Decorative panel and method for manufacturing a decorative panel

Abstract

Sheet material for producing a decorative panel (1), wherein said sheet material (2) comprises a printed sheet (3), and a wear layer (4) on said printed sheet (3), preferably wherein said wear layer (4) is embossable by a thermal pressing operation, characterized in that said sheet material (2) comprises a plurality of holes (5) and / or wherein said sheet material (2) has a Gurley value lower than 80 seconds, preferably lower than 50 seconds, more preferably lower than 30 seconds.

Description

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

[0002] The invention relates to a sheet material used for producing a decorative panel, i.e. a decorative panel such as a floor and / or wall panel as well as to a method of producing a sheet material. The invention also relates to a method for manufacturing a decorative panel as well as to a decorative panel.

[0003] More particularly, the present invention relates to a sheet material to be laminated onto a substrate to form a decorative panel. The sheet material comprises a printed sheet as well as a wear layer. It is known from W02020 / 095196A1 that a sheet material comprising a printed sheet as well as a wear layer can be laminated onto a substrate e.g. a wood fiber board in the production of a decorative panel. The wear layer can be provided with a structured upper surface during athermal pressing operation. The printed sheet can comprise a motif, for example a wood motif print.

[0004] From WO 01 / 96689, WO 2006 / 063803, WO 2006 / 066776 and WO 2007 / 054812 it is known, for example, to provide the decorative panel with a structured upper surface imitating a wood structure which corresponds to the wood motif print. Such structure drastically improves the look and feel of the decorative panel and contributes to a more realistic imitation of real wood.

[0005] However, when a structured upper surface with deeper structures is desired, an increase in the occurrence of pressing defects is noticed. Pressing defects such as white spots and milkiness result in an undesirable appearance on the end product. Additionally, the process for providing the decorative panel with a structured upper surface comprising deeper structures is more difficult to control in comparison with the process for providing the decorative panel with more shallow structures. In particular, the pressing time is drastically higher for deeper structures than for more shallow structures. The present invention in the first place aims at an alternative sheet material used for producing a decorative panel, wherein in accordance with preferred embodiments, solutions are offered for one or more of the problems with the state of the art.

[0006] With this aim, the present invention, in accordance with its first aspect, is a sheet material for producing a decorative panel, wherein said sheet material comprises a printed sheet, and a wear layer on said printed sheet, preferably wherein said wear layer is embossable by a thermal pressing operation, with the characteristic that said sheet material comprises a plurality of holes and / or wherein said sheet material has a Gurley value lower than 80 seconds, preferably lower than 50 seconds, more preferably lower than 30 seconds, even more preferably lower than 20 seconds as measured in accordance with the TAPPI T- 460 om-21 standard for measuring the air resistance (Gurley method) or in accordance with ISO 5636-5:2013.

[0007] The inventors have found that in the manufacturing process of a decorative panel comprising a sheet material laminated onto a substrate, during a thermal pressing operation making use of a structured press element such as a press plate, a roller and / or a texturing foil, air can become entrapped between the surface of the material to be pressed, e.g. the upper surface of the sheet material, and the possible protrusions for imparting a structure, of the structured press element. The entrapped air may cause white spots, milkiness and / or other pressing defects on the surface of the obtained decorative panel if the air is not evacuated properly during the thermal pressing operation. This is especially the case when deeper structures are to be provided. Additionally, if the air is not evacuated properly, the required pressing time can be significantly higher than it would be if the air is able to escape. The sheet material of the present invention solves these problems according to two possibilities. A first possibility is for the sheet material to comprise a plurality of holes, effectively increasing the air permeability of the sheet material. A second possibility, which may be combined with the first possibility, is for the sheet material to have a Gurley value lower than 80 seconds, preferably lower than 50 seconds, more preferably lower than 30 seconds. The entrapped air may be evacuated through the sheet material. It is preferred that the entrapped air can be evacuated through the sheet material into and preferably subsequently out of the substrate. Within the disclosure of the invention, the term laminating should be interpreted as providing a bond between two or more material layers. This may include thermal laminating, glueing or other ways of providing a bond between two or more material layers.

[0008] With the feature that said wear layer is embossable by a thermal pressing operation is meant that in a pressing operation at increased temperatures - e.g. above 80 °C - a textured press element can press embossments and / or impressions in the wear layer, e.g. to simulate a wood texture or a natural stone texture, embossments and / or impressions which after cooling are permanent in the wear layer. In the pressing operation at increased temperatures, the contact of a textured press element or a texturing foil and the increased temperatures will cause the wear layer to flow and / or undergo a plastic deformation, in which embossments and / or impressions are pressed into the coating layer.

[0009] The inventors have noticed that in the embodiment wherein the sheet material comprises a plurality of holes, after a thermal pressing operation in which the sheet material is provided with an embossed structure, the holes are not visible any more with the naked eye. When the sheet material is used in the manufacture of a decorative panel, the holes will not hamper the visual aspect of the decorative panel.

[0010] It should be noted that the holes are preferably directed from the top surface of the sheet material to the bottom surface of the sheet material, with the top surface being the outermost surface that will be visible and exposed to the environment in the final product.

[0011] In a preferred embodiment, said printed sheet comprises or consists of a printed decorative paper. Alternatively, said printed sheet comprises or consists of a printed thermoplastic foil, preferably comprising one or a combination of two or more of the following: polyvinylchloride (PVC), polyethylene terephthalate (PET), glycol modified polyethylene terephthalate (PETG), thermoplastic polyurethane (TPU), polypropylene (PP). Said printed sheet may refer to a paper or a thermoplastic foil that is provided with a printed decorative image or a printed motif, for example a decorative image or motif corresponding to a natural wood pattern or a natural stone pattern or a fantasy pattern.

[0012] Preferably said printed decorative paper is impregnated with a resin, preferably with a partially cured thermosetting resin.

[0013] Preferably said resin comprises one or a combination of two or more components chosen from the list of: amino resins, acrylate, urea formaldehyde (UF), melamine urea formaldehyde (MUF), melamine formaldehyde (MF), polyurethane (PU), urethane- acrylic copolymer, melamine acrylate, melamine formaldehyde acrylate, latex, optionally in combination with a crosslinking agent.

[0014] In a preferred embodiment, said wear layer comprises a synthetic material layer comprising an acrylate resin; and preferably mainly consists of said acrylate resin.

[0015] It is preferred that said acrylate resin is of the aliphatic type.

[0016] Preferably, said wear layer comprises a synthetic material layer comprising an unsaturated polyester, preferably an unsaturated polyester resin and preferably mainly consists of said unsaturated polyester resin.

[0017] Preferably, said wear layer comprises a synthetic material layer comprising reactive acrylate groups.

[0018] The inventors have found that in the case said wear layer comprises a synthetic material layer comprising an acrylate resin and / or an unsaturated polyester, an exceptionally high level of transparency for this wear layer could be obtained in the eventually obtained decorative panel, resulting in a higher visibility of the underlying printed sheet. Additionally, such wear layers allow for a reduction in high pitched noises, such as a ticking sound, produced when walking on decorative panels comprising such a wear layer. The inventors have also found that an increased scratch resistance of the wear layer is possible if said wear layer comprises a synthetic material layer comprising an acrylate resin and / or an unsaturated polyester.

[0019] However, a wear layer comprising a synthetic material layer comprising an acrylate resin and / or an unsaturated polyester resin, typically has a low air permeability if no measures are taken. The present invention is particularly useful in the case said sheet material comprises a synthetic material layer comprising an acrylate resin and / or an unsaturated polyester.

[0020] It is preferred that said wear layer is partially cured, preferably wherein said wear layer comprises double carbon-carbon bonds. The partially cured wear layer may be in a gelled state, preferably a non-tacky gelled state. The partially cured state of the wear layer makes it easier for the wear layer to be embossed.

[0021] Preferably said wear layer comprises a thermoinitiator. The thermoinitiator is able to initiate a polymerization or curing reaction within said wear layer when sufficient heat is applied, for example during a pressing operation.

[0022] It is preferred that said thermoinitiator is an organic peroxide, preferably benzoyl peroxide or lauryl peroxide or tertiary butylperoxyl-3,5,5-trimethylhexanoate (TBPIN).

[0023] In a preferred embodiment, the sheet material comprises a wear layer comprising a transparent or translucent thermoplastic foil, preferably wherein said thermoplastic foil comprises one or a combination of two or more of the following: polyvinylchloride (PVC), polyethylene terephthalate (PET), glycol modified polyethylene terephthalate (PET-G), thermoplastic polyurethane (TPU), polypropylene (PP).

[0024] In another preferred embodiment, the sheet material comprises a wear layer comprising or consisting of a resin impregnated sheet of overlay paper wherein said resin comprises one or a combination of two or more components chosen from the list of: amino resins, acrylate, urea formaldehyde (UF), melamine urea formaldehyde (MUF), melamine formaldehyde (MF), polyurethane (PU), urethane-acrylic copolymer, melamine acrylate, melamine formaldehyde acrylate, latex, optionally in combination with a crosslinking agent.

[0025] It is also possible that the wear layer is composed of multiple layers, preferably wherein the composition of at least two of said multiple layers differs from one another. For example, said wear layer may comprise two layers, wherein a first, uppermost layer comprises or mainly consists of an acrylate resin and wherein a second layer, situated underneath said first layer comprises an acrylate - polyurethane mixture.

[0026] It is preferred that the wear layer is present in an amount of more than 30 grams per square meter, preferably of between 30 and 500 grams per square meter, more preferably of between 30 and 300 grams per square meter.

[0027] It is preferred that the wear layer has a thickness of between 50 and 500 micrometers, preferably of between 100 and 350 micrometers, more preferably of between 150 and 250 micrometers, even more preferably of between 170 and 210 micrometers.

[0028] In a preferred embodiment, said sheet material comprises a glue layer situated on the bottom side of the printed sheet. Preferably said glue layer comprises polyurethane, preferably said glue layer mainly consists of polyurethane.

[0029] It is preferred that the sheet material comprises a plurality of holes wherein at least a portion of said plurality of holes, and preferably all of said holes, are blind holes having a depth which is more than 25% of the total thickness of said sheet material. The inventors have found that the air permeability of the sheet material could be increased significantly by providing the sheet material with holes of such depth. It is also possible that at least a portion of said plurality of holes, preferably all of said holes, are blind holes, at least fully penetrating through the wear layer and penetrating into at least 10% of the total thickness of the printed sheet.

[0030] In a preferred embodiment, at least a portion of the plurality of holes, and preferably all of the hole, are blind holes having a depth at least the depth of the wear layer. In a preferred embodiment the sheet material comprises a plurality of holes wherein at least a portion of said plurality of holes, and preferably all of said holes, are through holes extending through the entire thickness of said sheet material. The inventors found that the air permeability of the sheet material could be increased the most by providing the sheet material with through holes.

[0031] Preferably, said sheet material comprises a plurality of holes wherein said plurality of holes are arranged in a straight pattern over the upper surface of said sheet material. A straight pattern refers to a series of holes aligned over the direction substantially parallel to the width direction of the sheet material, being arranged in a linear sequence substantially parallel to the length direction of the sheet material. Preferably each hole is equidistant from its neighboring hole along the width direction of the sheet material and / or preferably each hole is equidistant from its neighboring hole along the length direction of the sheet material.

[0032] Alternatively, the sheet material comprises a plurality of holes wherein said plurality of holes are arranged in a staggered pattern over the upper surface of said sheet material. A staggered pattern refers to a series of holes arranged in an alternating sequence along both the width and length directions of the sheet material. This arrangement ensures that each hole in one row is offset from their respective neighboring holes in adjacent rows, creating a staggered or zigzag pattern. Preferably, each hole is equidistant from its neighboring holes along the width direction of the sheet material and / or equidistant from its neighboring holes along the length direction of the sheet material, ensuring uniform spacing and alignment in the staggered configuration. The staggered pattern may be able to distribute the stress more evenly in the sheet material, potentially increasing its strength and durability during processing and further limiting the risk of pressing defects.

[0033] It is preferred that said sheet material comprises a plurality of holes wherein said plurality of holes are distributed over at least a portion and preferably over the entirety of the upper surface of said sheet material in a density of between 2 - 500 holes per square centimeter, preferably of between 4 - 300 holes per square centimeter, more preferably of between 4 - 100 holes per square centimeter, even more preferably of between 4 - 50 holes per square centimeter.

[0034] According to one embodiment said sheet material comprises a plurality of holes wherein said plurality of holes are distributed over at least portion and preferably over the entirety of the upper surface of said sheet material in a density of between 10 - 500 holes per square centimeter, preferably of between 20 - 300 holes per square centimeter, more preferably of between 30 - 100 holes per square centimeter.

[0035] In a particular embodiment having desirable results, said plurality of holes are distributed over at least a portion and preferably over the entirety of the upper surface of said sheet material in a density of between 10-30 holes per square centimeter, more preferably between 15 - 25 holes per square centimeter.

[0036] In one embodiment said plurality of holes are distributed over at least a portion and preferably over the entirety of the upper surface and / or the bottom surface of the sheet material with a repetition rate of 1 hole per millimeter in the length direction of said sheet material and 1 hole per two millimeters in the width direction of said sheet material. The inventors found that with such a distribution of holes, an increased air permeability could be obtained without negatively impacting the visual appearance of the sheet material.

[0037] It is preferred that for every given square centimeter of sheet material, at least 10 holes are present.

[0038] It is preferred that said sheet material comprises a plurality of holes wherein said plurality of holes are uniformly distributed over the upper surface of said sheet material. Uniform distribution of the holes may ensure that air can pass through the sheet material evenly across the entire surface on which the holes are provided.

[0039] In a preferred embodiment, the plurality of holes are only locally present. The plurality of holes can e.g. be only locally present at zones in the sheet material in which deeper structures or a deeper structure will be pressed than in the remainder of the sheet material. The plurality of holes can e.g. be present in zones where a deep structure will be pressed for providing a bevel in the decorative panel which is made. This has the benefit that the deeper structures can be more easily and more reliably pressed.

[0040] In a preferred embodiment, the sheet material comprises a first section with a higher density of holes than in a second section. The first section can be a section in which deeper structures will be pressed than in the second section of the sheet material. This has the benefit that the deeper structures can be more easily and more reliably pressed.

[0041] In one particular embodiment, said sheet material comprises a plurality of holes wherein said plurality of holes are arranged in a predetermined pattern, wherein said predetermined pattern forms an identifiable code. This predetermined pattern is carefully designed to form a code that can be identified. Such a code could enable encoding certain information.

[0042] It is preferred that said code is configured to be detected and preferably interpreted by an optical reading device, preferably in combination with dedicated signal processing software. Examples of such an optical reading device include an optical scanning device, a camera, preferably a smartphone camera, an optical mark reader, and the like.

[0043] Preferably, said code comprises information or a link to a digital location comprising information on at least one, preferably on a combination of two or more of the following: manufacturing process, product details, material composition, supplier details, instructions for the customer, of the sheet material and / or of the decorative panel. Such a digital location may be a database, or a location within a database or a website-page, and the like. It is preferred that said information is made available upon decryption, preferably by dedicated decryption software and / or by a dedicated decryption key. Said dedicated decryption software and / or said dedicated decryption key may be comprised within a mobile application configured to run on a smartphone and / or a computer program configured to run on a computer. Said information may have multiple advantages, for example ensuring that the product is authentic and thereby limiting the risk of counterfeit products, provide the end-consumer with instructions on how to install the decorative panel comprising said sheet material, providing relevant information for waste management and recycling facilities.

[0044] It may be preferable that said code comprises multiple encryption levels, for example wherein person A, for example the end-consumer, has access to a first layer of information by using dedicated decryption software A and / or by using dedicated decryption key A; and where person B, for example a worker at a recycling facility, has access to a second layer of information, and perhaps also to said first layer of information, by using dedicated decryption software B and / or by using dedicated decryption key B. This way the producer is able to control who gets to see which information about the decorative panel.

[0045] Preferably said code is arranged within a two dimensional matrix format. Such a matrix format may delimit a coordinate system, wherein each hole is assigned a horizontal or X-coordinate and a vertical or Y-coordinate, within said coordinate system. Other examples of a code arranged within such a two dimensional matrix format may be braille or a QR-code. As an example said code may be arranged within a surface area of between 0.3 and 2.5 square centimeters, preferably between 0.5 and 1.5 square centimeters, more preferably around 1 square centimeter.

[0046] It is also preferred that said sheet material comprises a plurality of repetitions of said code, preferably wherein said sheet material is substantially entirely covered by said code or by repetitions of said code. Having multiple repetitions of the code ensures that even if part of the sheet material is damaged or obscured, the code can still be read on another part of said sheet material. This further increases the readability of the code as the code can be read from any part of the decorative panel.

[0047] Preferably said code comprises a plurality of redundant data elements. Such redundant data elements may provide error detection and / or error correction encoding and provide for an inherent statistical robustness of the code, so as to be detectable and identifiable even if parts of the base pattern are missing at the instant of detecting said code. It is preferred that said code is defined by one or a combination of two or more of the following parameters: spacing between individual holes, grouping pattern of a set of holes within a specified area, amount of repetitions of a grouping pattern of a set of holes within a specified area, size of individual holes, shape of individual holes, color contrast between the holes and the upper surface of the printed sheet, said upper surface of said printed sheet, preferably being a decorative surface. Preferably said redundant data elements are defined by one of the above mentioned parameters.

[0048] In one example, said code is defined by multiple grouping patterns overlayed on each other. The dedicated decryption software and / or the dedicated decryption key is preferably able to distinguish between the overlayed grouping patterns and is able to recognize a specific combination of grouping patterns. A specific combination of grouping patterns may represent a specific piece of information, for example corresponding to one or more positions in a database.

[0049] The sheet material preferably comprises a plurality of holes, wherein the shape of said plurality of holes in a direction perpendicular to the upper surface of said sheet material is substantially cylindrical or tapered, for example conical or pyramidical.

[0050] Preferably, said sheet material comprises a plurality of holes, wherein said plurality of holes have an equivalent diameter at the height of the upper surface of the sheet material and / or at the height of the bottom surface of the sheet material of between 0.01 millimeter and 1 millimeter, preferably of between 0.05 millimeter and 0.6 millimeter, more preferably of between 0.08 millimeter and 0.6 millimeter, even more preferably of between 0.1 millimeter and 0.5 millimeter.

[0051] In one embodiment said plurality of holes have an equivalent diameter at the height of the upper surface of the sheet material and / or at the height of the bottom surface of the sheet material of between 0.01 millimeter and 1 millimeter, preferably of between 0.05 millimeter, more preferably of between 0.08 millimeter and 0.5 millimeter. The equivalent diameter can be defined as the diameter of a circle with an equal aggregate sectional area. The inventors have found that when the holes have an equivalent diameter as specified, the air permeability could be increased without negatively impacting the visual appearance of the sheet material.

[0052] The inventors have found that good results can be obtained in the case that the sheet material comprises a plurality of holes distributed over the upper surface and / or the bottom surface of said sheet material in a density of at least 4 holes per square centimeter, wherein the holes have an equivalent diameter at the height of the upper surface of the sheet material and / or at the height of the bottom surface of the sheet material of between 0.08 mm and 0.6 mm, more preferably of between 0.1 mm and 0.5 mm.

[0053] In an alternative embodiment, said sheet material comprises a plurality of holes wherein said plurality of holes are essentially a plurality of micro-tears. A micro-tear is a microscopic tear or rupture in the material, which is not immediately visible with the naked eye.

[0054] Preferably, said plurality of micro-tears have a maximum width of between 0.01 millimeter and 1 millimeter, preferably of between 0.05 millimeter and 0.5 millimeter, more preferably of between 0.08 millimeter and 0.5 millimeter. The inventors have found that when the micro-tears have a maximum width as specified, the air permeability could be increased without negatively impacting the visual appearance of the sheet material.

[0055] It is preferred that said printed sheet comprises a printed motif, wherein said plurality of holes are in register with said motif. Said motif may be a natural wood imitation or a natural stone imitation or a fantasy pattern. Such a motif may visually imitate structural characteristics such as wood grains, cracks, knots and / or other features typical for a motif imitating natural wood. In one particular embodiment, said plurality of holes are substantially situated in regions where said motif imitates such structural characteristics. The inventors have found that by providing said plurality of holes in those regions, the visibility of said holes could be hidden to a greater extent. In another embodiment, said plurality of holes are substantially in an area situated outside the regions where said motif imitates such structural characteristics. It was found by the inventors that in a subsequent thermal pressing operation, a larger amount of air becomes entrapped in the areas outside said regions where said motif imitates such structural characteristics. Therefore, a higher air permeability may be required in said areas.

[0056] In an alternative embodiment, said sheet material comprises a plurality of holes wherein said plurality of holes comprise a burnt edge, preferably at least at the height of the upper surface of said sheet material. Said burnt edge can be the result of a laser having provided said plurality of holes.

[0057] A second aspect of the invention relates to a method of producing a sheet material, according to the first aspect of the invention and wherein the method comprises the steps of: providing a multilayered structure comprising a printed sheet and a wear layer provided on top of said printed sheet; providing said multilayered structure with said plurality of holes.

[0058] The step of providing said multilayered structure with said plurality of holes may be carried out starting from an upper surface of the multilayered structure to and preferably all the way through a bottom surface of the multilayered structure. Alternatively, the step of providing said multilayered structure with said plurality of holes may be carried out starting from a bottom surface of the multilayered structure to and preferably all the way through a top surface of the multilayered structure. It should be noted that an upper surface of said multilayered structure refers to the surface that is intended to be visible on a decorative panel comprising a sheet material obtained from the method of the second aspect of the invention. A bottom surface of said multilayered structure refers to the surface opposite to the upper surface of the multilayered structure.

[0059] It is preferred that said step of providing said multilayered structure with said plurality of holes is carried out by means of a pressing system comprising a pressing element comprising a plurality of needles on its outer surface, pushing at least partially into, and preferably all the way through, said multilayered structure.

[0060] Preferably said needles are arranged in a straight pattern over the outer surface of said pressing element. By having the needles arranged in a straight pattern, the holes provided into said multilayered structure can be arranged in a straight pattern as well. A straight pattern refers to a series of needles arranged in a linear sequence. Preferably each needle is equidistant from its neighboring needle along a first direction of the pressing element and / or preferably each needle is equidistant from its neighboring needle along a second direction perpendicular to said first direction. Alternatively, in the case said pressing element is a roller, a straight pattern refers to a series of needles aligned over the outer circumferential direction of the roller, being arranged in a linear sequence in the axial direction of the roller. Preferably each needle is equidistant from its neighboring needle over the direction corresponding to the outer circumferential direction of the roller and / or preferably each needle is equidistant from its neighboring needle over the axial direction of the roller.

[0061] In another embodiment, said plurality of needles are arranged in a staggered pattern over the outer surface of said pressing element. A staggered pattern refers to the arrangement wherein each needle in one row is offset from their respective neighboring holes in adjacent rows.

[0062] In one particular embodiment, said plurality of needles are arranged in a uniquely identifiable predetermined pattern. Preferably said uniquely identifiable predetermined pattern of said needles is able to provide holes in a uniquely identifiable pattern, wherein said predetermined pattern of said holes forms an identifiable code.

[0063] It is preferred that said pressing system comprises two or more pressing elements arranged in series, each of said two or more pressing elements comprising a plurality of needles. Preferably each of said two or more pressing elements comprises a plurality of needles, wherein each plurality of needles is arranged in a distinct pattern. A higher diversity in predetermined patterns of holes may be provided by having a plurality of pressing elements each comprising a plurality of needles arranged in a distinct pattern. For example, a method of producing a sheet material in accordance with the second aspect of the invention, comprising N pressing elements, where each of said N pressing elements comprises a plurality of needles arranged in a distinct pattern, may be able to provide for [(2AN)-1] distinct predetermined patterns of holes forming an identifiable code.

[0064] Preferably said plurality of needles are distributed along said outer surface of said pressing element in a density of between 2 - 500 needles per square centimeter, preferably of between 4 - 300 needles per square centimeter, more preferably of between 4 - 100 needles per square centimeter, even more preferably of between 4 - 50 needles per square centimeter.

[0065] According to one embodiment said plurality of needles are distributed along said outer surface of said pressing element in a density of between 10 - 500 needles per square centimeter, preferably of between 20 - 300 needles per square centimeter, more preferably of between 30 - 100 needles per square centimeter.

[0066] It is preferred that said needles are essentially tapered in shape and extend outwardly from said outer surface of said pressing element. Said tapered shape may facilitate the pushing of said needles into and preferably through said multilayered structure. Said needles may also comprise a cylindrical base and a tapered tip.

[0067] Preferably said pressing system comprises a counter pressure surface, for example the circumferential outer surface of a counter pressure roller. Alternatively, said counter pressure surface may be a stationary or moving substantially flat surface, for example a belt. It is preferred that said counter pressure surface has a Shore A hardness lower than 90, preferably lower than 70, more preferably lower than 60.

[0068] In one embodiment, said counter pressure surface comprises a material chosen from the list of: soft PVC, soft PU, brush, Tampico fiber, felt, rubber, sponge.

[0069] Alternatively or additionally to said pressing system comprising a counter pressure surface, said multilayered structure is tensioned while being provided with said plurality of holes.

[0070] In a preferred embodiment, said pressing element is a roller comprising a circumferential outer surface comprising the plurality of needles.

[0071] In another embodiment, said step of providing said multilayered structure with said plurality of holes is carried out by means of a roller system comprising a roller comprising a circumferential outer surface comprising a plurality of needles and / or protrusions, wherein the protrusions vary in shape, such that at least two protrusions have different geometrical configurations from one another. Said plurality of protrusions may have a substantially wedged shape. It is preferred that said plurality of protrusions comprise a geometrical configuration adapted to provide said plurality of holes, preferably being micro-tears, into said multilayered structure.

[0072] Preferably said roller is a powered roller, preferably an electrically powered roller.

[0073] It is preferred that the position of said roller relative to the multilayered structure is adjustable. As a result of this feature, the penetration depth of the needles and / or protrusions into said multilayered structure may be set to a desired value.

[0074] In a preferred embodiment, said roller system comprises a cleaning brush in contact with said roller. Said cleaning brush may be provided on a cleaning roller. Said cleaning brush may remove residual material sticking to the needles and / or protrusions of said roller after the step of providing said multilayered structure with said plurality of holes. In an alternative embodiment said step of providing said multilayered structure with said plurality of holes is carried out by means of a laser treatment including a laser beam. A laser may be digitally controlled which may significantly increase the freedom in pattern design of said plurality of holes.

[0075] Preferably said laser treatment uses a Nano laser and / or a Pico laser and / or a Femto laser. It is preferred that said laser treatment uses a pulsed laser. Nano lasers are lasers which typically exhibit pulse durations in the order of nanoseconds. Pico lasers are lasers which typically exhibit pulse durations in the order of picoseconds and Femto lasers are lasers which typically exhibit pulse durations in the order of femtoseconds. Nano, Pico and Femto lasers can focus on very small areas, allowing for highly precise material removal. The high precision of both laser types results in limited heat-affected zones, which are zones adjacent to the location where material is removed that are affected by the generated heat of said laser removal treatment. Limited heat-affected zones may decrease the amount of visible defects in the eventual decorative panel.

[0076] It is preferred that said laser treatment includes a device, preferably a scanner, used to control the direction of the laser beam. Said scanner preferably comprises one or more mirrors mounted on electronically controlled actuators, for example galvanometers. Said one or more mirrors are able to deflect said laser beam in different directions. By increasing the speed of said scanner, the pulse energy of said laser beam can be limited, while still achieving a good throughput of said laser treatment.

[0077] Preferably said laser treatment includes beam splitting of the laser beam. The inventors have found that by beam splitting said laser beam into two or more laser beams, a good throughput of said laser removal treatment can be achieved while limiting the pulse energy of a single laser beam.

[0078] Preferably said laser operates in a burst regime. Said burst regime refers to a specific mode of laser operation where multiple femtosecond pulses are emitted in quick succession, typically within a time frame of a few picoseconds to nanoseconds. Each burst consists of a series of femtosecond pulses that interact with the material surface. It is preferred that the pulse energy of each pulse within a burst can be controlled. Preferably the amount of pulses within a burst can be controlled. Said burst regime can allow for better control of said laser removal treatment.

[0079] As an alternative to the method of the second aspect of the invention, in an aspect of the invention the sheet material of the first aspect of the invention is manufactured by providing a printed sheet, wherein the printed sheet comprises the plurality of holes; and applying a wear layer on top of the printed sheet comprising the plurality of holes.

[0080] A third aspect of the invention, with the same goal as the first and second aspect of the invention, relates to a method for manufacturing decorative panels, comprising at least a substrate and a decorative top layer, wherein the method comprises the steps of: providing a sheet material; providing a substrate; stacking the sheet material on the substrate; subsequently providing said sheet material with a structured upper surface in a thermal pressing operation, by means of a structured press element; laminating said sheet material to said substrate in said thermal pressing operation; wherein in the thermal pressing operation, the decorative panel is provided with a decorative top layer comprising the structured upper surface, with as a characteristic that said sheet material is a sheet material according to the first aspect of the invention.

[0081] Said structured upper surface may effectively imitate the structure of natural wood or natural stone or any other structure of a decorative surface the printed sheet imitates. Such structure drastically improves the look and feel of the decorative panel and contributes to a more realistic imitation. Said structured upper surface may comprise areas having a microstructure. Said microstructure comprising impressions with a depth of between 5 and 20 pm. Additionally or alternatively, said structured upper surface may comprise areas having a macrostructure. Said macrostructure comprising impressions with a depth greater than 40 pm, preferably with a depth greater than 80 pm even more preferably with a depth greater than 100 pm. The depth of an impression being the maximum depth of said impression wherein said depth of said impressions may be measured in a direction perpendicular to a general upper surface of the decorative panel.

[0082] Preferably, the resin - e.g. an acrylate resin - of the synthetic material layer of the wear layer is thermally cured in the thermal pressing operation, preferably initiated by dissociation of one or more thermoinitiators present in the resin of the synthetic material layer of the wear layer.

[0083] Said structured press element may be a press plate or a roller, preferably an embossing roller, or a texturing foil, preferably a texturing foil forming part of a double belt press system.

[0084] Preferably the step of stacking the sheet material on the substrate further comprises the step of positioning the wear layer onto the printed sheet.

[0085] Preferably said step of stacking the sheet material on the substrate further comprises the step of positioning a backing layer, preferably a counterbalancing layer, on the side of the substrate opposite to the side where the sheet material is stacked on the substrate. Such a counterbalancing layer in the decorative panel may help prevent curling and warping of the decorative panel by balancing the stresses on both sides of the substrate.

[0086] It is preferred that said substrate comprises a plurality of microscopic voids, preferably open cell microscopic voids. When a substrate has a plurality of voids, preferably interconnected voids, it can allow air to pass through or into the substrate, preventing said air from becoming entrapped between the upper surface of the decorative panel and the structured press element, which may lead to visual defects in the eventual decorative panel.

[0087] Preferably said substrate is a wood-based substrate - preferably a wood fiberboard or a chipboard or a particleboard - or wherein said substrate is a mineral-based substrate, preferably a cement-based substrate or a gypsum-based substrate, or wherein said substrate is a thermoplastic material board, preferably a filled thermoplastic material board. Examples of wood fiberboard are MDF (medium density fiberboard) or HDF (high density fiberboard). Such a mineral-based substrate may be an MgO (magnesium oxide) board. Examples of thermoplastic material boards may include SPC (solid polymer composite), WPC (wood polymer composite) and the like. Other thermoplastic material boards may comprise PET (polyethylene terephthalate), PETG (glycol modified PET), PP (polypropylene), PVC (polyvinyl chloride) and preferably a filler chosen from the list of calcium carbonate, talcum powder, silica, clay, kaolin, glass fibers, carbon fibers and the like, or combinations thereof. Said substrate may be a physically and / or chemically foamed substrate.

[0088] It is preferred that said press element is a heated press element. A heated press element may facilitate the thermal pressing operation by lowering the resistance to indentation of the sheet material. In the case said wear layer comprises a thermoinitiator, said heated press element may enable a curing, preferably a final curing of said wear layer.

[0089] In one preferred embodiment, said step of providing said sheet material with a structured upper surface coincides with said step of laminating said sheet material to said substrate.

[0090] A fourth aspect of the invention relates to a decorative panel, preferably obtained through a method according to the third aspect of the invention, comprising a substrate and a decorative top layer comprising a printed sheet and a transparent or translucent wear layer provided on the printed sheet (e.g. via coating or via lamination), with as a characteristic that said printed sheet comprises a plurality of holes extending at least partially into and preferably fully through the thickness of said printed sheet, said holes being at least partially, preferably fully filled with resin, preferably resin from said wear layer.

[0091] It is preferred that said transparent or translucent wear layer comprises an acrylate resin and / or an unsaturated polyester. The inventors have found that in the case said wear layer comprises an acrylate resin and / or an unsaturated polyester, an exceptionally high level of transparency for this wear layer can be obtained in the decorative panel, resulting in a higher visibility of the underlying printed sheet. Additionally, such wear layers may allow for a reduction in high pitched noises, such as a ticking sound, produced when walking on decorative panels comprising such a wear layer. The inventors have also found that an increased scratch resistance of the wear layer is possible if said wear layer comprises a synthetic material layer comprising an acrylate resin and / or an unsaturated polyester.

[0092] Preferably said printed sheet comprises or consists of a printed decorative paper, preferably impregnated with a resin, preferably wherein said resin comprises one or a combination of two or more components chosen from the list of: amino resins, acrylate, urea formaldehyde (UF), melamine urea formaldehyde (MUF), melamine formaldehyde (MF), polyurethane (PU), urethane-acrylic copolymer, melamine acrylate, melamine formaldehyde acrylate, latex.

[0093] Advantages of the specifics of the plurality of holes are the same as disclosed within the context of the first aspect of the invention.

[0094] It is preferred that at least a portion of said plurality, preferably all of said holes have a depth which is more than 25% of the total thickness of said printed sheet.

[0095] In a more preferred embodiment, at least a portion of said plurality of holes, preferably all of said plurality of holes are holes extending through the entire thickness of said printed sheet.

[0096] Preferably said plurality of holes are arranged in a straight pattern or a staggered pattern over the upper surface of said sheet material.

[0097] It is preferred that said plurality of holes are uniformly distributed over the upper surface of said printed sheet.

[0098] In one particular embodiment, said printed sheet comprises a plurality of holes, wherein said plurality of holes are arranged in a predetermined pattern, wherein said pattern forms an identifiable code. Preferably said code is configured to be detected and preferably interpreted by an optical reading device, preferably in combination with dedicated signal processing software. Examples of such an optical reading device include an optical scanning device, a camera, preferably a smartphone camera, an optical mark reader, and the like.

[0099] Preferably said code comprises information or a link to a digital location comprising information on at least one, preferably a combination of two or more of the following: manufacturing process, product details, material composition, supplier details, instructions for the customer, of the sheet material and / or of the decorative panel.

[0100] Preferably said code is arranged within a two dimensional matrix format. Such a matrix format may delimit a coordinate system, wherein each hole is assigned a horizontal or X-coordinate and a vertical or Y-coordinate, within said coordinate system. Other examples of a code arranged within such a two dimensional matrix format may be braille or a QR-code. As an example said code may be arranged within a surface area of between 0.3 and 2.5 square centimeters, preferably between 0.5 and 1.5 square centimeters, more preferably around 1 square centimeter.

[0101] It is preferred that said printed sheet comprises a plurality of repetitions of said code, preferably wherein said printed sheet is substantially entirely covered by said code or by repetitions of said code.

[0102] Preferably said code comprises a plurality of redundant data elements. Such redundant data elements may provide error detection and / or error correction encoding and provide for an inherent statistical robustness of the code, so as to be detectable and identifiable even if parts of the base pattern are missing at the instant of detecting said code.

[0103] It is preferred that said code is defined by one or a combination of two or more of the following parameters: spacing between individual holes, grouping pattern of a set of holes within a specified area, amount of repetitions of a grouping pattern of a set of holes within a specified area, size of individual holes, shape of individual holes, color contrast between the holes and the upper surface of the printed sheet, said upper surface of said printed sheet, preferably being a decorative surface. Preferably, said redundant data elements are defined by one of the above mentioned parameters.

[0104] Preferably, said plurality of holes are distributed along said printed sheet in a density of between 2 - 500 holes per square centimeter, preferably of between 4 - 300 holes per square centimeter, more preferably of between 4 - 100 holes per square centimeter, even more preferably of between 4 - 50 holes per square centimeter.

[0105] According to one embodiment said sheet material comprises a plurality of holes wherein said plurality of holes are distributed over at least portion and preferably over the entirety of the upper surface of said sheet material in a density of between 10 - 500 holes per square centimeter, preferably of between 20 - 300 holes per square centimeter, more preferably of between 30 - 100 holes per square centimeter.

[0106] It is preferred that the shape of said plurality of holes in a direction perpendicular to the upper surface of said decorative top layer is substantially cylindrical or tapered, for example conical or pyramid! cal.

[0107] Preferably said substrate is a wood-based substrate, preferably a wood fiberboard, or wherein said substrate is a mineral-based substrate, preferably a cement-based substrate or a gypsum-based substrate, or wherein said substrate is a thermoplastic material board, preferably a filled thermoplastic material board. Examples of wood fiberboard are MDF (medium density fiberboard) or HDF (high density fiberboard). Such a mineral-based substrate may be an MgO (magnesium oxide) board. Examples of thermoplastic material boards may include SPC (solid polymer composite), WPC (wood polymer composite) and the like. Other thermoplastic material boards may comprise PET (polyethylene terephthalate), PETG (glycol modified PET), PP (polypropylene), PVC (polyvinyl chloride) and preferably a filler chosen from the list of: calcium carbonate, talcum powder, silica, clay, kaolin, glass fibers, carbon fibers and the like. Said substrate may be a physically and / or chemically foamed substrate. Preferably said decorative panel comprises a structured upper surface. Said structured upper surface may comprise areas having a microstructure. Said microstructure comprising impressions with a depth of between 5 and 20 pm. Additionally or alternatively, said structured upper surface may comprise areas having a macrostructure. Said macrostructure comprising impressions with a depth greater than 40 pm, preferably with a depth greater than 80 pm even more preferably with a depth greater than 100 pm. The depth of an impression being the maximum depth of said impression wherein said depth of said impressions may be measured in a direction perpendicular to a general upper surface of the decorative panel.

[0108] In one preferred embodiment, said panel comprises a lowered edge region at at least a first pair of opposite edges, wherein said printed sheet extends continuously along said lowered edge region. For example, said lowered edge region may be a bevel, preferably a pressed in bevel. A decorative panel wherein said printed sheet extends continuously along said lowered edge region may provide for a better imitation of natural materials, this is especially the case for imitation of natural wood. Said lowered edge region may have a depth which is greater than 80 pm, preferably greater than 100 pm.

[0109] It is preferred that at least a portion of said plurality of holes are situated in said lowered edge region.

[0110] Said lowered edge region may be obtained during a thermal pressing operation, for example during said thermal pressing operation according to a third aspect of the invention.

[0111] Preferably said decorative panel comprises a backing layer, preferably a counterbalancing layer on the side of the substrate opposite to the side where the sheet material is situated.

[0112] In a preferred embodiment, said decorative panel comprises mechanical coupling parts at both edges of at least one pair of opposite edges of said decorative panel, wherein said mechanical coupling parts allow two of such panels to be 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.

[0113] The different aspects of the invention describe a printed sheet. However, in all these aspects, the sheet does not need to be a printed sheet of paper. As an alternative in any of the aspects of the invention, the sheet can be an unprinted sheet or a colored sheet of uniform color.

[0114] The unprinted sheet of the colored sheet of uniform color can be an unprinted sheet of paper or a sheet of paper of uniform color.

[0115] Embodiments wherein the sheet is an unprinted sheet of paper or a sheet of paper of uniform color can e.g. be used as backing layer in the production of a decorative panel.

[0116] The invention describes that the sheet material of the first aspect of the invention can be used as a decorative layer in the production of a decorative panel. The sheet of material of the first aspect of the invention - and preferably the variant wherein the sheet is an unprinted sheet or a sheet of material of uniform color - can be used as a backing layer in the production of a decorative panel. In such embodiments, the lamination of the backing layer in the pressing operation is facilitated.

[0117] With the intention of better showing the characteristics of the invention, hereafter, as an example without any limitative character, preferred embodiments are described, with reference to the accompanying drawings, wherein:

[0118] Figure 1 is a schematic representation of a sheet material according to the first aspect of the invention;

[0119] Figure 2 at a larger scale shows a view on the area indicated with F2 in figure 1;

[0120] Figure 3 is an alternative embodiment in the view shown in figure 2; Figure 4 is an alternative embodiment in the view shown in figures 2 and 3;

[0121] Figure 5 at a larger scale shows a superposition of patterns used for creating the pattern on the area indicated with D in figure 4;

[0122] Figure 6 at a larger scale, is a cross-section over the line indicated with VI- VI on figure 2;

[0123] Figure 7 is an alternative embodiment in the view shown in figure 6;

[0124] Figure 8 is an alternative embodiment in the view shown in figures 6 and 7;

[0125] Figure 9 is an alternative embodiment in the view shown in figures 6, 7 and 8;

[0126] Figure 10 at a larger scale shows a view on the area indicated with F2 in figure 1, though for a different embodiment;

[0127] Figure 11 is an alternative embodiment in the view shown in figure 10;

[0128] Figure 12 shows schematically some steps in a method according to the second aspect of the invention;

[0129] Figure 13 shows schematically some steps in a method according to the third aspect of the invention;

[0130] Figure 14 is a schematic representation of a decorative panel according to the fourth aspect of the invention;

[0131] Figure 15 at a larger scale is a cross-section indicated by XV-XV on figure 13;

[0132] Figure 16 at a larger scale shows a view on the area indicated by F 16 in figure 15; and

[0133] Figure 17 shows an embodiment of the invention.

[0134] The reference numerals have the same meaning in the different figures.

[0135] Figure 1 shows a sheet material 2 for producing a decorative panel 1. A detailed view of the layered buildup of the sheet material from figure 1 is shown in figure 2. The sheet material 2 comprises a printed sheet 3, and a wear layer 4 on said printed sheet 3. The wear layer 4 may be embossable by a thermal pressing operation, and the sheet material 2 comprises a plurality of holes 5 and / or has a Gurley value lower than 30 seconds, as measured in accordance with the TAPPI T-460 om 21 standard for measuring the air resistance (Gurley method) or in accordance with ISO 5636-5:2013. In the case the sheet material 2 comprises a plurality of holes 5, said plurality of holes are preferably not visible with the naked eye, in order not to disturb the visual appearance of the sheet material 2. The sheet material 2 from figure 1 may be in a continuous format or in a predetermined slab format. In the embodiment shown in figure 1, the printed sheet 3 comprises a printed motif 12, imitating a natural wood decor. The sheet material 2 may comprise the material for the decorative top layer 22 for a plurality of decorative panels 1, which may be separated from the sheet material 2 in a further processing step. The sheet material 2 may also comprise a technical zone 6, which may be used during manufacturing of a decorative panel 1, for example for correctly positioning the sheet material 2 on a substrate 19 for a thermal pressing operation.

[0136] A detailed top view of the area indicated by F2 is given by figure 2. The given area of the sheet material 2 comprises a plurality of holes 5 arranged in a straight pattern, wherein a series of holes 5 aligned over the direction substantially parallel to the width direction of the sheet material 2, being arranged in a linear sequence substantially parallel to the length direction of the sheet material 2. In the shown embodiment of figure 2 each hole 5 is equidistant from its neighboring hole 5 in the width direction of the sheet material 2 and each hole 5 is equidistant from its neighboring hole 5 in the length direction of the sheet material 2. Preferably said plurality of holes 5 are distributed over said printed sheet 2 in a density of between 2 - 500 holes per square centimeter, preferably of between 4 - 300 holes per square centimeter, more preferably of between 4 - 100 holes per square centimeter, even more preferably of between 4 - 50 holes per square centimeter.

[0137] An alternative embodiment to the one shown in figure 2 is shown in figure 3. The shown area of the sheet material 2 comprises a plurality of holes 5 arranged in a staggered pattern over the upper surface of said sheet material 2. A staggered pattern refers to a series of holes 5 arranged in an alternating sequence along both the width and length directions of the sheet material 2. This arrangement ensures that each hole 5 in one row is offset from their respective neighboring holes 5 in adjacent rows, creating a staggered or zigzag pattern. In the shown embodiment of figure 3, each hole 5 is equidistant from its neighboring holes 5 in the width direction of the sheet material 2 and equidistant from its neighboring holes 5 in the length direction of the sheet material 2. Preferably said plurality of holes 5 are distributed over said printed sheet 2 in a density of between 2 - 500 holes 5 per square centimeter, preferably of between 4 - 300 holes 5 per square centimeter, more preferably of between 4 - 100 holes 5 per square centimeter, even more preferably of between 4 - 50 holes per square centimeter.

[0138] Yet another alternative embodiment to the one shown in figure 2 is shown in figure 4. The sheet material 2 comprises a plurality of holes 5 wherein said plurality of holes 5 are arranged in a predetermined pattern 9 (D), wherein said predetermined pattern 9 forms an identifiable code 9. This predetermined pattern 9 is carefully designed to form a code 9 that can be identified. Such a code 9 could enable encoding certain information.

[0139] It is preferred that said code 9 is configured to be detected and preferably interpreted by an optical reading device, preferably in combination with dedicated signal processing software. Examples of such an optical reading device include an optical scanning device, a camera, preferably a smartphone camera, an optical mark reader, and the like.

[0140] Preferably said code 9 is arranged within a two dimensional matrix format. Such a matrix format may delimit a coordinate system, wherein each hole 5 is assigned a horizontal or X-coordinate and a vertical or Y-coordinate, within said coordinate system. Other examples of a code 9 arranged within such a two dimensional matrix format may be braille or QR-code, or dot code. As an example said code 9 may be arranged within a surface area of between 0.3 and 2.5 square centimeters, preferably between 0.5 and 1.5 square centimeters, more preferably around 1 square centimeter. Preferably said plurality of holes 5 are distributed along said printed sheet 2 in a density of between 2 - 500 holes 5 per square centimeter, preferably of between 4 - 300 holes 5 per square centimeter, more preferably of between 4 - 100 holes 5 per square centimeter, even more preferably of between 4 - 50 holes per square centimeter.

[0141] It is also preferred that said sheet material 2 comprises a plurality of repetitions of said code 9, preferably wherein said sheet material 2 is substantially entirely covered by said code 9 or by repetitions of said code 9. Having multiple repetitions of the code 9 ensures that even if part of the sheet material 2 is damaged or obscured, the code 9 can still be read on another part of said sheet material 2. This further increases the readability of the code 9 as the code 9 can be read from any part of the decorative panel 1 and / or sheet material. In the embodiment shown in figure 4, said code 9 is defined by multiple grouping patterns 10 overlayed on each other.

[0142] The predetermined pattern 9 shown in the area indicated by D in figure 4 is composed of a superposition of multiple distinct grouping patterns 10 as shown in figure 5. By overlaying grouping patterns 10 (A), (B) and (C), the predetermined pattern 9 (D) is obtained. The dedicated decryption software and / or the dedicated decryption key is able to distinguish between the overlayed grouping patterns 10 and is able to recognize a specific combination of grouping patterns 10. A specific combination of grouping patterns 10 may represent a specific piece of information, for example corresponding to one or more positions in a database. The order in which said distinct grouping patterns 10 are overlaid on each other may be switched, as long as the eventually obtained predetermined pattern 9 (D) is the same.

[0143] Figure 6 shows a cross section along the line indicated with VI- VI in figure 2. In the shown embodiment, the sheet material 2 has a layered buildup, comprising a transparent or translucent wear layer 4 and comprising a printed sheet 3, which is a printed decorative paper 3. Said printed decorative paper 3 comprises a printed motif 12. Said printed decorative paper 3 is impregnated with a resin 7, preferably with a thermosetting resin 7. Said thermosetting resin 7 may be partially cured. In the shown embodiment, the printed decorative paper 3 is saturated with said thermosetting resin 7 and a portion of the thermosetting resin 7 is present at the bottom side as well as on the top side of the printed decorative paper 3.

[0144] The thermosetting resin 7 of the shown embodiment may comprise one or a combination of two or more components chosen from the list of: amino resins, acrylate, urea formaldehyde (UF), melamine urea formaldehyde (MUF), melamine formaldehyde (MF), polyurethane (PU), urethane-acrylic copolymer, melamine acrylate, melamine formaldehyde acrylate, latex, optionally in combination with a crosslinking agent. The sheet material 2 in the shown embodiment comprises a glue layer 8 situated on the bottom side of the printed decorative paper 3, more particularly underneath the portion of the thermosetting resin 7 at the bottom side of the printed decorative paper 3. Preferably said glue layer 8 comprises polyurethane, preferably said glue layer 8 mainly consists of polyurethane.

[0145] In a preferred embodiment, the wear layer 4 comprises a synthetic material layer comprising an acrylate resin; and preferably said synthetic material layer mainly consists of said acrylate resin. It is preferred that said wear layer 4 is partially cured. It is also preferred that the acrylate resin comprises one or more than one thermoinitiators.

[0146] It is preferred that the wear layer 4 is present in an amount of more than 30 grams per square meter, preferably of between 30 and 500 grams per square meter, more preferably of between 30 and 300 grams per square meter.

[0147] It is preferred that the wear layer 4 has a thickness of between 50 and 500 micrometers, preferably of between 100 and 350 micrometers, more preferably of between 150 and 250 micrometers, even more preferably of between 170 and 210 micrometers.

[0148] At least a portion of said plurality, and preferably all, of said holes 5 are through holes 5 extending through the entire thickness of said sheet material 2, wherein the shape of said plurality of holes 5 in a direction perpendicular to the upper surface of said sheet material 2 is substantially cylindrical.

[0149] Figure 7 shows an alternative embodiment in the view shown in figure 6, with the difference that the shape of said plurality of holes 5 in a direction perpendicular to the upper surface of said sheet material 2 is substantially tapered.

[0150] Figure 8 shows an embodiment wherein at least a portion of the plurality of holes 5, and preferably all of said holes 5, are blind holes 5 having a depth which is more than 25% of the total thickness of said sheet material 2. In the shown embodiment, the shape of said plurality of holes 5 in a direction perpendicular to the upper surface of said sheet material 2 is substantially cylindrical. At least a portion of said plurality, and preferably all, of said holes 5 are blind holes 5, at least fully penetrating through the wear layer 4 and penetrating into at least 10% of the total thickness of the printed sheet 3.

[0151] Figure 9 shows an embodiment wherein at least a portion of the plurality of holes 5, preferably all of said holes 5 are blind holes 5 having a depth which is more than 25% of the total thickness of said sheet material 2. In the shown embodiment, the shape of said plurality of holes in a direction perpendicular to the upper surface of said sheet material 2 is substantially tapered. At least a portion of said plurality, and preferably all, of said holes 5 are blind holes 5, at least fully penetrating through the wear layer 4 and penetrating into at least 10% of the total thickness of the printed sheet 2.

[0152] In the embodiment shown in figure 10, the sheet material 2 comprises a plurality of holes 5 wherein said plurality of holes 5 are essentially a plurality of micro-tears 11. Said plurality of micro-tears 11 have a maximum width of between 0.01 millimeter and 1 millimeter, preferably of between 0.05 millimeter and 0.5 millimeter, more preferably of between 0.08 millimeter and 0.5 millimeter. The micro-tears 11 as shown in figure 10 are distributed all over the upper surface of the sheet material 2.

[0153] Figure 11 shows an alternative embodiment to the one shown in figure 10. The printed sheet 2 comprises a printed motif 12, wherein said plurality of micro-tears 11 are in register with said motif 12. Said motif 12 in the shown embodiment is a natural wood imitation. Such a motif 12 visually imitates structural characteristics such as wood grains, cracks, knots and / or other features typical for a motif imitating natural wood. In the shown embodiment, said plurality of micro-tears 11 are substantially in an area situated outside the regions where said motif imitates such structural characteristics. The regions where said motif 12 imitates such structural characteristics are substantially free from holes, more particularly from micro-tears 11. It should be noted that in this embodiment, said micro-tears 11 may be replaced by the holes 5 as described in any of the previously discussed embodiments. Figure 12 shows a method for producing a sheet material 2, wherein a multilayered structure 13 comprising a printed sheet 3 and a wear layer 4 provided on top of said printed sheet 3 is provided. The multilayered structure 13 may be conveyed along the direction G, indicated with the arrow. The method comprises the step of providing said multilayered structure 13 with a plurality of holes 5.

[0154] Said step of providing said multilayered structure 13 with said plurality of holes 5 is carried out by means of a pressing system 14 comprising a pressing element 15 comprising a plurality of needles 16 on its outer surface 17, pushing at least partially into and preferably all the way through said multilayered structure 13.

[0155] In the shown embodiment, said pressing element 15 is a roller 15, wherein said plurality of needles 16 are arranged over the circumferential outer surface 17 of said roller 15. The pressing system 14 of figure 12 comprises multiple rollers 15 arranged in series, each of the rollers 15 comprising a plurality of needles 16, wherein each plurality of needles 16 is arranged in a distinct pattern. For example the arrangement of the needles 16 of a first roller 15 may impart holes 5 in the multilayered structure 13 corresponding to the grouping pattern 10 (A) of figure 5; a second roller 15 may impart holes 5 in the multilayered structure 13 corresponding to the grouping pattern 10 (B) of figure 5 and a third roller 15 may impart holes 5 in the multilayered structure 13 corresponding to the grouping pattern 10 (C) of figure 5.

[0156] The pressing system 14 further comprises a counter pressure surface 18, for example the circumferential outer surface of a counter pressure roller 18. In this embodiment, each roller 15 comprises a corresponding counter pressure roller 18.

[0157] Figure 13 shows a method for manufacturing decorative panels 1 comprising at least a substrate 19 and a decorative top layer 22. The method comprises at least the steps of providing a sheet material 2; providing a substrate 19; stacking the sheet material 2 on the substrate 19. In the shown embodiment said step of stacking the sheet material 2 further comprises the step of positioning a backing layer 23, preferably a counterbalancing layer 23, on the side of the substrate 2 opposite to the side where the sheet material 2 is stacked on the substrate 19. In this particular embodiment, a glue layer 8 is provided on the top side of the substrate 19. Said glue layer 8 may also be provided on a bottom side of the sheet material 2.

[0158] Subsequently the sheet material 2 is provided with a structured upper surface 20 in a thermal pressing operation, by means of a structured press element 21. During said thermal pressing operation, said sheet material 2 is at least partially deformed. It is not excluded that the substrate 19 is partially deformed as a result of said thermal pressing operation.

[0159] During said thermal pressing operation, said sheet material 2 is laminated to said substrate 19. During said thermal pressing operation, the decorative panel 1 is provided with a decorative top layer 22 comprising a printed motif 12 and the structured upper surface 20. The sheet material 2 can be a sheet material 2 as shown in figure 1.

[0160] The decorative panel 1 obtained through the method as shown in figure 13 may be further divided into a plurality of decorative panels 1. Additionally, some further processing steps, such as profile milling, may be necessary to arrive at the decorative panel 1 of figure 14.

[0161] The decorative panel 1 of figure 14, may be obtained through a method as shown in figure 13. Said decorative panel 1 comprises a decorative top layer 22 laminated on top of a substrate 19. The decorative panel 1 further comprises mechanical coupling parts 27-28 at both edges of at least one pair of opposite edges 29-30 of said decorative panel 1, wherein said mechanical coupling parts 27-28 allow two of such panels 1 to become locked to each other at the respective edges 29-30 in a vertical direction perpendicular to the plane of the coupled panels 1 and in a horizontal direction perpendicular to said edges 29-30 and in the plane of the coupled panels 1. The panel shown in figure 14 also comprises mechanical coupling parts 27-28 at the second pair of edges 31-32.

[0162] Figure 15 shows a cross section of the decorative panel 1 from figure 14, clearly showing the substrate 19 and the laminated thereon decorative top layer 22 comprising a printed sheet 3, comprising a printed motif 12, and a laminated thereon transparent or translucent wear layer 4. The coupling parts 27-28 are basically shaped as a tongue 33 comprising a portion 34 that protrudes from the respective edge 29 and a groove 35 being bordered by an upper lip 36 and a lower lip 37. In the shown embodiment, said panel 1 comprises a lowered edge region 26 at a first pair of opposite edges 29-30, wherein said printed sheet 3 extends continuously along said lowered edge region 26. For example, said lowered edge region 26 may be a bevel 26, preferably a pressed in bevel 26.

[0163] Figure 16 shows a more detailed view of the layer buildup of the decorative top layer 22 of the decorative panel 1. The decorative top layer 22 comprises a printed sheet 3 and a laminated thereon transparent or translucent wear layer 4. In the shown embodiment, said printed sheet 3 comprises a plurality of holes 5 extending at least partially into and preferably fully through the thickness of said printed sheet 3, said holes 3 being at least partially, and preferably fully, filled with resin 24, preferably resin 24 from said wear layer 4. In the shown embodiment, the printed sheet 3 is a printed decorative paper 3 impregnated with a thermoset resin 7. A distinction is made between a thermosetting resin and a thermoset resin, wherein a thermosetting resin is uncured or partially cured while a thermoset resin is fully cured or substantially fully cured, for example cured for more than 90% of its total curing capacity. It is also possible that said holes 5 are partially filled with said thermoset resin 7. In the shown embodiment a glue layer 8 is present on the bottom side of the printed decorative paper 3. It is also possible that said holes 5 are partially filled with glue from said glue layer 8.

[0164] In the shown embodiment, the decorative top layer 22 is provided with a structured upper surface 20.

[0165] Said structured upper surface 20 may effectively imitate the structure of natural wood or natural stone or of any other structure of a decorative surface the printed sheet 3 imitates. Such structure drastically improves the look and feel of the decorative panel 1 and contributes to a more realistic imitation. Said structured upper surface 20 may comprise areas having a micro structure. Said microstructure comprising impressions 25 with a depth L of between 5 and 20 pm. Additionally or alternatively, said structured upper surface may comprise areas having a macrostructure. Said macrostructure comprising impressions 25 with a depth L greater than 40 pm, preferably with a depth L greater than 80 pm even more preferably with a depth L greater than 100 pm. The depth L of an impression 25 being the maximum depth L of said impression 25 wherein said depth L of said impressions 25 may be measured in a direction perpendicular to a general upper surface of the decorative panel 1.

[0166] Figures 17A and 17B illustrate an embodiment of the invention. Figure 17A shows a sheet material 2 which will be laminated in a thermal pressing operation to a substrate 19. The sheet material 2 comprises in a local section 40 a plurality of holes 5.

[0167] Figure 17B shows the situation after the thermal pressing operation into which the sheet material 2 is laminated onto the substrate. A deep structure 41 has been pressed in the thermal pressing operation in the local section 40 in which the sheet material 2 is provided with plurality of holes 5.

[0168] Afterwards, the substrate 19 with the sheet material 2 laminated onto it is cut into decorative panels 1 and mechanical coupling parts are milled at the edges of the two decorative panels 1. The deep structure 41 results in bevels 26 at the edges of the two decorative panels 1. The cut and the mechanical coupling parts to be milled are shown in dashed lines in figure 17B. In the example shown, the mechanical coupling parts are basically shaped as a tongue 33 on the one hand, and on the other hand a groove 35 bordered by an upper lip 36 and a lower lip 37. Other configurations of mechanical coupling parts are possible.

[0169] Instead of holes only locally present in the sheet, it is also possible that the sheet material comprises a first section with a higher density of holes than in a second section. The first section having a higher density of zones can be the local section 40 shown in figure 17A in which in a thermal pressing operation a deep structure will be pressed which will result in the bevels when the board is cut and milled to decorative panels having coupling parts at their edges. The present invention is not limited to the preferred embodiments described here above, but such sheet materials, panels and methods may be realized according to several variants without leaving the scope of the invention.

Claims

Claims1.- Sheet material for producing a decorative panel (1), wherein said sheet material (2) comprises a printed sheet (3), and a wear layer (4) on said printed sheet (3), preferably wherein said wear layer (4) is embossable by a thermal pressing operation, characterized in that said sheet material (2) comprises a plurality of holes (5) and / or wherein said sheet material (2) has a Gurley value lower than 80 seconds, preferably lower than 50 seconds, more preferably lower than 30 seconds.

2. -The sheet material according to claim 1, characterized in that said printed sheet (3), comprises or consists of a printed decorative paper (3).

3. -The sheet material according to claim 2, characterized in that said printed decorative paper (3) is impregnated with a resin (7), preferably with a partially cured thermosetting resin (7).

4. -The sheet material according to claim 3, characterized in that said resin (7) comprises one or a combination of two or more components chosen from the list of: amino resins, acrylate, urea formaldehyde (UF), melamine urea formaldehyde (MUF), melamine formaldehyde (MF), polyurethane (PU), urethane-acrylic copolymer, melamine acrylate, melamine formaldehyde acrylate, latex, optionally in combination with a crosslinking agent.

5. -The sheet material according to any of the preceding claims, characterized in that said wear layer (4) comprises a synthetic material layer comprising an acrylate resin (24); and preferably mainly consists of said acrylate resin (24).

6. -The sheet material according to claim 5, characterized in that said acrylate resin (24) is of the aliphatic type.

7. -The sheet material according to any of the preceding claims, characterized in that said wear layer (4) comprises a synthetic material layer comprising an unsaturated polyester, preferably an unsaturated polyester resin and preferably mainly consists of said unsaturated polyester resin.

8. -The sheet material according to any of the preceding claims, characterized in that said wear layer (4) comprises a synthetic material layer comprising reactive acrylate groups.

9. -The sheet material according to any of the preceding claims, characterized in that said wear layer (4) is partially cured; preferably wherein said wear layer (4) comprises double carbon-carbon bonds.10.- The sheet material according to any of the preceding claims, characterized in that said wear layer (4) comprises a thermoinitiator.11.- The sheet material according to claim 10, characterized in that said thermoinitiator is an organic peroxide, preferably benzoyl peroxide or lauryl peroxide or tertiary butylperoxyl-3,5,5-trimethylhexanoate (TBPIN).12.- The sheet material according to any of the claims 1 to 4, characterized in that said wear layer (4) comprises a transparent or translucent thermoplastic foil, preferably wherein said thermoplastic foil comprises one or a combination of two or more of the following: polyvinylchloride (PVC), polyethylene terephthalate (PET), glycol modified polyethylene terephthalate (PET-G), thermoplastic polyurethane (TPU), polypropylene (PP).13.- The sheet material according to any of the claims 1 to 4, characterized in that said wear layer (4) comprises or consists of a resin impregnated sheet of overlay paper wherein said resin comprises one or a combination of two or more components chosen from the list of: amino resins, acrylate, urea formaldehyde (UF), melamine urea formaldehyde (MUF), melamine formaldehyde (MF), polyurethane (PU), urethane-acrylic copolymer, melamine acrylate, melamine formaldehyde acrylate, latex, optionally in combination with a crosslinking agent. - The sheet material according to any of the preceding claims, characterized in that said wear layer (4) is composed of multiple layers, preferably wherein the composition of at least two of said multiple layers differs from one another. - The sheet material according to any of the preceding claims, characterized in that the wear layer (4) is present in an amount of more than 30 grams per square meter, preferably of between 30 and 500 grams per square meter, more preferably of between 30 and 300 grams per square meter. - The sheet material according to any of the preceding claims, characterized in that said sheet material (2) comprises a glue layer (8) situated on the bottom side of said printed sheet (3). - The sheet material according to claim 16, characterized in that said glue layer (8) comprises polyurethane, preferably mainly consists of polyurethane. - The sheet material according to any of the preceding claims, characterized in that said sheet material (2) comprises a plurality of holes (5), wherein at least a portion of said plurality of holes (5), and preferably all of said plurality of holes (5), are through holes (5) extending through the entire thickness of said sheet material (2). - The sheet material according to any of the preceding claims, characterized in that said sheet material (2) comprises a plurality of holes (5), wherein at least a portion of said plurality of holes, and preferably all of said holes (5), are blind holes (5) having a depth which is more than 25% of the total thickness of said sheet material (2). - The sheet material according to any of the preceding claims, characterized in that said sheet material (2) comprises a plurality of holes (5), wherein said plurality ofholes (5) are arranged in a straight pattern over the upper surface of said sheet material (2). The sheet material according to any of the preceding claims, characterized in that said sheet material (2) comprises a plurality of holes (5), wherein said plurality of holes (5) are arranged in a staggered pattern over the upper surface of said sheet material (2). - The sheet material according to any of the preceding claims, characterized in that said sheet material (2) comprises a plurality of holes (5), wherein said plurality of holes (5) are distributed over the upper surface of said sheet material (2) in a density of between 2 - 500 holes per square centimeter, preferably of between 4 - 300 holes per square centimeter, more preferably of between 4 - 100 holes per square centimeter, even more preferably of between 4 - 50 holes per square centimeter. - The sheet material according to any of the preceding claims, characterized in that said sheet material (2) comprises a plurality of holes (5), wherein said plurality of holes (5) are uniformly distributed over the upper surface of said sheet material (5), or wherein the plurality of holes are only locally present, or wherein said sheet material comprises a first section with a higher density of holes than in a second section. - The sheet material according to any of the preceding claims, characterized in that said sheet material (2) comprises a plurality of holes (5), wherein said plurality of holes (5) are arranged in a predetermined pattern (9), wherein said predetermined pattern (9) forms an identifiable code (9). - The sheet material according to claim 24, characterized in that said code (9) is configured to be detected and preferably interpreted by an optical reading device, preferably in combination with dedicated signal processing software.- The sheet material according to claim 24 or 25, characterized in that said code (9) comprises information or a link to a digital location comprising information on at least one, preferably a combination of two or more of the following: manufacturing process, product details, material composition, supplier details, instructions for the customer, of the sheet material and / or of the decorative panel. - The sheet material according to any of the claims 24 to 26, characterized in that said code (9) is arranged within a two dimensional matrix format. - The sheet material according to any of the claims 24 to 27, characterized in that said sheet material (2) comprises a plurality of repetitions of said code (9), preferably wherein said sheet material (2) is substantially entirely covered by said code (9) or by repetitions of said code (9). - The sheet material according to any of the claims 24 to 28, characterized in that said code (9) comprises a plurality of redundant data elements. - The sheet material according to any of the claims 24 to 29, characterized in that said code (9) is defined by one or a combination of two or more of the following parameters: spacing between individual holes, grouping pattern (10) of a set of holes (5) within a specified area, amount of repetitions of a grouping pattern (10) of a set of holes (5) within a specified area, size of individual holes (5), shape of individual holes (5), color contrast between the holes (5) and the upper surface of the printed sheet (3). - The sheet material according to any of the preceding claims, characterized in that said sheet material (2) comprises a plurality of holes (5) wherein the shape of said plurality of holes (5) in a direction perpendicular to the upper surface of said sheet material (2) is substantially cylindrical or tapered, for example conical or pyramidical. - The sheet material according to any of the preceding claims, characterized in that said sheet material (2) comprises a plurality of holes (5) wherein said plurality of holes (5) have an equivalent diameter at the height of the upper surface of the sheet material(2) and / or at the height of the bottom surface of the sheet material (2) of between 0.01 millimeter and 1 millimeter, preferably of between 0.05 millimeter and 0.6 millimeter, more preferably of between 0.08 millimeter and 0.6 millimeter, even more preferably of between 0.1 millimeter and 0.5 millimeter. - The sheet material according to any of the claims 1 to 19, characterized in that said sheet material (2) comprises a plurality of holes (5) wherein said plurality of holes (5) are essentially a plurality of micro-tears (11). - The sheet material according to claim 33, characterized in that said plurality of micro-tears (11) have a maximum width of between 0.01 millimeter and 1 millimeter, preferably of between 0.05 millimeter and 0.5 millimeter, more preferably of between 0.08 millimeter and 0.5 millimeter. - The sheet material according to any of the preceding claims, characterized in that said printed sheet (3) comprises a printed motif (12) and wherein said plurality of holes (5) are in register with said printed motif (12). - The sheet material according to any of the preceding claims, characterized in that said sheet material (2) comprises a plurality of holes (5) wherein said plurality of holes (5) comprise a burnt edge, preferably at least at the height of the upper surface of said sheet material (2). - Method of producing a sheet material according to any of the claims 1 to 36; wherein the method comprises the steps of: providing a multilayered structure (13) comprising a printed sheet (3) and a wear layer (4) provided on top of said printed sheet (3); providing said multilayered structure (13) with said plurality of holes (5). - The method according to claim 37, characterized in that said step of providing said multilayered structure (13) with said plurality of holes (5) is carried out by means of a pressing system (14) comprising a pressing element (15) comprising a pluralityof needles (16) on its outer surface (17), pushing at least partially into and preferably all the way through said multilayered structure (13). - The method according to claim 38, characterized in that said plurality of needles(16) are arranged in a straight pattern over the outer surface (17) of said pressing element (16). - The method according to claim 38, characterized in that said plurality of needles(16) are arranged in a staggered pattern over the outer surface (17) of said pressing element (15). - The method according to claim 38, characterized in that said plurality of needles(16) are arranged in a uniquely identifiable predetermined pattern. - The method according to claim 38, characterized in that said pressing system (14) comprises two or more pressing elements (15) arranged in series, each of said two or more pressing elements (15) comprising a plurality of needles (16). - The method according to claim 42, characterized in that each of said two or more pressing elements (15) comprises a plurality of needles (16), wherein each plurality of needles (16) is arranged in a distinct pattern. - The method according to any of the claims 38 to 43, characterized in that said plurality of needles (16) are distributed over said outer surface (17) of said pressing element (15) in a density of between 2 - 500 needles per square centimeter, preferably of between 4 - 300 needles per square centimeter, more preferably of between 4 - 100 needles per square centimeter, even more preferably of between 4 - 50 needles per square centimeter. - The method according to any of the claims 38 to 44, characterized in that said needles (16) are essentially tapered in shape and extend outwardly from said outer surface (17) of said pressing element (15).- The method according to any of the claims 38 to 45, characterized in that said pressing system (14) comprises a counter pressure surface (18), for example the circumferential outer surface of a counter pressure roller (18). - The method according to claim 46, characterized in that said counter pressure surface (18) has a Shore A hardness of lower than 90, preferably lower than 70, more preferably lower than 60. - The method according to any of the claims 46 or 47, characterized in that said counter pressure surface (18) comprises a material chosen from the list of: soft PVC, soft PU, brush, Tampico fiber, felt, rubber, sponge. - The method according to any of the claims 38 to 48, characterized in that said pressing element (15) is a roller (15) comprising a circumferential outer surface (17) comprising the plurality of needles (16). - The method according to claim 37, characterized in that said step of providing said multilayered structure (13) with said plurality of holes (5) is carried out by means of a roller system (15) comprising a roller (15) comprising a circumferential outer surface (17) comprising a plurality of needles and / or protrusions, wherein the protrusions vary in shape, such that at least two protrusions have different geometrical configurations from one another. - The method according to any of the claims 49 or 50, characterized in that said roller (15) is a powered roller, preferably an electrically powered roller. - The method according to any of the claims 49 to 51, characterized in that the position of said roller (15) relative to the multilayered structure (13) is adjustable. - The method according to any of the claims 49 to 52, characterized in that said roller system (14) comprises a cleaning brush in contact with said roller (15).- The method according to claim 37, characterized in that said step of providing said multilayered structure (13) with said plurality of holes (5) is carried out by means of a laser treatment including a laser beam. - The method according to claim 54, characterized in that said laser treatment uses a Nano laser and / or a Pico laser and / or a Femto laser. - The method according to claim 54 or 55, characterized in that said laser treatment includes a device, preferably a scanner, used to control the direction of the laser beam. - The method according to any of the claims 54 to 56, characterized in that said laser treatment includes beam splitting of the laser beam. - The method according to any of the claims 54 to 57, characterized in that said laser operates in a burst regime. - Method for manufacturing decorative panels (1), comprising at least a substrate(19) and a decorative top layer (22), wherein the method comprises the steps of: providing a sheet material (2); providing a substrate (19); stacking the sheet material (2) on the substrate (19); subsequently providing said sheet material (2) with a structured upper surface (20) in a thermal pressing operation, by means of a structured press element (21); laminating said sheet material (2) to said substrate (19) in said thermal pressing operation; wherein in the thermal pressing operation, the decorative panel (1) is provided with the decorative top layer (22) comprising the structured upper surface (20), characterized in that said sheet material (2) is a sheet material (2) according to any of the claims 1 to 36.- The method according to claim 59, characterized in that the step of stacking the sheet material (2) on the substrate (19) further comprises the step of positioning the wear layer (4) onto the printed sheet (3). The method according to claim 59 or 60, characterized in that said step of stacking the sheet material (2) on the substrate (19) further comprises the step of positioning a backing layer (23), preferably a counterbalancing layer (23) on the side of the substrate (19) opposite to the side where the sheet material (2) is stacked on the substrate (19). - The method according to any of the claims 59 to 61, characterized in that said substrate (19) comprises a plurality of microscopic voids, preferably of open cell microscopic voids. - The method according to any of the claims 59 to 62, characterized in that said substrate (19) is a wood-based substrate - preferably a wood fiberboard or a chipboard or a particleboard - or wherein said substrate (19) is a mineral-based substrate, preferably a cement-based substrate or a gypsum-based substrate, or wherein said substrate is a thermoplastic material board, preferably a filled thermoplastic material board. - The method according to any of the claims 59 to 63, characterized in that said press element (21) is a heated press element. - The method according to any of the claims 59 to 64, characterized in that said step of providing said sheet material (2) with a structured upper surface (21) coincides with said step of laminating said sheet material (2) to said substrate (19). - Decorative panel, preferably obtained through a method according to any of the claims 59 to 65, comprising a substrate (19) and a decorative top layer (22) comprising a printed sheet (3) and a transparent or translucent wear layer (4) provided on the printed sheet, characterized in that said printed sheet (3) comprises a plurality of holes(5) extending at least partially into and preferably fully through the thickness of said printed sheet (3), said holes (5) being at least partially, preferably fully filled with resin (24), preferably with resin (24) from said wear layer (4). - The decorative panel according to claim 66, characterized in that said transparent or translucent wear layer (4) comprises an acrylate resin (24). - The decorative panel according to claim 66 or 67, characterized in that said printed sheet (3) comprises or consists of a printed decorative paper (3), preferably impregnated with a resin (7), preferably wherein said resin (7) comprises one or a combination of two or more components chosen from the list of: amino resins, acrylate, urea formaldehyde (UF), melamine urea formaldehyde (MUF), melamine formaldehyde (MF), polyurethane (PU), urethane-acrylic copolymer, melamine acrylate, melamine formaldehyde acrylate, latex. - The decorative panel according to any of the claims 66 to 68, characterized in that at least a portion of said plurality of said holes (5), and preferably all of said holes (5), have a depth which is more than 25% of the total thickness of said printed sheet (3). - The decorative panel according to any of the claims 66 to 69, characterized in that at least a portion of said plurality of holes (5), preferably all of said plurality of holes (5) are holes extending through the entire thickness of said printed sheet (3). - The decorative panel according to any of the claims 66 to 70, characterized in that said plurality of holes (5) are arranged in a straight pattern or a staggered pattern over the upper surface of said printed sheet (3). - The decorative panel according to any of the claims 66 to 71, characterized in that said plurality of holes (5) are uniformly distributed over the upper surface of said printed sheet (3).The decorative panel according to any of the claims 66 to 69, characterized in that said printed sheet (3) comprises a plurality of holes (5) wherein said plurality of holes (5) are arranged in a predetermined pattern (9), wherein said predetermined pattern (9) forms an identifiable code (9). - The decorative panel according to claim 73, characterized in that said code (9) is configured to be detected and preferably interpreted by an optical reading device. - The decorative panel according to claim 73 or 74, characterized in that said code(9) comprises information or a link to a digital location comprising information on at least one, preferably a combination of two or more of the following: manufacturing process, product details, material composition, supplier details, instructions for the customer, of the sheet material (2) and / or of the decorative panel (1). - The decorative panel according to any of the claims 73 to 75, characterized in that said code (9) is arranged within a two dimensional matrix format. - The decorative panel according to any of the claims 73 to 76, characterized in that said printed sheet (3) comprises a plurality of repetitions of said code (9), preferably wherein said printed sheet (3) is substantially entirely covered by said code (9) or by repetitions of said code (9). - The decorative panel according to any of the claims 73 to 77, characterized in that said code (9) comprises a plurality of redundant data elements. - The decorative panel according to any of the claims 73 to 78, characterized in that said code (9) is defined by one or a combination of two or more of the following parameters: spacing between individual holes (5), grouping pattern (10) of a set of holes (5) within a specified area, amount of repetitions of a grouping pattern (10) of a set of holes (5) within a specified area, size of individual holes (5), shape of individual holes (5), color contrast between the holes (5) and the upper surface of the printed sheet (3).- The decorative panel according to any of the claims 66 to 79, characterized in that said plurality of holes (5) are distributed along said printed sheet (3) in a density of between 2 - 500 holes per square centimeter, preferably of between 4 - 300 holes per square centimeter, more preferably of between 4 - 100 holes per square centimeter, even more preferably of between 4 - 50 holes per square centimeter. - The decorative panel according to any of the claims 66 to 80, characterized in that the shape of said plurality of holes (5) in a direction perpendicular to the upper surface of said decorative top layer (22) is substantially cylindrical or tapered, for example conical or pyramidical. - The decorative panel according to any of the claims 66 to 81, characterized in that said substrate (19) is a wood-based substrate, preferably a wood fiberboard, or wherein said substrate is a mineral-based substrate, preferably a cement-based substrate or a gypsum-based substrate, or wherein said substrate (19) is a thermoplastic material board, preferably a filled thermoplastic material board. - The decorative panel according to any of the claims 66 to 82, characterized in that said decorative panel (1) comprises a structured upper surface (20) comprising areas having a macrostructure, said macrostructure comprising impressions (25) with a depth (L) greater than 40 pm, preferably with a depth (L) greater than 80 pm. - The decorative panel according to any of the claims 66 to 83, characterized in that said panel comprises a lowered edge region (26) at at least a first pair of opposite edges (29-30), wherein said decorative top layer (22) extends continuously along said lowered edge region (26). - The decorative panel according to claim 84, characterized in that at least a portion of said plurality of holes (5) are situated in said lowered edge region (26).6.- The decorative panel according to any of the claims 66 to 85, characterized in that said decorative panel (1) comprises a backing layer (23), preferably a counterbalancing layer (23) on the side of the substrate (19) opposite to the side where the sheet material (2) is situated. 7.- The decorative panel according to any of the claims 66 to 86, characterized in that said decorative panel (1) comprises mechanical coupling parts (27-28) at both edges (29-30; 31-32) of at least one pair of opposite edges (29-30; 31-32) of said decorative panel (1), wherein said mechanical coupling parts (27-28) allow two of such panels (1) to be locked to each other at the respective edges (29-30; 31-32) in a vertical direction perpendicular to the plane of the coupled panels (1); and in a horizontal direction perpendicular to said edges (29-30; 31-32) and in the plane of the coupled panels (1); wherein said coupling parts (27-28) are basically shaped as a tongue (33) comprising a portion (34) that protrudes from the respective edge (29) and a groove (35) being bordered by an upper lip (36) and a lower lip (37).

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