Decorative plate, process for producing decorative plate and extrusion production line

Abstract

The invention relates to a decorative panel, in particular a floor, a ceiling, a building or a wall panel, as well as to a process and an extrusion line for producing the decorative panel. The invention relates to a decorative panel comprising at least one core layer and at least one decorative top layer, where the at least one core layer comprises at least one structural core component and at least one balancing core component, where the at least one structural core component comprises at least one mineral filler and at least one first polymer composition, and the at least one balancing core component comprises at least one second polymer composition. And the at least one balancing core component comprises at least one second polymer composition.

Description

Technical Field

[0001] The present invention relates to a decorative board. The present invention also relates to a process for producing a decorative board. The present invention further relates to an extrusion production line for producing a decorative board. Background Art

[0002] Halogenated amorphous thermoplastics, such as polyvinyl chloride (PVC), are often used in the production of decorative resilient flooring, ceiling panels, wall panels, furniture and / or building panels, such as decking consisting of a core layer and a decorative top layer, because of their beneficial properties including a balance between rigidity and flexibility, elasticity and chemical resistance, and ease of processing due to their wide temperature processing window, low processing temperature, fast cooling rate and relatively low melt viscosity, and the absence of crystalline residual stresses, which allows these materials to be easily formed into stable and uniform sheets such as decking, and their inherent properties allow the use of interlocking coupling mechanisms in such decking. However, the use of halogenated amorphous thermoplastics such as polyvinyl chloride (PVC) in building materials is a subject of ongoing debate due to environmental and health issues. Some of the key issues associated with the use of PVC in building materials and components include the environmental impact of its disposal (release of hazardous compounds such as dioxins when incinerated), toxic emissions during processing (including halogens such as chlorides and fluorides and hydrogen chloride gas), the use of harmful plasticizers to improve flexibility (such as phthalate plasticizers), recycling challenges if mixed with other materials, which require thorough separation before recycling, etc. Therefore, there is an increasing demand for the use of alternative materials that are essentially halogen-free, preferably plasticizer-free and more easily recyclable to produce decorative (resilient) panels and / or their composite layers, such as core layers, carrier layers, decorative top layers, wear layers, etc. As alternatives to PVC, people are considering the use of semi-crystalline thermoplastic polymers, more specifically semi-crystalline polyolefin polymers, such as polyethylene (PE), polyethylene terephthalate (PET), polybutene-1 (PB-1) and / or polypropylene (PP).

[0003] However, due to the formation of the crystal structure, semi-crystalline thermoplastics can develop residual stresses during cooling and solidification, which can cause the panels to warp and bend during production and use, and when produced in accordance with the state of the art may prove to be too brittle to be used as decorative floor, wall and / or ceiling panels. In addition, difficulties may arise during the manufacture of such decorative panels due to their high processing temperatures, rapid cooling rates and low viscosity compared to amorphous thermoplastics, resulting in uneven and / or unstable decorative panels. Summary of the invention

[0004] The object of the present invention is to provide a decorative panel, a production process and / or an extrusion line which can meet at least part of the above requirements and / or at least partly overcome the disadvantages of the prior art.

[0005] The invention provides a decorative panel, in particular a floor, ceiling, building or wall panel, comprising at least one core layer and preferably at least one decorative top layer, wherein the at least one core layer comprises at least one structural core component and / or at least one balancing core component, wherein the at least one structural core component has a first hardness and / or crystallinity, wherein the at least one balancing core component has a second hardness and / or crystallinity. The second hardness and / or crystallinity is preferably 3-35% higher than the first hardness and / or crystallinity.

[0006] The invention also provides a decorative panel, in particular a floor, ceiling, building or wall panel, comprising at least one core layer and preferably at least one decorative top layer, wherein the at least one core layer comprises at least one structural core component and / or at least one balancing core component, wherein the at least one structural core component comprises at least one mineral filler and at least one first polymer composition, and wherein the at least one balancing core component comprises at least one second polymer composition.

[0007] According to the invention, the decorative panel benefits from at least one core layer comprising at least one structural core component and at least one balancing core component, due to the combination of at least one structural core component and at least one balancing core component, wherein at least one structural core component has a first hardness and / or crystallinity, and wherein at least one balancing core component has a second hardness and / or crystallinity, wherein the second hardness and / or crystallinity is preferably 3-35% higher than the first hardness and / or crystallinity, and / or, the combination of at least one structural core component comprising at least one mineral filler and at least one first polymer composition and at least one balancing core component comprising at least one second polymer composition results in a dimensionally stable substantially semi-rigid decorative panel. The decorative panel according to the invention can be made such that the decorative panel is substantially free of halogens and / or plasticizers. Since the core layer comprises at least one structural core component and at least one balancing core component, the core layer itself substantially comprises an integrated balancing layer. At least one balancing core component substantially forms an integrally formed balancing layer within the core layer. In practice, decorative panels generally require an additional balancing layer to provide sufficient stability to the decorative panel. The use of an internal and / or integrated balancing layer within the core layer makes the product more stable and thus an additional production step, such as laminating at least one balancing layer to the core layer, can be omitted. Thus, such a decorative panel and its production method have significant advantages.

[0008] The decorative panel according to the invention may in particular be a substantially elastic and / or flexible panel suitable for adhesive mounting. For example, it is conceivable that the stiffness of at least one core layer is lower than 3,500 MPa, preferably lower than 2,000 MPa, and / or lower than 75 mm, more preferably lower than 50 mm or in the range of 25 to 50 mm when tested by a mandrel test according to ASTM F137. The decorative panel according to the invention may in particular be a substantially semi-rigid decorative panel comprising a core layer carrying an interlocking mechanism suitable for a floating device. For example, it is also conceivable that the stiffness of at least one core layer is in the range of 1,800 to 10,000 MPa, preferably in the range of 3,500 to 5,500 MPa, in particular when measured according to EN 310 or ASTM D790, and / or in the range of 50 to 350 mm when tested by a mandrel test according to ASTM F137.

[0009] When referring to the first polymer composition, it may also be referred to as the first polymer. When referring to the second polymer composition, it may also be referred to as the second polymer.

[0010] At least one core layer of the decorative panel according to the present invention is an extruded core layer. According to the present invention, the core layer can be formed by a single extrusion step, which is capable of forming the core layer. At least one core layer of the decorative panel can also be a coextruded core layer, preferably a single manifold coextruded core layer. At least one core layer is usually formed by coextrusion of a material forming at least one structural core component and a material forming at least one balancing core component. According to the present invention, it is also conceivable that at least one core layer includes a plurality of structural core components and / or a plurality of balancing core components. An embodiment is conceivable in which at least one structural core component is substantially closed and / or located between at least two balancing core components.

[0011] The at least one first polymer composition and / or the at least one second polymer composition preferably comprises at least one semi-crystalline thermoplastic polymer. It is also conceivable that the at least one first polymer composition and / or the at least one second polymer composition comprises or is formed of a semi-crystalline polyolefin and / or a semi-crystalline polymer, preferably a non-halogen semi-crystalline thermoplastic polymer. Such a combination of a first polymer composition and at least one mineral filler has been found to be successful as a structural core component of the core layer. For example, the at least one first polymer composition and / or the at least one second polymer composition may comprise or be formed of polyethylene (PE), polyethylene terephthalate (PET), polybutene-1 (PB-1), polymer environmental resin (PER), polylactic acid (PLA) and / or polypropylene (PP). The at least one first polymer composition and / or the at least one second polymer composition preferably has a relatively low glass transition temperature, for example a glass transition temperature greater than or equal to -50°C.

[0012] At least one structural core component preferably comprises at least 60% by weight, preferably at least 70% by weight, most preferably at least 75% by weight of at least one mineral filler. It is also conceivable that at least one structural core component preferably comprises 60 to 85% by weight, preferably 70 to 80% by weight, more preferably about 75% by weight of at least one mineral filler. At least one structural core component preferably comprises 5-30% by weight, preferably 10-20% by weight and more preferably about 15% by weight of at least one first polymer composition. In a further preferred embodiment, at least one structural core component, in particular at least one first polymer composition, comprises at least one semi-crystalline thermoplastic polymer and / or at least one plastic additive. At least one structural core component may comprise 5-30% by weight, preferably 10-20% by weight and more preferably about 15% by weight of at least one plastic additive, the remaining 5-30% by weight, preferably 5-15% by weight, most preferably about 10% by weight comprising at least one semi-crystalline polymer. According to the present invention, the combination of at least one mineral filler, at least one semi-crystalline thermoplastic polymer and at least one plastic additive can improve processing properties, reduce phase separation and interfacial energy, thereby enhancing interfacial adhesion, melt flow characteristics, adhesion of the polymer phase, reduce aggregation of mineral components, and improve the flexibility, impact resistance and elasticity of the resulting composite material. In short, it improves the overall compatibility and performance of the composition, thereby reducing thermal expansion, improving dimensional stability, and enhancing the mechanical properties of the core layer and the board itself. It further makes the resulting composition particularly suitable as a component of a decorative building board, preferably a structural core component, such as a decorative floor, wallboard, building and / or ceiling that needs to withstand long-term wear.

[0013] In one possible embodiment, at least one structural core component, in particular at least one first polymer composition, comprises at least one plastic additive. It must be noted that within the scope of the present invention, plastic additives are different from elastomeric additives. Plastic additives combine the properties of elastomers and plastics. It is conceivable that at least one structural core component contains 2-30% by weight, preferably 5-20% by weight, more preferably about 10-15% by weight of at least one plastic additive. For example, the plastic additive is a copolymer of a semi-crystalline thermoplastic polymer with ethylene and / or ethylene units. It is conceivable that the copolymer contains 2-30% by weight, preferably 5-20% by weight, more preferably about 10-15% by weight of the ethylene and / or ethylene units. It is presumed that the application of a specific weight percentage of ethylene content reduces the crystallinity of the resulting mixture, reduces the melting point of the melt, and exhibits a more amorphous structure compared to pure isotactic semi-crystalline polyolefins such as iPP and / or iBP-1. It is conceivable that the at least one plastic additive is prepared by metallocene catalysis and / or solution method.

[0014] At least one mineral filler of at least one structural core component is selected from, for example, limestone, talc, calcium carbonate, magnesium, magnesium oxide, magnesium sulfate, magnesium chloride, kaolin, talc, dolomite, calcite, iron oxide, magnesium hydroxide or magnesium dihydrate (MDH), aluminum hydroxide or aluminum trihydrate (ATH), sand and combinations thereof. At least one mineral filler is particularly configured to be mixed with at least one first polymer composition. The fineness of at least one mineral filler can be in the range of 80-1200 mesh, preferably 200-1000 mesh, more preferably 350-450 mesh or 800-1000 mesh. Within this fineness range, the mixing uniformity of the mineral filler and the first polymer is significantly improved. For example, the core layer includes 60-85 parts by weight, preferably 70-80 parts by weight, and most preferably about 75 parts by weight of filler. It is also conceivable that, for example, at least one structural core component contains 60-85 parts by weight, preferably 70-80 parts by weight, and most preferably about 75 parts by weight of filler. It is found that the amount of such filler can significantly control the thermal expansion rate of the first polymer composition in the composition of the structural core component to not exceed 0.2%, while also ensuring that the decorative panel has sufficient rigidity and dimensional stability.

[0015] In another embodiment, it is conceivable that at least one core layer, in particular at least one structural core member, may include at least one additional filler selected from the group consisting of steel, glass, wood, acrylic, alumina, curaua, carbon, cellulose, coconut, kevlar, nylon, perlon, expanded microspheres, PVC, PVA, rock wool, viburnum and fique. Adding at least one additional filler selected from the above materials helps to improve the water resistance and / or fire resistance of the decorative board.

[0016] In one possible embodiment, at least one structural core component comprises at least one plastic and / or elastomeric additive. In a preferred embodiment, at least one structural core component comprises at least one semi-crystalline thermoplastic polymer or at least one copolymer of a semi-crystalline thermoplastic polyolefin and ethylene. Possibly, if applicable, the semi-crystalline polyolefin is a polyolefin plastomer and / or a polyolefin elastomer, more preferably a propylene / ethylene copolymer. The plastic additive preferably has a viscosity of 0.8 to 1 g / cm 3 , especially 0.862 to 0.912 g / cm 3density. It is further conceivable that the at least one plastic and / or elastic additive comprises at least one elastic polyolefin, such as an elastic polypropylene, comprising isotactic, syndiotactic and / or random polyolefin blocks. It is conceivable that the blocks are alternating and / or repeating in a regular order, giving the resulting mixture a higher degree of flexibility and impact resistance compared to pure isotactic additives. Preferably, at least one structural core component, in particular at least one first polymer composition, comprises at least one copolymer of propylene and ethylene, and the copolymer more preferably comprises at least one polar functional group selected from hydroxyl, ether and carbonyl. At least one first polymer composition of at least one structural core component preferably comprises at least one plastic and / or elastic polyolefin comprising isotactic, syndiotactic and / or random polyolefin blocks. It is conceivable that the addition of vinyl groups to the plastic additive can improve or solve at least some of the shortcomings of the material by improving adhesion, reducing brittleness, improving processing properties and improving thermal properties. In one possible embodiment, the ethylene units in at least one first polymer composition, characterized by a carbon double bond C=C, can be further chemically modified to introduce polar functional groups, which can enhance the affinity of the copolymer for adhesives and other polar materials. The polar functional groups may include carbonyl (C=O) groups, hydroxyl (OH) groups and / or ether groups (COC). It is conceivable that these polar functional groups increase the surface energy of the copolymer, which may improve adhesion and lamination strength when combined with other layers such as a decorative top layer.

[0017] It is conceivable that the crystallinity of at least one balancing core component is 3-35% higher than the crystallinity of at least one structural core component and / or the Shore D hardness of at least one balancing core component is 3-35% higher than the Shore D hardness of at least one structural core component. The desired crystallinity and / or Shore D hardness of at least one region of the core layer makes it possible to effectively achieve the lamination of additional layers such as decorative top layers. Therefore, in one possible embodiment, the crystallinity gradient of at least one core layer of at least one core component, preferably at least one structural core component, is non-uniform throughout the volume. For example, this can be demonstrated by the variation in the Shore D hardness of the structural core component and the balancing core component. Optionally, the crystallinity inside the core layer can be reduced compared to the crystallinity of the outer surface of the polymer sheet. The Shore D hardness of different materials measured with a durometer is shown in the following table:

[0018]

[0019] It is believed that this different degree of hardness and / or crystallinity enhances the thermal stability of the core layer and the entire decorative panel. Experiments have found that this uneven crystallinity and / or hardness in the core layer improves the thermal stability of the decorative panel, especially when measured according to ISO23999, the thermal shrinkage of the polymer sheet and / or the entire decorative panel is less than or equal to 0.25%, and when measured according to the ISO23999 standard (heated to 60°C and measured at 60°C), the expansion rate of the core layer and / or the entire decorative panel is less than or equal to 0.13%. Therefore, the decorative panel according to the present invention can maintain its structural integrity, mechanical properties and functions at higher temperatures. Therefore, in a preferred embodiment, the structure of the core layer can be designed to facilitate the formation of crystallinity and / or hardness differences and / or gradients in the core layer. The Shore D hardness measured on at least one surface layer of at least one core layer may be 5-10% higher than the Shore D hardness measured on the side or middle of the core layer, preferably 20-40%, and most preferably about 30-35%. Therefore, it is conceivable and desirable that at least one of the structural core components has a lower hardness, particularly Shore D hardness, than the balancing core component.

[0020] At least one first polymer composition and / or at least one second polymer composition preferably comprise at least one polyolefin.At least one second polymer comprises polyethylene (PE), polyethylene terephthalate (PET), polybutene-1 (PB-1), polymer environmentally friendly resin (PER), polylactic acid (PLA) and / or polypropylene (PP).At least one first polymer composition may be different from at least one second polymer composition.However, it is also conceivable that at least one first polymer composition is substantially the same as at least one second polymer composition.This is conducive to the recycling of decorative panels.In a preferred embodiment, at least one first polymer composition and / or at least one second polymer composition comprise at least one isotactic polyolefin, preferably isotactic polypropylene.At least one balancing core component may also be substantially composed of isotactic polyolefins, such as isotactic polypropylene.

[0021] At least one structural core component can be located on the top of at least one core layer and at least one balancing core component can be located on the bottom of at least one core layer. The top can also be called the first side and / or the bottom can be called the second side. The first side or the top is preferably close to the decorative top layer. The decorative layer can be attached to the upper side of the core layer. The combination of at least one structural core component and at least one balancing core component according to the invention provides the core layer itself with beneficial properties in terms of strength and / or stiffness. The core layer according to the invention can be free of a reinforcement layer.

[0022] The at least one decorative layer comprises, for example, at least one semi-crystalline polymer, preferably at least one non-halogen semi-crystalline thermoplastic polymer. In another possible embodiment, the at least one decorative top layer comprises polypropylene, in particular a polypropylene foil. The at least one decorative top layer may comprise at least one polypropylene wear layer having a thickness of at least 0.1 mm, for example at least a portion of the polypropylene wear layer being transparent.

[0023] In a preferred embodiment, at least one core layer, in particular at least one structural core component, comprises 1-5 parts by weight, preferably up to 3 parts by weight, and more preferably up to 1.5 parts by weight of a stabilizer, the stabilizer comprising at least one compound selected from the group consisting of hindered phenols, phenolic stabilizers, phenol-thioester stabilizers, phosphites, phosphonates, thioethers, hydroxylamines, hindered amine light stabilizers (HALS), benzoates, UV absorbers, stearic acid, zinc oxide, magnesium hydroxide, calcium stearate and / or metal oxides. Stabilizers within this range can improve the melt flow index (MFI) of the core layer composition by reducing the effect of temperature changes on the physical properties of modified polypropylene, thereby improving the stability of the composition and the core layer itself. Therefore, the physical properties of the core layer, such as compressive strength, etc., are enhanced to a certain extent. It can also reduce the stress concentration of the core layer, thereby improving the impact strength of the decorative board, and reduce the risk of thermal degradation and / or oxidative degradation by scavenging free radicals and intermediates such as (hydrogen) peroxides. It is conceivable that the stabilizer can also include a material selected from acrylic acid, zinc phosphate and a combination thereof.

[0024] In a preferred embodiment, the core layer, in particular at least one structural core component, comprises 1-5 parts by weight, preferably up to 3 parts by weight, more preferably up to 1.5 parts by weight of a coupling agent, the coupling agent comprising at least one compound selected from the group of titanates, maleic anhydride grafted polypropylene, silanes and epoxidized fatty acid esters. Preferably, the coupling agent is a titanate coupling agent. It has been found that the addition of a titanate coupling agent in a specific amount can significantly enhance the PP composite material if applied. It significantly improves the compatibility and dispersibility of the composite material, thereby enhancing the mechanical properties of the composite material, such as increasing tensile strength and Young's modulus and improving aging resistance. The presence of at least one coupling agent can prevent agglomeration of inorganic materials, thereby ensuring uniform distribution of inorganic materials throughout the composite material. This increases the stiffness, toughness, elastic modulus and hardness characteristics of the decorative panel. The at least one coupling agent may also include at least one organofunctional coupling agent, which enables the use of relatively high levels of inorganic materials. In fact, the content of inorganic material can be increased compared to conventionally applied composites, since the organic functional groups enhance the overall properties of the composite. Conceivably, the coupling agent may include silicon, titanium or zirconium. It is also conceivable that the coupling agent is selected from the group comprising monoalkoxy titanate, titanium triisostearoyl isopropoxide, isoprophyl triisostearoyl titanate, distearoyl isopropoxy aluminate, neopentyl (diallyl) oxy tri (dioctyl) pyrophosphate titanate, cyclo [dineopentyl (diallyl)] pyrophosphate dineopentyl (diallyl) zirconate or combinations and derivatives thereof. In one embodiment, if a lubricant is applied, it is selected from the group consisting of zinc fatty acids, polyethylene waxes and combinations thereof. These lubricants are all commercially available. The presence of the lubricant can further increase the uniformity of component mixing, thereby improving the molding effect of the decorative board.

[0025] In another embodiment, at least one core layer further comprises a pigment, a modifier, a fiber, such as glass fiber, wood, straw and / or hemp. The fiber can be loose fibers and / or interconnected fibers to form a woven or non-woven layer. In one embodiment, the core layer has a thickness of at least 1 mm. For example, the thickness of the core layer may be between 2 and 10 mm, preferably between 3 and 8 mm, or between 4 and 7 mm.

[0026] In one embodiment, at least one core layer has a surface energy of at least 35 dynes / cm, more preferably at least 40 dynes / cm, and most preferably at least 45 dynes / cm. For example, such a surface energy of the core layer is achieved by surface modification of the core layer, such as by chemical modification, corona treatment, plasma treatment and / or polymer modification. The surface energy of the core layer can also be increased by adding a plastic additive containing vinyl groups. It is conceivable that the addition of a plastic additive with vinyl groups can improve adhesion, reduce brittleness, improve processability and change the thermal properties of the core layer. In one embodiment, the ethylene units in the copolymer, represented by the carbon double bond C=C, can be further chemically modified to introduce polar functional groups, which can enhance the affinity of the copolymer for adhesives and other polar materials. The polar functional groups can include carbonyl (C=O), hydroxyl (OH) and / or ether (COC). It is conceivable that these polar functional groups increase the surface energy of the copolymer, thereby improving adhesion and lamination strength when combined with other layers (such as a decorative top layer). It has been found that within this surface energy range, effective bonding between the core layer and the top layer (ie, the polypropylene-based top layer) is achieved. This solves the problem of the prior art that conflicting substrates (usually plastics) cannot be effectively bonded.

[0027] In a preferred embodiment according to the present invention, at least one decorative top layer may include at least one wear-resistant layer or protective coating, at least one paint layer and / or at least one decorative layer providing the desired visual effect for the final product. In one embodiment, the decorative top layer may also include a reinforcing layer. In a preferred embodiment, the decorative top layer includes at least one substantially transparent wear-resistant layer or protective coating. The wear-resistant layer may include a transparent layer of one or more layers of thermoplastic resin or thermosetting resin. Non-limiting examples that can be used for thermoplastic or thermosetting materials are polyvinyl chloride (PVC), polystyrene (PS), polyethylene (PE), polyurethane (PU), acrylonitrile butadiene styrene (ABS), polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polytrimethylene terephthalate (PTT), polyethylene naphthalate (PEN), phenolic resin and / or melamine or formaldehyde resin. The wear-resistant layer may also be in a liquid or paste form made of a thermosetting resin, such as but not limited to phenolic resin and / or melamine or formaldehyde resin. The wear layer may comprise or consist essentially of an inherently scratch-resistant thermosetting resin impregnating a carrier layer (e.g., paper or lignocellulose). An advantage of the latter embodiment is that the urea-formaldehyde also functions as a relatively scratch-resistant wear layer. Typically, the preferred thickness of the wear layer structure in the decorative panel of the present invention is in the range of 0.1 to 2.0 mm, more preferably between 0.15 mm and 1 mm, and most preferably between 0.2 mm and 0.8 mm. It is conceivable that the thickness of the wear layer (if applied) is greater than the thickness of the decorative layer (if used). For example, at least one wear layer has a thickness of about 0.15 to 1 mm. In this embodiment, the total thickness of the decorative top layer is typically between 0.17 and 1.07 mm. The at least one wear layer may, for example, partially cover the upper surface of the decorative layer, more preferably at least cover 50% of the upper surface of the decorative layer, and most preferably, the at least one wear layer covers the entire upper surface of the decorative layer. It is conceivable that the at least one wear layer may further contain an abrasive to improve its wear resistance. Non-limiting examples of the abrasive are: aluminum oxide, such as quartz, silicon dioxide, corundum, silicon carbide, glass, glass beads, glass balls, diamond particles, hard plastics, reinforced polymers and organics, or combinations thereof. For example, at least one wear-resistant layer can be based on any thermoplastic or thermosetting material. The wear-resistant layer can further include fillers, such as fillers based on calcium, carbonate, talc or magnesium.

[0028] In one possible embodiment, the decorative top layer consists essentially of a carrier material layer which is designed to have a decorative pattern on the upper side. Suitable materials are, for example, woven, extruded or calendered plastic meshes, sheets or films. Non-limiting examples of thermoplastic or thermosetting materials that can be used are polyvinyl chloride (PVC), polystyrene (PS), polyethylene (PE), polyurethane (PU), acrylonitrile butadiene styrene (ABS), polypropylene (PP), polybutylene terephthalate (PBT), polytrimethylene terephthalate (PTT), polyethylene naphthalate (PEN), phenolic resins and / or melamine or formaldehyde resins.

[0029] Optionally, the decorative top layer may comprise at least one cellulose base layer and possibly a cured resin, wherein the cellulose base layer is preferably paper, wood veneer, bamboo veneer, etc. Such a decorative top layer may comprise a plurality of such resin impregnated paper layers or wood veneer layers.

[0030] In another alternative embodiment, the decorative panel according to the present invention, in particular the structural core component, comprises 20-30 parts by weight of a modified polypropylene resin, 20-80 parts by weight of a filler, 1-5 parts by weight of a stabilizer and 1-5 parts by weight of a coupling agent. It has been found that the optimized ratio of raw materials in the core layer composition improves the melt fluidity of the polypropylene resin, thereby also significantly improving the production process of the decorative panel. The flow rate of the modified PP resin ranges from 1-7 g / 10min, more preferably 1.5-5 g / 10min, and most preferably 2-4 g / 10min. It has been found that such a melt flow rate can prevent the PP resin from flowing out of the production line, making it significantly easier to process (such as extrusion, molding, etc.). In addition, this melt flow rate enables the modified PP resin to be sheared more effectively, so that the modified PP resin is basically completely mixed with other raw materials, especially the filling material. Due to the uniform mixing of the core layer composite material, the produced decorative panel can be prevented from being delaminated. In one embodiment, the modified PP resin contains 1-5 parts by weight, preferably 2-4 parts by weight, and more preferably 2.1-2.5 parts by weight of maleic anhydride grafted polypropylene (PP-g-MAH). The presence of such an amount of PP-g-MAH in the modified PP resin improves the interfacial adhesion between the polypropylene and other components of the core layer, and has a higher adhesion to the filler material. Therefore, the modified PP resin can be uniformly mixed with other raw materials. In addition, the addition of PP-g-MAH significantly improves the melt fluidity of the modified PP resin. It is conceivable that the degree of polymerization of the modified PP resin is about 800-1000. It is also conceivable that the molecular weight of the modified PP resin is about 850-1200. Studies have found that within this range, the performance of the modified PP resin is optimized, and its properties such as tensile strength are enhanced. This makes the structure of the core layer more stable and less prone to delamination or breakage. In another embodiment of the present invention, the modified PP resin is considered to be a polyolefin-modified PP resin, an acrylic grafted PP resin, and a combination thereof. It is conceivable that the modified PP resin comprises a combination of 5-20 parts by weight of a polyolefin-modified PP resin and 5-20 parts by weight of an acrylic-grafted PP resin.

[0031] In a possible embodiment, at least one core layer comprises at least two layers, wherein the first layer is formed by at least one structural core component, wherein the second layer is composed of at least one balancing core component. It is further conceivable that at least one structural core component is a highly filled composition, which comprises at least 60% by weight, more preferably at least 70% by weight, most preferably at least 75% by weight of mineral filler and up to 30% by weight of at least one first polymer, such as a polymer resin, preferably at least two polymer resins, wherein at least one resin is selected from the group of semi-crystalline polyolefins, including but not limited to PP, POP, POE, polyolefin plastomers, polyolefin elastomers, plastic additives, PE, PB-1, and / or, polypropylene / ethylene copolymers. It is conceivable that at least one structural core component comprises at least one semi-crystalline polyolefin and at least one plastic additive. In a preferred embodiment, the semi-crystalline polyolefin is polypropylene, and the plastic additive is a polyolefin plastomer and / or a polyolefin elastomer, more preferably a propylene / ethylene copolymer. In a preferred embodiment, at least one structural core component comprises up to 15% by weight of PP, and at least 10% by weight, preferably at least 15% by weight of plastic additives. It is conceivable that the composition of the structural core component is adjusted to achieve a certain flexibility or rigidity, thereby imparting flexibility when needed as a glue or a flexible material and / or imparting rigidity for use as a component suitable for floating installation. As a non-limiting example, a semi-rigid to rigid structural core component with a thickness of at least 2 mm, preferably at least 3 mm, comprises, for example, 10% PP and 15% plastic additive, while a flexible structural core component of up to 2 mm, preferably up to 1.5 mm, comprises preferably 5-10% PP and 20-25% of at least one plastic additive to impart sufficient flexibility to the structural component. Surprisingly, the combination of a high mineral filler content of at least 60% by weight, preferably at least 70% by weight, with at least one polymer resin containing at least one plastic resin and / or plastic additive, up to 30%, imparts sufficient thermal stability to at least one structural core component, while maintaining sufficient flexibility and improving the processing properties of the highly filled composition. From the above composition, it can be seen that at least one structural core component can comprise a highly copolymeric composition with relatively low crystallinity and / or hardness.

[0032] The decorative panel according to the invention may also comprise a plurality of core layers, wherein at least two core layers, preferably each core layer, comprises at least one structural core component and at least one balancing core component.

[0033] It is further conceivable that, if applicable, at least one balancing core component is arranged on at least one surface of the structural core component, preferably opposite to the at least one decorative layer. It is conceivable that at least one balancing core component is arranged on both surfaces of the structural core component. It is conceivable that at least one balancing core component comprises a composition of a mineral filler of at most 40%, more preferably at most 30%, most preferably at most 20%. It is conceivable that at least one balancing core component does not contain mineral fillers and / or plastic additives. It is conceivable that at least one balancing core component, or at least one second polymer composition, consists essentially of at least partly isotactic polyolefins such as isotactic polypropylene and / or isotactic PB-1. In a possible embodiment, the at least one balancing core component does not contain any mineral fillers, in which case the balancing core component consists almost entirely of a semi-crystalline polyolefin, preferably polypropylene, most preferably isotactic polypropylene. In this case, the balancing core component may have a higher degree of crystallinity than the rest of the core layer, more specifically, a higher degree of crystallinity than at least one structural core component.

[0034] It is conceivable that at least the structural core component is extruded by a first extruder and at least the balancing core component is extruded by a second extruder. It is conceivable that the at least one structural core component and the at least one balancing core component are provided in at least two merged melt streams of an extrusion die, preferably a single manifold die. It is conceivable that in a coextrusion process, at least one structural core component and at least one balancing core component are applied in at least two separate melt streams by means of a single extrusion die through a coextrusion process. It is conceivable that at least one structural core component is extruded through a first extrusion barrel and a screw, and / or at least one balancing core component is extruded through a second extrusion barrel and a screw. It is therefore conceivable that at least one structural core component and at least one balancing core component constitute components of the same core layer. It is conceivable that when the at least one balancing core component is applied to at least one surface of the at least one structural core component, the at least one balancing core component forms an integral part of the core and is perhaps visually indistinguishable from the other layers constituting the core. It is conceivable that the differences in composition can be reflected and measured by density measurements, crystallinity and / or Shore D hardness measurements.

[0035] The invention also relates to a process for producing a decorative panel, in particular a decorative floor, ceiling, building or wall panel, in particular a decorative panel according to the invention, comprising the following steps:

[0036] a) extruding at least one mineral filler and at least one first polymer composition and / or at least one second polymer composition so as to form at least one polymer sheet comprising at least one structural core component and at least one balancing core component; and

[0037] b) Pressing at least an additional layer, in particular at least one decorative top layer, onto the upper surface of at least one polymer sheet.

[0038] The invention also relates to a process for producing a decorative panel, in particular a decorative floor, ceiling, building or wall panel, in particular a decorative panel according to the invention, comprising the following steps:

[0039] a) coextrusion, in particular single-manifold coextrusion, of at least one mineral filler and a combination of at least one first polymer composition and at least one second polymer composition to form at least one polymer sheet comprising at least one structural core component and at least one balancing core component; and

[0040] b) Laminating at least an additional layer, in particular at least one decorative top layer, to the upper surface of at least one polymer sheet.

[0041] Each process according to the present invention specifically specifies a decorative panel according to the present invention. Any embodiment and / or material for a decorative panel described according to the present invention is also applicable to a method for manufacturing such a decorative panel. Any preferred embodiment of the process is applicable to each process described in the present invention. The advantage of the process according to the present invention is that a relatively simple and continuous process can be used to produce a decorative panel, wherein the obtained decorative panel comprises a core layer with an integrated balancing layer. The process of the present invention enables relatively simple and stable production of polymer sheets, in particular crystalline or semi-crystalline polymer-based sheets, which can serve as the basis for decorative panels, such as decorative floors, ceilings, buildings or wall panels. When referring to a polymer sheet, it can also refer to a core layer. The core layer is generally formed by the polymer sheet mentioned in the present invention. Typically, the polymer sheet is cut into (one or more) core layers.

[0042] At least one first polymer composition and / or at least one second polymer composition comprises at least one semi-crystalline thermoplastic polymer, preferably having a glass transition temperature greater than or equal to -50°C. For example, it is conceivable that after step a), at least one polymer sheet is subjected to a first temperature in the range of 45°C to 115°C, preferably at least 75°C or in the range of 75°C to 95°C, in particular when passing through at least one first set of calendering rollers, which are preferably movable in a first and / or vertical direction, and subsequently the polymer sheet is subjected to a second temperature in the range of 45°C to 125°C, preferably at least 120°C, when passing through at least a second set of calendering rollers movable in a second and / or horizontal direction, in particular so that the core layer reaches a certain degree of crystallinity that allows at least one decorative layer to be laminated to the polymer sheet. These steps are preferably performed before step b). The polymer sheet is subjected to the second temperature so that the polymer sheet forms a crystallinity gradient. The polymer sheet is subjected to the first and second temperatures, preferably for a first time period and a second time period, respectively. The time period can be predetermined and depends on further process parameters. The obtained polymer sheet may have a reduced crystallinity inside the polymer sheet compared to the crystallinity of the outer surface of the polymer sheet. The process may also include subjecting the extruded polymer sheet to a first temperature in the range of 85°C to 100°C for a first period of time, followed by a step of subjecting the extruded sheet to a second temperature in the range of 50°C to 65°C for a second period of time. It is conceivable that, during the heating step, the polymer sheet is provided with a crystallinity gradient. More specifically, the crystallinity of the polymer sheet is reduced inside the polymer sheet compared to the crystallinity of the outer surface of the polymer sheet. This can be demonstrated, for example, by an uneven Shore D hardness in the polymer sheet. It has been found that the polymer sheet produced by the process of the present invention has a higher Shore D hardness at at least part of its outer surface than at least part of the inner portion of the polymer sheet. It has been found that such different Shore D hardness or uneven crystallinity throughout the volume of the polymer sheet enhances the thermal stability of the polymer sheet and the entire board. It has been found that this uneven crystallinity within the polymer sheet increases the expansion rate of the floor, in particular the expansion rate of the polymer sheet and / or the entire board is less than or equal to 0.25%. Therefore, the decorative board of the present invention is able to maintain its structural integrity, mechanical properties and functionality at higher temperatures. Prior to step b), at least one third set of calendering rollers is passed to subject the extruded polymer sheet to a third temperature in the range of 85°C to 100°C in a third time period, and then subsequently passed through at least one fourth set of calendering rollers to subject the extruded polymer sheet to a fourth temperature in the range of 50°C to 65°C in a fourth time period. Subsequently, the polymer sheet may be subjected to a fifth temperature in the range of 45°C to 60°C by at least one fifth set of calendering rollers, and to a sixth temperature in the range of 25°C to 40°C by at least one sixth set of calendering rollers.The polymer sheet is preferably subjected to a fifth temperature and a sixth temperature for a fifth time period and a sixth time period, respectively.The at least one polymer sheet may be provided with a thickness in the range of 1 to 10 mm, preferably in the range of 3 to 8 mm, more preferably in the range of 4 to 7 mm.

[0043] At least one additional layer, in particular at least one decorative top layer, may comprise at least one semi-crystalline thermoplastic polymer. It is also possible that at least one decorative top layer comprises polypropylene, in particular a polypropylene foil. By using at least one feeding device, at least one additional layer is preferably laminated onto the polymer sheet. It is also conceivable to laminate a plurality of additional layers onto the polymer sheet. For example, the lamination can be carried out by melt bonding. The polymer sheet or core layer, and the additional layer, such as the decorative top layer, can be fixed to each other in a melting step, wherein heating and pressure are applied to establish the melt bonding. It is also conceivable that at least one decorative top layer is a polypropylene foil or a polypropylene foil layer. Before the lamination step, at least part of the surface of the polypropylene foil (if used) can be surface treated. It is also conceivable that during the lamination step, at least part of the surface of the PP foil is simultaneously surface treated. The surface treatment is preferably selected from chemical modification, corona treatment, plasma treatment, polymer modification or a combination thereof. It is conceivable that in this step, the surface energy of at least one additional layer and / or the polymer sheet is increased so that it is easier to laminate the at least one additional layer onto the polymer sheet. As a result, the adhesion between the at least one additional layer and the polymer sheet is significantly improved. Furthermore, it is contemplated that this step may be performed to reduce defects (i.e., fish eyes, pinholes, gaps or bubbles) on the surface of at least one additional layer and / or polymer sheet when at least one coating is applied to the additional layer and / or polymer sheet.

[0044] The polymer sheet can be subjected to a calendering step, for example by using a calendering device. At least one roller of the calendering device can be movable in the vertical direction and / or can be heated to at least 75°C, preferably at least 85°C, more preferably at least 95°C. It is also conceivable that at least one roller of the calendering device is movable in the horizontal direction and / or is heated to at least 120°C, preferably at least 130°C, or more preferably at least 140°C. The polymer sheet can also be subjected to a calibration step, for example by means of a calibration device. At least some of the rollers of the calibration device can have a temperature range of 90°C at the first end and 60°C at the second end. At least some of the rollers of the calibration device can have a temperature range of 50°C at the first end and 30°C at the second end. It has been found that within these temperature ranges, the crystallinity of the polymer sheet is controlled, thereby ensuring that the crystallinity of the polymer sheet on the outer surface of at least a portion thereof is higher than the crystallinity of at least an inner portion thereof. It is also conceivable that the pressing means used and at least some of the rollers of the pressing means have a temperature range of 35°C at the first end to 25°C at the second end. It has been found that within such a temperature range, the internal stress of the polymer sheet is released, thereby ensuring the flatness of the polymer sheet and the entire decorative panel.

[0045] The invention also relates to an extrusion line for producing decorative floor, ceiling, building or wall panels or architectural panels, preferably by any one of the processes according to the invention, comprising:

[0046] at least one extruder configured for extrusion, in particular for coextrusion, more particularly single-manifold coextrusion of at least one mineral filler and / or at least one first polymer composition, preferably in combination with at least one second polymer composition;

[0047] at least one calendering device, comprising a plurality of calendering rollers, for forming the melt obtained from the extruder into a polymer sheet, wherein at least one roller is configured to be heated, preferably each roller is configured to be heated;

[0048] - at least one feeding device for feeding at least one additional layer to said polymer sheet so as to laminate said additional layer onto said polymer sheet; and

[0049] - at least one calibration device comprising at least two rollers, by which the polymer sheet can be guided.

[0050] The extrusion line according to the present invention is capable of producing decorative panels comprising at least one core layer, the core layer comprising at least one structural core component and at least one balancing core component. The extrusion line is also capable of producing laminated decorative panels having a polymer sheet (referred to herein as a core layer) and at least one additional layer, which can be used as, for example, a floor, ceiling, wall or building panel, wherein the panel has a uniform thickness and quality. Alternatively, at least one extruder can be configured for polymer extrusion, in particular polypropylene extrusion. For example, the extruded decorative panel obtained by the extrusion line according to the present invention can have a core layer with a thickness of at least 2 mm, for example a core layer with a thickness in the range of 2 to 8 mm or in the range of 3 to 7 mm. The core layer of the decorative panel produced, or therefore the polymer sheet, can have a thickness in the range of 1 to 10 mm, preferably in the range of 3 to 8 mm, more preferably in the range of 4 to 7 mm.

[0051] Since the extrusion line combines an extruder with at least one calendering device, at least one feeding device and at least one calibration device according to the present invention, it is possible to produce laminated decorative panels from semi-crystalline polymers with a low glass transition temperature in an efficient and effective manner. It is conceivable that the extrusion line can also be a co-extrusion, tri-extrusion or resin extruder using at least two different materials or resins with different properties. In a preferred embodiment of the present invention, the extrusion line is a co-extrusion extruder utilizing at least one highly filled polyolefin composition, the highly filled polyolefin composition comprising at least one plastic additive and at least one isotactic polyolefin, preferably isotactic polypropylene. In some specific embodiments, the other extruder materials can be wood or mineral materials, which can be extruded together with the main polymer, more specifically a semi-crystalline polymer with a low glass transition temperature. The extrusion line according to the present invention benefits from an integrated lamination process by using a feeding device that feeds at least one additional layer to the polymer sheet. The feeding device is, for example, capable of adding additional layers to the polymer sheet, such as a backing layer and / or an acoustic layer. It is also conceivable that the feed device is configured to apply an additional layer in the form of a decorative layer, such as but not limited to decorative papers and films, directly onto the polymer sheet. The at least one acoustic layer may be, for example, a foamed acoustic layer.

[0052] Semi-crystalline halogen-free thermoplastic polymers (i.e., polypropylene, low-density polyethylene, high-density polyethylene, polyoxymethylene, polybutene-1, etc.), hereinafter referred to as semi-crystalline thermoplastics, are a versatile class of thermoplastic polymers that have certain advantages over halogenated amorphous thermoplastics in plastic extrusion, including low cost, low coefficient of thermal expansion, ease of recycling, sustainability, and strength.

[0053] Semi-crystalline thermoplastic polymers or polyolefins such as PP with relatively low glass transition temperatures (Tg) melt at relatively high temperatures and have the characteristics of rapid cooling due to high thermal conductivity and low specific heat capacity. In addition, the crystalline blocks formed in the typical polymer chains of semi-crystalline polymers may cause residual stresses, as well as warping and bending of extruded plates or sheets. This leads to the challenge of extruding this type of semi-crystalline polymer into a flat and consistent sheet that lacks irregularities and is relatively thick. However, traditional extrusion lines, which are commonly used to produce thermoplastic polymers such as luggage, microwave food containers, cutting boards, window parts, etc., are not automatically suitable for the production of decorative boards such as flooring products. In conventional extrusion lines, the surface flatness of the extruded sheet is difficult to control, making it impossible for existing extrusion lines to produce very large, flat surfaces, which is a requirement that decorative boards such as flooring products need to meet. In addition, for semi-crystalline polymers with relatively low viscosity and in a near-liquid state at high temperatures, it is extremely difficult to achieve consistency in melt flow in traditional extrusion lines, making semi-crystalline polymers, especially semi-crystalline polyolefins, difficult to handle and process. Therefore, conventional extrusion lines are not suitable for producing decorative panels, such as flooring products, which require a consistent thickness and a high degree of structural stability to allow the application of locking mechanisms thereon. Furthermore, when such semi-crystalline thermoplastics or semi-crystalline polyolefin compositions have a high weight percentage of mineral fillers, i.e., when they are highly filled, the crystallinity of the extruded semi-crystalline thermoplastics combined with the high mineral content can lead to brittleness and fracture due to lack of flexibility, particularly when interlocking coupling devices are provided in such materials. Furthermore, due to the properties of said semi-crystalline thermoplastics, including low surface energy, heat sensitivity, and lack of polar groups that can promote adhesion, thermal lamination of at least one composite layer of said resilient decorative panel, such as thermal lamination of at least one decorative top layer to at least one core layer, may prove to be challenging.

[0054] In view of the above, semi-crystalline thermoplastic polymers, in particular semi-crystalline polyolefins, are considered to be a promising class of materials for the flooring industry, but still have disadvantages compared to the prior art. In view of this, there is a need for an improved extrusion line or equipment that can be used to produce decorative panels (such as flooring products). In particular, there is a need for an extrusion line that can process semi-crystalline thermoplastic polymers with low glass transition temperatures and low viscosities, wherein the temperature can be effectively controlled to solve the problems associated with obtaining a relatively large, flat surface and consistent thickness in the manufactured flooring product. There is also a need for an improved extrusion line or equipment that can be used to produce highly filled polypropylene flooring, sheets, composite layers and / or at least one core layer, and / or subsequently laminating the sheets and / or at least one core layer to a decorative top layer comprising polypropylene. The extrusion line according to the present invention meets this need.

[0055] At least one extruder of the extrusion production line according to the present invention is preferably a twin-screw extruder. For example, it is conceivable that at least one extruder is a twin-screw extruder rotating in the same direction, wherein the screws are preferably rotating in the same direction and / or intermeshing. This allows the screws to be self-wiped and better transfer polymers from one screw to another. Another benefit of using at least one twin-screw extruder is that a positive output of polymeric material can be achieved. Using a twin-screw extruder can further produce sheets with relatively large thicknesses. It has been found that single-screw extruders are limited to specific sheet or plate thicknesses because single-screw extruders generally tend to push back, resulting in the material usually being stuck in the screw if more material is fed in. Therefore, the deposited material may damage the screw and / or barrel, and the material may flow out of the exhaust port or vent. Therefore, in the case of producing relatively thick decorative panels, it is preferred to apply at least one twin-screw extruder.

[0056] The efficiency of the extruder depends at least in part on the ratio of the flighted length of the screw to its outer diameter, in particular the L / D ratio. The larger the ratio, the more shear heat can be generated uniformly in the polymer melt without degradation. A relatively large L / D ratio also provides good mixing characteristics, resulting in good homogeneity of the melt. In a preferred embodiment, the L / D ratio of at least one twin screw is in the range of 20-30:1.

[0057] The screw design can be adapted to the first and / or second polymers being applied and the desired product. For example, the screw design can be configured for pressure control, thereby enabling multiple feed and vent points, improving mixing and efficiency, and controlling the amount of material flowing within the barrel and the residence time of the material in that portion of the screw. A cooling system, such as a water cooling system, can be used to control the extruder temperature. A water cooling system is preferred over an air cooling system, which is common in conventional extrusion lines, because it provides more consistent and uniform cooling, as water is a better conductor of heat than air, but is less susceptible to changes in ambient temperature and humidity. It is conceivable that the screw profile of at least one twin-screw extruder includes a feed section, a transition section, and a metering section. The feed section is defined as the section where the polymer first enters the screw and is conveyed along a constant root diameter. The transition section is the section where the polymer is conveyed, compressed, and melted along the root diameter, which increases with a constant taper. The metering section is defined as the section where polymer melting is completed and the melt is conveyed forward along a constant root diameter to the temperature and viscosity required to form the part. In a preferred embodiment, the twin screw has at least 30% flight area (flighted length), preferably a flight area in the range of 30-60%, more preferably a flight area in the range of 40-50%, especially in its feed section. In a preferred embodiment, the twin screw has a screw profile with at least 20% flight area in the transition section and / or metering section, preferably in the range of 20-35%, more preferably in the range of 25-30%. This enables controlled extrusion of polymer materials, especially in the case of application of relatively crystalline or semi-crystalline polymers.

[0058] In a possible embodiment, the twin screw has a compression ratio range of 2: 1 to 4: 1, preferably a compression ratio range of 2.7: 1, and more preferably a compression ratio range of 3.3: 1. The higher the compression ratio, the greater the shear heat applied to the polymer, the greater the thermal uniformity of the melt and the possibility of generating stress in the polymer. The depth of the screw groove of at least one extruder can be adjusted based on the degree of shear heat applied to the polymer. For example, the twin screw may have a metering screw groove depth of 2% to 8%, preferably 2.7% to 7%, and more preferably 3.5% to 6% of the measured screw diameter. The helix angle of the screw is preferably a standard square pitch. The twin screw may also include a conveying element, a deeding block element and / or a restrictor. This can be used for softening and / or dispersing and / or reversing polymer melts and / or mixing of melts of polymers and / or additives.

[0059] The extruder may also include at least one melt pump and / or gear pump. The melt pump and / or gear pump may include at least two gears and is preferably driven by a single motor. Typically, the extruder fills the gear from the suction side and the rotating gear discharges the polymer from the other side. The principle is that a well-made gear will have a very precise profile, and when the gear is enclosed in a tight housing, the volume of plastic in each tooth will be very accurate. As the gears turn, they measure the exact amount of plastic on the discharge side. It is conceivable that the speed at which the gears rotate can be precisely controlled by an AC or DC drive, which is preferably designed to vary by less than 1%. One advantage of using the melt pump and / or gear pump is that its output pressure to the die can be precisely controlled, eliminating pressure variables and so-called pulsations that affect the stability of the extruder output, and compensating for factors such as poor or unstable temperature control, feed interruptions, changes in polymer mixtures (such as different amounts of regrind), and surges caused by inaccurate screw design and irregular composition.

[0060] Although the preferred extrusion line according to the invention preferably comprises a twin-screw extruder, it is also conceivable that the extrusion line comprises a single-screw extruder. Furthermore, an embodiment is conceivable in which the extrusion line comprises a combination of at least one twin-screw extruder and at least one single-screw extruder. The latter is particularly beneficial if a core layer comprising an integrated balancing layer is to be produced.

[0061] The extrusion line preferably comprises at least one traction device for traction of the polymer sheet through at least a portion of the extrusion line. The use of at least one traction device can further optimize the efficiency of the extruder. The traction device also contributes to the stability and uniformity of the final product. The traction device facilitates the control of the production process. It is conceivable that the extrusion line comprises at least one cutting device for cutting at least a portion of the polymer sheet, in particular at least one edge of the polymer sheet. When referring to a polymer sheet, it can also be referred to as a laminated polymer sheet or a laminate.

[0062] The extruder typically includes at least one main hopper for feeding at least one polymer into the screw. Preferably, the extruder also includes at least one secondary hopper for feeding at least one additive into the screw. The extruder typically also includes a barrel and a die. In a further preferred embodiment, it is conceivable that at least one gear pump is arranged between the barrel and the die. The gear pump is preferably configured to maintain a constant pressure and a consistent or uniform melt flow. Thus, a uniform melt flow will be fed into the die, so that the produced decorative panels have a consistent thickness.

[0063] The calendering device is particularly configured to melt the polymer into a processable form that can be shaped and processed in a desired manner. The calendering device is generally configured to gradually reduce the temperature of the polymer melt and to shape the polymer melt into a polymer sheet of a desired thickness. It is conceivable that at least part of the calendering rollers of the calendering device are therefore configured to be heated and / or cooled. Therefore, it is conceivable that at least one roller, preferably each roller, comprises a heater, such as an integrated heater and / or an oil-based or water-based temperature control system or device.

[0064] The calendering device is configured to control the temperature of the polymer melt, in particular the cooling rate of the polymer melt, thereby controlling the solidification process of the polymer melt by a temperature control device arranged in at least a portion of the extrusion line, wherein the temperature control device includes at least one temperature sensor; a processing device for determining whether the temperature is within an acceptable parameter range; and at least one heating or cooling element for changing the temperature in at least a portion of the extrusion line. When the polymer melt passes through the calendering device, the polymer chains are rearranged and begin to form crystalline regions. In the present invention, the calendering device allows the polymer melt to cool at a rate at which more extended chains migrate, thereby providing additional crystallization time. Therefore, the polymer melt has a higher degree of crystallinity.

[0065] In a preferred embodiment of the present invention, the calendering device comprises at least one set of first calendering rollers, which are heated to a first temperature range, for example, in the range of 45°C to 115°C or 75°C to 95°C, by at least one heating device, and the polymer melt is first subjected to the influence of this temperature range. When the polymer melt passes through the first set of calendering rollers, crystalline regions and / or blocks may be formed in the polymer melt, and this process can be called the nucleation period. In a preferred embodiment of the present invention, the calendering device comprises at least a second set of calendering rollers, which are heated to a second temperature range, for example, in the range of 45°C to 150°C, by at least one heating device, and then the polymer sheet is heated. When the polymer melt passes through the second set of calendering rollers, the nuclei formed in at least one area of ​​the polymer melt can grow by diffusion of polymer chains to the crystal surface. The crystal chains are then arranged in an orderly manner to increase their size. At this stage, the desired crystallinity of at least one area of ​​the polymer sheet is achieved, and the polymer sheet allows additional layers to be laminated thereon.

[0066] The calendering device generally comprises a plurality of calendering rollers for forming a polymer sheet from the melt obtained from the extruder, wherein at least one roller, preferably a plurality of rollers, more preferably each roller is configured for heating and / or cooling. For example, it is conceivable that at least one roller, preferably each roller, of the calendering device is an oil-heated roller. The temperature of the roller is efficiently and effectively controlled in this way. Oil-heated rollers generally allow relatively stable temperature control, preferably in the range of 1 to 2°C. However, it is also conceivable that at least one roller is an electrically heated roller, which is controlled by a temperature regulation system with a processing unit in order to more accurately control the heating and / or cooling. It is conceivable that the temperature regulation system comprises at least one sensor, preferably an optical sensor for measuring the temperature of the roller and / or any part of the extrusion line. At least one roller can also be heated with gas or with water, gas being particularly suitable for high-temperature rollers and water being particularly suitable for rollers with lower temperatures. The application of at least one heated roller is beneficial to the stability and consistency of the final product.

[0067] For example, the polymer sheet may be subjected to a temperature in the range of 45°C to 115°C, preferably at least 75°C or in the range of 75°C to 95°C, by at least one heating means. The polymer sheet may be subjected to a temperature in the range of 45°C to 125°C, preferably at least 120°C, or alternatively 75°C to 95°C, by at least one heating means. The extrusion line may be configured to cause the polymer sheet to achieve a degree of crystallinity that allows at least one additional layer to be laminated to the polymer sheet. A crystallinity gradient in the polymer sheet may be induced when the polymer sheet is subjected to at least a second set of calendering devices.

[0068] In a preferred embodiment, the calendering device comprises at least three calendering rollers, more preferably at least four rollers, which are configured to form the polymer sheet. Preferably, at least one roller, preferably a plurality of rollers, has good electrical conductivity. It is conceivable that at least one roller, preferably a plurality of rollers, is at least partially made of a conductive material, such as but not limited to metal. At least one roller is preferably a rigid roller. In a further preferred embodiment, the calendering device comprises at least one soft roller, in particular at least one rubber roller. At least one soft roller is configured to optimize the lamination process. The calendering device may include at least one embossing roller. In a preferred embodiment, the position of the soft roller and the embossing roller enables the soft roller to be laminated, while the embossing roller subsequently provides an embossed structure on at least one side of the polymer sheet. In another preferred embodiment, the calendering device comprises at least one heating device, such as a lamp, an infrared lamp or any other heating device arranged between the at least one soft roller and the at least one embossing roller. At least one heating device can be used to heat the material and / or facilitate lamination of at least one additional layer on the polymer sheet.

[0069] It is conceivable that the calendering device comprises a plurality of roller pairs, wherein a first roller pair is movable in a first direction and a second roller pair is movable in a second direction, wherein the first direction is different from the second direction. It is conceivable, for example, that at least one roller pair is movable in at least a vertical and / or horizontal direction. The calendering device is preferably configured so that at least one roller of the calendering device is movable in a vertical direction, at least one roller of the calendering device is movable in a horizontal direction and / or at least one roller is substantially fixed. It is also conceivable that the calendering device is configured so that at least one roller of the calendering device is movable in a vertical direction, at least one other roller of the calendering device is movable in a horizontal direction and / or at least another roller is substantially fixed. Preferably, in particular during the preparation of at least one decorative panel, at least one roller of the calendering device movable in the vertical direction is heatable or heated to at least 70°C, preferably at least 85°C, more preferably at least 95°C. Preferably, at least one roller of the calendering device movable in the horizontal direction is heatable or heated to at least 75°C, preferably at least 85°C, more preferably at least 120°C. In the case where the calendering device comprises at least one substantially fixed roller, the roller is preferably arranged between at least two rollers that are movable in the horizontal direction. When referring to a substantially stationary roll, it is meant that during the extrusion process when using the extrusion line according to the invention, the roll is substantially stationary.

[0070] It is conceivable that the diameter of at least one roller of the calendering device is in the range of 300 mm to 550 mm, preferably in the range of 350 mm to 500 mm, more preferably in the range of 400 mm to 450 mm.

[0071] In a preferred embodiment, a plurality of calibration devices are arranged throughout the extrusion line or at least part of the extrusion line, wherein the devices contribute to the calibration and stabilization of the polymer sheet and thus to the calibration and stabilization of the final product. The calibration device is configured to reduce internal stresses in the material, make the material flatter, control the crystallization of the material, and / or control the cooling rate of the material. Preferably, the sequence of calibration rollers has different temperatures, which functions similarly to tempering, helping to prevent the cupping effect. Experiments have found that a series of at least three calibration devices is best for achieving the desired technical effect of the present invention. It is also conceivable that the first calibration device and the second calibration device constitute part of a single calibration device having a first calibration component and a second calibration component.

[0072] The first calibration device preferably comprises at least four roller pairs, preferably at least six roller pairs. The second calibration device preferably comprises at least four roller pairs, preferably at least six roller pairs.

[0073] In a preferred embodiment, at least one roller, preferably a plurality of rollers, of the first calibration device and / or the second calibration device is configured to be heated by at least one heating device. It is conceivable that the at least one heating device heats the at least one roller to the desired temperature range using oil, water, gas or electricity. Preferably, oil is used in the high temperature range to keep the temperature stable.

[0074] During extrusion, the rollers of the first calibrated device preferably have a temperature range of 90° C. at the first end to 60° C. at the second end. Thus, at least parts of the rollers of the first calibrated device are heated or heatable to at least 60° C. It is conceivable that at least one of the rollers has a temperature gradient, in particular during use. It is also conceivable that there is a temperature gradient between adjacent rollers, in particular between adjacent rollers of the same calibrated device. For example, the rollers of the second calibrated device have a temperature range of 50° C. at the first end to 30° C. at the second end.

[0075] Further, the extrusion line may also include at least one further calibration device, the calibration device comprising at least three rollers, the three rollers being arranged in such a way that the polymer sheet is at least partially raised. For example, the rollers may be arranged so that the polymer sheet is raised to a predetermined degree. For example, it is conceivable that the rollers are arranged so that the polymer sheet is raised to an angle in the range of 10 to 35 degrees, preferably at least 10 degrees, more preferably at least 20 degrees.

[0076] The extrusion line may further comprise a device for applying pressure to at least one surface of the polymer sheet. Preferably, pressure is applied at least on the bottom surface of the polymer sheet after the polymer sheet passes through the calibration device, in particular the second calibration device. It is conceivable that the device for applying pressure comprises at least one roller, preferably at least five rollers. In a preferred embodiment, at least one roller, preferably a plurality of rollers, of the device for applying pressure is configured to be heated by at least one heating method. It is conceivable that the rollers of the pressure-applying device can be heated to a temperature range of 35°C at the first end to 25°C at the second end. It is conceivable that at least one heating method utilizes oil to heat at least one roller to the desired temperature range. It is also conceivable that at least one heating method uses gas or water. Preferably, oil is used in the high temperature range to keep the temperature stable.

[0077] The extrusion line according to the invention generally comprises at least one feeding device for feeding at least one additional material or additional layer to the polymer sheet, in particular laminating the additional layer to the polymer sheet. The extrusion line may also comprise a plurality of feeding devices, each of which is configured for feeding an additional layer to the (laminated) polymer sheet. It is conceivable that at least one feeding device is configured to feed at least one top layer to the polymer sheet so that the top layer is laminated to the polymer sheet. It is also conceivable that at least one feeding device is configured to feed at least one backing layer to the polymer sheet so that the backing layer is laminated to the polymer sheet. It is also conceivable that at least one feeding device is configured to feed a plurality of additional layers to the polymer sheet. The extrusion line, in particular the feeding device, may, for example, comprise at least one pair of rollers for guiding at least one additional layer, preferably wherein at least one roller is configured to be heated, preferably each roller is configured to be heated. At least one roller is preferably arranged to be heated to at least 35°C to 60°C, preferably from 40°C to 55°C, more preferably from 45°C to 50°C. At least one feed device is preferably arranged so that at least one additional layer is fed to the polymer sheet in a horizontal position between two adjacent rollers of the calendering device. In this way, the synergy between the feed device and the calendering device can be optimized. At least one feed device may include at least one feed tension controller. Such a controller is particularly configured to control the force applied to the additional layer when the additional layer is loaded. In addition, the feed device may include at least one pair of rollers, in particular configured to guide the at least one additional layer to the polymer sheet. The temperature of these rollers is preferably controllable. Therefore, at least one roller can be a heated or heatable roller. If applied, the temperature of the rollers of the feed device is generally lower than that of the calendering rollers during operation.

[0078] Further, the extrusion line may also include at least one cutting device for cutting at least a portion of the (laminated) polymer sheet, in particular at least one edge of the polymer sheet. The cutting device helps to obtain the desired final product. The extrusion line may also include at least one cooling device for cooling at least a portion of the polymer sheet. For example, at least one cooling device may be configured for cooling at least a portion of the polymer sheet by air cooling or a water bath. Air cooling can provide a controllable and effective cooling method without negatively affecting the product. It is also conceivable that the extrusion line may optionally include at least one unloading device. The unloading device may be configured to unload a semi-finished product or a final product.

[0079] The invention also relates to a process for producing decorative floor, ceiling or wall panels using an extrusion line according to the invention.

[0080] The present invention will be further described based on the following non-limiting terms.

[0081] 1. A decorative panel, in particular a floor, ceiling, building or wall panel, comprising at least one core layer, preferably at least one decorative top layer, wherein the at least one core layer comprises at least one structural core component and / or at least one balancing core component, wherein the at least one structural core component has a first hardness and / or crystallinity, wherein the at least one balancing core component has a second hardness and / or crystallinity, wherein the second hardness and / or crystallinity is preferably 3-35% higher than the first hardness and / or crystallinity.

[0082] 2. The trim panel according to clause 1, wherein at least one structural core component comprises at least one mineral filler and at least one first polymer composition, and wherein at least one balancing core component comprises at least one second polymer composition.

[0083] 3. A decorative panel according to any of the preceding clauses, wherein at least one core layer is a coextruded core layer and / or wherein at least one first polymer composition and / or at least one second polymer composition comprises at least one semi-crystalline thermoplastic polymer.

[0084] 4. The decorative panel according to claim 3, wherein at least one semi-crystalline thermoplastic polymer is a non-halogen semi-crystalline thermoplastic polymer, and the non-halogen semi-crystalline thermoplastic polymer is selected from the group consisting of polyethylene (PE), polyethylene terephthalate (PET), polybutene-1 (PB-1), polymer environmentally friendly resin (PER), polylactic acid (PLA) and / or polypropylene (PP).

[0085] 5. A trim panel according to any of the preceding clauses, wherein at least one structural core component comprises at least 60 wt. %, preferably at least 70 wt. %, most preferably at least 75 wt. % of at least one mineral filler.

[0086] 6. The decorative panel according to any of the preceding clauses, wherein a mineral filler of at least one structural core component is selected from the group consisting of limestone, talc, calcium carbonate, magnesium, magnesium hydroxide, magnesium dihydrate, aluminum hydroxide, aluminum trihydrate and combinations thereof.

[0087] 7. The trim panel according to any of the preceding clauses, wherein at least one structural core component, in particular at least one first polymer composition, comprises at least one plastic additive.

[0088] 8. The decorative panel according to clause 7, wherein the at least one plastic additive is a copolymer of ethylene and at least one semi-crystalline thermoplastic polymer.

[0089] 9. The decorative panel according to clause 7 or clause 8, wherein the at least one plastic additive comprises 2-30 wt%, preferably 5-20 wt%, more preferably about 10-15 wt% of ethylene and / or ethylene units.

[0090] 10. The decorative panel according to any one of clauses 7 to 9, wherein the density of at least one plastic additive is 0.8 to 1 g / cm 3 , especially 0.862 to 0.912 g / cm 3 .

[0091] 11. The decorative panel according to any one of clauses 7 to 10, wherein the at least one plastic additive comprises at least one elastomeric polyolefin comprising isotactic, syndiotactic and / or atactic polyolefin blocks.

[0092] 12. The decorative panel according to any one of clauses 7 to 11, wherein at least one plastic additive is prepared by metallocene catalysis and / or solution process.

[0093] 13. The decorative panel according to any of the preceding clauses, wherein at least one structural core component, in particular at least one first polymeric composition comprises at least one copolymer of polypropylene and ethylene, said copolymer comprising at least one polar functional group selected from hydroxyl, ether and / or carbonyl.

[0094] 14. The trim panel according to any of the preceding clauses, wherein the Shore D hardness of at least one balancing core component is 3-35% higher than the Shore D hardness of at least one structural core component.

[0095] 15. The trim panel according to any of the preceding clauses, wherein at least one balancing core component, in particular at least one second polymer composition, comprises at least one polyolefin, in particular an isotactic polyolefin.

[0096] 16. The decorative panel according to any of the preceding clauses, wherein at least one first polymer composition is substantially the same as at least one second polymer composition.

[0097] 17. A trim panel according to any preceding clause, wherein at least one core layer comprises at least two balancing core components, wherein at least one structural core component is substantially enclosed between the at least two balancing core components.

[0098] 18. The decorative panel according to any of the preceding clauses, wherein at least one decorative layer comprises at least one semi-crystalline thermoplastic polymer.

[0099] 19. The decorative panel according to any of the preceding clauses, wherein at least one decorative top layer comprises polypropylene, preferably a polypropylene foil.

[0100] 20. A process for producing a decorative panel, in particular a floor, ceiling, building or wall panel, in particular a panel according to any of the preceding clauses, comprising the following steps:

[0101] a) extruding at least one mineral filler and at least one first polymer and / or at least one second polymer composition to form at least one polymer sheet comprising at least one structural core component and at least one balancing core component;

[0102] b) Laminating at least an additional layer, in particular at least one decorative top layer, to the upper surface of at least one polymer sheet.

[0103] 21. The process according to clause 20, wherein the at least one first polymer composition and / or the at least one second polymer composition comprises at least one semi-crystalline thermoplastic polymer having a glass transition temperature greater than or equal to -50°C.

[0104] 22. A process according to clause 20 or 21, wherein, after step a), at least one polymer sheet is subjected to a first temperature of at least 75°C, in particular when passing through at least one first set of calendering rollers movable in a vertical direction, wherein the polymer sheet is subsequently subjected to a second temperature of at least 120°C when passing through at least a second set of calendering rollers movable in a horizontal direction, in particular to bring the core layer to a degree of crystallinity that allows at least one decorative layer to be laminated onto the polymer sheet.

[0105] 23. A process according to claim 22, wherein, prior to step b), the extruded polymer sheet is passed through at least one third set of calendering rollers to subject the extruded polymer sheet to a third temperature in the range of 85°C to 100°C for a third period of time, and then subsequently passed through at least one fourth set of calendering rollers to subject the extruded polymer sheet to a fourth temperature in the range of 50°C to 65°C for a fourth period of time.

[0106] 24. A process according to clause 23, wherein the polymer sheet is subsequently subjected to a fifth temperature in the range of 45°C to 60°C by at least one fifth set of calendering rolls and a sixth temperature in the range of 25°C to 40°C by at least one sixth set of calendering rolls.

[0107] 25. The process according to any of clauses 20-24, wherein the thickness of at least one polymer sheet is in the range of 1 to 10 mm, preferably in the range of 3 to 8 mm, more preferably in the range of 4 to 7 mm.

[0108] 26. Process according to any of clauses 20 to 25, wherein at least one additional layer, in particular at least one decorative top layer, comprises at least one semi-crystalline thermoplastic polymer, preferably polypropylene, more preferably a polypropylene foil.

[0109] 27. An extrusion line for producing decorative floor, ceiling, building or wall panels or architectural panels, in particular for producing panels according to any of clauses 1 to 19, preferably according to any of clauses 20 to 26, comprising:

[0110] - at least one extruder configured for single-manifold coextrusion of at least one mineral filler and a combination of at least one first polymer composition and at least one second polymer composition;

[0111] at least one calendering device, comprising a plurality of calendering rollers, for forming the melt obtained from the extruder into a polymer sheet, wherein at least one roller is configured to be heated, preferably each roller is configured to be heated;

[0112] - at least one feeding device for feeding at least one additional layer to the polymer sheet for laminating said additional layer onto the polymer sheet; and

[0113] - at least one calibration device comprising at least two rollers, by which the polymer sheet can be guided.

[0114] 28. Extrusion line according to clause 27, wherein the extruder comprises a twin-screw extruder, in particular a co-rotating twin-screw extruder and / or at least one single-screw extruder.

[0115] 29. An extrusion line according to clause 28, wherein the L / D ratio of the twin screw is in the range of 20-30:1.

[0116] 30. An extrusion line according to clause 28 or 29, wherein the twin screw has a screw profile having a flight area of ​​at least 40% in its feed section and / or at least 25% in its transition section and / or metering section.

[0117] 31. An extrusion line according to any one of clauses 27-29, wherein the compression ratio of the twin screws ranges from 2:1 to 4:1, preferably 2.7:1, more preferably 3.3:1.

[0118] 32. An extrusion line according to any one of clauses 27 to 31, wherein the twin screws have a metering groove depth of 2% to 8%, preferably 2.7% to 7%, more preferably 3.5% to 6% of the measured screw diameter.

[0119] 33. An extrusion line according to any of clauses 27 to 32, comprising at least one pulling device for pulling the polymer sheet through at least part of the extrusion line.

[0120] 34. Extrusion line according to any of clauses 27 to 33, wherein the extruder comprises at least one main hopper for feeding at least one polymer, in particular polypropylene, and at least one secondary hopper for feeding at least one additive.

[0121] 35. An extrusion line according to any of clauses 27 to 34, wherein the extruder further comprises a barrel and a die, and at least one gear pump, preferably arranged between the barrel and the die.

[0122] 36. An extrusion line according to any one of clauses 27 to 35, wherein at least one roller of the calendering device is an oil heated roller, preferably each roller is an oil heated roller.

[0123] 37. An extrusion line according to any of clauses 27 to 36, wherein the calendering device comprises at least one embossing roller.

[0124] 38. Extrusion line according to any of clauses 27 to 37, wherein the calendering device comprises at least one infrared lamp arranged between the at least one soft roller and the at least one embossing roller.

[0125] 39. An extrusion line according to any one of clauses 27-38, wherein at least one roller of the calendering device is movable in a vertical direction, at least one roller of the calendering device is movable in a horizontal direction and / or at least one roller of the calendering device is fixed.

[0126] 40. Extrusion line according to clause 39, wherein at least one fixed roller is arranged between at least two rollers movable in horizontal direction.

[0127] 41. Extrusion line according to any of clauses 27 to 40, comprising at least one cutting device for cutting at least a portion of the polymer sheet, in particular at least one edge of the polymer sheet.

[0128] 42. Extrusion line according to any of clauses 27 to 41, comprising at least one cooling device for cooling at least a portion of the polymer sheet, in particular by air cooling. BRIEF DESCRIPTION OF THE DRAWINGS

[0129] The present invention will be further illustrated by the non-limiting exemplary embodiments shown in the following figures, in which:

[0130] - Figure 1 shows a cross section of an embodiment of a floor panel according to the invention;

[0131] - Figure 2 shows a cross section of an embodiment of a floor panel according to the invention;

[0132] - Figure 3 a perspective view showing a portion of one embodiment of an extrusion line according to the present invention; and

[0133] - Figure 4 A schematic diagram showing a part of the production process according to the present invention is shown.

[0134] In the drawings, like reference numbers correspond to similar or equivalent elements or features. DETAILED DESCRIPTION

[0135] Figure 1 An exploded cross-sectional schematic diagram of an example of a first possible embodiment of a decorative panel 10 according to the present invention is shown. The decorative panel 10 comprises at least one core layer 100 and at least one decorative top layer 200 located on the upper surface of the core layer 100. The at least one core layer 100 further comprises at least one structural core component 101 and at least one balancing core component 102, the balancing core component 102 being located on at least one side of the at least one structural core component 101. In the embodiment shown, the structural core component 101 is located above the balancing core component 102. The balancing core component 102 constitutes the main part of the core layer 100. The at least one decorative top layer 200 of the embodiment shown comprises at least one decorative layer 201, at least one wear layer 202 located on the upper surface of the decorative layer 201, and a coating 203 located on the upper surface of the wear layer 202. The structural core component 101 comprises at least one mineral filler and at least one first polymer composition, and the at least one balancing core component 102 comprises at least one second polymer composition.

[0136] Figure 2 An exploded cross-sectional schematic diagram of another embodiment of a surface 20 (e.g., a floor panel) according to the present invention is shown. The decorative panel 20 includes at least one core layer 100, at least one decorative top layer 200 located on the upper surface of the core layer 100, and an optional acoustic layer 300 located on the bottom surface of the core layer 20. The at least one core layer 100 also includes at least one structural core component 101, which is sandwiched between at least two balancing core components 102. The at least one decorative top layer 200 also includes at least one decorative layer 201, at least one wear layer 202 located on the upper surface of the decorative layer 201, and a coating 203 located on the upper surface of the wear layer 202.

[0137] Figure 3A schematic diagram of a portion of an extruder 30 used in a process and extrusion line according to the present invention is shown. At least one extruder 30 is in particular a twin-screw extruder 30. The extruder 30 is configured to extrude a material for forming a structural core component and a material for forming a balancing core component to separate the screws 31a, 31b of the extruder 30, which can then be fed into the same die 35. The first extruder is a twin-screw extruder 31a for extruding a mineral filler and a first polymer material or a first polymer composition. The second extruder is a single-screw extruder 31b for extruding a second polymer material or a second polymer composition. A vacuum 32 can be applied to the twin-screw extruder 31b. Each extruder 31a, 31b includes a hopper 33 for feeding material into the screw. A heating device 34 is preferably used to heat at least part of the melt in the extruders 31a, 31b. The extruder 30 shown in the figure includes a single manifold extrusion die 35. The device also includes a gear box 36, a gear pump 37 and a filter 38. The diameter of the single screw 31b is smaller than the diameter of the twin screws 31a.

[0138] Figure 4 A schematic diagram of part of the production process according to the present invention is shown. The system basically shows a part of an extruder and laminating system for producing a decorative panel 25 according to the present invention. An extruder inlet 43 is shown, followed by a single manifold extrusion die 41. The produced polymer sheet 200 is fed through a series of rollers 50. One of the rollers can be an embossing roller or a textured roller. A further layer 300, in particular a decorative top layer 300, is fed to the polymer sheet 200 via a feeding device 51. A heating element 52 is provided for heating at least a portion of the polymer sheet 200. A pulling device 54 is also shown. Indicative temperatures for the process are shown.

[0139] It is obvious that the present invention is not limited to the exemplary embodiments shown and described herein, but that numerous variants are possible within the framework of the appended claims, which will be apparent to a person skilled in the art. In this case, it is conceivable to combine the different inventive concepts and / or technical measures of the above variant embodiments completely or partially without departing from the creative ideas described in the appended claims.

[0140] The verb "comprise" and its variations used in this patent document not only means "include", but also includes expressions such as "contain", "substantially contain'", "formed by" and their variations.

Claims

1. A decorative panel, in particular a floor, ceiling, building or wall panel, comprising: - at least one core layer; and - at least one decorative top layer; Therein, at least one core layer comprises at least one structural core component and at least one balancing core component, wherein at least one structural core component comprises at least one mineral filler and at least one first polymer composition, and wherein at least one balancing core component comprises at least one second polymer composition.

2. The decorative panel according to claim 1, wherein: At least one core layer is a coextruded core layer.

3. The decorative board according to claim 1 or 2, wherein: At least one first polymer composition and / or at least one second polymer composition comprises at least one semi-crystalline thermoplastic polymer, wherein the semi-crystalline thermoplastic polymer is preferably a non-halogen semi-crystalline thermoplastic polymer, and the non-halogen semi-crystalline thermoplastic polymer is selected from the group consisting of polyethylene (PE), polyethylene terephthalate (PET), polybutene-1 (PB-1), polymer environmentally friendly resin (PER), polylactic acid (PLA) and / or polypropylene (PP).

4. A decorative panel according to any one of the preceding claims, wherein: At least one structural core component comprises at least 60 wt.-%, preferably at least 70 wt.-%, most preferably at least 75 wt.-% of at least one mineral filler, and / or at least one structural core component, in particular at least one first polymer composition, comprises at least one plastic additive, preferably a copolymer of ethylene and at least one semi-crystalline thermoplastic polymer, and / or at least one plastic additive comprises 2-30 wt.-%, preferably 5-20 wt.-%, more preferably about 10-15 wt.-% of ethylene and / or ethylene units, and / or at least one plastic additive has a density of 0.8 to 1 g / cm 3 , especially 0.862 to 0.912 g / cm 3 .

5. A decorative panel according to any one of the preceding claims, wherein: The at least one mineral filler of the at least one structural core component is selected from the group consisting of limestone, talc, calcium carbonate, magnesium, magnesium hydroxide, magnesium dihydrate, aluminum hydroxide, aluminum trihydrate and combinations thereof.

6. The decorative plate according to claim 4, wherein: The at least one plastic additive comprises an elastomeric polyolefin of at least one isotactic, syndiotactic and / or random polyolefin block.

7. A decorative panel according to any one of the preceding claims, wherein: The at least one structural core component, in particular the at least one first polymer composition comprises at least one copolymer of polypropylene and ethylene, said copolymer comprising at least one polar functional group selected from hydroxyl, ether and / or carbonyl.

8. A decorative panel according to any one of the preceding claims, wherein: The Shore D hardness of at least one balancing core component is 3-35% higher than the Shore D hardness of at least one structural core component; And / or wherein at least one balancing core component, in particular the at least one second polymer composition comprises at least one polyolefin, in particular an isotactic polyolefin.

9. A decorative panel according to any one of the preceding claims, wherein: At least one core layer includes at least two balancing core components, wherein at least one structural core component is substantially enclosed between the at least two balancing core components.

10. A decorative panel according to any one of the preceding claims, wherein: At least one decorative layer comprises at least one semi-crystalline thermoplastic polymer, polypropylene or a polypropylene foil.

11. A process for producing a decorative panel, in particular a floor, ceiling, building or wall panel, in particular a decorative panel according to any one of the preceding claims, comprising the following steps: a) single-manifold coextrusion of at least one mineral filler and a combination of at least one first polymer composition and at least one second polymer composition to form at least one polymer sheet comprising at least one structural core component and at least one balancing core component; b) Laminating at least an additional layer, in particular at least one decorative top layer, to the upper surface of at least one polymer sheet.

12. The process according to claim 11, wherein The at least one first polymer composition and / or the at least one second polymer composition comprises at least one semi-crystalline thermoplastic polymer having a glass transition temperature greater than or equal to -50°C.

13. The process according to claim 11 or 12, wherein: After step a), at least one polymer sheet is subjected to a first temperature of at least 75°C, in particular by passing through at least one first set of calendering rollers movable in a vertical direction, wherein the polymer sheet is subsequently subjected to a second temperature of at least 120°C by passing through at least a second set of calendering rollers movable in a horizontal direction, in particular so that the core layer reaches a degree of crystallinity allowing at least one decorative layer to be laminated onto the polymer sheet.

14. The process according to claim 13, wherein: Prior to step b), the extruded polymer sheet is subjected to a third temperature in the range of 85°C to 100°C for a third time period by passing through at least one third set of calendering rollers, and then subsequently passed through at least one fourth set of calendering rollers to be subjected to a fourth temperature in the range of 50°C to 65°C for a fourth time period, wherein optionally, the polymer sheet is then subjected to a fifth temperature in the range of 45°C to 60°C by passing through at least one fifth set of calendering rollers, and optionally, subjected to a sixth temperature in the range of 25°C to 40°C by passing through at least one sixth set of calendering rollers.

15. The process according to any one of claims 11 to 14, wherein At least one additional layer, in particular at least one decorative top layer, comprises at least one semi-crystalline thermoplastic polymer, polypropylene or a polypropylene foil.

16. An extrusion line for producing decorative floor, ceiling, building or wall panels or architectural panels, in particular for producing decorative panels according to any one of claims 1 to 10, preferably by a process according to any one of claims 11 to 15, comprising: - at least one extruder configured for single-manifold coextrusion of at least one mineral filler and a combination of at least one first polymer composition and at least one second polymer composition; - at least one calendering device, comprising a plurality of calendering rollers, for forming the melt obtained from the extruder into a polymer sheet, wherein at least one roller is configured to be heated, preferably each roller is configured to be heated; - at least one feeding device for feeding at least one additional layer to said polymer sheet for laminating said additional layer onto said polymer sheet; and - at least one calibration device comprising at least two rollers, by which the polymer sheet can be guided.

17. The extrusion line according to claim 16, wherein: The extruder comprises a twin-screw extruder, in particular a co-rotating twin-screw extruder and / or at least one single-screw extruder, preferably wherein the L / D ratio of the twin screw is in the range of 20-30:1, and / or wherein the twin screw has a screw profile having a flight area of ​​at least 40% in its feed section and / or at least 25% in its transition section and / or metering section.

18. An extrusion line according to claim 16 or 17, wherein: The twin screw has a compression ratio in the range of 2:1 to 4:1, preferably 2.7:1, more preferably 3.3:1, and / or wherein the twin screw has a metering groove depth of 2% to 8%, preferably 2.7% to 7%, more preferably 3.5% to 6% of the measured screw diameter.

19. An extrusion line according to any one of claims 16 to 18, wherein: At least one pulling device is included for pulling the polymer sheet through at least a portion of the extrusion line.

20. The extrusion line according to any one of claims 16 to 19, wherein: The extruder comprises at least one main hopper for feeding at least one polymer, in particular polypropylene, and at least one secondary hopper for feeding at least one additive.

21. An extrusion line according to any one of claims 16 to 20, wherein: The extruder further comprises a barrel and a die, and at least one gear pump, which is preferably arranged between the barrel and the die.

22. An extrusion line according to any one of claims 16 to 21, wherein: At least one roller of the calendering device is an oil-heated roller, and preferably each roller is an oil-heated roller; and / or wherein the calendering device comprises at least one embossing roller; And / or wherein the calendering device comprises at least one infrared lamp arranged between the at least one soft roller and the at least one embossing roller.

23. An extrusion line according to any one of claims 16 to 22, wherein: At least one roller of the calendering device is movable in the vertical direction, at least one roller of the calendering device is movable in the horizontal direction and / or at least one roller of the calendering device is fixed, preferably, wherein at least one fixed roller is arranged between at least two rollers movable in the horizontal direction.

24. An extrusion line according to any one of claims 16 to 23, wherein: comprising at least one cutting device for cutting at least a portion of the polymer sheet, in particular cutting at least one edge of the polymer sheet, and / or wherein the extrusion line comprises at least one cooling device for cooling at least a portion of the polymer sheet, in particular by air cooling.

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