BE1030607A1 - Press element and method for manufacturing press elements - Google Patents

Abstract

Press element (1) and method for manufacturing a structured press element (1), wherein a heterogeneous mask (3) is applied to a metal base element (2), after which a surface treatment is carried out and the heterogeneous mask has a certain resistance to the surface treatment.

Description

1 BE2022/5454

Press element and method for manufacturing press elements

This invention relates to press elements, a method for manufacturing press elements, and clad panels obtained with press elements.

More specifically, the invention relates to the manufacture of pressed elements that are used in a method for manufacturing coated panels, wherein the coated panels are of the type that comprise a substrate and a decorative top layer applied thereto. This may, for example, involve floor panels that mainly consist of a substrate and a top layer. For example, the substrate may comprise a

MDF or HDF (Medium Density Fiberboard or High Density Fiberboard) panel, on which a top layer, such as a laminate top layer comprising resin-impregnated paper layers, has been applied. The substrate can also comprise one or more thermoplastic-based layers, whereby a top layer, such as a laminate top layer comprising thermoplastic-based sublayers, is applied. Other examples for possible substrates include mineral-based substrates, such as cement-based, MgO-based or gypsum-based substrates, or geopolymer-based substrates.

In particular, the invention concerns pressing elements that are used in a method for manufacturing covered panels with a printed decor with a transparent or translucent plastic layer extending above. It is known that such decor can be printed directly on the substrate, with or without the intervention of base layers. However, the decor can also be provided on a sheet of material, such as a paper sheet or a plastic foil, which is included in the aforementioned top layer. Optionally, a transparent or translucent plastic layer can form a protective layer above the printed decor and this transparent or translucent plastic layer can, for example, comprise wear-resistant particles such as aluminum oxide or corundum. It cannot be ruled out that this protective layer also contains a sheet of material, such as a sheet of paper or plastic foil. This may, for example, involve the manufacture of laminate floor panels, for example according to a DPL (Direct Pressure Laminate) or HPL (High Pressure Laminate) technique. In the case of a DPL technique, one or more material sheets are provided with resin

2 BE2022/5454 together with the substrate are placed in a pressing device where they are connected to each other and to the substrate using a pressing element and under the influence of increased pressure and temperature. In the case of an HPL technique, the top layer is formed separately on the basis of two or more material sheets provided with resin, before the top layer thus obtained is applied to the substrate, for example by gluing it to the substrate. Another possibility could involve the manufacture of plastic-based floor panels or floor coverings, such as vinyl panels, vinyl cladding and the like.

It is known, for example from WO 01/96689 or WO 2014/115086, that a relief of impressed portions can be formed on the surface or decorative side of such coated panels, with which, for example, the natural structure of the motif shown in the above-mentioned decor can be achieved. are imitated. For example, if the decor shows a wood motif, you can work with a relief that imitates a wood structure. Such a wood structure can possibly correspond to the underlying decor, which then produces so-called impressions in register with the printed decor.

As is known, structured pressed elements are used to create a relief on the decorative side. Various techniques are known for the production of such pressing elements, for example from WO 2006/066776, EP 2 123 476, EP 2 251 193, EP 1 987 395 and EP 2 834 076. A method is described in EP'395. known for manufacturing structured pressed elements, wherein the method comprises at least the following steps: - the step of providing an element made of metal, - the step of applying a mask to a surface of the element for shielding parts of the aforementioned surface; - the step of chemically processing or etching unshielded portions of the aforementioned surface of the element; and - the step of removing the aforementioned mask.

3 BE2022/5454

The pressing elements that are obtained using methods from the prior art still leave much to be desired, especially when they are used to realize relatively deep structural parts in the surface of the pressing element in question, for example in structural parts with a depth greater than 0.15 millimeters, or 0.3 millimeters or more.

When aiming for a deep structure, various cycles of mask provision and etching can be applied. However, such a method results in protrusions having side edges with disturbingly visible boundaries, such as step-like/step-like abrupt changes in slope angle. These boundaries are copied into the surface of the coated or laminated panels produced with them and distract from the generally fine imitation of a natural structure, such as a wood structure, or a structure that forms lowered edges, such as beveled edges. Another disadvantage is that several cycles are required in which a mask is applied, etched and the mask is removed again. This obviously takes a lot of time.

It may also be desirable to have subtle height differences in the pressing element, for example microstructures. This concerns, for example, structures with height differences between, for example, 5 and 30 microns. Gloss differences can be achieved with the help of such microstructures. With existing surface treatments it is difficult to apply these microstructures precisely and/or in a repetitive manner.

So for pressed elements with microstructures, as well as for pressed elements with deep structures, as for pressed elements with microstructures and deep structures, the current methods for manufacturing pressed elements leave much to be desired.

In existing methods for manufacturing pressed elements that use etching, additional processing steps are often carried out to further optimize the structure of the pressed element. Such additional processing steps may include one or more of the following operations:

4 BE2022/5454 milling operations, laser operations, sandblasting, polishing, etc. With such additional processing steps, the structure of the press element can be further optimized, but additional infrastructure is required for these additional processing steps.

The present invention aims at an alternative method for manufacturing a pressed element, an alternative pressed element and an alternative coated panel, which, according to various preferred embodiments of the invention, can offer advantages over the state of the art.

The invention concerns a method for manufacturing a structured press element, wherein this method comprises at least the following steps: - providing a metal base element, such as a plate or roller. This basic metal element includes, for example, steel and/or copper and/or brass; - applying a mask to a surface of the metal base element, whereby the mask has a certain resistance to a surface treatment in order to at least temporarily shield the surface from the surface treatment at the level of the mask; -carrying out the surface treatment; wherein said mask has a heterogeneous structure, and at least this structure determines the degree of said resistance to the surface treatment.

A structured pressing element refers to a pressing element comprising an outer surface with a certain structure/relief.

The metal base element can, for example, be a plate, wherein the pressing element is then, for example, a pressing plate. The surface of the metal base element then extends mainly along a plane. The metal base element can also be a roller, wherein the pressing element is, for example, a pressing roller. The surface of the metal base element is then preferably cylindrical. The metal base element can, for example, be mainly made of steel and may or may not comprise an additional coating. This additional coating may include copper and/or nickel. After the aforementioned surface treatment and any removal of the mask, the formed surface can be finished with one or more layers comprising chrome, being chrome layers. A chrome layer serves as protection against wear and mechanical damage. It also ensures that plates containing resins are properly released from the pressing element after pressing. This chrome layer can comprise one or more types of chrome, depending on the desired shine. This chrome layer can consist of one or more layers. For example, a basic chrome layer can be applied over the entire surface, which provides a certain shine, whereby an additional chrome layer with a different shine is then applied in specific places.

A surface treatment is preferably used here to refer to a material-removing surface treatment. By removing material, valleys and therefore mountains are formed, thus forming a surface structure. It is also possible that during the surface treatment only dents and the like are made in the surface, without removing any material. The surface treatment can also be a combination of removing material and applying dents and the like. The surface treatment, as indicated in the claims, may comprise one or more of the following treatments from the non-exhaustive list below: an etching treatment - for example a chemical etching treatment with an etching liquid -, a polishing treatment - for example a mechanical polishing treatment or an = electropolishing treatment -, a sandblasting treatment, laser treatment, milling treatment. The above treatments can each consist of one or more sub-steps. An etching treatment is preferably used here to refer to a chemical etching treatment, in which the surface is exposed, for example, to an etching liquid. For example, the base element can be placed in an etching bath filled with an etching liquid in such a way that at least part of the surface is exposed to the etching liquid. Another possibility is to spray an etching liquid once or several times on the surface of the metal base element, for example by moving the metal base element under a bridge comprising nozzles, whereby the

6 BE2022/5454 nozzles apply the etching liquid to the surface while moving the metal base element under the bridge.

The surface treatment, as indicated in the claims, can for example also relate to one type of surface treatment as shown above, being for example an etching treatment or a polishing treatment or a laser treatment or a milling treatment. Other surface treatments are also possible, but are then regarded, for example, as an additional surface treatment that takes place before, during or after the first-mentioned surface treatment. For example, the surface treatment can be an etching treatment that consists of one or more sub-steps.

The mask mentioned here has a heterogeneous structure, so that the resistance to the surface treatment, for example the etching treatment and/or the sandblasting treatment and/or the polishing treatment, is not the same everywhere. Certain parts of the mask, the less resistant parts, will therefore be more sensitive to the surface treatment than other parts, and will therefore break off/degrade more easily. During the surface treatment, certain parts of the mask will degrade and even disappear completely. This means that parts of the surface that were previously covered by the mask are no longer covered during the surface treatment, and are therefore also subjected to the surface treatment. During the surface treatment, the areas to which no mask has been applied will be treated and there will therefore be material removal from these areas, for example. However, areas that were originally covered by the mask, but where the mask degrades/breaks down during the surface treatment, will also be treated during the surface treatment, which will also result in material removal, for example. In these latter parts there will be less material removal than in the former parts, if the surface treatment is a material-removing surface treatment. The big advantage is that during the same surface treatment, parts of the surface can be treated differently. This way, the exposed areas are given the full surface treatment

7 BE2022/5454, certain originally covered parts are temporarily exposed to the surface treatment from a certain time of the surface treatment, depending on how quickly the mask degrades in those places, and for example certain parts of the covered parts are not exposed to the surface treatment. These pressing elements can be provided with the desired structure in a simple manner and without the need for, for example, multiple cycles of mask provision, etching and mask removal, and/or the need for the aforementioned additional treatment steps, such as milling or laser treatment, when the surface treatment, for example, involves a includes etching treatment, or a polishing treatment or a sandblasting treatment; and/or the need to apply multiple masks in the same place. Naturally, this method can also use multiple cycles of mask provision and mask removal, and/or the aforementioned additional treatment steps.

The mask may contain one or more of the following, if not contradictory: a wax, (UV) inks, powder fixed to the surface using a laser treatment, thermoplastics, coatings, acrylics, thermosets, polystyrenes, epoxy compounds, a lacquer . It is possible that the mask can be referred to by two or more names from the above list. For example, the mask can be a coating comprising a thermoset or the mask can be a lacquer comprising acrylics.

The invention makes it possible to obtain the desired pressing element in a simple manner, for example by applying a mask once and carrying out a surface treatment that only uses, for example, chemical etching. Preferably, a mask is applied only once, after which the metal base element with the mask is subjected to the surface treatment, which is a material-removing surface treatment.

Furthermore, preferably, the surface treatment comprises only an etching treatment. This etching treatment can consist of one or more sub-steps. Additional surface treatments are not excluded.

8 BE2022/5454

Also preferably, this method comprises, after carrying out the surface treatment, an additional step of removing the mask.

This indicates the step where the remaining part of the mask is removed. This is because it is possible that the less resistant parts of the mask have already been partially or completely removed during the surface treatment.

More resistant parts may also have been partially removed by the surface treatment, for example become thinner, but in the case of these more resistant parts, for example, the surface covered by these more resistant parts always remains covered during the entire surface treatment. During mask removal there may be a minor structural change to the surface, but this is not considered part of the material removing surface treatment as the main purpose is mask removal only. To remove the remaining mask, you can, for example, use a cleaning and/or neutralizing agent. An ultrasonic vibrator or the like can also be used. Laser ablation and/or milling and/or polishing can also be used. Combinations of multiple techniques are also possible. The major advantage of this method is that during the surface treatment, part of the mask is already removed, so that during the step of removing the mask, there is already less mask present and there is therefore less need for cleaning and/or cleaning. or neutralizing agent and/or this step can be performed in a shorter time period. The step of removing the mask can also be regarded as a, preferably final, sub-step of the surface treatment, whereby the resistance of the mask is such that the mask has completely disappeared after the surface treatment. Preferably, the step of removing the mask is regarded as an additional step, in addition to the surface treatment, since during the step of removing the mask there is preferably no or virtually no change in the relief of the surface of the metal basic element.

It is also possible that the method does not include a step for removing the mask, for example because the mask has already completely disappeared due to the surface treatment (see above) or because it may be desirable for a

9 BE2022/5454 part of the mask remains. The remaining part of the mask will then determine the surface structure of the pressing element.

In a preferred embodiment, the mask divides the said surface of the metal base element into one or more covered parts, on which the mask is located, and one or more uncovered parts, on which there is no mask or virtually no mask - for example only a base layer, and, wherein the mask comprises one or more edge portions and one or more internal portions, wherein the one or more internal portions are each completely surrounded by adjacent one or more edge portions, and the one or more edge portions extend between adjacent one or more multiple uncovered parts of the surface, and adjacent one or more internal parts of the mask, whereby the method includes one or more of the following features, as long as they are not contradictory: - the structure of the mask is such that at least one of the edge portion, the resistance to the surface treatment increases from a respective adjacent exposed portion to a respective adjacent internal portion, preferably gradually increasing. During the surface treatment, the edge areas will be more affected and may themselves partially and/or completely break off, causing the parts of the surface that were under these edge areas at the beginning of the surface treatment to become exposed during the surface treatment and these parts therefore also be processed, but processed less than the uncovered parts. This makes it possible to obtain a structured pressed element with a relief with smooth transitions, with which aesthetic covered panels can be produced. - the structure of the mask is such that at least one edge portion, the thickness of the mask increases from a respective adjacent uncovered portion to a respective adjacent internal portion, preferably gradually increasing. For example, during surface treatment the thickness of the mask may decrease, gradually or not. This means that thinner parts of the mask can even completely disappear during the surface treatment, so that the surface of these thinner parts will also be treated by the surface treatment, but to a lesser extent than the uncovered parts. This allows

10 BE2022/5454 to obtain a structured pressed element with a relief with smooth transitions, with which aesthetic covered panels can be produced. - said one or more edge portions form lateral flanks of the mask, wherein these lateral flanks preferably merge with a rounding into the adjacent one or more uncovered portions.

Such flanks allow the edge portions to gradually disappear during the etching treatment, first at the exposed portions and later towards the internal portions.

This makes it possible to obtain a structured pressed element with a relief with smooth transitions, with which aesthetic covered panels can be produced.

- the thickness of the mask is heterogeneous, so that the mask comprises thicker sections with a thickness higher than a certain threshold value and thinner sections with a thickness lower than this threshold value, whereby preferably said edge portions form at least part of these thinner sections and where furthermore preferably the thinner sections are directly adjacent to the one or more uncovered parts.

This threshold value corresponds, for example, to the maximum thickness of the mask that can be removed during the entire surface treatment.

At the height of thicker sections, this means that even after the surface treatment, the respective surface is still covered, while at the thinner sections the mask has almost completely disappeared after the surface treatment.

In the possible step of removing the mask,

mask must only be removed at the thicker sections.

- the construction of the mask is such that the resistance to the surface treatment at the level of at least one internal part mentioned is higher than the resistance to the surface treatment at the adjacent edge part mentioned.

- the thickness of the mask at the level of said one or more internal parts is always higher than the thickness at the level of corresponding one or more edge parts.

-the chemical composition of a said edge portion differs from the chemical composition of a respective adjacent internal portion.

For example, due to the difference in chemical composition, the edge part may be less resistant than the internal part, as a result of which the edge part will completely break off during the surface treatment.

This allows you to create a structured press element with a smooth relief

Il BE2022/5454 to obtain transitions with which aesthetic covered panels can be produced. - the mask is made of at least one curable substance, whereby the degree of curing at the level of a mentioned edge part is lower than the degree of curing at the level of a respective adjacent internal part.

With a lower degree of curing, the mask may be less resistant to the surface treatment, for example causing the less hardened parts to completely break off during the surface treatment. - said one or more edge portions all have the same first chemical composition and said one or more internal portions all have the same second chemical composition, wherein the first chemical composition is less resistant to the surface treatment than the second chemical composition.

For example, when the surface treatment is an etching treatment or includes an etching treatment, the mask portions with the second chemical composition may be more resistant to an etching liquid used in the etching treatment than the mask portions with the first chemical composition.

Additionally or alternatively, the mask parts with the second chemical composition can, for example, adhere better to the surface than mask parts with the first chemical composition, so that they break down/degrade less quickly.

- the mask is made of at least one curable substance, whereby the degree of curing at the level of said one or more internal parts is greater than the degree of hardening at the level of said one or more edge parts.

- the mask is composed of two or more layers, being at least a binding layer and a second layer, whereby these layers may or may not be composed of several sublayers, whereby the binding layer strengthens the bond between the surface and the second layer, and where of the edge parts, the mentioned binding layer is missing.

This binding layer can, for example, provide higher resistance to surface treatment.

-before applying the mask, the surface can be subjected to an ultrasonic treatment.

For example, with the help of ultrasonic treatment, parts of the mask to be applied can adhere better to the surface.

The ultrasonic treatment, for example, can cause a very serious problem here

12 BE2022/5454 good adhesion between the surface and the internal parts, so that the surface at the level of the internal parts remains covered during the entire surface treatment.

For example, the internal parts and edge parts can be made of different materials, whereby the material from which the edge parts are made adheres less well to the surface than the material from which the internal parts are made.

-marks are applied to the surface prior to applying the mask to the surface, whereby the mask is positioned and/or heterogeneously constructed based on the marks.

Positioning and/or heterogeneous construction can take place using one or more detection systems, such as cameras, that can detect these marks.

The marks can, for example, indicate where which thicknesses are desired, where which curing is desired, where to print - if the mask is printed -, etc.

For example, the mask can consist of at least two materials, each with a different chemical composition, whereby the markings can then indicate which material should be applied to.

With the help of markings one can accurately apply a heterogeneous mask to the surface.

- for example, the mask can consist of at least two materials, each with a different chemical composition.

For example, the materials can be provided to harden under the influence of visible light or UV radiation, whereby one material, based on weight percentages, contains more photoinitiators than the second material, such that the first material will harden more than the second material under the influence of visible light or UV radiation, so that said embodiment can easily be obtained with different degrees of hardening as shown above.

- the mask is made of at least one hardenable substance, the applied mask includes markings and the mask is at least partially hardened on the basis of the markings.

- a greyscale printer is used, so that the thickness of the mask can vary depending on the location.

For example, this grayscale printer can contain at least one printing fluid for printing the mask, whereby one can then use the grayscale printer to choose for each location on the surface how many droplets of the printing fluid, for example between 0 and 7 drops or between

13 BE2022/5454 0 and 5 drops or between 0 and 10 drops, to be applied. All integers - 1, 2, 3, 4, 5, 6, 7, 8, 9 and 10 - in the above ranges are possible here for the number of drops. The droplet size can be, for example, between 4 and 8 picoliters, for example 6 picoliters. , which, if there is the possibility to go up to 7 drops, one can vary between 0 times, once, twice, three times, four times, five times, six times and seven times the above drop size. -the mask is applied by applying a powder to the metal base element, after which this powder is melted using a laser and attached to the surface. Here you can choose at which locations the powder will or will not be attached to the surface and/or the degree of attachment can also be determined here and/or the amount of powder that is sprinkled in a specific location can also be selected. The unattached powder is preferably removed prior to the surface treatment, but can also be removed during the surface treatment. The amount of attached powder and/or the degree of attachment ensure a heterogeneous mask. - the mask is at least printed on the surface and at least two print heads are used, each of which is equipped to print an ink with a different chemical composition, in order to print a heterogeneous mask. These print heads may or may not apply the above-mentioned grayscale system. Using the greyscale system, you can easily vary the applied thickness of the ink.

In ideal circumstances it is desirable that the exposed areas and the covered areas are well separated from each other and therefore there is no mask on top of the uncovered areas. However, during application of the mask it is possible that small amounts of the mask will also cover the uncovered areas to a small extent and/or it may be easier to apply continuously, whereby almost the entire surface is covered by the mask. mask. However, the thickness of the mask at these exposed parts will be small, preferably thinner than 0.1 mm, even more preferably thinner than 0.01 mm, most preferably thinner than 10 or 1 micron. One can therefore speak of a base layer that may or may not be present on the entire surface of the exposed parts. For

14 BE2022/5454 For the sake of simplicity, however, we speak here of uncovered areas, as it can be ensured that this base layer will have a minor influence. The base layer can be manufactured in such a way that after starting the surface treatment, this base layer disappears quickly, for example immediately, so that areas that were only covered with the base layer will undergo almost the entire surface treatment and one can therefore speak of uncovered areas that are exposed to the complete surface treatment. For example, if the mask is obtained using curing, the base layer cannot be cured. If at least two chemical materials are used to apply the mask, and these chemical materials have a different resistance to the surface treatment, the base layer can be made of the material with the least resistance to the surface treatment. The base layer here is preferably always thinner than the edge parts and preferably always thinner than the internal parts. Another option is to remove this base layer before starting the surface treatment, by carrying out another treatment, for example a local polishing treatment or sandblasting treatment of only the exposed areas.

By implementing one or more of the above-mentioned features, a pressed element is obtained with the desired structure, whereby this structure does not include unwanted sharp points, unwanted step-like transitions, unwanted transitions between different parts, etc., resulting in covered panels that are pressed using This pressing element also has the desired surface structure and can therefore be very aesthetic. For example, the pressing element may have relatively deep valleys, for example valleys of more than 0.15 mm or more than 0.30 mm deep and without sharp structures and/or the pressing element may comprise microstructures ranging between, for example, 5 and 30 microns, whereby these microstructures are applied very precisely. In other words, using the above-mentioned method, a press element with a very high precision can be obtained.

In a specific embodiment, said surface treatment comprises at least one etching treatment, wherein this etching treatment preferably comprises two or more

BE2022/5454 comprises sub-steps in which an etching liquid is each time brought into contact with the said surface.

Furthermore, preferably etching parameters of the etching treatment - such as the etching liquid used, the temperature of the etching liquid, the flow of the etching liquid, etc. - are identical in the two or more sub-steps mentioned, or at least differ per one etching parameter. For example, the etching fluids used in the two or more sub-steps mentioned may be identical, or at least differ per two. Using two or more different etching liquids, one can determine very accurately in which substeps certain parts of the mask, for example the edge parts, will degrade and/or how fast the degradation occurs and/or how gradually the degradation takes place. The etching of material from the base element can therefore take place very accurately, so that the pressed element has the desired structure. You can also etch very precisely using parameters such as temperature, current, etc. By working with sub-steps, you can etch more precisely and thus obtain a press element with a very high precision.

Even further preferably, in two sub-steps, which may or may not follow each other directly, i.e. a first sub-step and a second sub-step hereinafter, the etching parameters differ at least for one parameter, whereby the edge portions at least partially break off during the first sub-step and the edge portions are complete. broken off after the second sub-step, and wherein the internal portions still cover the same portion of the surface of the base metal element after the second sub-step. For example, the edge portions are gradually broken down, for example from the adjacent uncovered portions to the adjacent internal portions, as a result of which the pressing plate obtains the desired structure.

The mask is also preferably partially broken off during one or more sub-steps mentioned. Furthermore, preferably the edge portions break off completely during one or more sub-steps mentioned, gradually from the respective uncovered portions to the respective internal portions.

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Also preferably, during one or more sub-steps mentioned, at least the edge portions break off almost completely. During the etching treatment, the surface at the edge portions is exposed and is therefore also etched, but less than the uncovered portions.

In a preferred embodiment, the mask is heterogeneous by one or more of the following differences from the list including: thickness, chemical composition, amount of curing, bond strength to the surface.

In a specific embodiment, the mask is printed on the surface, preferably printed digitally. With the help of printing, and even more so with the help of digital printing, the desired mask can be applied very specifically and accurately. The correct position of the mask can also be obtained with printing. It is also possible to print different thicknesses, for example by using a greyscale system and/or printing multiple layers on top of each other. The chemical composition during printing can also be chosen. For example, one can print with at least two types of ink/material with a different chemical composition, in order to obtain a mask with said edge parts with a first chemical composition and said internal parts with a second chemical composition.

Furthermore, preferably the mask is printed on the surface with different thicknesses.

This is possible, for example, by printing only one layer in certain places and printing two or more layers on top of each other in several places and/or by changing the print flow rate, i.e. the amount of ink per time, and/or by changing the print head and/or or make the metal base element move faster or slower during application of the mask and/or by using a greyscale system.

In a specific embodiment, the mask comprises at least one curable substance, wherein the mask, after being applied to the surface, is hardened and wherein the hardening occurs or is uneven, so that the mask comprises parts with a higher degree of hardening and parts with a lower degree of hardening . Parts with

17 BE2022/5454 a higher degree of hardening may be more resistant to the etching treatment than the parts with a lower degree of hardening. The amount of hardening of parts of the mask will therefore determine how resistant these parts are to the etching treatment.

This makes it possible to determine which parts will break off during the etching treatment and also when during the etching treatment, so that the obtained press element has the desired structure and the desired structure can be applied very accurately using etching. Curing can, for example, take place using heat /

UV radiation / visible light / laser. A different amount of hardening can be achieved, for example, by exposing certain places to a hardening source for a longer or shorter period of time and/or by providing materials that harden faster or less quickly.

Furthermore, the curing of the mask preferably takes place with the aid of a curing source, where, for example, this curing source comprises a digitally controlled curing beam and/or the curing source is controlled in register with the applied mask. Curing can take place here in register. For example, the mask may contain markings, with curing taking place on the basis of these markings. It is also possible that the applied mask is first scanned and curing takes place on this basis, so that for example the edges of the mask, i.e. the edge parts mentioned, are hardened less than the internal parts mentioned.

In a specific embodiment, the mask is manufactured by at least sprinkling powder on the surface and fusing this powder to the surface at the desired locations using a laser source. This powder can be applied to the surface in such a way that the thickness is homogeneous, or that the thickness is heterogeneous and therefore in certain places where a thicker mask is desired, there is more powder per amount of surface.

Using the laser source, the powder can be attached to the surface, with or without different adhesion strengths. Due to the difference in adhesion strength and/or the difference in thickness due to the amount of powder per surface, the mask is heterogeneous.

In places where the powder was not adhered to the surface, the powder can be removed again.

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This invention also concerns a pressing element for manufacturing covered panels, more specifically a laminate panel, wherein this pressing element comprises a metal base element with a surface structure obtained by a surface treatment, wherein this surface treatment preferably comprises at least one etching treatment, wherein this etching treatment preferably comprises two or more comprises several sub-steps, in which an etching liquid is each time brought into contact with the metal base element, wherein this surface structure at least comprises one or more base parts that together form a base surface and one or more structure parts that form protrusions relative to the base surface, wherein the base parts preferably merge gently into the structural parts.

This pressing element is preferably obtained using a method as described above. All advantages and preferred embodiments of the method described above therefore apply to this pressing element. This pressing element can have a very high precision, so that very aesthetic covered panels can be manufactured using this pressing element.

Further preferably, the structural portions include one or more foot portions and one or more central portions, wherein the one or more central portions are each completely surrounded by adjacent one or more foot portions, and the one or more foot portions extend between adjacent one or more base portions, and adjacent one or more central parts, where the central parts are located at a maximum distance from the ground plane, viewed in a direction perpendicular to the ground plane or perpendicular to a tangent to the ground plane, and where the maximum distance from the foot parts to the ground plane , from the adjacent base part to the adjacent central part, increases gradually and preferably with a constant increase. The increase here is continuous and therefore not gradual and/or with sharp angles. This is very interesting to obtain covered panels with deep structural parts, with a maximum depth of more than 0.1 mm, preferably more than 0.3 mm and even more preferably deeper than 0.5 mm. This is also very interesting for microstructures, as these microstructures have a very high value here

19 BE2022/5454 can have precision, so that a coated panel obtained with such a pressed element has the desired gloss levels and transitions between gloss levels.

For example, the maximum distance between the top of a said central portion and the base portion may be at least 0.1 mm, preferably at least 0.3 mm and most preferably at least 0.5 mm and/or the maximum distance between the top of a said central portion and the base portion may for example be at most 30 microns, preferably at most 15 microns.

Preferably, the transition between the foot parts and the base parts has the shape of a rounded obtuse corner.

Also preferably, the foot portions form part of the flanks of the structural portions or co-form the flanks of the structural portions, wherein these flanks are free of sharp points and preferably each extend substantially at a constant angle of inclination with the ground plane.

This invention also concerns a coated panel, more specifically laminate panels, wherein the top surface of the coated panel comprises a surface structure with one or more base portions, each extending in substantially the same base plane and one or more recesses, these one or more recesses preferably being sloping. transition into one or more basic parts.

Such a covered panel is preferably obtained using a pressing step carried out with a pressing element as shown above, whereby this pressing element is preferably obtained using a method as described above. The advantages and embodiments described for the method and the pressing element therefore apply to this covered panel.

Preferably, in this clad panel, the recesses comprise one or more edge portions and one or more internal portions, wherein the one or more internal portions are each completely surrounded by adjacent one or more edge portions,

20 BE2022/5454 and the one or more edge parts extend between adjacent one or more base parts, and adjacent one or more internal parts, whereby the internal parts are located at a distance from the base plane, viewed in a direction perpendicular to the base plane and where the distance of the edge portions to the base plane, from the adjacent base portion to the adjacent internal portions, gradually increases. This is a very aesthetic looking covered panel. When the coated panel is obtained using a pressing step performed with a pressing element as shown above, the position of the edge portions and the internal portions of the coated panel corresponds to the position of the edge portions and the internal portions of the mask applied to the press element.

For example, the maximum distance between the bottom of a said internal part and the base part can be at least 0.1 mm, preferably at least 0.3 mm and most preferably at least 0.5 mm and/or the minimum distance between the bottom of a said internal portion and the base portion may for example be at most 30 microns, preferably at most 15 microns.

Furthermore, the transition between edge portions and the base portions preferably has the shape of a rounded obtuse corner.

With the aim of better demonstrating the features of the invention, some preferred embodiments are described below, as an example without any limiting character, with reference to the accompanying drawings, in which: figure 1 is a schematic representation of a cross-section of a pressing plate according to the invention; figure 2 is a schematic representation of a cross-section of a metal base element on which a mask has been applied for manufacturing the press plate shown in figure 1, according to a first embodiment of a method according to the invention; figure 3 is a schematic representation of a cross-section of a metal base element on which a mask has been applied for manufacturing the press plate shown in figure 1, according to a second embodiment of a method according to the invention;

BE2022/5454 - figure 4 is a schematic representation of a cross-section of a metal base element on which a mask has been applied for manufacturing the press plate shown in figure 1, according to a third embodiment of a method according to the invention; figure 5 is a schematic representation of a cross-section of a metal base element on which a mask has been applied for manufacturing the press plate shown in figure 1, according to a fourth embodiment of a method according to the invention; - figure 6 is a schematic perspective representation of a part of a covered panel according to the invention, obtained with a press plate as shown in figure 1; figure 7 is a schematic representation of a perspective representation of a part of a press plate according to the invention.

The press plate 1 described here is provided to form covered panels 4 with deep structures 7, being indentations 7 with a maximum depth of more than 0.15 mm, preferably more than 0.3 mm. However, this invention is not limited to this. Thus, this invention also relates to pressed plates/coated panels with microstructures and also to pressed plates/coated panels with microstructures and with high/deep structures. The pressing plate 1 here comprises a base section that forms a base surface and one or more structure sections 8 that form protrusions relative to the base surface, wherein the base section merges gently into the structure sections 8. The structure sections 8 each comprise a foot section 8b and a central section 8a, wherein each central portion 8a is each completely surrounded by the adjacent base portion 8b, and each foot portion 8b extends between the base portion and the adjacent central portion 8a. The difference between the foot parts 8b and the central parts 8a is not visible in the resulting press plate 1. This is shown via lines in figure 1. This is possible because the foot parts 8b extend at the level of the edge parts 3b of the sheet that break off during the surface treatment. the mask 3 (see below) and the central portions 8a extend at the level of the internal portions 3a of the mask 3 (see below) such that the position of said foot portions 8b and the central portions 8a correspond to the positions of the edge portions 3b and the internal parts 3a of the mask 3.

22 BE2022/5454

The press plate 1 shown schematically in figure 1 has a maximum height h and can be obtained in various ways. With the help of figures 2 to 5, 4 possible methods are discussed below, all of which concern methods according to the invention.

All these methods have the following features in common:

It always concerns a method for manufacturing a structured pressing element 1, wherein these methods comprise at least the following steps: - providing a metal base element 2 with a height h, being a plate comprising a surface to be structured, wherein the plate is manufactured made of steel, for example, with an optional copper coating on the surface to be structured. The metal base elements 2 shown here are plate-shaped, but cylindrical metal base elements are also possible, for example, to obtain structured press rolls (not shown here). - applying a mask 3 to a surface of the metal base element 2, wherein the mask 3 has a certain resistance to a surface treatment in order to shield the surface from the surface treatment at the level of the mask 3; - carrying out of the surface treatment; -removing the mask 3; wherein said mask 3 has a heterogeneous structure, and at least this structure determines the degree of said resistance to the surface treatment.

In these methods, the surface treatment includes at least an etching treatment.

This etching treatment comprises two or more sub-steps, wherein in each sub-step the surface mentioned is brought into contact with an etching liquid and this by, for example, placing the metal base element 2 with the mask 3 applied to it in an etching bath containing an etching liquid in such a way that the surface and the mask 3 come into contact with the etching liquid. For example, the metal base element 2 can be immersed in the etching liquid at each substep for a number of minutes,

23 BE2022/5454 for example 1, 2, 3, 4, 5, 6 or more minutes. The etching liquid can also be sprayed onto the metal base element 2.

As visible in figures 2 to 4, the mask 3 divides the said surface of the metal base element 2 into one or more covered parts, on which the mask 3 is located, and one or more uncovered parts, on which no mask 3 is located, and, the mask 3 comprises a plurality of edge portions 3b and a plurality of internal portions 3a, wherein the internal portions 3a are each completely surrounded by adjacent edge portions 3b, and the edge portions 3b extend between adjacent one or more exposed portions of the surface, and adjacent one or more internal parts 3a of the mask 3.

Figure 5 shows that the entire surface is covered with the mask 3, with certain parts only covered with a thin base layer 3c. Given the small thickness of this base layer 3c and given that this base layer 3c will quickly disappear during the surface treatment, for the sake of simplicity we also refer to the parts of the surface that are only covered by the base layer 3c as uncovered parts as described above. Here too, there are mentioned uncovered parts and covered parts. Furthermore, the mask 3 comprises protrusions 3d with respect to the base layer 3c, wherein these protrusions 3d also comprise said edge portions 3b and internal portions 3a (not shown in the figure), wherein the edge portions 3b are located between the adjacent base layer 3c and adjacent internal portions respectively. 34 stretch. Figures 2 to 5 are therefore discussed together below.

The masks 3 shown in figures 2 to 5 all have a heterogeneous structure, so that the resistance of the mask 3 is not the same everywhere and the etching treatment will not or will be able to remove material from the metal base element 2 in certain places. In places where the etching treatment is able to remove material, this can be done during the entire etching treatment and/or only from a certain sub-step and/or after a certain time.

24 BE2022/5454

As shown in Figure 2, the mask 3 is constructed from one material, for example a wax or a varnish or one ink, whereby the thickness of the mask 3 is heterogeneous. The construction of the mask 3 is such that at the said edge portions 3b, the thickness of the mask 3 increases from the respective adjacent uncovered portions to the adjacent internal portions 3a, this increase being gradual.

Due to this construction, the resistance of the edge portions 3b of the mask 3 increases from respective adjacent uncovered portions to respective adjacent internal portions 3a, gradually. The result is that during the etching treatment, the edge portions 3b start to degrade from the exposed portions towards the internal portions 3a, resulting in a pressing element 1 with sloping transitions between the base portions and the structural portions 8, with structural portions 8 comprising said foot portions 8b and central parts 8a. Since there is only a thickness difference here, and the material is always the same, the edge parts 3b and the internal parts 3a are not shown here as separate parts of the mask 3, since in practice the edge parts 3b and the internal parts 3a are not shown either. are visible as separate parts of the mask 3. In practice, only sloping bulges are visible.

In figure 3, the mask 3 always has approximately the same thickness, but the mask 3 is constructed from two materials, being a first material and a second material, whereby the resistance of the first material to the etching treatment is greater than the resistance of the second material to the etching treatment. etching treatment. The edge portions 3b are constructed from the second material and the internal portions 3a are constructed from the first material. The result is that during the etching treatment, the edge portions 3b start to degrade from the exposed portions towards the internal portions 3a, resulting in a pressing element 1 with sloping transitions between the base portions and the structural portions 8, with structural portions 8 comprising said foot portions 8b and central parts 8a. For example, it is possible that an etching liquid is used during a sub-step of the etching treatment, where the second material is not resistant to this liquid and the first material is resistant or is more resistant than the second material. The result is that during this substep at least the second material and therefore at least the edge portions 3b degrade. There can then be

25 BE2022/5454 involves an additional sub-step, in which the surface at the level of the edge parts 3b that have disappeared is processed. The surface treatment may optionally include additional treatments such as sandblasting, for example to gradually reduce the thickness of the mask 3 at the edge portions 3b towards the uncovered portions, prior to the etching treatment. This additionally ensures that the edge portions 3b will gradually decrease, from the uncovered portions towards the internal portions 34, so that the transitions between the resulting foot portions 8b and central portions 8a of the pressing element 1 are very sloping.

In Figure 4, the thickness of the mask 3 is heterogeneous. The construction of the mask 3 is such that at the said edge portions 3b, the thickness of the mask 3 increases from the respective adjacent uncovered portions to the adjacent internal portions 3a, this increase being gradual. Furthermore, the mask 3 is constructed from two materials, being a first material and a second material, whereby the resistance of the first material to the etching treatment is greater than the resistance of the second material. The edge portions 3b are constructed from the second material and the internal portions 3a are constructed from the first material. The result is that during the etching treatment, the edge portions 3b gradually degrade from the exposed portions towards the internal portions 3a, resulting in a pressing element 1 with sloping transitions between the base portions and the structural portions 8, with structural portions 8 comprising said foot portions 8b. and central portions 8a.

As shown in Figure 5, the mask 3 is constructed from one material, for example a wax or a varnish or one ink, whereby the thickness of the mask 3 is heterogeneous. The construction of the mask 3 is such that at the said edge portions 3b, the thickness of the mask 3 increases from the respective adjacent uncovered portions to the adjacent internal portions 3a, this increase being gradual.

Furthermore, the mask 3 always comprises a base layer 3c that covers the entire surface of the surface, such that the edge portions 3b always merge into the base layer 3c.

Due to this construction, the resistance of the edge portions 3b of the mask 3 increases from respective adjacent uncovered portions to respective adjacent

26 BE2022/5454 internal parts 3a, and here gradually. The result is that during the etching treatment, the base layer 3c degrades almost immediately and the edge portions 3b start to degrade from the exposed portions towards the internal portions 3a, resulting in a pressing element 1 with sloping transitions between the base portions and the structure portions 8, with structure portions 8 comprising said foot portions 8b and central portions 8a. Another option is to carry out another type of surface treatment prior to the etching treatment, such as sandblasting, polishing, or a laser treatment - such as laser ablation - in which the base layer 3c of the mask 3 is removed. For example, the removal of the base layer 3c can take place in 1 register.

Using the pressing element 1 as obtained using the above-mentioned methods, a laminate panel 4 can be pressed. This laminate panel 4 comprises, for example, a hard core/substrate 6 made of, for example, MDF, HDF, a mineral-based plate, a thermoplastic-based plate, whereby a top layer 5 comprising one or more sublayers is applied on top of this hard core/substrate 6. these sublayers may include resin impregnated papers, thermoplastic layers, etc. The press plate 1 is here able to transfer its relief to the top layer 5. The result is a top layer 5 comprising a base surface 9 and sloping recesses 7 relative to this base surface 9.

Claims (22)

27 BE2022/5454 Conclusions. 1. Method for manufacturing a structured press element (1), wherein this method comprises at least the following steps: - providing a metal base element (2), such as a plate or a roller; - applying a mask (3) to a surface of the metal base element (2), whereby the mask (3) has a certain resistance to a surface treatment in order to at least temporarily remove the surface at the level of the mask (3) to screen the surface treatment;, -carry out the surface treatment; characterized in that said mask (3) has a heterogeneous structure, and at least this structure determines the degree of said resistance to the surface treatment. Method according to claim 1, wherein the mask (3) divides said surface of the metal base element (2) into one or more covered parts, on which the mask (3) is located, and one or more uncovered parts, on which there is no or virtually no mask (3), and, wherein the mask (3) comprises one or more edge portions (3b) and one or more internal portions (3a), wherein the one or more internal portions (3a) are each completely surrounded by adjacent one or more edge portions (3b), and the one or more edge portions (3b) extend between adjacent one or more uncovered portions of the surface, and adjacent one or more internal portions (3a) of the mask (3), wherein the method includes one or more of the following features, as long as they are not contradictory: - the structure of the mask (3) is such that at least one edge part (3b) mentioned, the resistance to the surface treatment increases from a respectively adjacent uncovered portion to a respective adjacent internal portion (3a), preferably gradually increasing; - the structure of the mask (3) is such that at least one edge part (3b) mentioned, the thickness of the mask (3) increases from a 28 BE2022/5454 respectively adjacent uncovered part to a respective adjacent internal part (3a), preferably gradually increases; - the construction of the mask (3) is such that the resistance to the surface treatment at the level of at least one said internal part (3a) is higher than the resistance to the surface treatment at the level of a respective adjacent edge part (3b); -the chemical composition of a said edge portion (3b), differs from the chemical composition of a respective adjacent internal portion (3a); - the mask (3) is made of at least one hardenable substance, wherein the degree of hardening at the level of a mentioned edge part (3b) is lower than the degree of hardening at the level of a respective adjacent internal part (3a); - said one or more edge portions (3b) all have the same first chemical composition and said one or more internal portions (3a) all have the same second chemical composition, wherein the first chemical composition is less resistant to the surface treatment than the second chemical composition; - the mask (3) is at least printed on the surface and use is made of at least two print heads, each equipped with printing an ink with a different composition, in order to print a heterogeneous mask (3), preferably with the edge parts (3b) are printed with one mentioned print head and the internal parts (3a) are printed with the other mentioned print head. 3. Method according to claim 1 or 2, wherein the surface treatment comprises one or more of the following treatments: an etching treatment, a sandblasting treatment or a polishing treatment. Method according to any of the preceding claims, characterized in that said surface treatment comprises at least one etching treatment, and wherein this etching treatment preferably comprises two or more sub-steps, 29 BE2022/5454 in which an etching liquid is each time brought into contact with the said surface. 5. Method according to claim 4, characterized in that etching parameters - such as the etching liquid used, the temperature of the etching liquid, the flow of the etching liquid, etc. - are identical in said two or more sub-steps, or at least different for one etching parameter are. 6. Method according to claim 5, wherein in two sub-steps, which may or may not follow each other directly, i.e. a first sub-step and a second sub-step mentioned below, the etching parameters differ for at least one parameter, whereby the edge portions (3b) are at least partially breaking off and the edge portions (3b) being completely broken off after the second sub-step, and the internal portions (3a) still covering the same portion of the surface of the base metal element (2) after the second sub-step. Method according to one or more of claims 4 to 6, characterized in that the mask (3) partially breaks off during one or more said sub-steps. Method according to one or more of claims 4 to 7, characterized in that during one or more said sub-steps at least the edge portions (3b) break off almost completely. Method according to one or more of the preceding claims, wherein the structure of the mask (3) is heterogeneous due to one or more of the following differences from the list including: thickness, chemical composition, amount of curing, bond strength with the surface. Method according to any of the preceding claims, characterized in that the mask (3) is printed on the surface, preferably printed digitally. 30 BE2022/5454 Method according to claim 10, wherein the mask (3) is printed with different thicknesses on the surface. Method according to one of the preceding claims, characterized in that the mask (3) comprises at least one hardenable substance, wherein the mask (3), after being applied to the surface, is hardened and wherein the hardening is uneven, so that the mask (3) comprises parts with a higher degree of curing and parts with a lower degree of curing. 13. Method according to claim 12, wherein the curing of the mask (3) takes place using a curing source, wherein, for example, this curing source is controlled digitally, for example comprising a digitally controlled curing beam, and/or the curing source is controlled in register with the applied mask (3). 14. Press element (1) for manufacturing covered panels (4), more especially laminate panels (4), wherein this press element (1) comprises a metal base element (2) with a surface structure obtained by a surface treatment, wherein this surface treatment preferably has a comprises etching treatment, wherein this surface structure at least comprises one or more base parts that together form a base surface and one or more structure parts (8) that form bulges relative to the base surface, wherein the base parts preferably merge gently into the structure parts (8). 15. Press element (1) according to claim 14, wherein the structural parts (8) comprise one or more foot parts (8b) and one or more central parts (8a), wherein the one or more central parts (8a) are each completely surrounded by adjacent one or more foot portions (8b), and the one or more foot portions (8b) extend between adjacent one or more base portions, and adjacent one or more central portions (8a), with the central portions (8a) being at a maximum distance of the ground plane, viewed in a direction perpendicular to the ground plane or perpendicular to a 31 BE2022/5454 tangent to the base, and whereby the maximum distance of the foot parts (8b) to the base, from the adjacent base part to the adjacent central part (8a), increases gradually, preferably with a constant increase. Press element (1) according to claim 14 or 15, characterized in that the maximum distance between the top of a said central part (8a) and the base part is at least 0.1 mm, preferably at least 0.3 mm and most preferably preferably at least 0.5 mm and/or wherein the maximum distance between the top of a said central portion (8a) and the base portion is at most 30 microns, preferably at most 15 microns. Press element (1) according to one of claims 14 to 16, characterized in that the transition between the foot parts (8b) and the base parts has the shape of a rounded obtuse corner. Press element (1) according to one of claims 14 or 17, wherein the foot parts (8b) form part of the flanks of the structural parts (8) or form part of the flanks of the structural parts (8), wherein these flanks are free from sharp spiers and preferably each extending essentially at a constant angle of inclination with the ground plane. 19. Press element (1), optionally according to one or more of claims 14 to 18, wherein the press element (1) is obtained according to a method according to one of claims 1 to 13. 20. Clad panel (4), more particularly a laminate panel (4), wherein the upper surface of the clad panel (4) comprises a surface structure with one or more base portions (9) each extending in substantially the same base plane and one or more recesses (7), wherein these one or more recesses (7) preferably merge gently into the one or more base parts (9). 32 BE2022/5454 21. Clad panel (4) according to claim 20, wherein the recesses (7) comprise one or more edge portions and one or more internal portions, the one or more internal portions each being completely surrounded by adjacent one or more edge portions, and the one or more edge portions extend between adjacent one or more base portions (9), and adjacent one or more internal portions, wherein the internal portions are at a distance from the base plane, viewed in a direction perpendicular to the base plane and where the distance of a said edge portion to the base plane, from the respective adjacent base portion (9) to the respective adjacent internal portion, gradually increases. 22. Covered panel (4), optionally according to claim 20 or 21, wherein the covered panel (4) is obtained by pressing with a pressing element (1) according to any of claims 14 to 19.