[0076] 9. Panel according to any of the previous clauses, wherein at least one reinforcement framework forms integral part of at least one thermoplastic foamed substrate.

[0077] 10. Panel according to any of the previous clauses, wherein at least part of at least one reinforcement framework is substantially rigid.

[0078] 11 . Panel according to any of the previous clauses, wherein at least part of at least one reinforcement framework is defined by a honeycomb and / or a twinwall and / or strips and / or a cloth-like and / or a grid and / or a mesh and / or a wire-like structure.

[0079] 12. Panel according to any of the previous clauses, wherein at least part of at least one reinforcement framework is defined by strips and / or a cloth-like structure.

[0080] 13. Panel according to any of the previous clauses, wherein at least part of at least one reinforcement framework comprises at least one of the following materials: aluminium, steel, brass, bronze or any combination thereof.

[0081] 14. Panel according to any of the previous clauses, wherein at least one reinforcement framework comprises a rigid thermoplastic composite, a rigid thermoset composite and / or a stone plastic composite (SPC) or any combination thereof.

[0082] 15. Panel according to any of the previous clauses, wherein at least part of at least one reinforcement framework is positioned under an angle with respect to a plane defined by the front surface and / or the back surface of at least one composite layer.

[0083] 16. Panel according to any of the previous clauses, wherein at least one core layer comprises at least two reinforcement frameworks, wherein a first reinforcement framework is positioned at a distance from at least one second reinforcement framework, and preferably wherein at least one first reinforcement framework is arranged at an angle with respect to at least one second reinforcement framework.

[0084] 17. Panel according to any of the previous clauses, comprising at least one decorative layer, in particular at least one digitally printed decorative layer.

[0085] 18. Panel according to any of the previous clauses, wherein at least one core layer is an extruded layer.

[0086] 19. Panel according to any of the previous clauses, wherein at least one thermoplastic foamed substrate is an extruded substrate.

[0087] 20. Panel according to any of the previous clauses, wherein at least one core layer comprises at least one side edge and wherein at least one decorative layer is attached to at least one side edge.

[0088] 21 . Panel according to any of the previous clauses, comprising complementary coupling parts.

[0089] 22. Panel according to any of the previous clauses, wherein a compression strength of at least one reinforcement framework is higher than the compression strength of at least one thermoplastic foamed substrate, measured according to ASTM-D1037 in a direction from the front surface to the back surface of the core layer.

[0090] 23. Panel according to any of the previous clauses, wherein at least part of at least one reinforcement framework is made of the same thermoplastic material as at least one thermoplastic foamed substrate, wherein the density of the at least one reinforcement framework is higher than the density of the thermoplastic foamed substrate.

[0091] 24. Panel according to any of the previous clauses, wherein an average cell volume of at least one thermoplastic foamed substrate is larger than an average cell volume of at least one reinforcement framework. 25. Panel according to any of the previous clauses, wherein at least one thermoplastic foamed substrate and / or at least one reinforcement framework comprises at least one polymer selected from polyvinyl chloride (PVC), polystyrene (PS), polyethylene (PE), high-density polyethylene (HDPE), low-density polyethylene (LDPE), cross-linked polyethylene (XPE), polyurethane (PU), acrylonitrile butadiene styrene (ABS), polypropylene (PP), Polyethylene terephthalate (PET), thermoplastic starch (TPS), cross-linked polystyrene (XPS), styrene acrylonitrile (SAN), polyphenylene oxide (PPO), polylactic acid (PLA), phenolic resin, melamine resin, formaldehyde resin, or any combination thereof.

[0092] 26. Panel according to any of the previous clauses, wherein the density of at least one thermoplastic foamed substrate is lowest at a position most remote from the reinforcement framework and wherein the density of said at least one thermoplastic foamed substrate is highest at another position which is closest to at least part of the at least one reinforcement framework.

[0093] 27. Panel according to any of the previous clauses, wherein the density of at least one thermoplastic foamed substrate has a density gradient.

[0094] 28. Panel according to any of the previous clauses, wherein a density of at least one thermoplastic foamed substrate ranges between 80 and 1000 kg / m3, preferably between 100 and 1000 kg / m3, more preferably between 300 and 1000 kg / m3, such as approximately 600 kg / m3.

[0095] 29. Panel according to any of the previous clauses, wherein at least one thermoplastic foamed substrate and / or at least one reinforcement framework comprises a wood plastic composite (WPG) and / or foamed thermoplastic.

[0096] 30. Panel according to any of the previous clauses, wherein at least one core layer and preferably the panel as such is substantially free of adhesives.

[0097] 31 . Method for manufacturing a panel, in particular a panel according to any of clauses 1 - 30, comprising the following steps: a) extruding at least one mixture comprising at least one expandable thermoplastic material, such that at least one thermoplastic foamed substrate is formed; b) embedding at least one reinforcement framework within the thermoplastic foamed substrate such that a reinforced core layer is obtained; c) optionally cooling at least part of the core layer; d) adhering at least one decorative layer to at least one surface of the at least one core layer.

[0098] 32. Method according to clause 31 , wherein step a) and step b) are performed substantially simultaneously.

[0099] 33. Method according to clause 31 or 32, wherein the adhering in step d) is a thermolamination step.

[0100] 34. Method according to any of clauses 31 - 33, wherein the mixture comprises at least one expansion agent, in particular supercritical CO2.

[0101] The invention will now be elucidated on the basis of non-limitative exemplary embodiments shown in the following figures. Herein shows:

[0102] - Figure 1 a first possible embodiment of a panel according to the present invention;

[0103] - Figures 2a, 2b, and 2c embodiments of panels according to the present invention, wherein a reinforcement framework is located at various positions;

[0104] Figures 3a - 3f represent different possible embodiments of reinforcement frameworks according to the invention; and

[0105] Figures 4a, 4b, 4c and 4d show exploded side views of possible embodiments of panels according to the present invention;

[0106] Within these figures, the same reference number refers to similar or equivalent technical features or elements.

[0107] Figure 1 shows a first possible embodiment of panel 100 according to the present invention. The panel 100 comprises a composite layer 101 and a decorative layer 105. The decorative layer 105 is attached to the composite layer 101 , in particular to an upper surface of the composite layer 101. The composite layer 101 comprises a thermoplastic foamed substrate 103 and an embedded first reinforcement framework 102a and second reinforcement framework 102b. The composite layer 101 comprises an upper surface 101 a and a lower surface 101 b located on opposite sides of the composite layer 101 , wherein the decorative layer 105 is attached to the upper surface 101a. The first reinforcement framework 102a is located near the upper surface 101 a of the composite layer 101 , while the second reinforcement framework 102b is located near the lower surface 101 b of the composite layer 101. Both reinforcement frameworks 102a, 102b are embedded off centre in the composite layer 101 . The panel further comprises a coating layer 104 on top of the decorative layer 1O5.The panel also comprises coupling elements 107 that are part of the composite layer 101 .

[0108] Figures 2a to 2c show embodiments of panels 200, 300, 400 according to the present invention. Figure 2a shows a panel 200 similar to the panel 100 in figure 1 . The panel 200 comprises a reinforcement framework 202 situated in the composite layer 201 near the top of the composite layer201 . A decorative layer 205 is located on top of the composite layer 201 . Figure 2a further shows a part of the panel encircled by a dotted line, enlarged within a circle 206. It can be seen that the reinforcement framework 202 is a mesh-like structure embedded within the thermoplastic foamed substrate 203. Figure 2b shows a panel 300 wherein the reinforcement framework 302 comprises a mesh-like structure that is situated near the bottom of the panel 300 and thus near the bottom of the composite layer 301 . Figure 2b further shows a part of the panel 300 encircled by a dotted line, enlarged within a circle 306. The panel 300 also has a decorative layer 305. Finally, Figure 2c shows a panel 400 having an upper reinforcement framework 402a and a lower reinforcement framework 402b. Both reinforcement frameworks 402a, 402b are embedded off centre in the composite layer 401 . The upper reinforcement framework 402a is embedded in the composite layer 401 , near the decorative layer

[0109] 405. The lower reinforcement framework 402b is embedded in the composite layer 401 , near the bottom of the panel 400. Again, the reinforcement frameworks 402a, 402b have a mesh-like structure, as can be seen in the enlarged part in the circle

[0110] 406. Thermoplastic foamed substrate 403 is situated in between the decorative layer 405 and the upper reinforcement framework 402a, in between the upper reinforcement framework 402a and the lower reinforcement framework 402b, and below the lower reinforcement framework 402b.

[0111] Figures 3a - 3f show different types of reinforcement frameworks 102. Figure 3a shows a reinforcement framework 102 having evenly distributed pores, whereas Figure 3d shows a similar reinforcement framework 102 with a higher number of evenly distributed pores. The pores can also be randomly distributed, as can be seen in a reinforcement framework as shown in Figure 3c. Mesh-like structures, wave-like structures, and large openings, as shown in the reinforcement frameworks 102 in Figures 3d - 3f, respectively, are also possible.

[0112] Figures 4a, 4b, 4c and 4d show schematic representations of exploded side views of possible embodiments of panels 500, 600, 700, 800 according to the present invention. The panels could optionally be provided with coupling parts.

[0113] Figures 4a and 4b show panels 500, 600 comprising a composite layer 501 , 601 comprising a thermoplastic foamed substrate 503, 603 and a reinforcement framework 502, 602. In the panel 501 of Figure 4a the reinforcement framework 502 is located in an upper part of the composite layer 501 , while the reinforcement framework 602 of the panel 600 of Figure 4b is located in a bottom part of the composite layer 601 . Both panels comprise a decorative layer 505, 605, a coating layer 504, 604 on top, and coupling parts 507, 607.

[0114] Figure 4c and 4d show panels 700, 800 comprising a composite layer 701 , 801 comprising a thermoplastic foamed substrate 703, 803. The panels 700, 800 both comprise an upper reinforcement framework 702a, 802a embedded in the thermoplastic foamed substrate 703, 803, near the upper part of the composite layer 701 , 801 , and al lower reinforcement framework 702b, 802b embedded in the thermoplastic foamed substrate 703, 803, near the lower part of the composite layer 701 , 801 . The panel 800 in Figure 4d lacks a decorative layer 705 as present in the panel 700 in Figure 4c. The panel 800 in Figure 4d does have a backing layer 808 to strengthen the panel 800. Both panels comprise a coating layer 704, 804 as a top layer, and coupling parts 707, 807.

[0115] It will be apparent that the invention is not limited to the working examples shown and described herein, but that numerous variants are possible within the scope of the attached claims that will be obvious to a person skilled in the art.

[0116] The verb “comprise” and conjugations thereof used in this patent publication are understood to mean not only “comprise”, but are also understood to mean the phrases “contain”, “substantially consist of”, “formed by” and conjugations thereof.

Claims

Claims1 . Panel, in particular a furniture panel, comprising:- at least one core layer, in particular at least one composite core layer, comprising:• at least one thermoplastic foamed substrate; and• at least one reinforcement framework, wherein at least part of the at least one reinforcement framework comprises aluminium; and- at least two decorative layers provided at opposing sides of the panel; wherein the at least one core layer comprises a front surface and a back surface located on opposite sides, wherein the at least one reinforcement framework is embedded within at least one core layer such that at least part of an outer circumference of the at least one framework is located at 20% or less of the thickness of the at least one core layer seen from the front surface and / or back surface of at least one core layer, wherein the panel, and in particular the at least one core layer, comprises at least one coupling part for coupling with an adjacent panel.

2. Panel according to claim 1 , wherein at least one reinforcement framework is encapsulated within at least one core layer, and in particular within at least one thermoplastic foamed substrate.

3. Panel according to any of the previous claims, wherein an internal crust is present within the polymeric matrix of the thermoplastic foamed substrate around at least part of at least one reinforcement framework.

4. Panel according to any of the previous claims, wherein an internal crust layer is formed around at least part of at least one reinforcement framework such that at least part of at least one reinforcement framework is encapsulated by said internal crust layer within at least one core layer, and in particular within at least one thermoplastic foamed substrate.

5. Panel according to any of the previous claims, wherein at least one core layer comprises at least one upper crust layer at the front surface and / or at least one lower crust layer at a back surface.

6. Panel according to claim 5, wherein at least one reinforcement framework is located at a distance from at least one upper crust layer and / or at least one lower crust layer.

7. Panel according to any of the previous claims, wherein at least one reinforcement framework is embedded within and / or provided onto at least one core layer by means of at least one adhesive.

8. Panel according to claim 7, wherein at least one adhesive is chosen from the group of: polyurethane (PU), epoxy, acrylic, cyanoacrylate (CA) and / or polyvinyl acetate (PVA) adhesives.

9. Panel according to any of the previous claims, wherein the at least one substrate has an acoustic impedance of at most 6MRayl, more preferably at most 5MRayl, most preferably at most 4MRayl.

10. Panel according to any of the previous claims, wherein the at least one reinforcement framework comprises at least one reinforcing material having an acoustic impedance of at least 4 MRayl, more preferably at least 6MRayl, preferably at least 8MRayl.11 . Panel according to any of the previous claims, wherein a first decorative layer is attached to the front surface of the at least one core layer and a second decorative layer is attached to the back surface of the at least one core layer.

12. Panel according to claim 11 , wherein the first decorative layer is substantially identical to the second decorative layer.

13. Panel according to any of the previous claims, wherein the at least part of the outer circumference of at least one reinforcement framework is located 10% or less of the thickness of the core layer seen from the front surface and / or back surface of at least one core layer.

14. Panel according to any of the previous claims, wherein at least part of the outer circumference of at least one reinforcement framework is substantially parallel to the front surface and / or back surface of at least one core layer.

15. Panel according to any of the previous claims, wherein at least part of at least one reinforcement framework extends over the thickness of at least one core layer and in particular over the thickness of at least one thermoplastic foamed substrate.

16. Panel according to any of the previous claims, wherein at least one reinforcement framework forms integral part of at least one thermoplastic foamed substrate.

17. Panel according to any of the previous claims, wherein at least part of at least one reinforcement framework is substantially rigid.

18. Panel according to any of the previous claims, wherein at least part of at least one reinforcement framework is defined by a honeycomb and / or a twinwall and / or strips and / or a cloth-like and / or a grid and / or a mesh and / or a wire-like structure.

19. Panel according to any of the previous claims, wherein at least part of at least one reinforcement framework is defined by strips and / or a cloth-like structure.

20. Panel according to any of the previous claims, wherein at least part of at least one reinforcement framework comprises at least one of the following materials: steel, brass, bronze or any combination thereof.21 . Panel according to any of the previous claims, wherein at least one reinforcement framework comprises a rigid thermoplastic composite, a rigid thermoset composite and / or a stone plastic composite (SPC) or any combination thereof.

22. Panel according to any of the previous claims, wherein at least part of at least one reinforcement framework is positioned under an angle with respect to aplane defined by the front surface and / or the back surface of at least one composite layer.

23. Panel according to any of the previous claims, wherein at least one core layer comprises at least two reinforcement frameworks, wherein a first reinforcement framework is positioned at a distance from at least one second reinforcement framework, and preferably wherein at least one first reinforcement framework is arranged at an angle with respect to at least one second reinforcement framework.

24. Panel according to any of the previous claims, comprising at least one decorative layer, in particular at least one digitally printed decorative layer.

25. Panel according to any of the previous claims, wherein at least one core layer is an extruded layer.

26. Panel according to any of the previous claims, wherein at least one thermoplastic foamed substrate is an extruded substrate.

27. Panel according to any of the previous claims, wherein at least one core layer comprises at least one side edge and wherein at least one decorative layer is attached to at least one side edge.

28. Panel according to any of the previous claims, wherein at least one coupling part is a groove or a tongue.

29. Panel according to any of the previous claims, wherein the panel comprises complementary coupling parts on opposing side edges of the panel.

30. Panel according to any of the previous claims, wherein a compression strength of at least one reinforcement framework is higher than the compression strength of at least one thermoplastic foamed substrate, measured according to ASTM-D1037 in a direction from the front surface to the back surface of the core layer.31 . Panel according to any of the previous claims, wherein at least part of at least one reinforcement framework is made of the same thermoplastic material as at least one thermoplastic foamed substrate, wherein the density of the at least one reinforcement framework is higher than the density of the thermoplastic foamed substrate.

32. Panel according to any of the previous claims, wherein an average cell volume of at least one thermoplastic foamed substrate is larger than an average cell volume of at least one reinforcement framework.

33. Panel according to any of the previous claims, wherein at least one thermoplastic foamed substrate and / or at least one reinforcement framework comprises at least one polymer selected from polyvinyl chloride (PVC), polystyrene (PS), polyethylene (PE), high-density polyethylene (HDPE), low-density polyethylene (LDPE), cross-linked polyethylene (XPE), polyurethane (PU), acrylonitrile butadiene styrene (ABS), polypropylene (PP), Polyethylene terephthalate (PET), thermoplastic starch (TPS), cross-linked polystyrene (XPS), styrene acrylonitrile (SAN), polyphenylene oxide (PPO), polylactic acid (PLA), phenolic resin, melamine resin, formaldehyde resin, or any combination thereof.

34. Panel according to any of the previous claims, wherein the density of at least one thermoplastic foamed substrate is lowest at a position most remote from the reinforcement framework and wherein the density of said at least one thermoplastic foamed substrate is highest at another position which is closest to at least part of the at least one reinforcement framework.

35. Panel according to any of the previous claims, wherein the density of at least one thermoplastic foamed substrate has a density gradient.

36. Panel according to any of the previous claims, wherein at least one core layer comprises at least one mineral filler.

37. Panel according to any of the previous claims, wherein the at least one core layer comprises talc and limestone.

38. Panel according to any of the previous claims, wherein a density of at least one thermoplastic foamed substrate ranges between 80 and 1000 kg / m3, preferably between 100 and 1000 kg / m3, more preferably between 300 and 1000 kg / m3, such as approximately 600 kg / m3.

39. Panel according to any of the previous claims, wherein at least one thermoplastic foamed substrate and / or at least one reinforcement framework comprises a wood plastic composite (WPG) and / or foamed thermoplastic.

40. Panel according to any of the previous claims, wherein at least one thermoplastic foamed substrate comprises at least one fire retardant.41 . Panel according to any of the previous claims, wherein at least one thermoplastic foamed substrate comprises aluminium trihydrate (ATH), magnesium dihydroxide (MDH), halogenated compounds, phosphorus-based compounds, nitrogen-based compounds and / or expandable graphite.

42. Panel according to any of the previous claims, wherein at least one core layer and preferably the panel as such is substantially free of adhesives.

43. Method for manufacturing a panel, in particular a panel according to any of claims 1 - 42, comprising the following steps: a) extruding at least one mixture comprising at least one expandable thermoplastic material, such that at least one thermoplastic foamed substrate is formed; b) embedding at least one reinforcement framework within the thermoplastic foamed substrate such that a reinforced core layer is obtained; c) optionally cooling at least part of the core layer; d) adhering at least two decorative layer to opposing sides of the panels, in particular to opposing surfaces of the core layer.

44. Method according to claim 43, wherein step a) and step b) are performed substantially simultaneously.

45. Method according to claim 43 or 44, wherein the adhering in step d) is a thermolamination step.

46. Method according to any of claims 42 - 45, wherein the mixture comprises at least one expansion agent, in particular supercritical CO2.

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