Decorative panel and method for manufacturing a decorative panel

Abstract

Method for manufacturing a decorative panel (1) comprising a substrate (2) of thermoplastic material and a top layer (3) provided thereon, said method comprising a step (S1) of preparing a feedstock material with a polymer fraction comprising polyethylene terephthalate (PET) and / or modified PET, and at least one additive, said method comprising a subsequent step (S2) of extruding said feedstock material characterized in that said additive is a chain extender showing one or more of the following properties: - said chain extender comprises an epoxide; - said chain extender comprises a cyclic carboxylic anhydride; - said chain extender comprises an isocyanate; - said chain extender comprises an oxazoline; - said chain extender comprises an epoxy acrylate with terminal and / or internal epoxy groups; - said chain extender comprises a methacrylate; - said chain extender comprises a caprolactam; - said chain extender comprises a pyromellitic dianhydride; - said chain extender comprises a polyol.

Description

[0001] Decorative panel and method for manufacturing a decorative panel.

[0002] The present invention relates to decorative panels and to methods for manufacturing decorative panels.

[0003] Said panels are of the type that comprise a substrate and a top layer applied thereon. These may be for example floor panels that consist mainly of a substrate and a top layer. The substrate may comprise one or more thermoplastic-based layers. A top layer, such as a laminated top layer comprising thermoplastic-based sublayers, may be applied on said one or more thermoplastic-based layers of said substrate.

[0004] In particular, the invention relates to a method for manufacturing decorative panels, wherein said substrate comprises a thermoplastic polyester, more particularly a polyethylene terephthalate (PET) or modified PET.

[0005] From WO 2017 / 122149 Al, a floor panel for forming a floor covering is known of the type wherein the floor panel comprises a layer-shaped substrate, as well as a decorative top layer situated above the substrate; and wherein the substrate comprises at least a layer which is realized on the basis of a composition comprising at least a thermoplastic synthetic material, wherein the composition, apart from thermoplastic synthetic material, also comprises at least one or more elastomers; and that said thermoplastic synthetic material concerns thermoplastic polyester. From that same document, it is known that said substrate layer can be manufactured by means of extrusion.

[0006] Decorative panels comprising a substrate that is formed as a sheet by an extrusion process are known per se, for example from EP 3 703 926. The example method of EP’ 926 includes providing a filler and polymer in powder form, optionally providing additives, such as stabilizers, and heating the obtained mixture until the polymer powder softens to form a kneadable mass and filler powder at least partially bonds thereto. The obtained mass is subjected to cooling; and is subsequently conveyed to an extruder; wherein said mass is molten and extruded. The extruder feeds a die, and the sheet is extruded through the opening of the die. The obtained sheet is then pressed to a desired final thickness by means of, for example calendar rolls.

[0007] The efficiency of the known methods for manufacturing decorative panels, wherein said substrate comprises a thermoplastic polyester, more particularly a polyethylene terephthalate (PET), leaves room for improvement. Additionally, PET is a hygroscopic polymer, which results in hydrolysis of the polymer chains at elevated temperatures, for example during extrusion, which further results in a loss of intrinsic viscosity and subsequently reduces the processability of the material during and after extrusion. To combat the negative effects of the hygroscopic nature of PET, often quite extensive drying cycles, requiring a high energy consumption, are needed prior to processing. These difficulties in processability result in rather low processing speeds. Decorative panels, wherein the substrate comprises PET tend to warp, affecting the structural integrity and aesthetic appeal of the final product. Furthermore, the adhesion between the substrate comprising PET and a top layer leaves room for improvement.

[0008] Throughout this specification, when reference is made to PET as opposed to modified PET, this term should be understood to represent the base form of polyethylene terephthalate that is without any chemical modifications or copolymerization.

[0009] The present invention, in the first place, aims to provide an alternative and / or an improved method for manufacturing such decorative panels, as well as alternative and / or improved decorative panels. In accordance with one or more of the preferred embodiments, the present invention provides solutions to one or more problems associated with methods and / or decorative panels of the state of the art.

[0010] Thereto, in accordance with its first aspect, the present invention is a method for manufacturing a decorative panel, wherein said panel comprises a substrate and a top layer provided thereon, wherein said substrate comprises a thermoplastic material, wherein said method comprises a step of preparing a feedstock material, said feedstock material comprising a polymer fraction and an optional filler fraction, said polymer fraction at least comprising polyethylene terephthalate (PET) and / or modified PET, and at least one additive, wherein said method comprises a subsequent step of extruding said feedstock material for providing said substrate, with as a characteristic that said at least one additive is a chain extender and wherein said chain extender shows one or a combination of two or more of the following properties: the property that said chain extender comprises an epoxide, preferably bisepoxide, and / or one or more epoxide groups; the property that said chain extender comprises a cyclic carboxylic anhydride, preferably bis-(cyclic carboxylic anhydride); the property that said chain extender comprises an isocyanate, preferably diisocyanate; the property that said chain extender comprises an oxazoline, preferably bis- oxazoline, more preferably 2,2’-bis(2-oxazoline); the property that said chain extender comprises an epoxy acrylate chain extender with terminal epoxy groups and / or an epoxy acrylate chain extender with internal epoxy groups; the property that said chain extender comprises a methacrylate, preferably methacrylate random copolymer, more preferably styrene-acrylonitrile-glycidyl methacrylate random copolymer (SAN-g-GMA); the property that said chain extender comprises a caprolactam, preferably biscaprolactam; the property that said chain extender comprises a pyromellitic dianhydride (PMDA); the property that said chain extender comprises a polyol, preferably a pentaerythritol (PENTA).

[0011] Said chain extender, comprised in said polymer fraction, is able to enhance the mechanical properties and durability of the substrate by increasing the molecular weight, and consequently the intrinsic viscosity, of the polymer fraction, more particularly of the PET and / or modified PET. Said chain extender also improves the overall processability of the feedstock material, for example less sagging, tearing and / or blister formation in the extrudate. It should be noted that "improving the overall processability of the feedstock material" encompasses enhancements not only during extrusion but also throughout subsequent processing steps, such as calendaring and / or lamination and / or separating and / or milling of possible coupling parts. During extrusion of said feedstock material, said feedstock material is molten and conveyed through said extruder. Said extruded feedstock material is also referred to as the extrudate.

[0012] In the context of the present invention, extrusion can refer to two distinct processes: one where the feedstock material upon exiting the extruder is forced through a die, preferably a slot nozzle die, to obtain a continuous web material. In this first process, it is the die that determines the basic shape of the continuous web material (i.e. a continuous sheet material). In the second process the feedstock material is passed from the extruder through calendaring rolls without the intermediate use of a die to determine the basic shape of the continuous web material. The inventors have found that adding a chain extender to the feedstock material is particularly beneficial for the first process, as it may improve the extrudate’s mechanical properties and processability under the high shear conditions of this process.

[0013] In the case said feedstock material comprises a filler fraction, it is preferred that the resulting extrudate, and consequently the obtained substrate, is a filled synthetic material comprising a polymer matrix of said PET and / or modified PET, in which said filler fraction is dispersed.

[0014] Said modified PET can for example be a glycol modified PET. By glycol modified PET is meant a type of PET in which some of the ethylene glycol is replaced with another glycol, such as cyclohexanedimethanol (CHDM) or neopentylglycol (NPG), for example to improve transparency, impact resistance and / or processability.

[0015] The inventors have found that when chain extenders are comprised in the polymer fraction, polymer chains which have been broken due to hydrolysis as a result of the hygroscopic nature of PET and / or modified PET, can to a certain extent be re-attached through a crosslinking process at a location where water molecules cause the breakage of ester bonds in the polymer chains. This chain scission results in an undesired decrease in molecular weight. Chain extenders, such as epoxides, contain reactive groups that can interact with the terminal groups of the separated chains as a result of said chain scission, more particularly with carboxyl and hydroxyl end groups formed due to hydrolysis. These reactive groups can form covalent bonds with the end groups of the hydrolyzed PET chains. Through these reactions, the chain extender may link the broken polymer chains back together.

[0016] According to a first possible property of said chain extender, said chain extender comprises an epoxide, preferably bis-epoxide, and / or comprises one or more epoxide groups. The inventors have found that epoxides are especially well suited for use as a chain extender, due to a high reactivity as well as a high thermal stability. Even better results in terms of reactivity, and thermal stability were obtained when a bis-epoxide was used as chain extender in said polymer fraction. The inventors have additionally found that an improved processability of the PET and / or modified PET can be achieved when said chain extender comprises a substance comprising four epoxide groups. An example of a substance comprising four epoxide groups is tetraglycidyl-4,4’- diaminodifenylmethane.

[0017] The inventors have achieved improved processability of the PET and / or modified PET with chain extenders comprising 1,4-butanediol diglycidyl ether, as well as with chain extenders comprising tetrahydrophtalic acid diglycidyl.

[0018] According to a second possible property of said chain extender, said chain extender comprises a cyclic carboxylic anhydride, preferably bis-(cyclic carboxylic anhydride). The inventors have found that cyclic carboxylic anhydrides are suitable chain extenders for improving the overall processability of the feedstock material. Even better results were obtained when a bis-(cyclic carboxylic anhydride) was used as chain extender in said polymer fraction.

[0019] According to a third possible property of said chain extender, said chain extender comprises an isocyanate, preferably diisocyanate. The inventors have found that isocyanates are also suitable chain extenders for improving the overall processability of the feedstock material. Even better results were obtained when a diisocyanate, for example 1,6-diisocyanatohexane, was used as chain extender in said polymer fraction. The inventors have additionally found that isocyanurates are also suitable chain extenders for improving the overall processability of the feedstock material. Good results were achieved with triglycidyl isocyanurate (TGIC).

[0020] According to a fourth possible property of said chain extender, said chain extender comprises an oxazoline, preferably bis-oxazoline, more preferably 2,2’-bis(2-oxazoline). The inventors have found that oxazolines are also suitable chain extenders for improving the overall processability of the feedstock material. Even better results were obtained when a bis-oxazoline, more particularly 2,2’-bis(2-oxazoline) was used as chain extender in said polymer fraction.

[0021] According to a fifth possible property of said chain extender, said chain extender comprises an epoxy acrylate chain extender with terminal epoxy groups (PEAT -BA) and / or an epoxy acrylate chain extender with internal epoxy groups (PEAI-BA). The inventors have found that a chain extender comprising epoxy acrylate chain extenders with terminal epoxy groups and / or epoxy acrylate chain extenders with internal epoxy groups are suitable for improving the overall processability of the feedstock material.

[0022] According to a sixth possible property of said chain extender, said chain extender comprises a methacrylate, preferably methacrylate random copolymer, more preferably styrene-acrylonitrile-glycidyl methacrylate random copolymer (SAN-g-GMA). The inventors have found that methacrylates are also suitable chain extenders for improving the overall processability of the feedstock material. The inventors have found that improved processability of the PET and / or modified PET is achieved when said chain extender comprises epoxy-functional (meth)acrylic monomers and styrenic and / or (meth)acrylic monomers. An example of a chain extender comprising a methacrylate is BTCE-9013 from Nanjing Baitong New Material Co., Ltd. Even better results were obtained when a methacrylate random copolymer, more particularly SAN-g-GMA, was used as chain extender in said polymer fraction. According to a seventh possible property of said chain extender, said chain extender comprises a caprolactam, preferably bis-caprolactam. The inventors have found that caprolactams are also suitable chain extenders for improving the overall processability of the feedstock material. Even better results were obtained when a bis-caprolactam was used as chain extender in said polymer fraction.

[0023] According to an eighth possible property of said chain extender, said chain extender comprises a pyromellitic dianhydride (PMDA). The inventors have achieved improved processability of the PET and / or modified PET with 1,2,3,5-benzenetetracarboxylic anhydride PMDA from Acros Organics.

[0024] According to a ninth possible property of said chain extender, said chain extender comprises a polyol, preferably a pentaerythritol (PENTA). The inventors have achieved improved processability of the PET and / or modified PET with Irgafos 123 (bis-(2,4-di- t-butylphenol) pentaerythritol diphosphate) from Ciba.

[0025] Preferably, said chain extender comprises a combination of two or more of the above described properties. In one preferred embodiment, said chain extender comprises both an epoxide and an isocyanate, for example bis-epoxide and diisocyanate.

[0026] In another preferred embodiment, said chain extender comprises both an oxazoline and a caprolactam, more particularly a bisoxazoline and a biscaprolactam.

[0027] All possible combinations of the aforementioned properties are disclosed herein, encompassing any combination of two up to nine of the above described properties.

[0028] The inventors have achieved good results with the following chain extenders: CESA extend from Clariant, DSM Allinco, Dufor Cumabatch CE01, Polychem Ausipol PP30, Resalloy EPl 14, Sukano me S606 melt viscosity enhancer, loncryl ADR 4468; loncryl ADR 4400, Polyadd PR-002, OPTIPET 213M from Pluss Advanced Technologies Pvt. Ltd. It is preferred that said polymer fraction further comprises one or a combination of two or more of the additives chosen from the list of: a flexibilizer, an impact modifier, a compatibilizer, a nucleating agent, a desiccant, a hydrolysis stabilizer.

[0029] All possible combinations of the aforementioned additives are disclosed herein, encompassing any combination of two up to six of the above described additives.

[0030] With the same aim as in the first aspect, the present invention in accordance with its second aspect is a method for manufacturing a decorative panel, wherein said panel comprises a substrate and a top layer provided thereon, wherein said substrate comprises a thermoplastic material, wherein said method comprises a step of preparing a feedstock material, said feedstock material comprising a polymer fraction and an optional filler fraction, said polymer fraction comprising polyethylene terephthalate (PET) and / or modified PET and at least one additive, wherein said method comprises a subsequent step of extruding said feedstock material for providing said substrate, with as a characteristic that said at least one additive is a flexibilizer, wherein said flexibilizer shows one or a combination of two or more of the following properties: the property that said flexibilizer comprises a polyurethane, preferably a thermoplastic polyurethane; the property that said flexibilizer comprises an elastomer, preferably a thermoplastic elastomer; the property that said flexibilizer comprises a polyolefin elastomer , preferably a propylene-based elastomer; the property that said flexibilizer comprises an ethylene methyl acrylate copolymer; the property that said flexibilizer comprises an ester group.

[0031] As a consequence of the hydrolysis of the polymer chains taking place during extrusion, the extrudate, and consequently the obtained substrate, may show an undesirable brittleness. Said flexibilizer, comprised in said polymer fraction, is able to enhance the mechanical properties, such as flexibility and toughness, and durability of the substrate. Said flexibilizer also improves the overall processability of the feedstock material, for example, reducing brittleness, cracking, and / or deformation in the extrudate, and as a consequence in the obtained decorative panel. It should be noted that "improving the overall processability of the feedstock material" encompasses enhancements not only during extrusion but also throughout subsequent processing steps, such as calendaring and / or lamination and / or separating and / or milling of possible coupling parts. The inventors have also found that a flexibilizer comprised in said polymer fraction leads to a more dimensionally stable decorative panel.

[0032] According to a first possible property of said flexibilizer, said flexibilizer comprises a polyurethane, preferably a thermoplastic polyurethane. The inventors have found that polyurethanes are especially well suited for use as a flexibilizer. It was found that the flexibility and toughness of the decorative panel can be significantly improved by having polyurethane in said polymer fraction. While it is not excluded that a thermosetting polyurethane is used, thermoplastic polyurethane (TPU) is preferred since TPU is able to be reprocessed, for example remelted and reformed, multiple times. This is advantageous during manufacturing and recycling processes. TPU is also able to be processed under similar conditions as PET and / or modified PET.

[0033] According to a second possible property of said flexibilizer, said flexiblizer comprises an elastomer, preferably a thermoplastic elastomer. Examples of thermosetting elastomers include rubbers, synthetic rubbers such as ethylene propylene diene monomer (EPDM) or styrene butadiene rubber (SBR). Examples of thermoplastic elastomers include: styrene butadiene styrene (SBS), thermoplastic vulcanizates (TPVs), copolyester elastomers (COPEs), polyether block amides (PEBAs), thermoplastic polyamide elastomers (TPAEs), ethylene vinyl acetate (EVA), ethylene butyl acrylate copolymers (EBA), ethylene acrylic acid copolymer (EAA).

[0034] According to a third possible property of said flexibilizer, said flexibilizer comprises a polyolefin elastomer, preferably a propylene-based elastomer. An example of such a propylene-based elastomer for which good results have been obtained is Vistamaxx ™ by ExxonMobil. Preferably, the propylene-based elastomer is primarily composed of isotactic propylene repeat units with random ethylene distribution, as may be the case with Vistamaxx 6102, for example.

[0035] According to a fourth possible property of said flexibilizer, said flexibilizer comprises an ethylene methyl acrylate (EMA) copolymer. It was found that said EMA copolymer is generally well-compatible with PET and / or modified PET, such that the physical properties of the PET and / or modified PET matrix are effectively modified to improve flexibility of the decorative panel, without causing issues with processing or performance of the decorative panel.

[0036] According to a fifth possible property of said flexibilizer, said flexibilizer comprises an ester group. Ester groups in the flexibilizer can interact more favorably with the ester groups in PET and / or modified PET due to similar chemical structures. This chemical similarity helps the flexibilizer to blend more uniformly with PET and / or modified PET, resulting in a more homogenous material.

[0037] It is preferred that said flexibilizer is grafted with maleic anhydride (MAH) and / or glycidyl methacrylate (GMA).

[0038] It is preferred that said polymer fraction further comprises one or a combination of two or more of the additives chosen from the list of: a chain extender, an impact modifier, a compatibilizer, a nucleating agent, a desiccant, a hydrolysis stabilizer.

[0039] Preferably said chain extender is a chain extender as described in the context of the first aspect of the invention.

[0040] All possible combinations of the aforementioned additives are disclosed herein, encompassing any combination of two up to six of the above described additives.

[0041] With the same aim as in the previous aspects, the present invention in accordance with its third aspect is a method for manufacturing a decorative panel, wherein said panel comprises a substrate and a top layer provided thereon, wherein said substrate comprises a thermoplastic material, wherein said method comprises a step of preparing a feedstock material, said feedstock material comprising a polymer fraction and an optional filler fraction, said polymer fraction comprising polyethylene terephthalate (PET) and / or modified PET and at least one additive, wherein said method comprises a subsequent step of extruding said feedstock material for providing said substrate, with as a characteristic that said at least one additive is an impact modifier and wherein said impact modifier shows one or a combination of two or more of the following properties: the property that said impact modifier comprises an acrylate, preferably a methyl acrylate; the property that said impact modifier comprises a polyethylene, preferably a maleic anhydride grafted polyethylene, more preferably a maleic anhydride grafted low density polyethylene; the property that said impact modifier comprises a maleic anhydride grafted polymer, preferably a maleic anhydride grafted copolymer, more preferably a maleic anhydride grafted ethylene octene copolymer; the property that said impact modifier comprises a polyolefin-based copolymer, preferably a polyolefin-based copolymer functionalized with epoxy groups; the property that said impact modifier comprises an ethylene terpolymer; the property that said impact modifier comprises an elastomeric terpolymer, preferably a reactive elastomeric terpolymer.

[0042] As a consequence of the hydrolysis of the polymer chains taking place during extrusion, the extrudate, and consequently the obtained substrate, may show an undesirable brittleness. Said impact modifier, comprised in said polymer fraction, enhances the mechanical properties and resilience of the substrate by improving its ability to absorb and distribute impact forces, thereby reducing brittleness and increasing toughness. Specifically, the impact modifier improves the overall durability of the decorative panel. This impact modifier also contributes to better processability of the feedstock material, helping to minimize issues such as cracking, fracturing, and surface defects in the extruded material. It should be noted that "improving the overall processability of the feedstock material" encompasses enhancements not only during extrusion but also throughout subsequent processing steps, such as calendaring and / or lamination and / or separating and / or milling of possible coupling parts.

[0043] According to a first possible property of said impact modifier, said impact modifier comprises an acrylate, preferably a methyl acrylate. The inventors have found that acrylates have good compatibility with the PET and / or modified PET in said polymer fraction. This compatibility ensures that the impact modifier integrates well in the PET and / or modified PET matrix without causing phase separation or processing issues. An even better compatibility was achieved with a methyl acrylate. An example of such an impact modifier comprising acrylate is DOW Paraloid EXL2314.

[0044] According to a second possible property of said impact modifier, said impact modifier comprises a polyethylene, preferably a maleic anhydride grafted polyethylene, more preferably a maleic anhydride grafted low density polyethylene (LDPE). The inventors have found that polyethylene has good compatibility with the PET and / or modified PET in said polymer fraction. An even better compatibility was achieved with a maleic anhydride grafted low density polyethylene. An even more improved compatibility was achieved with maleic anhydride grafted low density polyethylene. An example of such an impact modifier comprising maleic anhydride grafted LDPE is Orevac IM800.

[0045] According to a third possible property of said impact modifier, said impact modifier comprises a maleic anhydride grafted polymer, preferably a maleic anhydride grafted copolymer, more preferably a maleic anhydride grafted ethylene octene copolymer. The inventors have found that maleic anhydride grafted polymer has good compatibility with the PET and / or modified PET in said polymer fraction. An even better compatibility was achieved with a maleic anhydride grafted copolymer. An even more improved compatibility was achieved with maleic anhydride grafted ethylene octene copolymer. An example of an impact modifier comprising such a maleic anhydride grafted ethylene octene copolymer is Scona TSPOE 1002.

[0046] According to a fourth possible property of said impact modifier, said impact modifier comprises a polyolefin-based copolymer, preferably a polyolefin-based copolymer functionalized with epoxy groups (POE-g-GMA). The inventors have found that polyolefin-based copolymer has good compatibility with the PET and / or modified PET in said polymer fraction. An even better compatibility was achieved with a polyolefin- based copolymer functionalized with epoxy groups.

[0047] According to a fifth possible property of said impact modifier, said impact modifier comprises an ethylene terpolymer. The inventors have found that ethylene terpolymers have good compatibility with the PET and / or modified PET in said polymer fraction. An example of such an impact modifier comprising ethylene terpolymer is Dupont Elvaloy PTW.

[0048] According to a sixth possible property of said impact modifier, said impact modifier comprises an elastomeric terpolymer, more preferably a reactive elastomeric terpolymer. The inventors have found that elastomeric terpolymers have good compatibility with the PET and / or modified PET in said polymer fraction. An even better compatibility was achieved with a reactive elastomeric terpolymer. An example of such an impact modifier comprising reactive elastomeric terpolymer is Dupont Elvaloy 4170.

[0049] It is preferred that said polymer fraction further comprises one or a combination of two or more of the additives chosen from the list of: a chain extender, a flexibilizer, a compatibilizer, a nucleating agent, a desiccant, a hydrolysis stabilizer.

[0050] Preferably said chain extender is a chain extender as described in the context of the first aspect of the invention.

[0051] Preferably said flexibilizer is a flexibilizer as described in the context of the second aspect of the invention.

[0052] All possible combinations of the aforementioned additives are disclosed herein, encompassing any combination of two up to six of the above described additives. With the same aim as in the previous aspects, the present invention in accordance with its fourth aspect is a method for manufacturing a decorative panel wherein said panel comprises a substrate and a top layer provided thereon, wherein said substrate comprises a thermoplastic material, wherein said method comprises a step of preparing a feedstock material, said feedstock material comprising a polymer fraction and an optional filler fraction, said polymer fraction comprising polyethylene terephthalate (PET) and / or modified PET and at least one additive, wherein said method comprises a subsequent step of extruding said feedstock material for providing said substrate, with as a characteristic that said at least one additive is a compatibilizer and wherein said compatibilizer shows one or a combination of two or more of the following properties: the property that said compatibilizer comprises a maleic anhydride grafted polymer, preferably a maleic anhydride grafted polyolefin, preferably a maleic anhydride grafted polypropylene; the property that said compatibilizer comprises a glycidyl acrylate, preferably a glycidyl methacrylate.

[0053] Said compatibilizer, comprised in said polymer fraction, is able to enhance the mechanical properties and durability of the substrate by improving the interfacial adhesion between different phases within said polymer fraction, and consequently ensuring a more uniform distribution of the polymer fraction. Said compatibilizer also improves the overall processability of the feedstock material, for example less sagging, tearing and / or blister formation in the extrudate. It should be noted that "improving the overall processability of the feedstock material" encompasses enhancements not only during extrusion but also throughout subsequent processing steps, such as calendaring and / or lamination and / or separating and / or milling of possible coupling parts. Compatibilizers are especially useful when other additives are added to the polymer fraction and / or when the feedstock material comprises fillers, as they ensure better dispersion and integration of said other additives and / or fillers in the feedstock material, leading to improved overall performance of the final product.

[0054] According to a first possible property of said compatibilizer, said compatibilizer comprises a maleic anhydride grafted polymer, preferably a maleic anhydride grafted polyolefin, preferably a maleic anhydride grafted polypropylene. Maleic anhydride grafted polymers are produced by grafting maleic anhydride onto the polymer backbone. The inventors have found that when said polymer fraction comprises a compatibilizer comprising a maleic anhydride grafted polymer an improved adhesion between the substrate and the top layer of said decorative panel could be achieved, minimizing the risk of delamination. Examples of such maleic anhydride grafted polymers are Paraloid EXL 3808, Orevac CA100, Fusabond E100, Scona TPPP 2003, Scona TPPP 8112 GA.

[0055] According to a second possible property of said compatibilizer, said compatibilizer comprises a glycidyl acrylate, preferably a glycidyl methacrylate. The inventors have found that when said polymer fraction comprises a compatibilizer comprising a glycidyl acrylate an improved adhesion between the substrate and the top layer of said decorative panel could be achieved, minimizing the risk of delamination. Even better results were obtained when said polymer fraction comprises a compatibilizer comprising a glycidyl methacrylate. Examples of such glycidyl methacrylates are Lotader AX8900 and Lotader AX8840.

[0056] It is preferred that said polymer fraction further comprises one or a combination of two or more of the additives chosen from the list of a chain extender, a flexibilizer, an impact modifier, a nucleating agent, a desiccant, a hydrolysis stabilizer.

[0057] Preferably said chain extender is a chain extender as described in the context of the first aspect of the invention.

[0058] Preferably said flexibilizer is a flexibilizer as described in the context of the second aspect of the invention.

[0059] Preferably said impact modifier is an impact modifier as described in the context of the third aspect of the invention.

[0060] All possible combinations of the aforementioned additives are disclosed herein, encompassing any combination of two up to six of the above described additives. In a preferred embodiment of the fourth aspect of the invention, said polymer fraction comprises a compatibilizer according to the first and / or second possible property and a flexibilizer, preferably according to the second aspect of the invention and / or an impact modifier, preferably according to the third aspect of the invention. The inventors have found that a compatibilizer according to the fourth aspect of the invention is able to provide a better dispersion of flexibilizer, for example according to the second aspect of the invention, and / or impact modifier, for example according to the third aspect of the invention, within said polymer fraction. Said better dispersion results in a more stable polymer fraction and increases the overall processability of the feedstock material as well as the overall mechanical properties of the decorative panel.

[0061] Preferably said polymer fraction comprises a compatibilizer according to the first possible property of said compatibilizer and a flexibilizer comprising a polyolefin-based elastomer, for example Vistamaxx 6102 or DOW Engage 7387.

[0062] With the same aim as in the previous aspects, the present invention in accordance with its fifth aspect is a method for manufacturing a decorative panel wherein said panel comprises a substrate and a top layer provided thereon, wherein said substrate comprises a thermoplastic material, wherein said method comprises a step of preparing a feedstock material, said feedstock material comprising a polymer fraction and an optional filler fraction, said polymer fraction comprising polyethylene terephthalate (PET) and / or modified PET and at least one additive, wherein said method comprises a subsequent step of extruding said feedstock material for providing said substrate, with as a characteristic that said at least one additive is a nucleating agent and wherein said nucleating agent shows one or a combination of two or more of the following properties: the property that said nucleating agent comprises an ionomer, preferably a sodium ionomer; the property that said nucleating agent comprises an antimony catalyst; the property that said nucleating agent comprises a modified polyolefin; the property that said nucleating comprises a sodium salt. A decorative panel comprising a substrate made of a thermoplastic material, obtained through the extrusion of a feedstock material comprising at least a polymer fraction of PET and / or modified PET, tends to warp due to residual crystallization of the PET and / or modified PET, especially during cooling. By incorporating a nucleating agent into the polymer fraction, the crystallization process is encouraged and controlled during extrusion, thereby minimizing residual crystallization in the substrate of the decorative panel. This controlled crystallization reduces internal stresses and minimizes the risk of warping, resulting in a more dimensionally stable and reliable decorative panel.

[0063] According to a first possible property of said nucleating agent, said nucleating agent comprises an ionomer, preferably a sodium ionomer. The inventors have found that ionomers, especially sodium ionomers, are chemically compatible with PET and / or modified PET, ensuring good dispersion within the polymer fraction. An example of such a compatibilizer comprising a sodium ionomer is Honeywell Aclyn 285.

[0064] According to a second possible property of said nucleating agent, said nucleating agent comprises an antimony catalyst. The inventors have found that antimony catalysts are chemically compatible with PET and / or modified PET, ensuring good dispersion within the polymer fraction.

[0065] According to a third possible property of said nucleating agent, said nucleating agent comprises a modified polyolefin. An example of such a nucleating agent comprising a modified polyolefin is Procaster MB-NRC.

[0066] According to a fourth possible property of said nucleating agent, said nucleating agent comprises a sodium salt. The inventors have found that sodium salts are chemically compatible with PET and / or modified PET, ensuring good dispersion within the polymer fraction. An example of such a nucleating agent comprising sodium salt is LicomontNaV 101. It is preferred that said polymer fraction further comprises one or a combination of two or more of the additives chosen from the list of: a chain extender, a flexibilizer, an impact modifier, a compatibilizer, a desiccant, a hydrolysis stabilizer.

[0067] Preferably said chain extender is a chain extender as described in the context of the first aspect of the invention.

[0068] Preferably said flexibilizer is a flexibilizer as described in the context of the second aspect of the invention.

[0069] Preferably said impact modifier is an impact modifier as described in the context of the third aspect of the invention.

[0070] Preferably said compatibilizer is a compatibilizer as described in the context of the fourth aspect of the invention.

[0071] All possible combinations of the aforementioned additives are disclosed herein, encompassing any combination of two up to five of the above described additives.

[0072] With the same aim as in the previous aspects, the present invention in accordance with its sixth aspect is a method for manufacturing a decorative panel wherein said panel comprises a substrate and a top layer provided thereon, wherein said substrate comprises a thermoplastic material, wherein said method comprises a step of preparing a feedstock material, said feedstock material comprising a polymer fraction and an optional filler fraction, said polymer fraction comprising polyethylene terephthalate (PET) and / or modified PET and at least one additive, wherein said method comprises a subsequent step of extruding said feedstock material for providing said substrate, with as a characteristic that said at least one additive is a desiccant and wherein said desiccant shows one or both of the following properties: the property that said desiccant comprises a zeolite; the property that said desiccant comprises calcium oxide. PET is a hygroscopic polymer, which results in hydrolysis of the polymer chains at elevated temperatures, for example during extrusion, which further results in a loss of intrinsic viscosity and subsequently reduces the processability of the material during and after extrusion. To mitigate this issue, it is beneficial to have a feedstock material comprising at least a polymer fraction containing PET and / or modified PET, along with a desiccant. The inclusion of a desiccant helps to absorb and remove moisture from the polymer fraction before and during extrusion, thereby preventing hydrolysis. This maintains the intrinsic viscosity of the polymer fraction, ensuring better mechanical properties of the decorative panel and improved processability of the feedstock material.

[0073] According to a first possible property of said desiccant, said desiccant comprises a zeolite. Zeolite is a naturally occurring or synthetically produced mineral composed of aluminosilicates. It has a porous, crystalline structure that allows it to act as a molecular sieve, making it highly effective at adsorbing and trapping molecules, such as water and gases. The inventors have surprisingly found that the formation of blisters and / or tears in the extrudate could be significantly reduced when said polymer fraction comprises a desiccant comprising a zeolite.

[0074] According to a second possible property of said desiccant, said desiccant comprises a calcium oxide. The inventors have surprisingly found that the formation of blisters and / or tears in the extrudate could be significantly reduced when said polymer fraction comprises a desiccant comprising calcium oxide.

[0075] It is preferred that said polymer fraction further comprises one or a combination of two or more of the additives chosen from the list of: a chain extender, a flexibilizer, an impact modifier, a compatibilizer, a nucleating agent, a hydrolysis stabilizer.

[0076] Preferably said chain extender is a chain extender as described in the context of the first aspect of the invention.

[0077] Preferably said flexibilizer is a flexibilizer as described in the context of the second aspect of the invention. Preferably said impact modifier is an impact modifier as described in the context of the third aspect of the invention.

[0078] Preferably said compatibilizer is a compatibilizer as described in the context of the fourth aspect of the invention.

[0079] Preferably said nucleating agent is a nucleating agent as described in the context of the fifth aspect of the invention.

[0080] All possible combinations of the aforementioned additives are disclosed herein, encompassing any combination of two up to six of the above described additives.

[0081] With the same aim as in the previous aspects, the present invention in accordance with its seventh aspect is a method for manufacturing a decorative panel wherein said panel comprises a substrate and a top layer provided thereon, wherein said substrate comprises a thermoplastic material, wherein said method comprises a step of preparing a feedstock material, said feedstock material comprising a polymer fraction and an optional filler fraction, said polymer fraction comprising polyethylene terephthalate (PET) and / or modified PET and at least one additive, wherein said method comprises a subsequent step of extruding said feedstock material for providing said substrate, with as a characteristic that said at least one additive is a hydrolysis stabilizer and wherein said hydrolysis stabilizer comprises a carbodiimide, preferably a polycarbodiimide.

[0082] To improve the resistance against hydrolysis of PET and / or modified PET, it is beneficial to have a feedstock material comprising at least a polymer fraction containing PET and / or modified PET, along with a hydrolysis stabilizer. The inclusion of a hydrolysis stabilizer helps to neutralize the reactive components that are obtained as a result of a hydrolysis reaction, thereby limiting the extent of further hydrolysis of the PET and / or modified PET. The inventors have achieved good results with the following hydrolysis stabilizers: Stabaxol® KE 7646 from Lanxess, HyMax 1010 and HyMax 213 from Langyi New Materials.

[0083] It is preferred that said polymer fraction further comprises one or a combination of two or more of the additives chosen from the list of: a chain extender, a flexibilizer, an impact modifier, a compatibilizer, a nucleating agent, a desiccant.

[0084] Preferably said chain extender is a chain extender as described in the context of the first aspect of the invention.

[0085] Preferably said flexibilizer is a flexibilizer as described in the context of the second aspect of the invention.

[0086] Preferably said impact modifier is an impact modifier as described in the context of the third aspect of the invention.

[0087] Preferably said compatibilizer is a compatibilizer as described in the context of the fourth aspect of the invention.

[0088] Preferably said nucleating agent is a nucleating agent as described in the context of the fifth aspect of the invention.

[0089] Preferably said desiccant is a desiccant as described in the context of the sixth aspect of the invention.

[0090] All possible combinations of the aforementioned additives are disclosed herein, encompassing any combination of two up to six of the above described additives.

[0091] With the same aim as in the previous aspects, the present invention in accordance with its eighth aspect is a method for manufacturing a decorative panel, wherein said panel comprises a substrate and a top layer provided thereon, wherein said substrate comprises a thermoplastic material, wherein said method comprises a step of preparing a feedstock material, said feedstock material comprising a polymer fraction and an optional filler fraction, said polymer fraction comprising polyethylene terephthalate (PET) and / or modified PET and at least one additive, wherein said method comprises a subsequent step of extruding said feedstock material for providing said substrate, with as a characteristic that said polymer fraction comprises one or a combination of two or more of the additives chosen from the list of: a chain extender, a flexibilizer, an impact modifier, a compatibilizer, a nucleating agent, a desiccant, a hydrolysis stabilizer.

[0092] Preferably said chain extender is a chain extender as described in the context of the first aspect of the invention.

[0093] Preferably said flexibilizer is a flexibilizer as described in the context of the second aspect of the invention.

[0094] Preferably said impact modifier is an impact modifier as described in the context of the third aspect of the invention.

[0095] Preferably said compatibilizer is a compatibilizer as described in the context of the fourth aspect of the invention.

[0096] Preferably said nucleating agent is a nucleating agent as described in the context of the fifth aspect of the invention.

[0097] Preferably said desiccant is a desiccant as described in the context of the sixth aspect of the invention.

[0098] Preferably said hydrolysis stabilizer is a hydrolysis stabilizer as described in the context of the seventh aspect of the invention.

[0099] It is preferred that said polymer fraction comprises a combination of at least two of said additives, for example a chain extender and a flexibilizer. Even more preferably, said polymer fraction comprises an additional third additive, for example a compatibilizer. The inventors have found that the combination of a chain extender, a flexibilizer and a compatibilizer in said polymer fraction, results in a highly processable feedstock material, and a decorative panel with desirable mechanical properties.

[0100] Preferably said compatibilizer is grafted to said flexibilizer, either before said step of preparing the feedstock material or after.

[0101] Preferably said polymer fraction further comprises a fourth additive, for example an impact modifier.

[0102] Preferably said polymer fraction further comprises a fifth additive, for example a nucleating agent.

[0103] Preferably said polymer fraction further comprises a sixth additive, for example a desiccant.

[0104] It should be noted that other combinations than the ones directly disclosed in the context of the eighth aspect of the invention are also possible and should be considered as being disclosed, for example said polymer fraction comprises a combination of a chain extender, a desiccant and a nucleating agent.

[0105] With the same aim as in the previous aspects, the present invention in accordance with its ninth aspect is a method for manufacturing a decorative panel, optionally according to any of the preceding aspects, wherein said panel comprises a substrate and a top layer provided thereon, wherein said substrate comprises a thermoplastic material, wherein said method comprises a step of preparing a feedstock material, said feedstock material comprising a polymer fraction and an optional filler fraction, said polymer fraction comprising polyethylene terephthalate (PET) and / or modified PET, wherein said method comprises a subsequent step of extruding said feedstock material for providing said substrate, with as a characteristic that in said step of extruding, said feedstock material is extruded by means of an extruder and a die connected to the outlet of said extruder, said extruder at least comprising a barrel and a screw, wherein the method shows one or a combination of two or more of the following properties: the property that said die comprises a choker bar which is mounted under an angle lower than 90°, preferably lower than 70°, preferably between 40° and 70°, more preferably between 55° and 65°; the property that said die comprises a manifold, wherein said manifold has a fishtail shape; the property that a vacuum is applied to at least a portion of said barrel.

[0106] During said step of extruding, the feedstock material is passed through said extruder, during which said feedstock material is melted into a molten feedstock material. Said die comprises a flow channel through which the molten feedstock material passes. The height of said flow channel helps controlling the flow of the molten feedstock material as well as the thickness of the molten feedstock material upon exiting said die.

[0107] According to a first possible property of said method, said die comprises a choker bar which is mounted under an angle lower than 90°, preferably lower than 70°, preferably between 40° and 70°, more preferably between 55° and 65°. The choker bar can be locally deformed and / or displaced by a plurality of actuators, preferably bolts, located along the width of the die, in order to control the height of said flow channel and thereby control the flow of the feedstock material through the die. The inventors have found that mounting said choker bar under an angle in the above mentioned ranges, drastically improves the sensitivity with which the height of said flow channel can be controlled, resulting in the possibility to optimally control the flow of the molten feedstock material through said die, thereby minimizing the risk of processing defects such as tearing. This is especially useful for controlling the flow of molten feedstock material comprising a polymer fraction comprising polyethylene terephthalate (PET) and / or modified PET. Due to the tendency of PET and / or modified PET to degrade as a result of hydrolysis of the polymer chains, the viscosity of the molten feedstock material may vary, more particularly decrease, over time, which results in a need for precise control of the flow of the molten feedstock material. According to a second possible property of said method, said die comprises a manifold, wherein said manifold has a fishtail shape. The inventors have found that a manifold with a fishtail shape was able to provide the most stable process, due to uniform flow of the feedstock material through the die and consistent pressure distribution across the die.

[0108] However, it is not excluded that said die comprises a manifold, wherein said manifold has a coat hanger shape or a T shape.

[0109] According to a third possible property of said method, a vacuum is applied to at least a portion of said barrel. The inventors have found that by doing so, water and other possible contaminants present in the feedstock material can be effectively removed during extrusion, minimizing hydrolysis reactions during extrusion and thereby reducing the risk of degradation of the polymer chains. The removal of moisture is crucial to maintain the intrinsic viscosity and overall quality of the extrudate, resulting in improved mechanical properties of the decorative panel and enhanced processability of the extrudate.

[0110] In a preferred embodiment of the eight aspect of the invention, the method shows the combination of the first and second possible property. The inventors have found that said combination is particularly advantageous since the choker bar mounted at an angle in the above mentioned ranges ensures precise control of material flow and pressure distribution, while the fishtail manifold promotes uniform material distribution across the die, leading to a high quality extrudate with minimal defects. Said preferred embodiment can be further improved by adding the third possible property to said method.

[0111] It is preferred that said die comprises a slot nozzle opening bordered by at least a first lip, wherein said first lip preferably is flexible.

[0112] Preferably said slot nozzle opening is further bordered by a second lip. With the same aim as in the previous aspects, the present invention in accordance with its tenth aspect is a method for manufacturing a decorative panel, optionally according to any of the preceding aspects, wherein said panel comprises a substrate and a top layer provided thereon, wherein said substrate comprises a thermoplastic material, wherein said method comprises a step of preparing a feedstock material, said feedstock material comprising a polymer fraction and an optional filler fraction, said polymer fraction comprising polyethylene terephthalate (PET) and / or modified PET, wherein said method comprises a subsequent step of extruding said feedstock material for providing said substrate, with as a characteristic that said step of preparing said feedstock material further comprises the sub-step of compounding, wherein at least said polymer fraction is passed through a compounder.

[0113] Preferably in said sub-step of compounding, said filler fraction is also passed through said compounder.

[0114] It is preferred that after said sub-step of compounding, said feedstock material is passed through an extruder.

[0115] By compounding said polymer fraction and possibly said filler fraction, all constituents of said polymer fraction and possibly said filler fraction are intensively mixed, ensuring a uniform distribution of all constituents and possibly said filler fraction. Extruding feedstock material with a uniform distribution of all constituents reduces the risk of defects during the extrusion process and improves the overall processability of said feedstock material.

[0116] With the same aim as in the previous aspects, the present invention in accordance with its eleventh aspect is a method for manufacturing a decorative panel, optionally according to any of the preceding aspects, wherein said panel comprises a substrate and a top layer provided thereon, wherein said substrate comprises a thermoplastic material, wherein said method comprises a step of preparing a feedstock material, said feedstock material comprising a polymer fraction and an optional filler fraction, with as a characteristic that said polymer fraction at least comprises one or a combination of the following properties: the property that said polymer fraction comprises cyclohexanedimethanol (CHDM) modified PET; the property that said polymer fraction comprises a neopentyl glycol (NPG) modified PET; the property that said polymer fraction comprises polycyclohexylenedimethylene terephthalate (PCTG).

[0117] The inventors have found that CHDM modified PET has an improved processability with respect to unmodified PET, owing to a lower melting temperature, making it easier to process and reducing the overall energy consumption during mixing and extrusion.

[0118] Additionally, the inventors have found that an extrudate comprising CHDM modified PET has a good flexibility so that handling of the extrudate after extrusion is facilitated.

[0119] Finally, CHDM modified PET comprised in said polymer fraction significantly contributes to a substrate with good mechanical properties, particularly a high impact resistance, ensuring durability of the eventual decorative panel.

[0120] The inventors have found that NPG modified PET shows similar characteristics as CHDM modified PET, but to a lesser extent. However, NPG typically has a lower cost than CHDM modified PET.

[0121] The inventors have found that PCTG results in a substrate with even better mechanical properties, as well as a better chemical resistance than CHDM modified PET, owing to a higher percentage of modification than CHDM modified PET.

[0122] In a preferred embodiment of said eleventh aspect, said polymer fraction comprises both a portion of CHDM modified PET and a portion of NPG modified PET, in order to obtain a polymer fraction having a good compromise between processability and cost. The embodiments that follow can be combined with any of the already described aspects of the present invention, and their respective embodiments.

[0123] It is preferred that said polymer fraction comprises recycled PET, preferably sourced from bottles and / or carpet fibers.

[0124] Preferably said polymer fraction comprises recycled glycol modified PET (PET-G).

[0125] Preferably said PET-G is cyclohexanedimethanol (CHDM) modified PET or neopentyl glycol (NPG) modified PET, or a combination of CHDM modified PET and NPG modified PET.

[0126] Preferably said polymer fraction comprises recycled PET, preferably sourced from bottles and / or carpet fibers, and virgin grade PET.

[0127] Preferably said polymer fraction comprises recycled PET-G and virgin grade PET-G.

[0128] A combination of both recycled and virgin grade material in said polymer fraction reduces the environmental impact and cost, while maintaining the quality and performance of the decorative panel obtained through extrusion of the feedstock material comprising said polymer fraction.

[0129] With the same aim as in the previous aspects, the present invention in accordance with its twelfth aspect is a method for manufacturing a decorative panel, wherein said panel comprises a substrate and a top layer provided thereon, wherein said substrate comprises a thermoplastic material, wherein said method comprises a step of preparing a feedstock material, said feedstock material comprising a polymer fraction and an optional filler fraction, said polymer fraction comprising a first component and a second component, wherein said method comprises a subsequent step of extruding said feedstock material for providing said substrate, with as a characteristic that said polymer fraction shows the following properties: the property that said first component comprises polyethylene terephthalate

[0130] (PET); the property that said second component comprises glycol modified PET (PET- G).

[0131] Said first and second component can for example be provided in powder form, in flake form, granule form or in pellet form. It should be noted that in the context of said first component comprising PET, and said second component comprising PET-G, it is meant that said first component substantially consists of PET and said second component substantially consists of PET-G. It is possible that said first and / or said second component additionally comprises other constituents such as additives or contaminants.

[0132] Preferably said PET-G is cyclohexanedimethanol (CHDM) modified PET or neopentyl glycol (NPG) modified PET, or a combination of CHDM modified PET and NPG modified PET.

[0133] In a first preferred embodiment of the twelfth aspect of the present invention, the volume fraction of said first component in said polymer fraction is greater than the volume fraction of said second component in said polymer fraction. Extrusion of feedstock material comprising a polymer fraction in accordance with this first preferred embodiment of the twelfth aspect of the present invention results in a cost-effective, rigid substrate for use in a decorative panel, with an improved impact resistance, when compared to a substrate where the polymer fraction does not comprise PET-G.

[0134] Preferably the volume fraction of said first component in said polymer fraction is greater than or equal to 55% and the volume fraction of said second component in said polymer fraction is smaller than or equal to 45%.

[0135] Preferably, the volume fraction of said first component in said polymer fraction is greater than or equal to 70% and the volume fraction of said second component in said polymer fraction is smaller than or equal to 30%. Preferably, the volume fraction of said first component in said polymer fraction is greater than or equal to 80% and the volume fraction of said second component in said polymer fraction is smaller than or equal to 20%.

[0136] In a second preferred embodiment of the twelfth aspect of the present invention, the volume fraction of said second component in said polymer fraction is greater than the volume fraction of said first component in said polymer fraction. Extrusion of feedstock material comprising a polymer fraction in accordance with this second preferred embodiment of the twelfth aspect of the present invention results in a more flexible substrate for use in a decorative panel, with a high impact resistance.

[0137] Preferably the volume fraction of said second component in said polymer fraction is greater than or equal to 55% and the volume fraction of said first component in said polymer fraction is smaller than or equal to 45%.

[0138] Preferably, the volume fraction of said second component in said polymer fraction is greater than or equal to 70% and the volume fraction of said first component in said polymer fraction is smaller than or equal to 30%.

[0139] Preferably, the volume fraction of said second component in said polymer fraction is greater than or equal to 80% and the volume fraction of said first component in said polymer fraction is smaller than or equal to 20%.

[0140] It is preferred that said polymer fraction according to the twelfth aspect of the present invention, comprises one or a combination of two or more of the additives chosen from the list of: a chain extender, a flexibilizer, an impact modifier, a compatibilizer, a nucleating agent, a desiccant, a hydrolysis stabilizer.

[0141] Preferably said chain extender is a chain extender as described in the context of the first aspect of the invention. Preferably said flexibilizer is a flexibilizer as described in the context of the second aspect of the invention.

[0142] Preferably said impact modifier is an impact modifier as described in the context of the third aspect of the invention.

[0143] Preferably said compatibilizer is a compatibilizer as described in the context of the fourth aspect of the invention.

[0144] Preferably said nucleating agent is a nucleating agent as described in the context of the fifth aspect of the invention.

[0145] Preferably said desiccant is a desiccant as described in the context of the sixth aspect of the invention.

[0146] Preferably said hydrolysis stabilizer is a hydrolysis stabilizer as described in the context of the seventh aspect of the invention.

[0147] The same advantages of a polymer fraction comprising any one or more of the above respective additives, as disclosed in any of the first up to the seventh aspect of the invention, can also be attributed to the twelfth aspect of the invention.

[0148] It is preferred that said polymer fraction comprises at least three of said additivies, one of which is a flexiblizer.

[0149] Preferably said polymer fraction further comprises a chain extender and a compatibilizer. Even more preferably, said polymer fraction further comprises a nucleating agent.

[0150] Preferably said compatibilizer is grafted to said flexibilizer.

[0151] It is preferred that said PET-G is a cyclohexanedimethanol (CHDM) modified PET or a neopentyl glycol (NPG) modified PET or a combination of both. The same advantages attributed to these types of PET-G in the context of the eleventh aspect of the present invention also apply to the twelfth aspect of the present invention.

[0152] Preferably said first component comprises recycled PET, preferably sourced from bottles and / or carpet fibers.

[0153] Preferably said second component comprises recycled PET-G.

[0154] It is preferred that said first component comprises recycled PET, preferably sourced from bottles and / or carpet fibers and said second component comprises virgin grade PET-G. Alternatively, said first component comprises virgin grade PET and said second component comprises recycled PET-G. A combination of both recycled and virgin grade material in said polymer fraction reduces the environmental impact and cost, while maintaining the quality and performance of the decorative panel obtained through extrusion of the feedstock material comprising said polymer fraction.

[0155] The embodiments that follow can be combined with any of the already described aspects of the present invention, and their respective embodiments.

[0156] It is preferred that said polymer fraction comprises one or a combination of two or more of the following properties: the property that said polymer fraction comprises a chain extender and that said polymer fraction comprises less than 10 wt% of said chain extender, preferably between 0.1 wt% and 5 wt% of said chain extender, more preferably between 0.2 wt% and 3.5 wt% of said chain extender; the property that said polymer fraction comprises a flexiblizer and that said polymer fraction comprises less than 25 wt% of said flexibilizer, preferably between 1 wt% and 15 wt% of said flexibilizer, more preferably between 2 wt% and 6 wt% of said flexibilizer; the property that said polymer fraction comprises an impact modifier and that said polymer fraction comprises less than 10 wt% of said impact modifier, preferably between 1 wt% and 7 wt% of said impact modifier, more preferably between 3 wt% and 6 wt% of said impact modifier; the property that said polymer fraction comprises a compatibilizer and that said polymer fraction comprises less than 5 wt% of said compatibilizer, preferably between 0.5 wt% and 4 wt% of said compatibilizer, more preferably between 2 wt% and 4 wt% of said compatibilizer; the property that said polymer fraction comprises a nucleating agent and that said polymer fraction comprises less than 2 wt% of said nucleating agent, preferably between 0.1 wt% and 1 wt% of said nucleating agent, more preferably between 0.3 wt% and 0.5 wt% of said nucleating agent; the property that said polymer fraction comprises a desiccant and that said polymer fraction comprises less than 10 wt% of said desiccant, preferably between 1 wt% and 7 wt% of said desiccant, more preferably between 3 wt% and 6 wt% of said desiccant; the property that said polymer fraction comprises a hydrolysis stabilizer and that said polymer fraction comprises less than 15 wt% of said hydrolysis stabilizer, preferably between 0.1 wt% and 10 wt% of said hydrolysis stabilizer, more preferably between 1 wt% and 10 wt% of said hydrolysis stabilizer.

[0157] Preferably said feedstock material, more preferably said polymer fraction comprises one or a combination of two or more processing aids chosen from the list of polyethylene (PE) wax, polypropylene (PP) wax, PE / PP -maleic anhydride wax, ethylene bis stearamide (EBS), stearate, acrylate.

[0158] The inventors have found that the above suggested processing aids help in achieving better quality, reduced amount of processing defects such as melt fracture and an increase in overall processing stability, of the extrudate.

[0159] It is preferred that said feedstock material, more preferably said polymer fraction comprises one or a combination of two or more of the above mentioned processing aids in an amount of between 0.10 wt% and 8 wt%, preferably of between 0.10 wt% and 2.5 wt%, more preferably of between 0.10 wt% and 0.30 wt%, even more preferably in an amount of between 0.10 wt% and 0.20 wt%.

[0160] Preferably said feedstock material, more preferably said polymer fraction comprises one or a combination of two or more fire retardants chosen from the list of: magnesium hydroxide (Mg(OH)2), aluminum hydroxide (A1(OH)2) and / or zinc borate (ZB).

[0161] Preferably said feedstock material, more preferably said polymer fraction comprises an antioxidant. The inventors have found that the addition of an antioxidant in said feedstock material, more preferably in said polymer fraction helps prevent oxidation of the polymer fraction during processing.

[0162] Preferably said antioxidant is a phenolic antioxidant, Pentaerythritol tetrakis (3-(3,5-di- tert-butyl-4-hydroxyphenyl)propionate) or Tetra[P-(3,5-di-tert-butyl-4- hydroxyphenyl)propionic acid] pentaerythritol ester.

[0163] Said phenolic antioxidant may also bring about a stabilization of hydrolysis, in particular, in the case of Pentaerythritol tetrakis (3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate) or Tetra[P-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid] pentaerythritol ester.

[0164] Examples of antioxidants with which good results have been obtained include: Rianox 1010 from Rianlon, Rianox 168 from Rianlon, BC-1010 from Belike Chemicals, BC- 168 from Belike Chemicals, BC-B225 from Belike Chemicals, Irganox 1010 from BASF.

[0165] It is preferred that said feedstock material, more preferably said polymer fraction comprises an antioxidant in amount of between 0.1 wt% and 0.5 wt%, more preferably of between 0.15 wt% and 0.4 wt%.

[0166] Preferably said feedstock material comprises a filler fraction comprising one or a combination of two or more fillers chosen from the list of: calcium carbonate (CaCO3), talc, glass fibers, chopped glass fibers, silica (SiO2), clay, wood chips, wood fibers and / or cellulose fibers.

[0167] Preferably said feedstock material comprises more than 50 wt% filler fraction, more preferably said feedstock material comprises more than 65 wt% filler fraction. Preferably the weight ratio filler fraction : (PET and / or PETG) is at least 1: 1, preferably at least 2: 1 or at least 3: 1.

[0168] A substrate obtained through the extrusion of said feedstock material comprising a filler fraction may have a larger weight for a same volume when compared to a substrate obtained through the extrusion of a feedstock material that does not comprise a filler fraction. This enhances the dimensional stability of the substrate and, consequently, of the decorative panel.

[0169] In general, fillers are more economic than the constituents of the polymer fraction. Consequently, the material cost for a decorative panel produced by extruding a feedstock material containing a filler fraction is lower than the material cost for a decorative panel of the same volume produced without fillers.

[0170] In a particular embodiment said feedstock material comprises a polymer fraction comprising a compatibilizer, preferably said compatibilizer comprises a maleic anhydride grafted polymer, and a filler fraction, wherein said feedstock material comprises more than 55 wt%, preferably more than 60 wt%, more preferably between 60 wt% and 90 wt% of said filler fraction. The inventors have found that said compatibilizer improves the bond between said polymer fraction and said filler fraction, resulting in an improved processability of the feedstock material and the extrudate.

[0171] It is preferred that said step of preparing said feedstock material comprises the sub-step of mixing the constituents of said polymer fraction in a hot mixer, preferably at a temperature of between 70 °C and 180 °C, preferably of between 100 °C and 150 °C, more preferably of between 125°C and 145 °C, and preferably subsequently mixing the constituents of said polymer fraction in a cold mixer, preferably at a temperature of between 10 °C and 80 °C.

[0172] Preferably, said step of preparing said feedstock material comprises the sub-step of mixing said polymer fraction and said filler fraction in a hot mixer, preferably at a temperature of between 100 °C and 150 °C, and preferably subsequently mixing said polymer fraction and said filler fraction in a cold mixer.

[0173] It is preferred that said hot mixer and said cold mixer are comprised within the same device, preferably a so called hot / cold mixer. A hot / cold mixer offers the advantage of precise temperature control during mixing, which enhances the uniformity and quality of the polymer fraction and / or the feedstock material. By heating or cooling the material as needed, it improves the dispersion of additives and possible fillers in the polymer matrix, optimizes the polymer melt’ s viscosity for better processing, and helps achieve consistent material properties, ultimately leading to more efficient and reliable extrusion.

[0174] Alternatively, said filler fraction, wholly, essentially wholly, or partially, is directly added to the extruder. It is clear that in such case, said step of preparing said feedstock material comprises the sub-step of mixing said polymer fraction, i.e. said PET and / or PETG and the one or more additives, without the filler fraction, or without a portion of the filler fraction that is destined for direct addition of said extruder.

[0175] Further alternatively, said filler fraction, wholly, essentially wholly, or partially, is added to the feedstock material after a premix of said polymer fraction, i.e. said PET and / or PETG and the one or more additives, without the filler fraction, or without a portion of the filler fraction, has been obtained. The addition of said filler fraction, wholly, essentially wholly, or partially may be in a sub-step of compounding, for example using a so-called Banbury mixer.

[0176] Preferably, said step of preparing said feedstock material further comprises the sub-step of compounding, wherein at least said polymer fraction is passed through a compounder, and wherein said sub-step of compounding is performed after said sub-step of mixing the constituents of at least said polymer fraction.

[0177] Preferably, said step of preparing said feedstock material further comprises the sub-step of compounding, wherein said polymer fraction and said filler fraction are passed through a compounder, and wherein said sub-step of compounding is performed after said sub-step of mixing the constituents of at least said polymer fraction and, potentially additionally said filler fraction, or a portion thereof.

[0178] For said sub-step of compounding, any compounder can be used, preferably with one or more rotors or screws. Preferably, a compounder is used having at least two counterrotating spiral rotors within an enclosed chamber. An intense shearing and mixing action may be obtained. For example, a so-called Banbury mixer may be used.

[0179] It is preferred that said top layer comprises one or a combination of two or more of the following properties: the property that said top layer comprises a decorative foil comprising PET-G; the property that said top layer comprises a transparent or translucent wear layer comprising PET-G; the property that said top layer comprises a decorative foil comprising PET; the property that said top layer comprises a transparent or translucent wear layer comprising PET; the property that said top layer comprises a transparent or translucent wear layer comprising an acrylic; the property that said top layer comprises a top coat and / or a primer.

[0180] The inventors have found that an excellent adhesion between the substrate and said decorative foil can be achieved, in the case where said polymer fraction and said decorative foil comprise the same material. The inventors have found that a higher transparency of said wear layer can be achieved if said wear layer comprises PET-G, more preferably CHDM modified PET or NPG modified PET.

[0181] It is preferred that said step of extruding comprises the sub-step of melting the feedstock material, and forcing the molten feedstock material through a die or feeding the molten feedstock material into a nip of calendaring rolls, in order to form a continuous material web. It should be noted that said molten feedstock material can also be referred to as the extrudate.

[0182] Preferably, said feedstock material is extruded by means of an extruder, said extruder at least comprising a barrel and a screw, wherein said extruder is a single-screw extruder.

[0183] Preferably, said feedstock material is extruded by means of an extruder, said extruder at least comprising a barrel and a screw, wherein said extruder is a twin-screw extruder.

[0184] Preferably, said feedstock material is extruded by means of an extruder, said extruder at least comprising a barrel and a screw, wherein said extruder is a multi-rotating screw (MRS) extruder.

[0185] Preferably the method comprises the step of controlling the thickness by feeding said continuous material web into a nip of calibrating rolls in order to control the thickness of said continuous web material.

[0186] Said thickness of said continuous web material, after said step of controlling the thickness is within the range of between 0,5 mm and 8 mm, preferably of between 1 mm and 6 mm, more preferably of between 1.5 mm and 5 mm.

[0187] Preferably said top layer is provided onto said continuous web material by means of a lamination step or by means of a gluing step, wherein said gluing step preferably makes use of a polyurethane based glue. Alternatively, said top layer is provided onto a slab, sheet or board material obtained from said continuous web material. Preferably said top layer comprises a decorative foil and preferably a transparent or translucent wear layer provided on top of said decorative foil. Preferably the decorative foil and / or the transparent or translucent wear layer comprise PET or PETG.

[0188] Preferably said decorative foil comprises a printed pattern, for example imitating a wood pattern or a stone pattern or a fantasy pattern.

[0189] Preferably said lamination step comprises a sub-step of laminating said decorative foil onto said continuous web material.

[0190] Preferably said lamination step further comprises a sub-step of laminating said transparent or translucent wear layer onto said decorative foil.

[0191] In the cases where said top layer is provided onto a slab, sheet or board material obtained from said continuous web material, a stack may be formed of one or more sheets obtained from said continuous web material, an optional backing layer at one side of said sheets, and a decorative foil and a transparent wear layer at another side of said sheets. Said stack may be brought into a static or discontinuous heated press device, preferably comprising a structured press element at said another side. A release foil may be applied between said wear layer and said structured press element. The stack may be pressed at a pressure of 15 to 30 kg / m2, for example 20-25 kg / m2and a temperature of at least 125°C, for example about 160°C during 20 to 60 minutes, for example during 35 to 45 minutes. The heated press treatment may be followed by a cooled press cycle in the same or in another press device. Herein, the stack pay be pressed at a pressure of 20-35 kg / m2, for example 25-30 kg / m2and be cooled to room temperature, or at least below 60°C. The cooled press cycle may last for 15 to 55 minutes, for example for 25 to 35 minutes. The inventors have found that an excellent lamination strength with a PET or PETG comprising decorative foil and / or wear layer may be obtained by using a static or discontinuous heated press device. No additional layers, such as tie layers or adhesives, are required between the decorative foil and said sheet or sheets. It is preferred that the method further comprises a lamination step or a gluing step for providing a backing layer to the surface of said continuous web material opposite the surface on which said top layer is provided. Said backing layer can for example be a counterbalancing layer, preferably comprising PET and / or modified PET. Said backing layer can also be a cushioning layer, preferably a foam layer, preferably comprising ethylene vinyl acetate (EVA).

[0192] It is preferred that the method further comprises an embossing step for providing excavations onto a top surface of said top layer and / or onto a bottom surface of said continuous web material. Said excavations are preferably provided in order to imitate a natural wood structure.

[0193] It is preferred that the method further comprises the following steps: the step of cutting and / or sawing said continuous web material into a plurality of individual slabs; the step of sawing and / or punching said plurality of slabs into a plurality of individual planks; the step of finishing said plurality of individual planks into a plurality of individual decorative panels.

[0194] The decorative panels obtained after said finishing step can be of the so called looselay type or the so called gluedown type or the so called floating type. The latter preferably comprises coupling parts.

[0195] It is preferred that the method comprises the step of providing mechanical coupling parts to one or both edges of a pair of opposite edges of said decorative panel, wherein said mechanical coupling parts allow two of such panels to become locked to each other at the respective edges in a vertical direction perpendicular to the plane of the coupled panels and in a horizontal direction perpendicular to said edges and in the plane of the coupled panels, wherein said coupling parts are basically shaped as a tongue comprising a portion that protrudes from the respective edge and a groove being bordered by an upper lip and a lower lip. Preferably said step of providing mechanical coupling parts, is performed by means of a milling machine, preferably by means of a so called double end tenoner.

[0196] It is preferred that the method comprises the step of adding a foaming agent to said feedstock material.

[0197] It is preferred that said PET and / or modified PET has an intrinsic viscosity higher than 0.5 dl / g, more preferably of higher than 0.55 dl / g, as measured in accordance with ASTM D4603-18. The inventors have found that maintaining this level of intrinsic viscosity is crucial for achieving decent processability, ensuring that the molten feedstock material flows smoothly during extrusion and results in a high-quality final product.

[0198] As already mentioned in the introduction of this specification, decorative panels, wherein the substrate comprises PET tend to warp, affecting the structural integrity and aesthetic appeal of the final product. The present invention additionally provides an improved decorative panel. Thereto, in accordance with its thirteenth aspect, the present invention pertains to a decorative panel, optionally obtained through a method in accordance with any of the previously disclosed aspects of the present invention, comprising a substrate and a top layer provided thereon, with as a characteristic that said substrate comprises one or a combination of two or more of the following properties: the property that said substrate comprises cyclohexanedimethanol (CHDM) modified PET; the property that said substrate comprises a neopentyl glycol (NPG) modified PET; the property that said substrate comprises polycyclohexylenedimethylene terephthalate (PCTG).

[0199] It is preferred that said top layer comprises one or a combination of two or more of the following properties: the property that said top layer comprises a decorative foil comprising PET-G; the property that said top layer comprises a transparent or translucent wear layer comprising PET-G; the property that said top layer comprises a decorative foil comprising PET; the property that said top layer comprises a transparent or translucent wear layer comprising PET; the property that said top layer comprises a transparent or translucent wear layer comprising an acrylic; the property that said top layer comprises a top coat and / or a primer.

[0200] Preferably said substrate is at least partially foamed, preferably said at least partial foaming is of a closed-cell type.

[0201] Preferably said substrate comprises at least 50 wt% of filler material, more preferably at least 60 wt% of filler material.

[0202] Preferably said filler material is chosen from the list of: calcium carbonate (CaCO3), talc, glass fibers, chopped glass fibers, silica (SiO2), clay, wood chips, wood fibers and / or cellulose fibers.

[0203] It is preferred that said decorative panel is provided with mechanical coupling parts at both edges of at least one pair of opposite edges of said decorative panel. Said mechanical coupling parts allow two of such panels 1 to become locked to each other at the respective edges in a vertical direction perpendicular to the plane of the coupled panels 1 and in a horizontal direction perpendicular to said edges and in the plane of the coupled panels, wherein said coupling parts are basically shaped as a tongue comprising a portion that protrudes from the respective edge and a groove being bordered by an upper lip and a lower lip.

[0204] It is clear that the feedstock material according to any of the previously described aspects, can have a plurality of possible compositions which can result in a highly processable extrudate and consequently a decorative panel having desirable mechanical properties. EXAMPLE 1 :

[0205] A first practical example of a composition of the feedstock material is given in table 1, which outlines the weight ratios of the various components used in the formulation:

[0206] Table 1 : Components and weight ratios of a first feedstock material

[0207] The PET-G can be a CHDM or NPG modified PET and forms the primary polymer matrix of the extrudate resulting from the extrusion of this feedstock material. TPU is added both as flexibilizer and as impact modifier. CaCO3 is added to reduce material costs and increases the dimensional stability of the decorative panel obtained. The antioxidant helps prevent oxidation of the polymer fraction during processing.

[0208] Extrusion of the feedstock material of example 1 results in an extrudate that is particularly suitable for use in the substrate of decorative panels comprising a wear layer comprising PET-G and a decorative foil comprising PET-G. The decorative foil is thermally laminated to the substrate.

[0209] Decorative panels obtained by extrusion of the feedstock material from example 1 are especially suitable for use as so called floating floor coverings.

[0210] EXAMPLE 2:

[0211] A second practical example of a composition of the feedstock material is given in table

[0212] 2, which outlines the weight ratios of the various components used in the formulation: Table 2: Components and weight rations of a second feedstock material

[0213] Example 2 is similar to Example 1 in that the formulation comprises PET-G as component for the primary polymer matrix and CaCO3 as a filler to enhance dimensional stability and reduce costs. Example 2 incorporates linear low density polyethylene grafted with maleic anhydride (LLDPE-g-MAH), which is a polyolefin elastomer grafted with maleic anhydride. Both formulations are suitable for producing substrates used in decorative panels with wear layers comprising PET-G and decorative foils comprising PET-G. Decorative panels obtained by extrusion of the feedstock material from example 2 are especially suitable for use as so called floating floor coverings.

[0214] EXAMPLE S: A third practical example of a composition of the feedstock material is given in table 3, which outlines the weight ratios of the various components used in the formulation:

[0215] Table 3: Components and weight rations of a third feedstock material In this third practical example of a composition of the feedstock material, a significantly larger amount of flexibilizer is used, resulting in a substrate, and consequently a decorative panel that is more flexible than the decorative panels obtained with the feedstock material from example 1 and example 2.

[0216] The extrudate obtained after extrusion of the feedstock material from table 3 is used as the substrate of a decorative panel comprising a wear layer, comprising PET-G, and a decorative foil, comprising PET-G, as well as a backing layer. The backing layer is also produced by extrusion. A practical example of a formulation of a feedstock material used for producing said backing layer is given in table 4, which outlines the weight ratios of the various components used in the formulation:

[0217] Table 4: Components and weight rations of a feedstock material for producing a backing layer

[0218] The decorative foil and the backing layer are thermally laminated to opposite sides of the substrate. Decorative panels obtained after said lamination may be thinner than the decorative panels obtained with the formulations of feedstock material from examples 1 and 2. A typical thickness range for panels obtained with the formulations of feedstock material from example 2 is between 1 mm and 3 mm, preferably of between 1.8 mm and 2.8 mm. Such decorative panels are especially suitable as so called gluedown or dryback floor coverings. EXAMPLE 4:

[0219] A fourth practical example of a composition of the feedstock material is given in table 5, which outlines the weight ratios of the various components used in the formulation:

[0220] Table 5: Components and weight rations of a fifth feedstock material

[0221] Example 4 is similar to the previous examples in that the formulation comprises PET-G as component for the primary polymer matrix and CaCO3 as a filler to enhance dimensional stability and reduce costs. Example 4 incorporates linear low density polyethylene grafted with maleic anhydride (LLDPE-g-MAH), which is a polyolefin elastomer grafted with maleic anhydride. When comparing Example 2 and Example 4 it can be seen that the filler : PET-G ratio can be augmented from 3: 1 to about 3.5 : 1 by adding additional flexibilizer. In Example 2 5 phr of flexibilizer is used, while in Example 4 8 phr of flexibilizer is used. The present formulation is suitable for producing substrates used in decorative panels with wear layers comprising PET-G, for example with a thickness of 0.3 mm, and decorative foils comprising PET-G. The wear layer may further comprise a superficial UV cured coating forming the top surface of the decorative panel.

[0222] Decorative panels obtained by extrusion of the feedstock material from example 4 are especially suitable for use as so called floating floor coverings. Herein, the substrate of the decorative panels may be formed as a single or multi-layer substrate. For example, initially 3 to 9, preferably 5 or 7, layers are obtained from the extruded feedstock material. Each of the layers may have a thickness from 0.4 to 1 mm, for example 0.7 mm. Subsequently, the layers may be thermally laminated by means of a continuous or discontinuous heated press treatment.

[0223] EXAMPLE 5:

[0224] A fifth practical example of a composition of the feedstock material is given in table 6, which outlines the weight ratios of the various components used in the formulation:

[0225] Table 6: Components and weight rations of a third feedstock material

[0226] In this fifth practical example of a composition of the feedstock material, a mix of two flexibilizers is used. The flexibility of the decorative panel is comparable to that of the panel of example 3.

[0227] The extrudate obtained after extrusion of the feedstock material from table 6 is used as the substrate of a decorative panel. Such substrate may for example have a thickness between 0.4 and 1 mm, preferably about 0.7 mm. The decorative panel may further comprise a wear layer, comprising PET-G for example with a thickness of 0.3 mm, and a decorative foil, comprising PET-G, as well as a backing layer. A UV coating is applied on said PET-G wear layer forming an upper surface of the obtained panel. The backing layer may be thicker than the substrate and is also produced by extrusion. The backing layer may have a thickness between 0.4 and 1.2 mm, preferably about 0.9 mm. A practical example of a formulation of a feedstock material used for producing said backing layer is given in table 7, which outlines the weight ratios of the various components used in the formulation:

[0228] Table 7: Components and weight rations of a feedstock material for producing a backing layer

[0229] The decorative foil and the backing layer are thermally laminated to opposite sides of the substrate. Decorative panels obtained after said lamination may be thinner than the decorative panels obtained with the formulations of feedstock material from examples 1, 2 and 4, and be comparable in thickness to the panels of example 3. A typical thickness range for panels obtained with the formulations of feedstock material from example 5 is between 1 mm and 3 mm, preferably of between 1.8 mm and 2.8 mm, for example about 2.5 mm. Such decorative panels are especially suitable as so called gluedown or dryback floor coverings.

[0230] Preferably, in all of the above examples, all materials of the described formulations are mixed together, with the exception of at least half of the filler amount, preferably with the exception of essentially the whole filler amount or the whole filler amount. The mixing is preferably executed without heating, for example at a speed of 1000 rpm or more, during at least 1 minute, for example during 1.5 minutes. In so doing a premix compound is formed. The premix compound, together with the remaining filler amount, preferably the entire filler amount, can then be brought in a so-called Banbury mixer, where the mix is heated by the friction caused by the rotor. The rotor is preferably moving at a speed of 45 rpm or more. The material may be intensively mixed in said Banbury mixer during 5 to 10 minutes, for example 7 or 8 minutes. The batch being mixed in the Banbury mixer may amount to 85 liters or 160 kg. The obtained mix is then extruded and formed using calendaring rollers, alternatively a slot nozzle die may be used.

[0231] The formulations of feedstock material from the preceding examples are especially well suited for directly feeding the extruded feedstock material through calendaring rolls. Extrusion followed by forcing the molten feedstock material through a die, preferably a slot nozzle die, is also possible with the formulations given in the examples, however it is preferable that, in such case, a chain extender, preferably a chain extender as disclosed in the context of the first aspect of the invention, is added to the polymer fraction of the feedstock material for example so that said polymer fraction comprises less than 10 wt% of said chain extender, preferably between 0.1 wt% and 5 wt% of said chain extender, more preferably between 0.2 wt% and 3.5 wt% of said chain extender. In the feedstock materials of examples 1, 2 and 3, the polymer fraction consists of the PET-G, the flexibilizer and the anti-oxidant. Alternatively, it is possible to feed the mixture of the feedstock materials of the present invention and examples directly into the nip of one or more pairs of rollers, preferably counter-rotating rollers. The rollers are preferably heated, for example at a temperature of 175 to 250°C, preferably about 220°C. Herein a compaction, and preferably plasticization, of the powder may be obtained to form a solid sheet. The thickness of the sheet may be calibrated by means of one or more pairs of rollers, for example 2 to 6 pairs of rollers, which are preferably heated as well, for example to temperatures that diminish in a downstream direction of the sheet travelling through the respective nips. Potentially cooling to room temperature or about room temperature may be performed after calibrating, preferably using rollers as well.

[0232] With the intention of better showing the characteristics of the invention, herein below, as an example without any limitative character, some preferred embodiments are described, with reference to the accompanying drawings, wherein: Figure 1 illustrates some steps in a method, amongst others according to the ninth aspect of the invention;

[0233] Figure 2, at a larger scale, shows the panel as shown in figure 1 and is a perspective drawing representing a decorative panel obtained through a method according to the invention;

[0234] Figure 3, at a larger scale, is a cross-section along the line indicated with III-III in figure 2;

[0235] Figure 4, at a larger scale, represents a view of the area indicated with F4, in figure 1, though for a variant;

[0236] Figure 5 is an alternative of the view shown in figure 4;

[0237] Figure 6, at a larger scale, is a cross-sectional perspective view of the element indicated with F6, in figure 4;

[0238] Figure 7, at a larger scale, is a cross-section along the line indicated with VII- VII in figure 6.

[0239] Figure 1 shows steps in a method for manufacturing a decorative panel 1, more particularly a floor panel 1, wherein said panel 1 comprises a substrate 2 and a top layer 3 provided thereon wherein said substrate 2 comprises a thermoplastic material. The method comprises a step SI of preparing a feedstock material. The feedstock material comprises a polymer fraction and an optional filler fraction. The polymer fraction comprises polyethylene terephthalate (PET) and / or modified PET and optionally one or a combination of two or more additives chosen from the list of: a chain extender, a flexibilizer, an impact modifier, a compatibilizer, a nucleating agent, a desiccant. The step SI of preparing a feedstock material comprises the sub-step Si l of mixing the constituents of said polymer fraction in a hot mixer 4, preferably at a temperature of between 100 °C and 150 °C, and subsequently mixing the constituents of said polymer fraction in a cold mixer 5, preferably at a temperature of between 10°C and 80°C. It is also possible that both said polymer fraction and said filler fraction are mixed in said hot mixer 4 and subsequently in said cold mixer 5. It is also possible that said hot mixer 4 and said cold mixer 5 are comprised within the same device, preferably a so called hot / cold mixer.

[0240] The method comprises a subsequent step S2 of extruding said feedstock material for providing said substrate 2. The feedstock material is extruded by means of an extruder 6, at least comprising a barrel 7 and a screw 8, and a die 9 connected to the outlet of said extruder 6. The feedstock material is first fed to the extruder, for example in a hopper 10 of the extruder 6. During said step S2 of extruding, the feedstock material is passed through said extruder 6, during which said feedstock material is melted into a molten feedstock material 11. The molten feedstock material 11 is then forced through said die 9, in order to form a continuous material web 12.

[0241] The method further comprises the step S3 of controlling the thickness by feeding said continuous material web 12 into a nip of calibrating rolls 13 in order to control the thickness of said continuous material web 12.

[0242] A top layer 3 is provided onto said continuous web material 12 by means of a lamination step S4. In the embodiment shown in figure 1, said top layer 3 comprises a decorative foil 14, comprising a printed pattern 15, and a transparent or translucent wear layer 16 provided on top of said decorative foil 14.

[0243] Said lamination step S4 comprises a sub-step S41 of laminating said decorative foil 14 onto said continuous web material 12, and a sub-step S42 of laminating said transparent or translucent wear layer 16 onto said decorative foil 14. The laminating of both said decorative foil 14 and said wear layer 16 is performed by means of separate laminating rollers 17-18. It is also possible that said decorative foil 14 and said wear layer 16 are already laminated to each other before said lamination step S4.

[0244] The method further comprises an embossing step S5 for providing excavations onto a top surface 19 of said top layer 3 and / or onto a bottom surface 20 of said continuous web material 12. The excavations are provided by means of a structured embossing roller 21 and a counter pressure roller 22. It is possible that said counter pressure roller 22 also provides excavations, but on the bottom surface 20 of said continuous web material 12.

[0245] The method further comprises the step S6 of cutting said continuous web material 12 into a plurality of individual slabs 23, in the shown embodiment of figure 1 by means of a guillotine 24.

[0246] The method as shown in figure 1 further comprises the step S7 of providing a topcoat onto said top layer 3. In the shown embodiment of figure 1, said step S7 of providing a topcoat is performed after said step S6 of cutting said continuous web material 12. It is however also possible that said step S7 of providing a topcoat is performed before said step S6 of cutting said continuous web material 12, for example between said embossing step S5 and said step S6 of cutting said continuous web material 12. Said topcoat is applied by means of a coating roller 25 and a doctor roller 26.

[0247] In order to obtain the decorative panel, the method can further comprise the following steps, which are not shown in figure 1 : the step of sawing and / or punching said plurality of slabs 23 into a plurality of individual planks; the step of finishing said plurality of individual planks into a plurality of individual decorative panels 1.

[0248] The decorative panel 1, more particularly the floor panel 1, as shown in figure 2 is rectangular and oblong and is provided with a longitudinal pair of opposite edges 25-26 and a short pair of opposite edges 27-28.

[0249] Figure 3 shows that the decorative panel 1 comprises a substrate 2 and a top layer 3 provided thereon. Said top layer 3 comprises a decorative foil 14, comprising a printed pattern 15 on the upper surface of said decorative foil 14, and a transparent or translucent wear layer 16. The decorative panel 1 is provided with mechanical coupling parts 29-30 at both edges 25-26 of at least one pair of opposite edges of said decorative panel. Said mechanical coupling parts allow two of such panels 1 to become locked to each other at the respective edges 25-26 in a vertical direction perpendicular to the plane of the coupled panels 1 and in a horizontal direction perpendicular to said edges 25-26 and in the plane of the coupled panels 1, wherein said coupling parts 29-30 are basically shaped as a tongue 31 comprising a portion 32 that protrudes from the respective edge 25 and a groove 33 being bordered by an upper lip 34 and a lower lip 35. The decorative panel 1 from figure 3 further comprises a backing layer 36 applied to the surface of said continuous web material 12 opposite the surface on which said top layer 3 is provided. Said backing layer 36 can for example be a counterbalancing layer. Said backing layer 36 can also be a cushioning layer.

[0250] Figure 4 shows some steps in a method for manufacturing a decorative panel 1. The method comprises a step SI of preparing a feedstock material. The feedstock material comprises a polymer fraction and an optional filler fraction. The polymer fraction comprises polyethylene terephthalate (PET) and / or modified PET and optionally one or a combination of two or more additives chosen from the list of: a chain extender, a flexibilizer, an impact modifier, a compatibilizer, a nucleating agent, a desiccant. The step SI of preparing a feedstock material comprises the sub-step Si l of mixing the constituents of said polymer fraction in a hot mixer 4, preferably at a temperature of between 100 °C and 150 °C, and subsequently mixing the constituents of said polymer fraction in a cold mixer 5. It is also possible that both said polymer fraction and said filler fraction are mixed in said hot mixer 4 and subsequently in said cold mixer 5.

[0251] It is also possible that said hot mixer 4 and said cold mixer 5 are comprised within the same device, preferably a so called hot / cold mixer.

[0252] Said step SI of preparing said feedstock material further comprises the sub-step S12 of compounding, wherein at least said polymer fraction is passed through a compounder 37. In said sub-step S12 of compounding, a filler fraction is also passed through said compounder 37. After said sub-step S12 of compounding, said feedstock material is passed through an extruder 6. It is also possible that said filler fraction is only added to the feedstock material, after said sub-step S12 of compounding. The method comprises a subsequent step S2 of extruding said feedstock material for providing said substrate 2. The feedstock material is extruded by means of an extruder 6, at least comprising a barrel 7 and a screw 8, and a die 9 connected to the outlet of said extruder 6. The feedstock material is first fed to the extruder 6, for example in a hopper 10 of the extruder 6. During said step of extruding, the feedstock material is passed through said extruder 6, during which said feedstock material is melted into a molten feedstock material. The molten feedstock material is then forced through said die 9, in order to form a continuous material web 12.

[0253] Figure 5 shows a variant of the steps of the method shown in figure 4, with as a difference that in said subsequent step S2 of extruding said feedstock material for providing said substrate 2, the feedstock material is extruded by means of an extruder 6, at least comprising a barrel 7 and a screw 8, the molten feedstock material is fed into a nip of calendaring rolls 38, in order to form a continuous material web 12.

[0254] Figure 6 shows that the molten feedstock material 11 is forced through a die 9 in order to form a continuous web material 12. The molten feedstock material 11 enters the die 9 through a feed port 39, from where it is directed into a manifold 40. The manifold evenly distributes the molten feedstock material 11 across the width of the die 9. From the manifold 40, the molten feedstock material 11 flows into a flow channel 41. Said die 9 also comprises a choker bar 42 which is mounted under an angle A lower than 70°, preferably between 40° and 70°, more preferably between 55° and 65°, with respect to the flow direction F of the molten feedstock material 11. The choker bar 42 can be locally deformed by tightening and / or loosening a number of actuators 43, in this case bolts 43, located along the width of the die 9, in order to control the height of said flow channel 41 and thereby control the flow of the molten feedstock material 11 through the die 9. The molten feedstock material 11 further flows through a slot nozzle opening 44 which is bordered by at least a first lip 45, preferably a flexible lip 45, and a second lip 46. wherein said first lip 45 can be locally deformed by means of a plurality of actuators 47, in this case bolts 47, along the width of said first lip 45, i.e. in a direction along the width of the slot nozzle opening 44. Figure 8 clearly shows the flow direction F of the molten feedstock material 11 through the internal channels of the die 9. The manifold 40 of the die from figure 7 is of the fishtail type, meaning that the manifold 40 comprises two arms 48-49 that extend symmetrically away from the feed port 39. In the shown embodiment, the channels formed by the arms 48-49 have a diameter tapering down to a smaller radius further from the feed port 39. As the molten feedstock material 11 passes through the slot nozzle opening 44 and out of the die 9, said molten feedstock material 11 is now referred to as the continuous web material 12.

Claims

Claims1.- A method for manufacturing a decorative panel (1), wherein said panel (1) comprises a substrate (2) and a top layer (3) provided thereon, wherein said substrate (2) comprises a thermoplastic material, wherein said method comprises a step (SI) of preparing a feedstock material, said feedstock material comprising a polymer fraction and an optional filler fraction, said polymer fraction at least comprising polyethylene terephthalate (PET) and / or modified PET, and at least one additive, wherein said method comprises a subsequent step (S2) of extruding said feedstock material for providing said substrate (2), characterized in that said at least one additive is a chain extender and wherein said chain extender shows one or a combination of two or more of the following properties: the property that said chain extender comprises an epoxide, preferably bisepoxide, and / or one or more epoxide groups; the property that said chain extender comprises a cyclic carboxylic anhydride, preferably bis-(cyclic carboxylic anhydride); the property that said chain extender comprises an isocyanate, preferably diisocyanate; the property that said chain extender comprises an oxazoline, preferably bis- oxazoline, more preferably 2,2’-bis(2-oxazoline); the property that said chain extender comprises an epoxy acrylate chain extender with terminal epoxy groups and / or an epoxy acrylate chain extender with internal epoxy groups; the property that said chain extender comprises a methacrylate, preferably methacrylate random copolymer, more preferably styrene-acrylonitrile-glycidyl methacrylate random copolymer (SAN-g-GMA); the property that said chain extender comprises a caprolactam, preferably biscaprolactam; the property that said chain extender comprises a pyromellitic dianhydride (PMDA);the property that said chain extender comprises a polyol, preferably a pentaerythritol (PENTA).2.- The method according to claim 1, characterized in that said polymer fraction further comprises one or a combination of two or more of the additives chosen from the list of: a flexiblizer, an impact modifier, a compatibilizer, a nucleating agent, a desiccant, a hydrolysis stabilizer.3.- A method for manufacturing a decorative panel (1), wherein said panel (1) comprises a substrate (2) and a top layer (3) provided thereon, wherein said substrate (2) comprises a thermoplastic material, wherein said method comprises a step (SI) of preparing a feedstock material, said feedstock material comprising a polymer fraction and an optional filler fraction, said polymer fraction comprising polyethylene terephthalate (PET) and / or modified PET and at least one additive, wherein said method comprises a subsequent step (S2) of extruding said feedstock material for providing said substrate (2), characterized in that said at least one additive is a flexibilizer, wherein said flexibilizer shows one or a combination of two or more of the following properties: the property that said flexibilizer comprises a polyurethane, preferably a thermoplastic polyurethane; the property that said flexibilizer comprises an elastomer, preferably a thermoplastic elastomer; the property that said flexibilizer comprises a polyolefin elastomer, preferably a propylene-based elastomer; the property that said flexibilizer comprises an ethylene methyl acrylate copolymer; the property that said flexibilizer comprises an ester group.4.- The method according to claim 3, characterized in that said polymer fraction further comprises one or a combination of two or more of the additives chosen from the list of: a chain extender, an impact modifier, a compatibilizer, a nucleating agent, a desiccant, a hydrolysis stabilizer.5.- A method for manufacturing a decorative panel (1), wherein said panel (1) comprises a substrate (2) and a top layer (3) provided thereon, wherein said substrate (2) comprises a thermoplastic material, wherein said method comprises a step (SI) of preparing a feedstock material, said feedstock material comprising a polymer fraction and an optional filler fraction, said polymer fraction comprising polyethylene terephthalate (PET) and / or modified PET and at least one additive, wherein said method comprises a subsequent step (S2) of extruding said feedstock material for providing said substrate (2), characterized in that said at least one additive is an impact modifier and wherein said impact modifier shows one or a combination of two or more of the following properties: the property that said impact modifier comprises an acrylate, preferably a methyl acrylate; the property that said impact modifier comprises a polyethylene, preferably a maleic anhydride grafted polyethylene, more preferably a maleic anhydride grafted low density polyethylene; the property that said impact modifier comprises a maleic anhydride grafted polymer, preferably a maleic anhydride grafted copolymer, more preferably a maleic anhydride grafted ethylene octene copolymer; the property that said impact modifier comprises a polyolefin-based copolymer, preferably a polyolefin-based copolymer functionalized with epoxy groups; the property that said impact modifier comprises an ethylene terpolymer; the property that said impact modifier comprises an elastomeric terpolymer, preferably a reactive elastomeric terpolymer.6.- The method according to claim 5, characterized in that said polymer fraction further comprises one or a combination of two or more of the additives chosen from the list of: a chain extender, a flexiblizer, a compatibilizer, a nucleating agent, a desiccant, a hydrolysis stabilizer.7.- A method for manufacturing a decorative panel (1) , wherein said panel (1) comprises a substrate (2) and a top layer (3) provided thereon, wherein said substrate (2) comprises a thermoplastic material, wherein said method comprises a step (SI) ofpreparing a feedstock material, said feedstock material comprising a polymer fraction and an optional filler fraction, said polymer fraction comprising polyethylene terephthalate (PET) and / or modified PET and at least one additive, wherein said method comprises a subsequent (S2) step of extruding said feedstock material for providing said substrate (2), characterized in that said at least one additive is a compatibilizer and wherein said compatibilizer shows one or a combination of two or more of the following properties: the property that said compatibilizer comprises a maleic anhydride grafted polymer, preferably a maleic anhydride grafted polyolefin, preferably a maleic anhydride grafted polypropylene; the property that said compatibilizer comprises a glycidyl acrylate, preferably a glycidyl methacrylate.8.- The method according to claim 7, characterized in that said polymer fraction further comprises one or a combination of two or more of the additives chosen from the list of: a chain extender, a flexibilizer, an impact modifier, a nucleating agent, a desiccant, a hydrolysis stabilizer.9.- A method for manufacturing a decorative panel (1), wherein said panel (1) comprises a substrate (2) and a top layer (3) provided thereon, wherein said substrate (2) comprises a thermoplastic material, wherein said method comprises a step (SI) of preparing a feedstock material, said feedstock material comprising a polymer fraction and an optional filler fraction, said polymer fraction comprising polyethylene terephthalate (PET) and / or modified PET and at least one additive, wherein said method comprises a subsequent step (S2) of extruding said feedstock material for providing said substrate, characterized in that said at least one additive is a nucleating agent and wherein said nucleating agent shows one or a combination of two or more of the following properties: the property that said nucleating agent comprises an ionomer, preferably a sodium ionomer; the property that said nucleating agent comprises an antimony catalyst; the property that said nucleating agent comprises a modified polyolefin;the property that said nucleating agent comprises a sodium salt.10.- The method according to claim 9, characterized in that said polymer fraction further comprises one or a combination of two or more of the additives chosen from the list of: a chain extender, a flexibilizer, an impact modifier, a compatibilizer, a desiccant, a hydrolysis stabilizer.11.- A method for manufacturing a decorative panel (1), wherein said panel (1) comprises a substrate (2) and a top layer (3) provided thereon, wherein said substrate (2) comprises a thermoplastic material, wherein said method comprises a step (SI) of preparing a feedstock material, said feedstock material comprising a polymer fraction and an optional filler fraction, said polymer fraction comprising polyethylene terephthalate (PET) and / or modified PET and at least one additive, wherein said method comprises a subsequent step (S2) of extruding said feedstock material for providing said substrate, characterized in that said at least one additive is a desiccant and wherein said desiccant shows one or both of the following properties: the property that said desiccant comprises a zeolite; the property that said desiccant comprises calcium oxide.12.- The method according to claim 11, characterized in that said polymer fraction further comprises one or a combination of two or more of the additives chosen from the list of: a chain extender, a flexibilizer, an impact modifier, a compatibilizer, a nucleating agent, a hydrolysis stabilizer.13.- A method for manufacturing a decorative panel (1), wherein said panel (1) comprises a substrate (2) and a top layer (3) provided thereon, wherein said substrate (2) comprises a thermoplastic material, wherein said method comprises a step (SI) of preparing a feedstock material, said feedstock material comprising a polymer fraction and an optional filler fraction, said polymer fraction comprising polyethylene terephthalate (PET) and / or modified PET and at least one additive, wherein said method comprises a subsequent step (S2) of extruding said feedstock material for providing said substrate (2), characterized in that said at least one additive is a hydrolysis stabilizer andwherein said hydrolysis stabilizer comprises a carbodiimide, preferably a polycarbodiimide.14.- The method according to claim 13, characterized in that said polymer fraction further comprises one or a combination of two or more of the additives chosen from the list of: a chain extender, a flexibilizer, an impact modifier, a compatibilizer, a nucleating agent, a desiccant.15.- A method for manufacturing a decorative panel (1), wherein said panel (1) comprises a substrate and a top layer (3) provided thereon, wherein said substrate (2) comprises a thermoplastic material, wherein said method comprises a step (SI) of preparing a feedstock material, said feedstock material comprising a polymer fraction and an optional filler fraction, said polymer fraction comprising polyethylene terephthalate (PET) and / or modified PET and at least one additive, wherein said method comprises a subsequent step (S2) of extruding said feedstock material for providing said substrate (2), characterized in that said polymer fraction comprises one or a combination of two or more of the additives chosen from the list of: a chain extender, a flexibilizer, an impact modifier, a compatibilizer, a nucleating agent, a desiccant, a hydrolysis stabilizer.16.- A method for manufacturing a decorative panel (1), optionally according to any of the preceding claims, wherein said panel (1) comprises a substrate (2) and a top layer (3) provided thereon, wherein said substrate (2) comprises a thermoplastic material, wherein said method comprises a step (SI) of preparing a feedstock material, said feedstock material comprising a polymer fraction and an optional filler fraction, said polymer fraction comprising polyethylene terephthalate (PET) and / or modified PET, wherein said method comprises a subsequent step (S2) of extruding said feedstock material for providing said substrate (2), characterized in that in said step (S2) of extruding, said feedstock material is extruded by means of an extruder (6) and a die (9) connected to the outlet of said extruder (6), said extruder (6) at least comprising a barrel (7) and a screw (8), wherein a vacuum is applied to at least a portion of said barrel (7).17.- A method for manufacturing a decorative panel (1), optionally according to any of the preceding claims, wherein said panel (1) comprises a substrate (2) and a top layer (3) provided thereon, wherein said substrate (2) comprises a thermoplastic material, wherein said method comprises a step (SI) of preparing a feedstock material, said feedstock material comprising a polymer fraction and an optional filler fraction, said polymer fraction comprising polyethylene terephthalate (PET) and / or modified PET, wherein said method comprises a subsequent step (S2) of extruding said feedstock material for providing said substrate, characterized in that said step (SI) of preparing said feedstock material further comprises the sub-step (S 12) of compounding, wherein at least said polymer fraction is passed through a compounder (37).18.- A method for manufacturing a decorative panel (1), optionally according to any of the preceding aspects, wherein said panel (1) comprises a substrate (2) and a top layer (3) provided thereon, wherein said substrate (2) comprises a thermoplastic material, wherein said method comprises a step (SI) of preparing a feedstock material, said feedstock material comprising a polymer fraction and an optional filler fraction, characterized in that said polymer fraction at least comprises one or a combination of the following properties: the property that said polymer fraction comprises cyclohexanedimethanol (CHDM) modified PET; the property that said polymer fraction comprises a neopentyl glycol (NPG) modified PET; the property that said polymer fraction comprises polycyclohexylenedimethylene terephthalate (PCTG).19.- The method according to any of the preceding claims, characterized in that said polymer fraction comprises recycled PET, preferably sourced from bottles and / or carpet fibers.20.- The method according to any of the preceding claims, characterized in that said polymer fraction comprises recycled glycol modified PET (PET-G).21.- The method according to any of the preceding claims, characterized in that said polymer fraction comprises recycled PET, preferably sourced from bottles and / or carpet fibers, and virgin grade PET.22.- The method according to any of the preceding claims, characterized in that said polymer fraction comprises recycled PET-G and virgin grade PET-G.23.- A method for manufacturing a decorative panel (1), wherein said panel (1) comprises a substrate (2) and a top layer (3) provided thereon, wherein said substrate (2) comprises a thermoplastic material, wherein said method comprises a step (SI) of preparing a feedstock material, said feedstock material comprising a polymer fraction and an optional filler fraction, said polymer fraction comprising a first component and a second component, wherein said method comprises a subsequent step (S2) of extruding said feedstock material for providing said substrate (2), characterized in that said polymer fraction shows the following properties: the property that said first component comprises polyethylene terephthalate (PET); the property that said second component comprises glycol modified PET (PET- G).24.- The method according to claim 23, characterized in that the volume fraction of said first component in said polymer fraction is greater than the volume fraction of said second component in said polymer fraction.25.- The method according to claim 23, characterized in that the volume fraction of said second component in said polymer fraction is greater than the volume fraction of said first component in said polymer fraction.26.- The method according to any of the claims 23 to 25, characterized in that said polymer fraction comprises one or a combination of two or more of the additives chosen from the list of: a chain extender, a flexiblizer, an impact modifier, a compatibilizer, a nucleating agent, a desiccant, a hydrolysis stabilizer.27.- The method according to claim 26, characterized in that said polymer fraction comprises at least three of said additives, one of which is a flexibilizer.28.- The method according to claim 27, characterized in that said polymer fraction further comprises a chain extender and a compatibilizer.29.- The method according to claim 28, characterized in that said compatibilizer is grafted to said flexiblizer.30.- The method according to claim 28 or 29, characterized in that said polymer fraction further comprises a nucleating agent.31.- The method according to any of the claims 23 to 30, characterized in that said PET-G is a cyclohexanedimethanol (CHDM) modified PET or a neopentyl glycol (NPG) modified PET or a combination of both.32.- The method according to any of the claims 23 to 31, characterized in that said first component comprises recycled PET, preferably sourced from bottles and / or carpet fibers.33.- The method according to any of claims 23 to 32, characterized in that said second component comprises recycled PET-G.34.- The method according to any of the claims 23 to 33, characterized in that said first component comprises recycled PET, preferably sourced from bottles and / or carpet fibers and said second component comprises virgin grade PET-G.35.- The method according to any of the claims 23 to 34, characterized in that said first component comprises virgin grade PET and said second component comprises recycled PET-G.36.- The method according to any of the preceding claims, characterized in that said polymer fraction comprises one or a combination of two or more of the following properties: the property that said polymer fraction comprises a chain extender and that said polymer fraction comprises less than 10 wt% of said chain extender, preferably between 0.1 wt% and 5 wt% of said chain extender, more preferably between 0.2 wt% and 3.5 wt% of said chain extender; the property that said polymer fraction comprises a flexiblizer and that said polymer fraction comprises less than 25 wt% of said flexibilizer, preferably between 1 wt% and 15 wt% of said flexibilizer, more preferably between 2 wt% and 6 wt% of said flexibilizer; the property that said polymer fraction comprises an impact modifier and that said polymer fraction comprises less than 10 wt% of said impact modifier, preferably between 1 wt% and 7 wt% of said impact modifier, more preferably between 3 wt% and 6 wt% of said impact modifier; the property that said polymer fraction comprises a compatibilizer and that said polymer fraction comprises less than 5 wt% of said compatibilizer, preferably between 0.5 wt% and 4 wt% of said compatibilizer, more preferably between 2 wt% and 4 wt% of said compatibilizer; the property that said polymer fraction comprises a nucleating agent and that said polymer fraction comprises less than 2 wt% of said nucleating agent, preferably between 0.1 wt% and 1 wt% of said nucleating agent, more preferably between 0.3 wt% and 0.5 wt% of said nucleating agent; the property that said polymer fraction comprises a desiccant and that said polymer fraction comprises less than 10 wt% of said desiccant, preferably between 1 wt% and 7 wt% of said desiccant, more preferably between 3 wt% and 6 wt% of said desiccant; the property that said polymer fraction comprises a hydrolysis stabilizer and that said polymer fraction comprises less than 15 wt% of said hydrolysis stabilizer, preferably between 0.1 wt% and 10 wt% of said hydrolysis stabilizer, more preferably between 1 wt% and 10 wt% of said hydrolysis stabilizer.37.- The method according to any of the preceding claims, characterized in that said feedstock material comprises one or a combination of two or more processing aids chosen from the list of: polyethylene (PE) wax, polypropylene (PP) wax, PE / PP -maleic anhydride wax, ethylene bis stearamide (EBS), stearate, acrylate.38.- The method according to any of the preceding claims, characterized in that said feedstock material comprises one or a combination of two or more fire retardants chosen from the list of: magnesium hydroxide (Mg(0H)2), aluminum hydroxide (Al(0H)2) and / or zinc borate (ZB).39.- The method according to any of the preceding claims, characterized in that said feedstock material comprises an antioxidant.40.- The method according to any of the preceding claims, characterized in that said feedstock material comprises a filler fraction comprising one or a combination of two or more fillers chosen from the list of: calcium carbonate (CaCO3), talc, glass fibers, chopped glass fibers, silica (SiO2), clay, wood chips, wood fibers and / or cellulose fibers.41.- The method according to any of the preceding claims, characterized in that said step (SI) of preparing said feedstock material comprises the sub-step (SI 1) of mixing the constituents of said feedstock material in a hot mixer (4), preferably at a temperature of between 100 °C and 150 °C, and preferably subsequently mixing the constituents of said feedstock material in a cold mixer (5), preferably at a temperature of between 10 °C and 80 °C.42.- The method according to claim 41, characterized in that said step (SI) of preparing said feedstock material further comprises the sub-step (S12) of compounding, wherein at least said polymer fraction is passed through a compounder (37), and wherein said sub-step (SI 2) of compounding is performed after said sub-step (SI 1) of mixing the constituents of said polymer fraction.43.- The method according to any of the preceding claims, characterized in that said top layer (3) comprises one or a combination of two or more of the following properties: the property that said top layer (3) comprises a decorative foil (14) comprising PET-G; the property that said top layer (3) comprises a transparent or translucent wear layer (16) comprising PET-G; the property that said top layer (3) comprises a decorative foil (14) comprising PET; the property that said top layer (3) comprises a transparent or translucent wear layer (16) comprising PET; the property that said top layer (3) comprises a transparent or translucent wear layer (16) comprising an acrylic; the property that said top layer (3) comprises a top coat and / or a primer.44.- The method according to any of the preceding claims, characterized in that said step (S2) of extruding comprises the sub-step of melting the feedstock material, and forcing the molten feedstock material through a die (9) or feeding the molten feedstock material (11) into a nip of calendaring rolls (38), in order to form a continuous material web (12).45.- The method according to claim 44, characterized in that said top layer (3) is provided onto said continuous web material (12) by means of a lamination step (S4) or by means of a gluing step, wherein said gluing step preferably makes use a polyurethane based glue.46.- The method according to claim 44 or 45, characterized in that the method further comprises a lamination step or a gluing step for providing a backing layer to the surface of said continuous web material (12) opposite the surface on which said top layer (3) is provided.47.- The method according to any of claims 44 to 46, characterized in that the method further comprises an embossing step (S5) for providing excavations onto a top surface(19) of said top layer (3) and / or onto a bottom surface (20) of said continuous web material (12).48.- The method according to any of claims 44 to 47, characterized in that the method further comprises the following steps: the step (S6) of cutting and / or sawing said continuous web material (12) into a plurality of individual slabs (23); the step of sawing said plurality of slabs (23) into a plurality of individual planks; the step of finishing said plurality of individual planks into a plurality of individual decorative panels (1).49.- The method according to any of the preceding claims, characterized in that the method comprises the step of providing mechanical coupling parts (29-30) to one or both edges (25-26; 27-28) of a pair of opposite edges of said decorative panel (1), wherein said mechanical coupling parts (29-30) allow two of such panels (1) to become locked to each other at the respective edges (25-26; 27-28) in a vertical direction perpendicular to the plane of the coupled panels (1) and in a horizontal direction perpendicular to said edges and in the plane of the coupled panels (1), wherein said coupling parts (29-30) are basically shaped as a tongue (31) comprising a portion (32) that protrudes from the respective edge and a groove (33) being bordered by an upper lip (34) and a lower lip (35).50.- The method according to any of the preceding claims, characterized in that the method comprises the step of adding a foaming agent to said feedstock material.51.- The method according to any of the preceding claims, characterized in that said polymer fraction has an intrinsic viscosity higher than 0.5 dl / g, more preferably of higher than 0.55 dl / g.52.- A decorative panel, optionally obtained through a method in accordance with any of the previously disclosed aspects of the present invention, comprising a substrate (2)and a top layer (3) provided thereon, characterized in that said substrate (2) comprises one or a combination of two or more of the following properties: the property that said substrate (2) comprises cyclohexanedimethanol (CHDM) modified PET; the property that said substrate (2) comprises a neopentyl glycol (NPG) modified PET; the property that said substrate (2) comprises polycyclohexylenedimethylene terephthalate (PCTG).53.- Decorative panel according to claim 52, characterized in that said top layer (3) comprises one or a combination of two or more of the following properties: the property that said top layer (3) comprises a decorative foil (14) comprising PET-G; the property that said top layer comprises a transparent or translucent wear layer (16) comprising PET-G; the property that said top layer (3) comprises a decorative foil (14) comprising PET; the property that said top layer (3) comprises a transparent or translucent wear layer (16) comprising PET; the property that said top layer (3) comprises a transparent or translucent wear layer (16) comprising an acrylic; the property that said top layer (3) comprises a top coat and / or a primer.54.- Decorative panel according to claim 52 or 53, characterized in that said substrate(2) is at least partially foamed.55.- Decorative panel according to any of the claims 52 to 54, characterized in that said substrate (2) comprises at least 50 wt% of filler material.56.- Decorative panel according to any of the claims 52 to 55, characterized in that said decorative panel (1) is provided with mechanical coupling parts (29-30) at both edges of at least one pair of opposite edges (25-26; 27-28) of said decorative panel (1),wherein said mechanical coupling parts (29-30) allow two of such panels (1) to become locked to each other at the respective edges in a vertical direction perpendicular to the plane of the coupled panels (1) and in a horizontal direction perpendicular to said edges and in the plane of the coupled panels (1), wherein said coupling parts (29-30) are basically shaped as a tongue (31) comprising a portion (32) that protrudes from the respective edge and a groove (33) being bordered by an upper lip (34) and a lower lip (35).

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