EP2019735B2 - Coating method comprising a flowing coating material - Google Patents

Abstract

The sheet (6) guided on a conveying device is first coated with a fluid material (8) guided through a receptacle (5) formed by a foil (3) and two pulleys (4,13) of different diameters. The plane or structured foil (3) is removed from a first drum (1), positioned on top of the coating (8) and the sheet (6) guided to a drying and hardening unit (7). The position of the plane or structured foil (3) is controlled with speed sensors in order to synchronize the motion of the sheet (6) and the foil (3). After passing the drying device (7) the foil is wound up on a second drum (2).

Description

1. Field of the invention

The invention relates to a method for the coating of boards, in particular of wood-based panels for the production of floor panels, with a flowable coating material.

2. Background

From the prior art, a number of wood-based panels for the production of floor panels is known. Solid wood panels have an aesthetically pleasing surface but are very expensive. For this reason, veneer boards have been developed which have a base plate made of a relatively inexpensive wood material, such as an inexpensive wood species, to which a thin veneer layer of a higher quality wood species is applied. However, veneer sheets are still relatively expensive, so many consumers prefer laminate panels. Laminate panels essentially consist of an approx. 6 to 8 mm thick base plate made of MDF or HDF material, to which a decor paper layer is glued. The decor paper layer is impregnated with a resin and is usually further provided with abrasion-resistant particles. In the manufacture of the laminate panels, the application of pressure and heat hardens the resin, resulting in an extremely abrasion-resistant and decorative surface. Recently, new processes have been developed to produce wood-based panels, such as wood-based panels. MDF or HDF to be printed directly with a plastic material, i. without the use of a decorative paper. For this purpose, the e.g. Milled MDF board and provided with a primer. On this primer, in a second step, a colored decoration is printed, e.g. a wood decor. Thereafter, a plurality of very thin material layers are applied, wherein the individual material layers are cured in each case before the application of the next layer. The material layers are e.g. several, substantially transparent lacquer layers of a hardenable plastic. The resulting overall layer thus has a layered structure. Between the individual layers arise interfaces in which no good networking takes place. The individual layers usually have a thickness of 10 to 15 .mu.m and usually 5 to 7 layers are applied one above the other, resulting in a total thickness of the thin-layer system or layer stack of about 50-105 .mu.m.

From the publication DE 20 2004 018 710 U1 is a device for the coating of plates in the run out. Several plates are arranged on a conveyor belt, which are fed one after the other, inter alia coating stations. Such a coating station comprises an applicator roll, with which a lacquer is applied to a plate. This is followed by a post-processing device, with which the paint is cured, for example with UV radiation. The applicator roll may include a textured surface to pattern lacquer on the surface of a plate.

From the publication DE 199 33 100 A1 For example, a method and apparatus for coating workpieces with powder coatings is known wherein a resin powder is applied to a plate and liquefied under the action of heat and pressure and then cured. For this purpose, the use of a double-belt press is proposed, which pressurizes the dry powder layer, heated above the melting temperature of the powder and cooled again while maintaining the pressure to below the solidification temperature.

From the DE 20 2004 018 710 U1 It is also known that lacquer is applied in a structured manner to a surface of a plate by means of a jet printing technique, which is especially widespread in inkjet printers. This is followed, in turn, by a post-processing device with which the coating can be cured.

From the publication DE 20 2004 018 710 U1 Furthermore, there is a coating of workpieces such as plates, which is provided with a primer layer and a primer layer, Then there is a print layer, which is a decor, Above the decor a lacquer layer is arranged. It can be one

so-called filled paint can be used. These are paints which contain extremely fine solid particles such as corundum with diameters in the nanometer range.

From the DE 103 58 190 A1 is a method for controlling printing presses out. With the device known therefrom furniture panels are printed.

It is the object of the invention to provide a new method with which a fast and cost-effective coating of plates, in particular for the production of floor panels, in good quality is possible.

These and other objects, which will become apparent from the following description, are achieved by the present invention, which is defined by the technical features and method steps of independent claim 1. Further technical features and method sections are specified in the dependent claims.

3. Detailed description of the invention

In order to achieve the object, a device suitable for carrying out the method according to the invention and not belonging to the invention comprises transport means for the transport of plates. The device comprises means for supplying coating material to the plate surface. Subsequent to the feeding means, means for drying and / or curing the coating material are provided above the plate. In contrast to the above-mentioned prior art DE 20 2004 018 710 U1 For example, the apparatus comprises means for passing a web of material between the transport means for the transport of boards and the means for drying and / or curing.

If a material web with a structured surface is used, the surface of the coating material can be provided with a structure without having to exert high pressure, since the coating material is dried and / or cured in this state. So succeeds the coating of a plate with a textured surface, without this as in the publication DE 20 2004 018 710 U1 known prior art either have to use a press or a complex printing unit. Also, a multi-step coating can thus be uniformly dried and / or cured in one operation. Above all, it is possible that a chemical network extends through the entire structure of the layer, resulting in a particularly stable coating.

If a material web with a smooth surface is used, so drying and / or curing under exclusion of air is possible. Drying and / or curing under exclusion of air is frequently desired, for example in order to achieve particularly high crosslinking in the case of curing of a varnish with UV light, ie a particularly high conversion of double bonds within the varnish. In the case of curing with electron beams, an air seal is usually required.

The invention relates to a method for coating a wood-based panel, in particular a particleboard, MDF or HDF board, with a flowable plastic material. In particular, the process relates to the production of panels, e.g. the production of floor panels. In this process, a thick layer of at least 30 microns of a plastic material is applied to the wood-based panel in a single step. The plastic material is preferably transparent at least after drying or curing. The layer is preferably applied in a single operation in a thickness of 30 to 150 microns, more preferably applied in a thickness of 80 to 110 microns and most preferably in a thickness of about 95 microns. In a further step, the layer of plastic material is cured. The use of a single thick layer instead of a series of many thin layers has a number of advantages. First, larger abrasion resistant particles, such as e.g. Larger corundum particles are provided, as it is possible in a thin-film system. In the thin-film systems in which the individual thin layers only have a thickness of 10 to 15 .mu.m, and which are cured one after the other, in fact only relatively small particles can be used, since the particles are preferably incorporated as far as possible in the layers should be.

The flowable plastic material is an acrylate system. By an acrylate system is meant, for example, a polymerizable mixture of double bond-containing mono-, di- and polyfunctional acrylic acid-based compounds. Typical representatives are for example Dipropylenglycoldiacrylat, 1,6-Hexandioldiacrylat, polyurethane acrylic acid ester, polyester acrylic acid ester as they are available in the production program of the company BASF under the trade name Laromer ^™ types on the market.

• Zuerst wird die Trägerplatte, wie z.B. eine MDF-Platte, feingeschliffen und ausgerichtet bzw. kalibriert. Danach wird ein Primer aufgebracht und vorzugweise eine Grundierung aufgetragen. Anschließend erfolgt der Druck des Dekors auf den Primer bzw. die Grundierung. In einem weiteren Schritt wird ein weiterer Primer aufgetragen, der vorzugweise ein geeigneter Primer für die folgende Schicht aus Kunststoffmaterial ist. Dieser Primer wird vorzugsweise in einer Menge von bis zu 10 g/m², besonders bevorzugt von etwa 5 g/m² aufgetragen. Auf den Primer wird dann eine einzelne dicke Schicht eines Acrylatsystems durch z.B. Walzenauftrag aufgebracht. Dies geschieht vorzugsweise in einer Menge von bis zu 100 g/m², besonders bevorzugt von etwa 65 g/m². Auf das noch nicht gehärtete Acrylatsystem werden dann vorzugsweise Korundpartikel gestreut und zwar je nach geforderter Abriebklasse bis zu 70 g/m², bevorzugt 45 g/m². Über diese Schicht erfolgt dann ein Toplackauftrag über eine Strukturgeberfolie mit bevorzugt 2-100 g/m², besonders bevorzugt 30 g/m². Zum Schluss werden dann alle Schichten in einem einzigen Arbeitsgang vorzugsweise mittels UV - Strahlung durchgehärtet. Das gehärtete Acrylatsystem ist vorzugweise möglichst durchsichtig, damit der darunterliegende Dekordruck sichtbar ist.

The wood-based panel is preferably provided before the coating with the flowable plastic material with a colored decorative print, such as with a wood decor. The plastic material is applied via the decor pressure and is preferably as transparent as possible. The process can be carried out, for example, as follows:

• First, the carrier plate, such as an MDF plate, is honed and aligned or calibrated. Thereafter, a primer is applied and preferably applied a primer. Subsequently, the decoration is printed on the primer or the primer. In a further step, a further primer is applied, which is preferably a suitable primer for the following layer of plastic material. This primer is preferably applied in an amount of up to 10 g / m ² , more preferably of about 5 g / m ² . A single thick layer of an acrylate system is then applied to the primer by roll application, for example. This is preferably done in an amount of up to 100 g / m ² , more preferably of about 65 g / m ² . Corundum particles are then preferably scattered onto the not yet cured acrylate system, depending on the required abrasion class, up to 70 g / m ² , preferably 45 g / m ² . A topcoat application is then effected via this layer by means of a pattern-forming film with preferably 2-100 g / m ² , more preferably 30 g / m ² . Finally, all layers are then cured in a single operation, preferably by means of UV radiation. The cured acrylate system is preferably as transparent as possible, so that the underlying decorative pressure is visible.

The curing of the plastic material via a polymerization of the plastic material and not via a polycondensation. The plastic material is accordingly a polymerizable acrylate system. Particularly preferred is the plastic material, ie the polymerizable acrylate system according to the invention, a curable with UV radiation plastic. The UV radiation serves to start the polymerization. Since the polymerization can be stopped at any time, it is thus possible to produce a crosslinking gradient and thus a hardening gradient in the single thick layer, which may be, for example, 95 μm. The curing gradient is generated over a single, over the entire layer thickness occurring polymerization with the highest possible conversion. This is in contrast to painting with many thin films, which are applied layer by layer and then "annealed" by means of radiation, ie it is prematurely terminated the reaction. Thus, over the entire cross-section of all layers, there is no continuous polymer formation but boundary layers.

In an advantageous development of the process, several layers are applied wet on wet (for example primer, acrylate (roll application), corundum, topcoat application) and polymerized in a single step, preferably by UV excitation. The acrylate layer is cured according to the invention in a single thick layer. The individual layers differ in their function and thus also in the chemical structure: The primer has the task of producing good adhesion between the printing and the plastic layer. The middle layer is flexibly adjusted to relieve internal stresses and avoid embrittlement and to absorb impact energy when walking when the coated board is e.g. is used as a floor panel. The Toplackschicht, however, is modified so that it leads to high hardness and scratch resistance. Since the wet-to-wet application causes intermixing of the layers, there are no boundary layers but actually a hardness gradient from top to bottom. Chemically summarized: The polymerization is carried out so that a nearly complete double bond conversion over the entire layer is achieved. The primer is preferably designed so that better adhesion is achieved by greater functionalization of the acrylate mixture. In particular, the middle layer has chain growth and only minor cross-linking. The topcoat layer preferably contains a highly crosslinkable acrylate system.

In order to increase the abrasion resistance of the layer, abrasion-resistant particles, in particular corundum particles, are preferably introduced into the layer. Since the layer is very thick, it is possible to incorporate relatively thick particles which have better abrasion properties than smaller particles. Depending on the layer thickness used, e.g. Corundum particles in a range from DF 220 to DF 280 according to FEPA specification (Federation of European Producers of Abrasives) used. These then have an average particle size D50 of 36.5 to 63.0 μm. More preferably, particles in the range of DF 240 to DF 280 are used, i. with particle sizes D50 from 44.5 to 36.5 μm. In the above-mentioned multi-layered thin film systems (so-called thin-film systems) applied to one another, relatively small particles (such as corundum particles) must be used, otherwise they would protrude too far from the individual layers. The particle size is usually in the range of DF 320 to DF 500 according to the FEPA specification. That is, the previously usable grain sizes of the abrasion-resistant particles were limited to average grain size D50 of 29.2 to 12.8 μm. These relatively small particles result in lower levels of abrasion for the same additional amount, i. For the same abrasion class, a larger amount of weight must be used for finer particles than for larger particles. In addition, finer particles lead to a poorer transparency of the surface and graying phenomena.

The introduction of the particles into the layer can be carried out after application of the layer in which the particles are sprinkled, for example, on the not yet cured layer. After the particles have sunk or pressed into the layer, the material is cured so that the particles are firmly entrapped in the layer. Another possibility is to introduce the particles before the application of the layer in the flowable plastic material, for example in the form of a dispersion.

In a variant of the invention, prior to the curing step, ie after the layer has been applied to the plate, a material web having a structured surface, virtually without pressure, is applied to the layer of plastic material. In this way, a structure is embossed in the layer of plastic material. Since the layer is still liquid at this time, virtually no pressure needs to be expended. In a next step, the layer of plastic material is dried and / or cured, whereby the introduced into the layer of plastic material structure is fixed. Thereafter, in a further step, the material web with structured surface can be removed again. In an alternative method, a pattern roll is used to emboss a structure in the layer of plastic material. This in turn happens after the application of the plastic material to the plate but before the curing of the plastic material. If possible directly after the structure has been impressed, in a next step the layer of plastic material is dried and / or hardened, whereby the structure introduced into the layer of plastic material is fixed. Due to the thickness of the layer according to the invention, structure depths of 0 to 80 μm are possible. Structural depths of from 20 to 80 μm and particularly preferably up to about 35 μm are particularly preferred. In the prior art, in which a layer system of individual thin films was used, it was not possible to produce structure depths of more than 5 to 10 microns. These small structure depths are not sufficient for many purposes. For example, to realize a realistic real wood imitation, deeper structures must be imprinted into the layer. Therefore, with the very deep structures of the present method, patterns and structures that are aesthetically pleasing and not heretofore possible can be incorporated into the layer. A texture depth of 35 microns is clearly felt and visible to the naked eye and is particularly suitable to imitate the structure of real wood floors.

In an alternative embodiment of the invention, a smooth-surfaced web will be applied to the layer of plastic material without exerting much pressure. In this way it is prevented that air gets to the plastic material. In a next step, the layer of plastic material is dried and / or cured in the absence of air. In a further step, the material web with a smooth surface is removed again.

The material webs used, whether with a smooth or structured surface, are preferably permeable to UV light. If a UV-curable plastic is used, it is thus possible to cure the plastic, although it is covered by the material web.

In one embodiment of the above-mentioned. The associated feeding device comprises a collecting device for the coating material, which is arranged adjacent to the transport means for the transport of the plates. The collecting device further adjoins a roller for transporting the material web. The collecting device is designed so that liquid, located in the catcher coating material flows to the roller. It is thus achieved that, given a sufficiently large filling of the collecting device, liquid coating material can completely coat a material web with a liquid film when a material web is transported over the roller. Overall, it can be achieved with sufficient supply of liquid coating material that the liquid coating material completely fills the space between the surface of a plate and the material web located above it. It then gets very reliable no air in the area, a hardening can be carried out so particularly reliable under exclusion of air.

Also, in this embodiment, it is possible to apply relatively thick paint layers having a total thickness of, for example, 80 to 100 μm in thickness and to uniformly dry and cure. This in turn makes it possible to embed relatively thick abrasion-resistant particles such as corundum with a diameter of up to 100 μm within the paint. Since the abrasion resistance increases with the diameter of the abrasion-resistant particles, a relatively high abrasion resistance can be achieved. Nevertheless, as the diameter of the abrasion-resistant particles increases, the amount of abrasive material can also be reduced. This achieves both an improvement in abrasion values and an improvement in the transparency of the abrasion-resistant coating.

Particle sizes of DF 220 to DF 280 FEPA are particularly preferred. The thickness of the layer is preferably 30 to 150 μm, more preferably 80 to 110 μm.

In an embodiment of the e.g. Device comprises the means for transporting plates a circulating conveyor belt, on which the plates are stored for transport.

In a preferred embodiment of the method, after the application of the layer of plastic material, but before the curing or drying of the same, foreign materials are introduced into the layer, for example, interspersed, for example, to achieve an aesthetically pleasing effect. The foreign materials are preferably natural materials such as cork or hemp, but also plastics and metal particles are suitable. The foreign materials can be introduced in such a way that they partially protrude from the layer in relief, or else that they have completely sunk into the layer. The layer is preferably transparent, so that the foreign bodies therein are visible. For example, leaves or tree needles can be inserted into the liquid material layer, which are preferably completely sunk in and surrounded by the layer. Subsequently, the transparent layer is cured. Since the e.g. Natural materials completely surrounded by the layer, which may be an acrylic resin, for example, and are thus protected from the air and the weather, there is no decomposition of natural products. Such a treated plate, with a transparent hard plastic layer in which foreign materials are introduced, can thus have an aesthetically very appealing effect. Other conceivable materials are, for example, leaves, twigs, branches or wool. The introduction of foreign materials is made possible by the relatively large thickness of the layer.

In an embodiment of the e.g. Device, the associated material web is unrolled from a roll, passed over other rollers parallel to the surface of plates, which are transported, and then rolled up again by a roller. In contrast to the aforementioned prior art, an exchange of the material web is sufficient if a surface structure is to be changed or if a structure on the material web has damage, for example due to signs of wear. By using a material web, a consistent quality of a generated surface structure can also be ensured, since, in contrast to a roll with a structured surface, with the unrolling of the material web, the quality of the surface of the material web which produces the structure is not changed. In addition, the structure in the surface of the coating is generated virtually without pressure, so that the surface of the material web is subject to practically no signs of wear for this reason.

In one embodiment of the eg device, the associated rollers for the transport of a Material web arranged so that they are similar to the catcher in cross section a funnel. The supply of coating material to the surface of a plate then finally takes place via a gap. This ensures the proper supply of coating material between the web and surface of the plate to be coated further improved.

In one embodiment, the width of the aforementioned gap can be changed. This serves to control the amount of coating material which is fed to the surface of a plate. Also, in one embodiment, the gap may be closed so as to control the timing of delivery.

4. Description of preferred embodiments

The invention will be described below with reference to FIG FIG. 1 explained in more detail.

FIG. 1 shows the eg, not belonging to the invention device with which a support material 6, such as a chip, MDF or HDF plate can be coated in a continuous, as coating materials are preferably UV or electron beam crosslinkable, flowable systems of suitable viscosity used.

On the input side of the coating system, a carrier material 6 is supplied and coated with a flowable material 8. The coating takes place via a collecting device 5, which adjoins a roller 4. A web-shaped material, namely a UV-transparent and / or electron-permeable and radiation-resistant film 3, is guided over the roller 4. The film has a smooth surface facing the coating material 8 when the coating 8 is to have a smooth surface. The corresponding surface of the film 3 is structured if the coating 8 is to have a structured surface.

The web-shaped material or the film 3 is unrolled from a supply roll or supply roll 1 and finally rolled up again on a roll 2. Between the roller 1 and the roller 4, along the transport path for the sheet material 3, there are three further relatively small diameter rollers serving to guide the sheet material. The small diameter feeding roller 13 is disposed adjacent to the roller 4. causes together with the roller 4 that the web-like material together with the catcher 5 forms a funnel-shaped inlet for coating material 8. The coating material 8, such as a paint, is suitably brought between the carrier material 6 and sheet material 3 via this funnel shape ,

The funnel-shaped inlet opens into a gap. The gap width can be changed to control the supply of coating material.

Between the roller 4 and the roller 2, there are four further guide rollers of relatively small diameter, which serve to guide the sheet material from the roller 4 to the roller 2, the first guide roller 10 - seen from the roller 4 in the transport direction of the sheet material - causes together with the roller 4 that the web-like material is guided parallel to the surface of the carrier material 6.

Between the roller 4 and the roller 10 there are above the film 3 means 7, with which the underlying coating material can be dried and / or cured. These are above all devices for curing with UV light or electron beams.

With the device, during the coating process, a web-shaped smooth or structured material 3 is aligned at the same time from the supply roll 1 both in the longitudinal direction and in the transverse direction and applied synchronously to the carrier material 6 by means of the roller 4 and the catcher 5 on the still liquid coating material. The aim of the orientation of the web-shaped material is to synchronize certain points of the carrier material 6 with certain points of the web-like material fitting one above the other. For this purpose, the speed of a carrier material or a plate 6 is measured with measuring devices in an embodiment of the invention. Preferably, optical measuring devices are used to determine the speed of the carrier material, For example, by means of electronic or magnetic sensors, the rotational speed of at least one Roll involved in the transport of the sheet material is detected. The thus obtained information about the transport speed of each plate 6 and transport speed of the sheet material are used for the control. The two speeds are thus controlled so that a plate is brought together defined with the web-like material, so as to be able to structure a surface targeted.

In an embodiment of the e.g. Device, the web-shaped material, for example, optical markings, which are detected by optical sensors. The transport of the sheet material and / or the transport of the plates 6 are controlled so that a plate is coated in dependence on such an optical marking and the coating is structured in dependence on these optical markings.

The carrier material with the liquid coating material and the overlying sheet-like material then passes through the curing station 7, in which the liquid coating material 8 is crosslinked and goes into a solid state. During the curing process, the surface structure of the web-like material is fixed and imaged in the hardened layer.

On the output side of the coating system, the sheet-like material is removed from the cured solid coating material and wound up again into a roll.

It is still in an in FIG. 2 shown embodiment provided that a plurality of supply rolls 1 and take-up rolls 2 are present for the web-like material. The supply rolls and the take-up rolls can be endlessly connected to each other during production by a device without stop.

The connection is made for reasons of practicality, preferably at speeds up to 120 m / min. The respective at rest film receiving station is charged with a roll of web-like material and prepared the automatic connection by a double-sided adhesive tape is glued to the web start. The beginning of the sheet material is inserted into a gap, which serves to connect. Through this gap at the same time the web-like material is guided, which is currently being unrolled. The triggering of the connection is done automatically by electronically detecting the running meter of the roll from which web-shaped material is unrolled, or sensory detection of the associated end of a web-shaped material. Before joining, the running web-like material is stored in a dancer device operating as a web store. The driven roller is reduced to a speed of about 15 m / min. The missing length of the web-like material to the line speed pulls out of the dancer. After the joining process, the corresponding film roll accelerates again up to the maximum speed, for example 120 m / min, until the dancer roll has returned to its working position.

The automatic connection device comprises at least two unwind stations with flap bearings and pneumatic tension shafts. The unwinding is done by a servomotor. Means are available to automatically adjust cars with the films or web-like materials. The actual connecting device comprises four pneumatically operated mangle rolls. There are also two separating knives for cutting off the sheet material after bonding. An automatic braking force regulation of the unwinding rolls is available. This includes dancer rollers, pneumatic proportional linear cylinders with guide and guide rollers and an automatic crack control.

The carrier material or a plate 6 is first passed through the two superimposed, rotating rollers 4 and 11 passed through and transported. From here, the carrier material 6 reaches a conveyor belt 1 2, which further transports the carrier material. The web-shaped material or the film 3 and the carrier material 6 are transported at the same speed.

The distance between the two rollers 4 and 11 can be changed in order to vary the thickness of the coating can. In one embodiment, the height of the guide roller 10 can be changed in order to influence the thickness of the coating can.

Claims (8)

1. Method for coating a board of wooden material, in particular a particle-, MDF-, or HDF-board with a flowable plastic material, characterized in that the method comprises the following steps:

   applying the plastic material as acrylat layer in a single thick layer of at least 30 µm;

   applying of a finishing paint;

   curing both layers together in a further step by polymerization, wherein

   prior to the curing step, a web with a structured surface is arranged without application of pressure onto the plastic material, to provide the layer of plastic material with a structure;

   in a next step, the layer of plastic material is dried and/or cured, whereby the structure introduced into the layer of plastic material is fixed, and

   in a further step, the web with the structured surface is removed again;

   or
   prior to the curing step, a material web with a smooth surface is arranged onto the layer of plastic material without applying pressure, to prevent that air reaches the plastic material;

   in a next step, the layer of plastic material is cured and/or dried under exclusion of air, and

   in a further step, the web with the smooth surface is removed again.
2. Method according to claim 1, characterized in that the structure has a depth of up to 80 µm and preferably of up to approx. 35 µm.
3. Method according to claim 1, characterized in that the web is transparent for UV light.
4. Method according to any of claims 1 to 3, characterized in that the plastic material is a plastic, which is curable by means of UV radiation.
5. Method according to any of claims 1 to 4, characterized in that the layer is applied in a single process step in a thickness of 30 - 150 µm and preferably of 80 - 110 µm and particularly preferred in a thickness of approx. 35 µm.
6. Method according to any of claims 1 to 5, characterized in that, after application of the layer of plastic material and prior to the curing, abrasion-resistant particles, in particular corundum particles, with a grain size D50 of 36.5 - 63 µm and preferably D50 of 36.4 - 44.5 µm are embedded into the layer of plastic material.
7. Method according to any of claims 1 to 6, characterized in that prior to the application of the layer of plastic material, abrasion resistant particles, in particular corundum particles, with a grain size D50 of 36.5 - 63 µm and preferably D50 of 36.4 - 44.5 µm are embedded into the layer of plastic material.
8. Method according to any one of claims 1 to 7, characterized in that the method comprises the following steps:

   a) fine grinding of the board of wooden material;

   b) applying a primer;

   c) applying an undercoat;

   d) printing of the decor;

   e) applying the coating material in the form of a flowable UV curable acrylate system, in an amount of up to 100 g/m², preferably approx. 65 g/m²;

   f) spreading of corundum particles, preferably up to 70 g/m², and particularly preferred up to 45 g/m²;

   g) applying a finishing paint; and

   h) curing of the plastic material by means of UV radiation.

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