BE1030429B1 - Panels and method for manufacturing panels using a laser - Google Patents

Abstract

Method for manufacturing one or more panels (1), of the type with at least two layers and of which said layer is a top layer (2) based on plastic, wherein a plate is formed comprising said layers, and wherein the one or more several panels (1) are formed from this plate by carrying out one or more processing steps, whereby at least one said processing step is a laser processing, and where during this laser processing at least the top layer (2) is exposed to a laser beam from a laser, to form of one or more markings (3), whereby the one or more markings (3) form at least discolorations of the top layer (2) and such a panel (1).

Description

1 BE2022/5253

Panels and method for manufacturing panels using a laser

This invention concerns a method for manufacturing one or more panels, of the type with at least two layers and of which said layer is a top layer based on plastic, wherein a plate is formed comprising said layers, and wherein the one or more panels are formed from this plate by carrying out one or more processing steps, wherein at least one said processing step is a laser processing, and wherein during this laser processing at least the top layer is exposed to a laser beam from a laser, to form one or more markings.

This invention also concerns such a panel.

In particular, the invention relates to a method for manufacturing floor panels, wall panels or furniture panels. The panels are often of the type that have a plastic-based top layer. It is known that such panels can be of different construction, for example these panels can be laminate panels, where the top layer, for example, comprises a resin-impregnated paper, being a so-called 'overlay' or wear layer; e parquet panels or veneer parquet panels, comprising a wood layer on which one or more protective layers, such as resin-based lacquer layers, have been applied to protect the wood layer. The resin may be, for example, an acrylic resin, an alkyd resin, a polyurethane resin, a melamine-containing resin, an acrylate resin, a methacrylate resin, an epoxy resin, a polyester resin, a polyether resin or a mixture of the aforementioned resins. This resin can be a multi-component resin and/or a thermosetting resin and/or an aqueous dispersion with or without crosslinking system and/or a UV polymerizing resin.

The one or more protective layers form the top layer here; e panels based on polyvinyl chloride (PVC), such as LVT (luxury vinyl tile),

WPC (wood plastic composite), EPC (expanded polymer core), SPC (solid particle core), etc.;

2 BE2022/5253 e panels comprising a mineral-based substrate, such as a gypsum, magnesium oxide (MgO) or cement-based substrate, and a plastic-based top layer, e panels comprising a geopolymer-based substrate and a plastic-based top layer; e panels based on a plastic, where this plastic is not PVC, for example based on polyethylene terephthalate (PET), polyethylene (PE), polypropylene (PP), BMC (bulk mounding compound) based on unsaturated polyesters, polycarbonate (PC) , acrylonitrile butadiene styrene (ABS), styrene-ethylene-butylene-styrene (SEBS), polylactic acid (PLA), polyvinyl buteral (PVB), etc.

These panels often include a motif, such as a wood motif or a stone motif, for example a marble motif. This motif can be an imitated wood motif or stone motif. For example, laminate panels or PVC-based panels are provided with a decor, for example a decorative layer in the form of a resin-impregnated printed paper, a printed PVC layer or a printing layer largely comprising ink. Parquet panels or veneer parquet panels use a natural wood layer containing a real and natural wood motif. The disadvantage of existing panels is that, in the case of an imitated motif, the appearance of the panel can be synthetic.

With parquet panels or veneer parquet panels, the appearance of the wood layer can be changed in such a way that the appearance is less aesthetic by applying one or more protective layers.

There are already all kinds of techniques to improve the appearance of these panels.

However, there is still room for improvement.

WO 2006/063803 describes a floor panel, wherein this floor panel contains a top layer based on plastic, and wherein the decorative side of the floor panel imitates a wood motif, whereby the floor panel on its upper surface shows zones of different degrees of gloss that extend over the upper surface according to function of the imitated global wood motif. By working with zones of different

3 BE2022/5253 gloss levels, an extra dimension is added to the floor panel, which better displays hard-to-imitate wood types.

From WO 01/96689 it is known to provide a relief in the top of a laminate product that may or may not correspond to the decor. This relief is applied, for example, using an embossed press plate. Such a laminate product is known from EP2834076 with a better, i.e. a less synthetic, appearance.

The present invention primarily aims at an alternative method for manufacturing panels, of the type with at least two layers and of which one said layer is a top layer based on plastic, wherein, according to various embodiments, solutions are offered to the problems arising from the state of the art.

The invention concerns a method for manufacturing one or more panels, of the type with at least two layers and of which said layer is a top layer based on plastic, wherein a plate is formed comprising said layers, and wherein the one or more panels are formed from this plate by carrying out one or more processing steps, wherein at least one said processing step is a laser processing and whereby during this laser processing at least the top layer is exposed to a laser beam from a laser, to form one or more markings, and where Preferably the one or more marks form at least discolorations of the top layer. The laser mentioned can, for example, be a UV laser or a laser that emits green light, a so-called 'green laser'. Since at least the top layer is exposed to a laser beam from a laser, at least parts of the top layer are processed during the laser processing to form one or more markings. Discolorations here indicate deviations based on color compared to the visible color of the top layer prior to laser processing. The visible color at the top layer indicates the color that is visible when we view the top of the panel. The deviations mentioned can be, for example, a color enhancement,

4 BE2022/5253, for example, darker or lighter discolourations, but there may also be differences in color shades compared to the original visible shade at the marking. The discolorations are therefore changes based on hue and/or intensity and/or brightness. The markings here may or may not be separately visible to the naked eye. It is possible that the markings only change the overall perception of the panel, but it is, for example, impossible or difficult to distinguish with the naked eye where exactly the markings have been applied. The discolorations can therefore be subtle discolorations that contribute to the general appearance of the panel.

A UV laser emits one or more laser beams in the UV spectrum and therefore emits light with a wavelength between approximately 100 nm and approximately 400 nm. This concerns high-energy light that is able to process at least the top layer and virtually without the formation of additional heat. With the help of a UV laser, one can work very precisely to apply the desired markings without damaging the surrounding parts of the panel. In addition, with the help of a UV laser, the depth can be set very precisely and you can also make marks through different layers or sublayers. A UV laser allows precision down to the micrometer and even submicrometer. For example, with a selected pulse length and spot size, power, speed and frequency can be adjusted to obtain the desired markings. A 'green laser' emits one or more laser beams with a wavelength between 495 nm and 570 nm and therefore emits visible green light.

By working with a laser to apply markings, there are also no mechanical parts that need to come into contact with the top layer to apply these markings. The top layer can, for example, contain wear-resistant particles, such as corundum or aluminum oxide, which can damage mechanical parts and/or cause rapid wear of mechanical parts. A UV laser and a 'green laser' require little maintenance. Both can be used at room temperature and/or the temperature present during the production of the panels, so that the laser processing does not necessarily have to take place in a different room and/or in a temperature-conditioned room.

You can choose to work with very short pulse lengths, for example 5 pulse lengths of a few nanoseconds, in order to apply local and very controlled markings, for example by removing local material with the laser beam and/or changing the material structure.

Surprisingly, it was found that a UV laser is particularly suitable for processing top layers based on plastic. Plastics are highly absorbent

UV spectrum and only absorb at the level of the laser beam, so that surrounding parts are not damaged. The laser can, for example, be an excimer laser that, for example, radiates a laser beam with a wavelength between 157 nm and 360 nm.

The mentioned markings can be all kinds of marking types and all kinds of combinations of marking types are possible, as long as they are not contradictory.

The mentioned one or more markings may include one or more markings from the non-exhaustive list below, as long as they do not contradict each other: e words and/or logos and/or decorative images. This is useful, for example, when the panels are floor panels, wall panels or furniture panels that are used in companies or public spaces. Such floor panels, wall panels or furniture panels may also be desirable to provide the interior with eye-catching elements; e relief-forming marks, such as notches/recesses. With the help of the above-mentioned lasers, which work with mirrors, for example, pits/spots can be selectively applied, whereby line-shaped notches, wider notches, etc. can be made by choosing the movement of the mirrors. With the help of such markings, a relief is formed, for example at the top of the panels. These markings can also be used to obtain the relief present on the top of the panels

6 BE2022/5253 further optimizing/refining other embossing techniques, such as relief obtained using a press plate or using chemical means. For example, one can obtain a basic relief using a relief technique and then further personalize and/or optimize and/or refine this basic relief using laser processing, for example by updating and/or coloring the existing relief. . For example, there may be 'embossing-in-register'. In this way the appearance of the panels is optimized/improved; e relief accentuating markings. These markings can be used to further optimize/refine the relief present at the top of the panels obtained by other embossing techniques, such as relief obtained using a press plate or using chemical means. this by coloring the relief in a targeted manner.

In addition, these relief-accentuating marks can further adjust/refine the relief. e accentuating marks, where these marks, for example, accentuate certain parts of the wood motif such as knots, imperfections, pores, etc.; e colorable markers, such as stainable markers. These colorable markings ensure that pigments or dyes can penetrate into the top layer and/or the laser processing can form colorable indentations by removing material from the top layer or changing the structure of the material in the top layer. This means that the top layer can be colored locally using one or more markers. This is useful if you want to obtain certain effects. You can even leave the coloring to the person installing the panels, so that the appearance of the panels can be adjusted afterwards; e roughness-providing marks. These markings impart a certain roughness to the top layer. This may or may not be accompanied by the removal or ablation of the plastic material present in the top layer; e gloss-providing marks. For example, a mirror effect can be created by lasering fine lines at a small distance:

7 BE2022/5253 the light on the surface is reflected more in one specific direction and the reflection is lower in other directions. The reflection direction can be controlled in a specific direction for each individual part; e corrective markings. With plates comprising a top layer based on one or more layers of impregnated paper, it is possible that the paper tears during pressing and imperfections, such as white lines of the paper or even the substrate under the layer comprising the paper, become visible. You can opt to treat the top layer at the area of these imperfections with the laser in order to obtain the desired color; e underground markings. This is called 'subsurface laser engraving' where, for example, color changes are achieved at the bottom of the top surface of the top layer.

Preferably, two or more panels are formed from the plate. For this purpose the plate is sawn or cut. A processing step mentioned here is a sawing step or cutting step for forming two or more base panels from which the two or more panels are formed by carrying out the remaining processing steps mentioned, such as a processing step in which the edges of the base panels are provided with coupling parts to secure the panels. can be interconnected. The said laser processing can be carried out prior to the said sawing step or cutting step, but preferably takes place after the said sawing step or cutting step. For example, the laser processing can be the last or one of the last processing steps. The laser processing is then not a limiting factor for the speed at which the other steps can be carried out. This also ensures that the panel includes the marking. One can also easily choose that not all panels formed from a sheet undergo the aforementioned laser processing. This is useful, for example, if the panels formed from the plate all comprise a different wood motif, where, for example, not all panels comprise a wood motif with parts that need to be accentuated. Of course, all panels can include at least one named marking.

8 BE2022/5253

The laser source of the laser is preferably located outside the working area of the laser beam. In such a configuration, the laser beam is guided over a stabilized optical path to, for example, a lens.

In a preferred embodiment, a short focal distance is used, for example a focal distance of less than 10 cm, in such a way that the power of the laser can be optimally concentrated on the top layer of the floor panel. “Focal distance” refers to the distance from the laser lens to the top layer.

In a preferred embodiment, the laser beam can be split into several laser beams on its optical path using a so-called "beam splitter". With the help of multiple laser beams, the laser processing can be performed faster and without having to provide an additional laser source.

The above does not rule out that additional laser operations are carried out with this method with other types of lasers, such as a CO: laser. The processing with another type of laser may or may not take place simultaneously with the first-mentioned laser processing. This can be useful, for example, if one wishes to form coupling parts using a different type of laser in order to interconnect the panels with each other.

According to a first deviating variant, the invention concerns a method for manufacturing one or more panels, of the type with at least two layers and of which said layer is a top layer, wherein a plate is formed comprising said layers, and wherein the one or multiple panels are formed from this plate by carrying out one or more processing steps, whereby at least one said processing step is a laser processing, and where during this laser processing at least the top layer is exposed to a laser beam from a laser, to form one or more markings, wherein said laser is, for example, a UV laser or a 'green laser' and wherein the one or more markings preferably form at least discolorations of the top layer. The top layer may or may not be based on this

9 BE2022/5253 plastic. For example, the top layer can be based on an oil. Such panels are, for example, oiled veneer parquet or oiled parquet. A top layer based on a

UV oil for a veneer parquet or parquet can be regarded as a top layer comprising a plastic or as a top layer based on plastic.

According to a second deviating variant, the invention concerns a method for manufacturing a floor covering, of the type with one or more layers and of which a said layer is a top layer based on plastic or not, wherein a base is formed comprising said layers , and where one or more processing steps are carried out on this basis to form the floor covering, wherein at least one said processing step is a laser processing, and where during this laser processing at least the top layer is exposed to a laser beam from a laser, to form one or more markings, wherein the said laser is preferably a UV laser or a 'green laser' and wherein the one or more markings preferably form at least discolorations of the top layer. The floor covering here can, for example, be wall-to-wall vinyl or a linoleum floor covering.

According to a third deviating variant, the invention concerns a method for manufacturing one or more panels, of the type with at least two layers and of which a said layer is a top layer based on plastic, wherein a plate is formed comprising said layers, and wherein the one or more panels are formed from this plate by carrying out one or more processing steps, wherein during a said processing step at least the top layer is processed to form one or more markings, wherein the one or more markings form at least discolorations of the top layer . This processing step may be a laser treatment that causes the mentioned discolorations.

However, other processing steps that cause discoloration of the top layer are possible. Some examples of such processing steps are: printing an ink, painting, staining, etc. The said processing step is therefore a coloring step in which the top layer is colored locally to form one or more markings.

10 BE2022/5253

The additional features of the embodiments of the first-mentioned method according to the invention described below can also be combined with the above-mentioned deviating variants, according to all non-contradictory combinations.

Preferably, the one or more markings form notches in the top layer, with these notches preferably only ending at the top. Opening at the top indicates that it opens at the top of the top layer, viewed in a height direction that extends perpendicular to the plane in which the panel extends. For floor panels, this height direction usually corresponds to the vertical direction. For furniture panels and/or wall panels, this height direction often corresponds to the horizontal direction. These notches are obtained, for example, with laser processing by removing material from the top layer and/or by locally pressing the top layer and/or locally changing the structure of the top layer.

With the help of the laser, the desired relief can be obtained and thus the desired appearance. Since we work here with, for example, a UV laser or a 'green laser' to form the notches, the notches can have all kinds of dimensions and, for example, very narrow, thin, smooth and/or serrated notches can be obtained. The notches preferably only extend at the level of the top layer, but this does not rule out the possibility that the markings can also extend through other layers. Due to the high precision, the panels can be avoided having a synthetic appearance. These notches can also form recesses.

For example, the notches, viewed in a direction perpendicular to a plane extending along the panel, may have a size of at most 20 micrometers, preferably at most 10 micrometers. Although these dimensions are small, viewed in height, they have a major influence on the appearance of the panel. Because these dimensions are small, the laser processing can be carried out sufficiently quickly while still achieving the desired end result.

If these notches are obtained via material removal, little material needs to be removed here, making additional extraction and/or a separate material removal step unnecessary, for example. When the top layer comprises a resin-impregnated paper, the paper becomes slightly thinner

11 BE2022/5253 dimensions not exposed to the laser beam of the laser. With these small dimensions, virtually no indentation is visually visible, but a color difference or color enhancement is visible, for example.

Preferably, the laser processing is used at least to remove material parts from the top layer and this, for example, to form the mentioned notches. Notches per se can also be formed, for example comprising an undercut using laser processing. The desired shape of the notches can be obtained, for example, by tilting the laser beam, adjusting and/or positioning the focus of the laser beam relative to the workpiece or the like.

However, material can also be removed over the entire thickness of the top layer by laser processing, preferably in the form of a cut extending through the top layer.

In a specific embodiment, a relief-providing operation takes place prior to the said laser processing, wherein during the relief-providing operation the plate is provided with a basic structure at least at the level of the top layer, wherein the said one or marks further refine and/or accentuate this basic structure . The laser processing may, for example, also be able to remove material from notches and/or color in notches that were already present prior to the laser step. These notches may already be present by carrying out the relief-forming processing step prior to the laser processing, and this by, for example, pressing the plate with a pressing plate comprising relief, a so-called structured pressing plate, and/or by chemical embossing "chemical embossing". The laser processing then optimizes, for example, the structure corresponding to this relief by, for example, optimizing and/or coloring the notches of the structure and by applying one or more markings. With the help of a pressing plate comprising a relief, a certain structure can already be applied to the visible side of the panel, but the shape of

12 BE2022/5253 this structure is limited, which can cause the appearance of the panel to feel synthetic.

The mentioned laser processing is able to further optimize this structure.

In a special embodiment, said marking is applied in such a way that a said panel includes this marking and that, viewed along a plane extending along the panel, this marking is largely enveloped by remaining areas of the top layer. One or more mentioned marks then largely do not extend at the level of an end edge. The laser treatment is therefore not or not exclusively an 'edge treatment' and is used to provide the top of the panels with the desired markings. Surprisingly, it was found that a UV laser is particularly suitable for applying such markings because the material of the panel that extends next to the markings is virtually unaffected by the laser beam of the UV laser. Naturally, there may be markings at the level of an end edge and/or that have been applied at the level of an end edge.

In a specific embodiment, the markings exhibit a white tint, gray tint or black tint. Darker shades are advantageous if the markings are used to accentuate knots, grains, etc. of the wood motif. For example, white tones are advantageous to imitate joints or to imitate veins of a marble motif. Dark shades and white shades are ideal for achieving a wenge effect.

In a special embodiment, pigments are added before or during the laser processing. In this way the markings obtain the desired color.

Specifically in this special embodiment, the pigments can be sprinkled on top of the top layer prior to or during exposing at least the top layer to the laser beam, so that the pigments that come into contact with the laser beam are fixed in the panel. After exposing at least the top layer to the laser beam, the other pigments that have not been fixed in the panel can be removed. This is a particularly efficient way to provide the markings with the desired color.

13 BE2022/5253

In a special embodiment, the markings are additionally colored after being applied and/or, if the markings are notches, at least partially filled in. This can be done with, for example, a paint, a stain, a varnish or the like. If the markings are notches, material can be applied to these notches.

In a preferred embodiment, only material is removed from the top layer during laser processing. This top layer can comprise one or more layers.

When there are multiple layers, preferably only material is removed from the top layer and/or the one or more markings are only applied at the level of this top layer. This concerns a superficial operation that can be performed with sufficient speed.

Preferably, the plate comprises a decorative layer that may or may not form part of the top layer, wherein the formed one or more panels also comprise said decorative layer. For example, the plate can comprise at least 3 layers, being a substrate layer, the decorative layer and the top layer, wherein the decorative layer extends between the substrate layer and the top layer, whereby the formed one or more panels also comprise the said layers. The decorative layer can, for example, be a resin-impregnated printed paper, a printed PVC layer, a wood layer such as a veneer, a printing layer largely comprising ink, etc. The decorative layer can, for example, comprise a wood motif, a stone motif, etc. The laser processing can be carried out in such a way that the laser beam does not contact the decorative layer and thus the decorative layer is not marked by the laser beam and the appearance of the decorative layer is not damaged. If the panels are laminate panels, they include, for example, the substrate layer or core, the decorative layer or decor, as well as the plastic-based top layer. The top layer usually consists of one or more carrier sheets, for example paper, which have been soaked in resin, for example a melamine resin, such as melamine formaldehyde. In such a case it is common to use the laminate as so-called “DPL” (Direct Pressure Laminate), where the top layer is pressed directly onto the core, or so-called “HPL” (High Pressure Laminate), where the top layer itself is obtained with a pressing operation. is applied in its entirety before the top layer is applied

14 BE2022/5253 the core is applied, to be carried out. Other options for forming such a top layer are also possible, for example by using foils, applying a substance to be hardened, such as a varnish or the like, or in any other way. The decor is usually printed, either directly on the core with the possible intervention of a primer, or on one or more of the aforementioned carrier sheets or on the aforementioned foil. Furthermore, the plate can also comprise a counter layer, which is applied directly or indirectly to the substrate, wherein the counter layer and the top layer extend on either side of the substrate. The counterlayer in a laminate panel is, for example, a paper soaked in resin, in the case of veneer parquet or parquet the counterlayer is for example a veneer or the counterlayer comprises wood parts, in the case of PVC-based floor panels the counterlayer includes, for example, PVC, such as foamed PVC.

In a specific embodiment, the top layer comprises one or more wear layers based on plastic, whereby this one or more wear layers extend on top of the decorative layer. Preferably, only the upper wearing layer is processed by the laser treatment and the laser processing is a superficial treatment, so that this upper wearing layer is not processed over the entire thickness, i.e. the dimension along the height direction perpendicular to the plane in which the panel extends.

Alternatively, material parts can be removed over the entire thickness of the one or more wear layers during the laser processing, so that the decorative layer is uncovered at the level of these removed material parts. The appearance of the decorative layer is then not locally influenced by the top layer. Of course, it is also possible that parts of material are removed from the decorative layer during laser processing.

Furthermore, in a preferred embodiment, the decorative layer comprises a motif, such as a wood motif or a stone motif, and the laser processing is performed based on this motif. There may be natural motifs, such as veneer parquet floor panels or parquet floor panels that include a natural wood motif. There may also be imitated motifs, such as laminate panels, vinyl-based panels, and the like that have a natural wood motif or a natural stone motif, such as a

15 BE2022/5253 marble motif, imitation. By carrying out the laser processing, i.e. applying one or more markings, on the basis of the motif mentioned, this motif is additionally accentuated and the appearance of the panel is thus optimized, so that the appearance of the panels is experienced as very aesthetic. . For example, the laser processing, i.e. the application of the one or more markings mentioned, if the motif is a wood motif, can be carried out on the basis of the spring wood present (early wood or spring wood) and/or the summer wood present (autumn wood or late wood) and/or pores and/or wood imperfections such as knots, brushed parts, etc. The laser processing, if the motif is a marble motif, can be carried out on the basis of the veins. After carrying out the laser step, you can opt to additionally color the markings applied by the laser in order to create a specific look, such as a patinating or coloring effect. The laser processing can be done in register for imitated motifs or on the basis of a scanned motif for natural motifs. With the latter, for example, the motif can be scanned using cameras prior to laser processing and then the markings can be applied based on the scanned motif. This way, the laser can be controlled based on what has been scanned. After scanning, indications can also be applied to the top layer at desired locations, whereby the laser processing is then carried out at the location of these indications by detecting these indications.

Even further preferably, the motif is a wood motif with one or more motif elements such as knots and/or cracks and/or cracks and/or pores, and during the laser treatment, at least the top layer at the level of one or more of the one or more motif elements is removed. , exposed to the laser beam of the laser to accentuate this one or more motif elements. The one or more markings mentioned here accentuate motif elements. For example, the laser processing can color these knots and/or cracks and/or cracks darker and/or remove material at the level of these knots and/or cracks and/or tears.

In a specific embodiment, the laser treatment forms zones with different degrees of gloss by applying said one or more marks. The

16 BE2022/5253 laser processing can also accentuate zones with different gloss levels, which were formed during a previous processing step. In this way, extra dimensions are created which contributes to an aesthetic appearance. This can help to create the appearance of veneer parquet or parquet while there is a natural wood layer present.

Furthermore, preferably in this latter specific embodiment, the zones with different degrees of gloss extend depending on the motif.

Furthermore, in a special embodiment, a relief-providing operation takes place prior to the said laser processing, wherein during the relief-providing operation the plate is provided with a basic structure at least at the level of the top layer, and wherein preferably the laser processing, by applying said one or more markings, the basic structure obtained by the relief-providing processing, is further refined and/or accentuated. Further refining the relief may include coloring the parts forming the relief and/or additionally removing material. For example, an extra mattifying effect can be achieved by coloring and/or an extra glossy effect can be achieved by polishing. Relief obtained with conventional methods is limited and often leaves much to be desired. By using laser processing, which is carried out after, for example, conventional methods of creating relief, the existing relief can be adjusted and/or discolored in order to perfect the appearance. The embossing operation can, for example, include a pressing operation with a structured pressing plate, a chemical operation 'chemical embossing' and/or a combination of both.

This relief-providing processing step is, for example, a pressing operation, wherein during the pressing operation the plate is pressed with a pressing plate comprising relief, so that the plate comprises a basic structure corresponding to the relief at the level of the top layer, and wherein preferably this laser operation is carried out by applying one or more markings mentioned, the basic structure obtained by the

17 BE2022/5253 press processing, further refined. A press plate comprising relief is also referred to by the term 'structured press plate'.

The basic structure mentioned is preferably based on the motif. When one panel is formed from the plate, this means that the basic structure is based on the motif of this panel. When one or more panels are formed from the plate, this means that the relief is preferably based on the motifs of these panels.

In a specific embodiment in which a said relief-providing operation takes place prior to the laser processing and wherein the panel comprises a said motif, during the relief-providing operation, elements comprising relief are added in one or more places, such as for example notches and/or protrusions, formed independently of the motif, and during the laser processing said one or more marks are applied at none, one or more of the said one or more places. The elements comprising relief are here independent of the motif. This indicates that the elements comprising relief are preferably not a reflection of the motif. Said markings are, for example, applied at one or more of the said one or more places. This indicates that during the formation of the panels, a choice is made in which of the mentioned places a marking will or will not be applied, i.e. a choice will be made in which of the mentioned places there will be discolouration of the top layer. The elements comprising relief, after applying a mentioned discoloration, preferably represent motif elements such as knots and/or cracks and/or veins. In other words, one can choose whether or not to present additional elements of a wood motif or a stone motif. The elements comprising relief are preferably designed in such a way that, if one chooses not to apply markings in certain places mentioned, the elements comprising relief have little influence on the appearance of the panel. The motif of the decorative layer therefore forms the basic motif here and one can choose whether or not to add additional elements to this basic motif.

This way you can obtain panels that have a different appearance, but each have the same basic motif. For example, with a wood motif you can:

18 BE2022/5253 have different panels with the same basic wood motif, but where one panel, for example, has an extra knot and the other panel, for example, has an extra crack, etc. In this way, the repetition of patterns can be avoided in so-called imitation motifs, for example in laminate panels or Vinyl-based panels reduce their size and there is less so-called repetition. The more named places there are per panel, the smaller the repetition. It is clear that the application of markings here is not limited to the mentioned laser processing and/or that this is not limited to panels. The above therefore also applies to the above-mentioned second deviating variant, and also to the above-mentioned third deviating variant of the invention, wherein the laser treatment is then replaced by another operation in which markings are applied that include discolorations of the top layer.

Preferably, the plate comprises at least three layers, being a substrate layer, the said decorative layer and the said top layer, wherein the decorative layer extends between the substrate layer and the top layer, wherein the formed one or more panels also comprise the said layers.

Specifically, for example, the substrate layer comprises a wood-based substrate, such as a wood fiber board or a chipboard, and the decorative layer and the top layer comprise a resin-impregnated paper. The resin is, for example, a thermosetting resin such as a melamine resin, a melamine formaldehyde resin, a urea formaldehyde resin, etc. The decorative layer comprises, for example, a decorative paper and the top layer comprises, for example, one or more papers, each of which is impregnated with a resin. Preferably, the top layer comprises thin transparent paper, so that the decorative layer is clearly visible. The resin of the top layer can also contain wear-resistant particles, such as corundum and aluminum oxide. For example, this concerns laminate panels. Preferably, no processing of the above-mentioned paper of the top layer takes place during the laser processing and only the resin is processed.

In another specific embodiment, the decorative layer comprises a wood layer and the top layer comprises one or more lacquer layers. There is a veneer if the wood layer is thinner

19 BE2022/5253 is then 2.5 mm. It is evident that in another embodiment the decorative layer can also comprise a wood layer of more than 2.5 mm, in which case it is parquet if the panel is a floor panel. Furthermore, the top layer preferably comprises two or more lacquer layers. These lacquer layers preferably comprise a resin such as an acrylic resin, an alkyd resin or a polyurethane resin. Surprisingly enough, it has been found that with the help of a UV laser, markings can be made in the lacquer layer, which optimizes the appearance of a panel, for example the veneer parquet floor panel or the parquet floor panel, while one or more lacquer layers still have the provide the panel with the necessary wear-resistant and resistant properties.

Also in a specific embodiment, the decorative layer is a PVC-based layer. This is, for example, the case with vinyl-based floor panels. The top layer can comprise a lacquer layer at the top that hardens, for example, under the influence of UV light and possibly one or more additional PVC layers. The top layer can also comprise only one or more PVC layers. Surprisingly, it has been found that with the help of a

UV laser, markings can be applied to this top layer to optimize the appearance of the panel. The top layer can, for example, comprise several layers, wherein a mentioned layer is a decorative layer, which may or may not extend centrally in the top layer.

The substrate layer may, for example, comprise a mineral-based substrate, such as a gypsum-based or cement-based substrate. For example, the substrate can be a plasterboard or a plasterboard. The substrate can be, for example, a fiber cement board or a magnesium oxide board. The substrate can also be based on a geopolymer.

In a special embodiment, two or more laser beams from, for example, the UV spectrum are used during the laser processing. For example, a laser can be used with one laser source with a "beam splitter" that divides the basic laser beam emitted by the laser source into two or more laser beams. Multiple laser sources can also be used. For example, the laser source can be placed stationary, with other parts of the laser

20 BE2022/5253 are movable and/or adjustable so that the desired markings can be applied.

The wavelength of a said laser beam 1s is preferably between 150 and 400 nm, for example between 300 and 400 nm, or for example between 330 and 370 nm. For example, the wavelength can be 153 nm or 355 nm. When there are two or more laser beams, they can emit light with a different wavelength. This makes it easy to apply different types of markings, for example markings with a different shade. The wavelength of a said laser beam can also be between 500 and 560 nm, even more preferably between 520 and 540 nm.

In a very preferred embodiment, a said processing step is sawing the plate into one or more base panels, after which one or more of these one or more base panels is subjected to the said laser processing, preferably using a laser system comprising the laser at a fixed position for this purpose. is placed, and these basic panels are moved along this laser system. The laser system is placed here in a fixed position. Preferably, the laser source occupies a fixed position in this laser system and other parts, for example, are movably arranged so that the desired markings can be applied. In such a configuration, the base panels are moved along the laser beam.

In a specific embodiment, the top layer comprises additives, whereby these additives cause discoloration of the top layer when exposed to the laser beam. In this way, the desired discoloration can be achieved using laser processing. These additives can, for example, undergo a photochemical change and/or heat up strongly due to the influence of the laser beam, thus causing a color change in the top layer. This color change can, for example, be the result of foaming of the plastic. The additives themselves can also discolour under the influence of the laser beam.

By carrying out this method as described above, it may also be possible to make the panels easier to clean 'easy to clean'.

21 BE2022/5253

The invention also concerns a panel, such as a floor panel, manufactured using the above-mentioned method.

The invention also concerns a panel, such as a floor panel, of the type with at least two layers and of which one said layer is a top layer, wherein at least the top layer comprises one or more markings that, for example, form discolorations of the top layer and wherein the markings are preferably lasered. applied markings are, such as UV laser applied markings, and where the top layer is preferably based on plastic. In a specific version, the markings can be applied using a 'green laser'. This concerns a panel that can be manufactured according to the above-mentioned method according to the invention. All advantages and preferred embodiments described in the method therefore apply to this panel. Laser-applied markings refer to markings that have been created at least partly with the aid of a laser. This does not rule out that the markings were additionally applied using other techniques. For example, the markings can be indentations, where the indentations are created by a combination of pressing with a structured pressing plate or another relief-forming technique such as 'chemical embossing', and a laser, such as a UV laser.

Preferably, the one or more markings comprise notches, which open at least at the top and preferably only at the top of the panel and wherein furthermore, viewed along a plane extending along the panel, the one or more markings are each largely enveloped by remaining areas of the top layer. These markings may be superficial and, for example, have a dimension in a direction perpendicular to the plane in which the panel extends, of a maximum of 20 micrometers, preferably a maximum of 10 micrometers.

The panel also preferably comprises a decorative layer that may or may not form part of the top layer, wherein the decorative layer comprises a motif, such as a wood motif or stone motif. The stone motif, for example, is a marble motif.

22 BE2022/5253

In a preferred embodiment, the top layer comprises one or more wear layers based on plastic, wherein these one or more wear layers extend above the decorative layer and comprise the said notches. These notches are preferably UV laser-applied notches, but these notches can also be applied via other techniques, for example with other types of lasers and/or via structured press plates and/or chemical embossing and/or a combination of different techniques.

The motif is also preferably a wood motif with one or more motif elements such as knots and/or cracks and/or cracks and/or pores, and these one or more motif elements are accentuated with the aid of said markings. For example, the top layer at the level of these knots and/or cracks and/or pores is colored darker by the markings.

In a very preferred embodiment, the top layer comprises a relief, wherein zones of this relief have been obtained by the combination of a pressing operation with a pressing plate comprising a relief and/or another relief-providing technique such as 'chemical embossing', and the one or more laser-applied markings. The pressing operation, for example, creates a basic relief, while the laser-applied markings further refine and/or color the basic relief.

These panels can have all kinds of designs. Below is a non-exhaustive list of possible characteristics of the panels that can be combined with each other as long as they do not contradict each other: - the panel comprises at least 3 layers, being a substrate layer, the mentioned decorative layer and the mentioned top layer, whereby the decorative layer extends between the substrate layer and the top layer. - the panel comprises a wood-based substrate, such as a wood fiber board or a chipboard; -the decorative layer comprises a resin-impregnated paper; -the top layer comprises a resin-impregnated paper; -the decorative layer comprises a wood layer, such as a veneer;

23 BE2022/5253 -the top layer comprises one or more layers of lacquer; -the decorative layer is a PVC-based layer; -the panel includes a mineral-based substrate, such as a gypsum-based, cement-based or geopolymer-based substrate.

In a specific embodiment, the panel comprises fixed pigments in the top layer.

These pigments fixed in the top layer preferably extend at the level of one or more markings, whereby the pigments are removed with the aid of a laser, such as a

UV laser, fixed in the top layer. These markings are, for example, part of laser-applied markings. Preferably, these pigments extend superficially in the top layer, for example at a distance of at most 20 micrometers, preferably at most 10 micrometers from the top of the panel. It is even possible that pigments help form the top of the panel. However, other techniques are also possible to fix pigments in the top layer, for example using heat, pressing, etc.

With the aim of better demonstrating the features of the invention, some preferred embodiments are described hereinafter, as an example without any limiting character, with reference to the accompanying drawings, in which: - figure I is a perspective representation of a panel according to the invention comprising a wood motif, produced using a method according to the invention; figure 2 is a perspective representation of a panel according to the invention comprising a stone motif, manufactured using a method according to the invention; -figure 3 is a detailed view of the section F3 of the panel shown in figure 1; figure 4 is a detailed view of section F4 of the panel shown in figure 1; -figure 5 is a detail view of section F5 of the panel shown in figure 1.

The figures show two floor panels 1 according to the invention, which are manufactured according to a method according to the invention. The floor panel 1

24 BE2022/5253 shown in figure 1 includes a wood motif. The floor panel 1 shown in figure 2 comprises a stone motif.

Seen from bottom to top, these floor panels 1 optionally comprise a counter layer, a core layer, a decorative layer and a top layer 2. These floor panels 1 are, for example, laminate panels, wherein the top layer 2 comprises a resin-impregnated paper, being an 'overlay' or wear layer. 'wear layer', the decorative layer is a resin-impregnated printed paper, wherein this decorative layer comprises the aforementioned wood motif or stone motif, the core layer comprises a wood fiber board and the backing layer is a resin-impregnated paper. The floor panels 1 can also be based on PVC, where the core layer and the counter layer comprise soft or softer PVC respectively, the decorative layer is a printed PVC layer with the wood motif or the stone motif and the top layer 2 is a PVC wearing layer and a UV lacquer layer. which extends at the top of panel 1. Other constructions of the floor panels 1 are also possible. For example, the core layer can be mineral-based or in the case of the floor panel 1 shown in figure 1, the floor panel 1 can be a parquet or a veneer parquet, where the decorative layer is a wood layer, the top layer 2 comprises one or more lacquer layers and the core layer consists of a wood fiber board or slats. In all possible designs, the top layer 2 is always based on plastic.

To produce these panels 1, the following procedure is used. First, a plate is formed comprising the mentioned layers. This plate is then cut into multiple basic panels. Several processing steps are then carried out on these basic panels in order to arrive at the aforementioned floor panels 1. Processing steps include, for example, forming connecting elements so that these panels 1 can be easily connected to each other.

One of these processing steps is laser processing, in which the top layer 2 is exposed to one or more laser beams from a UV laser or a so-called 'green laser' that emits green visible light. For example, the UV laser emits light with a wavelength between 330 and 370 nm and the aforementioned 'green laser', for example, emits light with a wavelength between 495 nm and 570 nm. Here it becomes

25 BE2022/5253 only the top layer 2 is exposed to the mentioned one or more laser beams. Preferably, if the top layer 2 consists of several layers, only the top layer of the top layer 2 is exposed to the one or more laser beams. The result is one or more marks 3 that form discolorations of the top layer 2, whereby these marks 3 extend superficially. These markings 3 may, additionally or not, form indentations with heights of at most 20 micrometers, viewed along a height direction that extends perpendicular to the plane in which the floor panels 1 extend.

These markings 3 can take all kinds of forms. These marks can display 3 words, logos, images and the like. Figure 3 shows a marker 3 depicting a logo. In the case of a wood motif, these markings 3 can accentuate knots and/or cracks and/or fissures present in the wood motif of the decorative layer, because the markings 3 cause a local darker discoloration of the top layer 2. This is, for example, clearly visible in figures 4 and 5. The dark lines of the stone motif can also be accentuated by markings 3 because the markings 3 form dark discolorations of the top layer 2. The appearance of the stone motif in figure 2 is thus optimized.

The mentioned laser processing is very preferably used to improve the appearance of wood motifs. For example, prior to the laser processing, and preferably also prior to cutting into the base panels, a pressing operation can be carried out to form the plates. For example, the plates can be pressed using a structured pressing plate, i.e. a pressing plate provided with a relief. In this way, a structured plate is obtained, in which at least the top layer 2 is provided with a relief. Alternatively or additionally, the relief of the plate can also be achieved chemically by so-called 'chemical embossing'. Preferably, 'embossing in register' is used so that the relief matches the wood motif. The plate and therefore also the base panels are already provided with a basic relief, which optimizes the appearance. The laser processing further optimizes the appearance. This is possible, for example, because the markings 3 provide

26 BE2022/5253 local desired coloring, for example at the level of indentations in the base relief and/or by further refining the base relief, for example by removing local material and/or locally deforming the base relief.

Whether or not additionally, pigments can be sprinkled on top of the top layer 2 prior to or during the exposure of at least the top layer 2 to the said one or more laser beams, so that the pigments that come into contact with a said laser beam in the panel 1 are fixed. After laser processing, the other pigments that were not fixed in panel 1 can be removed. In this way the markings 3 can obtain the desired color.

Claims (22)

27 BE2022/5253 Conclusions 1.- Method for manufacturing one or more panels (1), of the type with at least two layers and of which one said layer is a top layer (2) based on plastic, whereby a plate is formed comprising said layers, and wherein the one or more panels (1) are formed from this plate by carrying out one or more processing steps, whereby at least one said processing step is a laser processing, and whereby during this laser processing at least the top layer (2) is exposed to a laser beam from a laser , to form one or more markings (3), characterized in that the one or more markings (3) form at least discolorations of the top layer (2). 2. Method according to claim 1, characterized in that said laser is a UV laser. 3. Method according to claim 1 or 2, wherein the one or more marks (3) form notches in the top layer (2), wherein these notches preferably only end at the top. Method according to claim 3, wherein these notches, viewed in a direction perpendicular to a plane extending along the panel (1), have a size of at most 20 micrometers, preferably at most 10 micrometers. Method according to any of the preceding claims, wherein the markings (3) have a white tint, gray tint or black tint. Method according to any of the preceding claims, wherein said marking (3) is applied in such a way that a said panel (1) includes said marking (3) and that, viewed along a plane extending along the panel (1), ), this marking (3) is largely covered by remaining areas of the top layer (2). 28 BE2022/5253 7. Method according to any of the preceding claims, wherein the plate comprises a decorative layer that may or may not form part of the top layer (2), wherein the formed one or more panels (1) also comprise said decorative layer. 8. Method according to claim 7, wherein the decorative layer comprises a motif, such as a wood motif or stone motif, and the laser processing is carried out on the basis of this motif. 9.- Method according to claim 8, wherein this motif is a wood motif with one or more motif elements such as knots and/or cracks and/or cracks and/or pores, and that during the laser treatment, at least the top layer (2) at the level of one or several motif elements mentioned, is exposed to the laser beam of the laser for accentuating this one or more motif elements. 10. - Method according to one of claims 7 to 9, wherein the top layer (2) comprises one or more wear layers based on plastic, wherein this one or more wear layers extend above the decorative layer and the said markings (3) extend largely extend at the level of one or more wear layers, preferably only extend at the level of the top wear layer. Method according to any one of claims 7 to 10, characterized in that the plate comprises at least 3 layers, being a substrate layer, the said decorative layer and the said top layer (2), wherein the decorative layer extends between the substrate layer and the top layer (2), wherein the formed one or more panels (1) also comprise the said layers. Method according to claim 11, wherein the substrate layer comprises a wood-based substrate, such as a wood fiber board or a chipboard, and the decorative layer and the top layer (2) comprise a resin-impregnated paper. 13. - Method according to any of the preceding claims, wherein pigments are added before or during the laser processing. 29 BE2022/5253 Method according to any of the preceding claims, characterized in that the wavelength of the light of a said laser beam is between 300 and 400 nm, preferably between 330 and 370 nm. Method according to any of the preceding claims, characterized in that the top layer (2) comprises additives, wherein these additives cause discoloration of the top layer (2) when exposed to the laser beam. 16. - Panel (1), such as a floor panel, characterized in that it is manufactured according to one of the preceding claims. 17.- Panel (1), of the type with at least two layers and of which one said layer is a top layer (2) based on plastic, characterized in that at least the top layer (2) includes one or more markings (3) that discolourations of the top layer (2), whereby preferably these markings (3) are laser-applied markings (3), such as, for example, UV laser-applied markings (3). 18.- Panel (1) according to claim 17, wherein the one or more markings (3) form notches in the top layer (2) which open at least at the top and preferably only at the top of the panel (1) and which are preferably seen according to a plane extending along the panel (1), largely enveloped by remaining areas of the top layer (2). 19.- Panel (1) according to one of claims 17 or 18, wherein the panel (1) comprises a decorative layer that may or may not form part of the top layer (2), wherein the decorative layer has a motif, such as a wood motif or stone motif, includes. 20. Panel (1) according to claim 19, wherein the top layer (2) comprises one or more wear layers based on plastic, wherein these one or more wear layers extend on top of the decorative layer and comprise the said markings (3). 21.- Panel (1) according to claim 19 or 20, wherein this motif is a wood motif with one or more motif elements such as knots and/or cracks and/or cracks and/or 30 BE2022/5253 pores, and that these one or more motif elements are accentuated with the help of said markings (3). Panel (1) according to any one of claims 17 to 21, wherein the panel (1) comprises pigments fixed in the top layer (2), wherein preferably said markings (3) comprise these fixed pigments.