Method and device for coating a workpiece

Abstract

A method for coating a workpiece, which preferably consists at least partially of wood, wood-based material, plastic or the like, comprises the following steps: applying at least one opaque base layer and / or at least one translucent top layer to a surface of the workpiece, wherein, after the application of the at least one layer, the coated surface of the workpiece has a gloss level in the matte, in particular dull matte, range, wherein the application of the at least one layer is preferably carried out by means of a digital printing machine.

Description

Technical field

[0001] The invention relates to a method according to the preamble of claim 1, a device according to the preamble of claim 8, and a processing system according to the preamble of claim 15 for coating a workpiece, which preferably consists at least partially of wood, wood-based material, plastic or the like. State of the art

[0002] For the manufacture of furniture components or other building elements, workpieces are frequently used that consist, at least in part, of wood, wood-based materials, plastic, or similar materials, and whose surfaces, for example, the wide and / or narrow edges of plate-shaped workpieces, may be coated with a coating material. In particular, the narrow edges of plate-shaped workpieces are provided with a (band-shaped) edge band. For optical and functional reasons, the surfaces of the workpieces are often printed or coated using printing inks and surface varnishes, whereby UV-curing printing inks and varnishes may be used. Corresponding printing devices are known, for example, from DE 10 2020 101 308 A1, DE 10 2019 133 335 A1, or DE 10 2022 108 850 A1.

[0003] In the printing technique described above, it is common practice to coat the applied color pigment layers and / or the coated surfaces with a surface varnish or topcoat in a final process step.

[0004] The purpose of the topcoat is to create a resistant, transparent protective layer, which primarily ensures the abrasion resistance, scratch resistance or chemical resistance of the workpiece surfaces.

[0005] Simultaneously, this layer is intended to set a specific gloss level on the printed or coated plastic or wood surface. Currently, gloss levels (measured in "Gloss Units" according to DIN EN ISO 2813:2015-06) can only be reduced to a limited extent with just one topcoat layer. Underlying color pigment layers are usually in the high-gloss range of approximately 95 to 100 GU. If gloss levels below these values ​​are required, particularly in the matte and ultra-matte ranges, an additional system for applying a topcoat layer must be integrated into the printing device, or several topcoat layers must be applied successively to the workpiece surface. Only then will the desired lower gloss level in the range of 3 to 5 GU be achieved, resulting in an ultra-matte appearance on the workpiece surface.

[0006] In other words, to achieve a gloss level in the matte range, the surface coating must be applied multiple times. This results in a thicker coating layer, is technically complex, and ultimately does not produce a visually satisfactory result. Simultaneously, it requires more space in the printing device and incurs additional costs due to the need for another topcoat application unit. Furthermore, the increased thickness of the applied topcoat also raises the cost per linear meter in the application. Description of the invention

[0007] The invention is therefore based on the objective of providing a method, a device and a system with the help of which workpieces, which consist at least partially of wood, wood-based material, plastic or the like, can be designed in a cost-effective and high-quality manner with a matte, in particular blunt matte (color) appearance and (optionally) sealed in a durable manner.

[0008] The invention is based on the idea that commercially available coating materials, whose chemical-physical (particle) composition is known and which are applied as a topcoat or as a translucent surface varnish to an existing color pigment layer, contain particles that reduce the gloss level of the finished coated surface. The particle size of the gloss-reducing particles is considerably larger compared to known color pigment particles, so that they can be unambiguously identified using known particle size analysis methods.

[0009] Typically, the topcoat is applied after (and separately from) the color pigment layer. However, it has been observed that by adding the topcoat, or its gloss-reducing particles, to the color pigment layer, the gloss level of the (modified) applied color pigment layer can be shifted into a matte range, particularly between 60 and 110 GU or less. After the (optional) application of the topcoat or translucent surface varnish to the (modified) applied color pigment layer, the resulting gloss level of the finished workpiece surface is 3 to 5 GU, producing a matte finish.

[0010] Furthermore, it was recognized that the modified color pigment layer material can only achieve a uniform and high-quality matte appearance on the workpiece surface (gloss level of the applied color pigment layer is between 60 and 110 GU or less) if suitable process and plant engineering measures are taken to prevent segregation and settling of the modified color pigment layer material and the topcoat or translucent surface coating (varnish) in the containers and lines of the coating system. This was previously unnecessary or only necessary to a limited extent with an unmodified color pigment layer material.

[0011] A method according to the invention is defined in claim 1. A device according to the invention is defined in claim 8. A system according to the invention is defined in claim 15. Particularly preferred embodiments of the invention are set forth in the dependent claims.

[0012] An inventive method for coating a workpiece, which preferably consists at least partially of wood, wood-based material, plastic or the like, comprises the following steps: applying at least one opaque base layer and / or at least one translucent top layer to a surface of the workpiece, characterized in that after the application of the at least one layer, the coated surface of the workpiece has a gloss level in the matte, in particular dull matte, range, wherein the application of the at least one layer is preferably carried out by means of a digital printing machine.

[0013] The method according to the invention is advantageous because a thin layer structure consisting of at least one opaque base layer and / or at least one translucent layer, which is in particular a transparent top layer, can be achieved, thus minimizing the cost per linear meter of printed workpiece surface. The thickness of the opaque base layer is, for example, in the range of 5 to 30 µm, and the thickness of the translucent, in particular transparent, top layer is, for example, in the range of 5 to 50 µm. At the same time, the method allows for the creation of a high-quality, color-designed workpiece surface that additionally features a durable and transparent protective layer, characterized above all by abrasion resistance, scratch resistance, and chemical resistance.Furthermore, the opaque base layer and / or the translucent, especially transparent, top layer formed on top of it create a layered structure that results in a matte appearance on the finished coated workpiece surface. It is also conceivable that, for example, two, three, four, five, or a multitude of opaque base layers and / or translucent, especially transparent, top layers can be applied to a single workpiece surface. The described coating process also allows for customization of the coated surface's feel.

[0014] Particularly preferred is the application of at least one opaque base layer and / or translucent, especially transparent, top layer to a narrow face of a plate-shaped workpiece, which preferably consists at least partially of wood, wood-based material, plastic, or the like. The narrow face of the plate-shaped workpiece can have a strip-shaped edge banding material. In other words, the opaque base layer and / or the translucent, especially transparent, top layer is applied directly to an already glued-on edge banding. In this way, an edge banding material can be visually customized after being applied to the narrow face of the workpiece. This also offers the advantage that the inventory of different (visually customized) edge banding materials can be reduced in a prior edge banding process.

[0015] It is particularly preferred that the application of the at least one opaque base layer and / or translucent, especially transparent, top layer is carried out using a digital printing press. Digital printing allows the print image to be transferred directly from a file or data stream from a computer to the printing press without the need for a static printing form. This has the particular advantage that a large number of different patterns can be flexibly applied to the workpiece. The use of a digital printing press is especially advantageous for coating a sheet-shaped workpiece, since an optical pattern stored in a print file (for example, a wood grain) can be seamlessly and precisely continued across a wide surface, over / along an edge, onto the narrow surface of the workpiece.

[0016] The coating process can be used in particular for coating a workpiece that preferably consists at least partially of wood, wood-based material and / or plastic. However, it is also conceivable that the coating is applied directly to a fibrous organic, mineral or synthetic insulating material, such as glass wool or extruded polystyrene.

[0017] In a preferred embodiment, at least one opaque base coat can be applied to the surface of the workpiece before the application of at least one translucent top coat. This has the advantage that the gloss level of the finished coated surface is in the matte and, in particular, the ultra-matte range. At the same time, the surface can be sealed to be durable and / or transparent.

[0018] In a preferred embodiment, the opaque base layer can have a gloss level of at most 110 GU, preferably at most 100 GU, more preferably at most 90 GU, even more preferably at most 80 GU, even more preferably at most 70 GU, and even more preferably at most 60 GU. In this way, it is possible to pre-adjust the gloss level of the workpiece to a matte range using the opaque base layer.

[0019] In a preferred embodiment, after application of the translucent topcoat to the applied opaque basecoat, the coated surface of the workpiece can have a gloss level of 3 to 5 GU. A workpiece surface with this gloss level has a matte appearance and simultaneously features a thin layer structure with a durable and / or transparent protective layer. The corresponding gloss level can be individually adjusted, particularly depending on the layer thickness (of the basecoat(s) and topcoat(s)), the color tone in the pigment layer, and the mixing ratio of the topcoat or gloss-reducing particles and the pigment layer material.

[0020] Preferably, only one translucent top layer can be applied to the surface of the workpiece or to the opaque base layer. This allows for a particularly thin overall layer structure, and applying only a single translucent top layer in a single application step reduces both process and material costs. For example, the thickness of the single translucent top layer is 5 to 50 µm.

[0021] In a further preferred embodiment, the opaque base layer can be a color pigment layer whose color pigments preferably correspond to one of the colors of the CMYK color model. The CMYK color model is a subtractive color model that forms the technical basis for four-color printing. CMYK stands for the three color components cyan, magenta, yellow, and black, which is referred to as key. The CMYK color model describes the proportions in which the color components are to be combined to produce a specific color. The color pigment layer material with these colors enables a wide color palette for the color design of the workpiece surface. At the same time, the number of base colors is reduced to a minimum, thereby simplifying storage and processing.However, it is also conceivable to use other color models with more or less than four basic colors, such as the RGB color model (red, green, blue).

[0022] The method can further preferably include curing the opaque base layer and / or the translucent top layer separately, preferably using a light source. In other words, after applying the opaque base layer, it is cured using a light source, such as an LED lamp, and then the translucent top layer is applied and also cured using a light source. In this way, the gloss level can be adjusted or further regulated directly after the application of each layer by individually fixing the gloss-reducing particles in the applied layer. The gloss level can be adjusted depending on the time between application and curing, the curing time, and / or the power of the curing device, which is preferably a light source.This method creates a particularly high-quality, matte, colored, and robust workpiece surface structure with individually adjustable gloss levels even during the application process. It is also conceivable that when applying a large number of (for example, one, two, three, four, five, six, seven, eight, nine, ten, or more) opaque base layers and / or translucent top layers, each individual layer can be cured separately and selectively using the light source.

[0023] An inventive device for coating a workpiece, preferably configured to carry out the method described above, wherein the workpiece preferably consists at least partially of wood, wood-based material, plastic or the like, comprises: at least one coating unit for applying at least one opaque base layer and / or at least one translucent top layer to a surface of the workpiece, a transport unit for bringing about a relative movement between the coating units and the workpiece, and a control unit for controlling the coating units and / or the transport unit.

[0024] This device advantageously enables the application of a thin layer structure to a workpiece surface, consisting of at least one opaque base layer and at least one translucent, particularly transparent, top layer. This structure is especially durable and produces a (matte) finish. The device is also characterized by its compact design and allows for efficient, fully automated coating of the workpiece surface in a single production run. The control and / or transport unit (e.g., conveyor belt or rollers) allows for customized and cost-effective coating of individual workpieces (in quantities of one). The device is particularly preferably configured to coat the narrow sides of a plate-shaped workpiece, where the narrow side preferably has an edge band.

[0025] In a preferred embodiment, the device can have at least one, two, three, four, five, or a plurality of curing devices for curing the opaque base layer and / or the translucent top layer. This enables individual and targeted curing to adjust the gloss level in a single compact device. The curing device can, for example, be a light source, preferably a UV lamp.

[0026] In a further preferred embodiment, the device can comprise at most three, four, five, six, seven, eight, nine, ten, eleven, twelve, or more coating units for applying the opaque base layer and / or at most one coating unit for applying the translucent top layer. This significantly reduces the required installation space within the device and its overall footprint. At the same time, existing devices can be modified with minimal effort. Furthermore, maintenance requirements and the risk of downtime during production are low with this number of coating units. In addition, it is possible to separate the difficult-to-process coatings from the base colors.

[0027] The coating units may more preferably comprise one or more of the following components: at least one coating head for ejecting the coating material, at least one storage container for storing the coating material, which preferably has a conical outlet, a pipe arrangement for connecting the at least one coating head and the at least one storage container, which preferably has a circulation line, a temperature control device for temperature control of the coating material in the coating unit, preferably with at least one temperature sensor and at least one heating element, and a conveying device for conveying the coating material in the pipe arrangement, which preferably has a diaphragm pump.

[0028] This design of the coating units enables suitable processing of the modified color pigment layer material and / or the topcoat material (varnish) to counteract settling and segregation of different particles within the color pigment layer material and / or topcoat material. In particular, the at least one storage container can be dimensioned to hold the required quantity of coating materials for only one production batch. This avoids prolonged storage that leads to segregation and optimizes the required installation space for the storage containers.Simultaneously, the conical outlet of the reservoir not only ensures optimal drainage of the coating materials but also prevents areas of low flow velocity where larger particles of the modified color pigment layer material and / or the topcoat material would accumulate. A conical angle is particularly advantageous here, as it allows for complete drainage of the coating material and emptying of the reservoir. However, the shape of the reservoir and its outlet are not limited to the geometry described above but can also have other configurations that facilitate suitable drainage and emptying of the coating material.

[0029] Furthermore, the coating material is in continuous circulation within the circulation line, so that the movement kinetics prevent the deposition of coating material particles. The interaction with the temperature control unit is particularly advantageous, as it ensures a constant coating material temperature of, for example, less than 60 degrees Celsius, preferably 35 to 42 degrees Celsius, throughout the entire coating unit. This counteracts segregation of the coating material and ensures an optimal processing temperature and optimal temperature-viscosity behavior during coating.

[0030] The conveying device ensures a continuous flow of the coating material in the circulation line of the coating unit. Flow velocities that prevent segregation and settling of the coating material particles are particularly advantageous. The use of low-pulsation diaphragm pumps is especially beneficial, as the coating material particles are subjected to only minimal shear stress. This prevents curing reactions in the (modified) coating materials.

[0031] Preferably, the inner surface of the storage container and / or the piping system can have an adhesion-reducing coating. This minimizes friction between the inner surface of the container and the coating material particles, ensuring a uniform flow within the storage container and / or the circulation line. This prevents the coating material particles from depositing and separating.

[0032] Even more preferably, the coating unit can further comprise a movement unit, in particular an agitator, which is configured to mix the coating material in the storage container. For example, the agitator motor is located in an area above the storage container. This promotes the mixing of the coating material within the storage container, thus preventing settling or segregation of the coating material particles. Rotational speeds of 5 to 30 rpm are particularly advantageous.

[0033] In an advantageous embodiment, the pipe assembly can have an inner diameter of at least 4 mm. A preferred range is between 6 and 10 mm, more preferably between 6 and 8 mm, and even more preferably between 6 and 7 mm. This ensures that the coating material can flow freely through the pipe assembly. It is also advantageous if the entire pipe assembly has a substantially constant inner diameter. This prevents abrupt changes in diameter or dead spaces where material or fillers can accumulate. Connection spigots, fittings, junctions, hoses, and other feedthroughs can, for example, be equipped with G 1 / 4 threads (DIN ISO 228-1).

[0034] A processing system comprises the device described above for coating a workpiece and at least one processing device for machining the workpiece, wherein the processing device is, for example, an edgebanding machine. Since the device described above for coating a workpiece is designed as a compact unit, it can easily be coupled with or integrated into another processing device. This enables a compact overall design in which various processing steps can be performed in a single pass without the need for intermediate workpiece storage. Brief description of the drawings

[0035] Further features and advantages of the method and device according to the invention will become apparent from the following description of embodiments with reference to the accompanying drawings. These drawings show: Fig. 1a a flow diagram of a prior art method; Fig. 1b a flow diagram of the inventive method according to one embodiment; Fig. 2 a perspective view of the inventive device for coating a workpiece according to one embodiment; Fig. 3 a perspective view of a coating unit of the inventive device for coating a workpiece according to a first embodiment; Fig. 4 a perspective view of a coating unit of the inventive device for coating a workpiece according to a second embodiment; and Fig. 5a a perspective view of a storage container of the inventive device for coating a workpiece according to one embodiment; Fig. 5b a side sectional view of a storage container of the inventive device for coating a workpiece according to one embodiment. Description of embodiments

[0036] Identical reference numerals shown in different figures denote identical, corresponding, or functionally similar elements. It is apparent to a person skilled in the art that individual features described in different embodiments can also be implemented in a single embodiment, provided they are not structurally incompatible. Likewise, various features described within a single embodiment can also be provided individually or in any suitable subcombination in several embodiments.

[0037] Fig. 1aFigure 1 shows a flowchart of a state-of-the-art coating process. Based on the CMYK color model (subtractive color model), color pigment layers such as cyan, magenta, yellow, and black are applied sequentially to a workpiece surface. These color pigment layers have a high-gloss gloss level of approximately 95 to 100 GU. To reduce the gloss level of the colored workpiece surface or to create a protective layer, a first layer of surface coating or topcoat (varnish) is then applied. To further reduce the gloss level, a second layer of surface coating or topcoat (varnish) is applied over the existing first layer, separately from the first application step. For process-related reasons (among others),Due to the application quantity and layer thickness, conventional coating systems always require two separate coating units. In other words, the first and second layers of surface coating or topcoat (varnish) are each applied by an independent coating unit.

[0038] In contrast, it shows Figure 1bAn exemplary flowchart of the inventive method according to one embodiment, in which, based on the CMYK color model (subtractive color model), the modified color pigment layers cyan, magenta, yellow, and the black component are successively applied to a workpiece surface, resulting in four opaque (modified) base layers on the workpiece surface. The modified color pigment layer material or base layer material can be produced by adding commercially available topcoat or its gloss-reducing particles to the color pigment layer material, and the amount of material used depends on the desired gloss level of the applied color pigment layer.It is understood that, depending on the desired color scheme, other color layer combinations can also be applied successively, resulting in at least one (modified) opaque base layer or two, three, four, or a multitude of (modified) opaque base layers (modified color pigment layers). The (modified) opaque base layer(s) have (before the application of a topcoat) a gloss level of at most 110 GU, preferably at most 100 GU, preferably at most 90 GU, preferably at most 80 GU, more preferably at most 70 GU, and even more preferably at most 60 GU. To further reduce the gloss level, i.e., to achieve a gloss level of the workpiece surface, for example, in the matte range (3 to 5 GU), only a single layer of surface lacquer or topcoat (varnish) subsequently needs to be applied.

[0039] The gloss level can be flexibly regulated by individually curing each applied (modified) opaque base layer(s) or the applied surface varnish or topcoat.

[0040] A corresponding embodiment of a device 10 according to the invention for coating a workpiece 1 with the method according to the invention is described in Figure 2The device shown comprises four successively arranged coating units 3, 4, 5, 6 for applying a (modified) opaque base layer to a surface 2 of the workpiece 1, in order to color the workpiece surface 2 with corresponding four (modified) color pigment layer materials. The coating device 10 includes only a single coating unit 7 for applying a translucent, in particular transparent, topcoat to a surface of the at least one base layer. In other words, only one coating unit 7 applies the surface coating or topcoat (varnish) to adjust the gloss level of the workpiece surface to the matte range (3 to 5 GU).Furthermore, the coating device 10 comprises a transport unit 18 in the form of transport rollers for effecting a relative movement between the coating units and the workpiece, and a control unit for controlling the coating units and / or the transport unit 18. In addition, the coating device 10 comprises at least one or at most one (not in . Figure 2The drying or curing unit (shown in detail) is designed to dry or cure the (modified) applied base layer(s) (optionally separately) and / or the applied translucent top layer (optionally separately). The one, two, three, four, or five curing units are, for example, arranged in one direction of movement of the workpiece 8 between the individual, successively arranged coating units 3, 4, 5, 6, 7, or after coating unit 7 for applying the translucent top layer. For example, one curing unit can be arranged before and one after coating unit 7 for applying the translucent top layer.The device 10 according to the invention is particularly compact due to the total of a maximum of 5 coating units in combination with the other components described above and can efficiently color a workpiece surface and then apply a resistant protective layer.

[0041] Figure 3Figure 1 shows a perspective view of a coating unit 3, 4, 5, 6, 7 of the device 10 according to the invention for coating a workpiece 1 according to a first embodiment. This includes, in this case, a first and a second storage container 8, 8' for storing and / or buffering the (modified) color pigment coating material 9, which are dimensioned such that only the quantity of coating material actually required for upcoming production batches is stored. For example, the storage container 8, 8' can have a capacity of 250 ml. In this context, the size of a refill pack can then be selected so that it is used up completely.

[0042] The coating unit 3, 4, 5, 6, 7 further comprises a temperature control device for maintaining the temperature of the coating material in the storage container 8, 8', preferably with at least one temperature sensor and at least one heating element. Depending on the temperature-viscosity behavior of the coating material, the system operating temperature can be adjusted via an integrated heater up to, for example, a maximum of 60 degrees Celsius. For this purpose, an electric heating rod or a heating coil can be arranged in the storage container 8, 8'. The coating unit 3, 4, 5, 6, 7 also includes a movement unit 13 in the form of a stirrer to mix the coating material in the storage container 8, 8'. The motor of the stirrer 13 is, for example, arranged outside, preferably above, the storage container 8, 8', with a stirrer connected to it being inserted into the interior of the storage container 8, 8'.

[0043] Furthermore, the coating unit 3, 4, 5, 6, 7 comprises a line assembly 12 for connecting a coating head 14, which ejects coating material onto the workpiece surface 2, and the storage container 8, 8', wherein the line assembly 12 is preferably configured as a circulation line. In this way, the coating material can be kept in motion until it is applied to the workpiece surface 2 via the coating head 14. This serves to prevent the deposition of coating material particles in the line assembly 12 and the storage container 8, 8'. The line assembly also includes a shut-off valve (not shown) to maintain a vacuum in the circulation system, which is generated by a vacuum pump.

[0044] Fig. 4Figure 1 shows a perspective view of a coating unit 3, 4, 5, 6, 7 of the device 10 according to the invention for coating a workpiece 1 according to a second embodiment. A conveying device 16 is provided for conveying the coating material in the line arrangement 12, which is preferably designed as a low-pulsation diaphragm pump to convey / pump the coating material with minimal shear force in the line arrangement of the coating unit 3, 4, 5, 6, 7. Additionally, a filter device 15 is provided for filtering the coating material, which, for example, includes a fine filter that can filter out unwanted particles in the coating material. The fine filter must be configured to filter out particle sizes larger than 10 µm, preferably larger than 20 µm, but not the particles in the (modified) coating materials that reduce the gloss level.

[0045] Fig. 5aFigure 1 shows a perspective view of a storage container 8, 8' of the device 10 according to the invention for coating a workpiece 1 according to one embodiment. The storage container 8, 8' is preferably elongated and cuboid in shape and is designed to be removable from the coating device 10.

[0046] Fig. 5bFigure 1 shows a side sectional view of a storage container 8, 8' of the device 10 according to the invention for coating a workpiece 1 according to one embodiment. In this side view or sectional view of the storage container 8, 8', the bottom of the storage container 8, 8' extends in a conical shape, with an outlet 17 arranged at the cone tip 20 through which the coating material can be discharged from the storage container 8, 8' into the line assembly 12. The cone can have a conical angle, and the conical bottom is bounded by the side walls of the storage container 8, 8'. Additionally, an inner surface of the storage container 8, 8', in particular the conical bottom and / or the side walls of the storage container 8, 8', can have an adhesion-reducing coating.

Claims

1. Method for coating a workpiece (1), which preferably consists at least partially of wood, wood-based material, plastic or the like, comprising the steps of: applying at least one opaque base layer and / or at least one translucent top layer to a surface (2) of the workpiece (1), characterized by the fact that After the application of at least one layer, the coated surface (2) of the workpiece (1) has a gloss level in the matte, in particular matte, range, wherein the application of the at least one layer is preferably carried out by means of a digital printing machine.

2. Method according to claim 1, characterized by the fact that Before applying at least one translucent top layer, at least one opaque base layer is applied to the surface (2) of the workpiece (1).

3. Method according to claim 1 or 2, characterized by the fact thatthe opaque base layer has a gloss level of at most 110 GU, preferably at most 100 GU, more preferably at most 90 GU, even more preferably at most 80 GU, even more preferably at most 70 GU, even more preferably at most 60 GU.

4. Method according to one of the preceding claims 2 or 3, characterized by the fact that After the application of the translucent top layer to the applied opaque base layer, the coated surface (2) of the workpiece (1) has a gloss level of 3 to 5 GU.

5. Method according to any of the preceding claims, characterized by the fact that only a translucent top layer is applied to the surface (2) of the workpiece (1) or to the opaque base layer.

6. Method according to any one of claims 2 to 5, characterized by the fact that The opaque base layer is a color pigment layer whose color pigments preferably correspond to one of the colors of the CMYK color model.

7. Method according to any of the preceding claims, characterized by the fact that This further comprises, preferably separately, curing of the opaque base layer and / or the translucent top layer, preferably with a light source.

8. Device (10) for coating a workpiece (1), preferably configured to carry out the method according to one of the preceding claims, wherein the workpiece (1) preferably consists at least partially of wood, wood-based material, plastic or the like, comprising: at least one coating unit (3, 4, 5, 6, 7) for applying at least one opaque base layer and / or at least one translucent top layer to a surface (2) of the workpiece (1), a transport unit (18) for bringing about a relative movement between the coating units (3, 4, 5, 6, 7) and the workpiece (2), and a control unit for controlling the coating units (3, 4, 5, 6, 7) and / or the transport unit (18).

9. Device according to claim 8, characterized by the fact thatThis includes at most three, four, five, six, seven, eight, nine, ten, eleven, twelve or more coating units for applying the opaque base layer and / or at most one coating unit for applying the translucent top layer.

10. Device according to claim 8 or 9, characterized by the fact that The device comprises at least one, two, three, four, five or a plurality of curing devices for curing the opaque base layer and / or the translucent top layer.

11. Device according to one of claims 8 to 10, characterized by the fact thatThe coating units (3, 4, 5, 6, 7) comprise one or more of the following components: - at least one coating head (14) for ejecting the coating material (11), - at least one storage container (8, 8') for storing the coating material (11), which preferably has a conical outlet (19), - a line arrangement (12) for connecting the at least one coating head (14) and the at least one storage container (8, 8'), which preferably has a circulation line (12), - a temperature control device for temperature control of the coating material in the coating unit (3, 4, 5, 6, 7), preferably with at least one temperature sensor and at least one heating element, and - a conveying device (16) for conveying the coating material in the line arrangement (14), which preferably has a diaphragm pump (16).

12. Device according to claim 11, characterized by the fact thatan inner surface of the storage container (8, 8') and / or the piping arrangement (14) has an adhesion-reducing coating.

13. Device according to claim 11 or 12, characterized by the fact that the coating unit (3, 4, 5, 6, 7) further comprises a movement unit (13), in particular a stirrer, which is designed to mix the coating material (11) in the storage container (8, 8').

14. Device according to one of claims 11 to 13, characterized by the fact that the conductor arrangement (12) has an inner diameter of at least 4 mm.

15. Machining system comprising the device for coating a workpiece (1) according to one of claims 11 to 14 and at least one machining device (10) for machining the workpiece (1), wherein the machining device is, for example, an edge banding machine.

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