Apparatus and method for coating a portion, in particular a chamfer and / or an end face, of a planar workpiece with a coating medium

Abstract

The present invention relates to an apparatus (1) for coating a portion, in particular a chamfer and / or an end face, of a planar workpiece with a coating medium, the apparatus comprising a coating unit (2) which has an application device (3) and a blow-off device (4) which are arranged such that the portion of the workpiece to be coated can be moved along first to the application device (2) and then to the blow-off device (3), wherein a negative pressure can be generated in a negative pressure region (8) of the coating unit (2), wherein the application device (3) has a coating medium supply (9) for supplying the coating medium to an application region (10) in which the coating medium can be applied to the portion of the workpiece by means of the negative pressure in the negative pressure region (8), wherein the blow-off device (4) has at least one blow-off nozzle (13) through which a gas, in particular air, can be blown onto the workpiece in order to blow applied coating medium off the workpiece into the negative pressure region (8) and thereby adjust a layer thickness of the coating medium on the workpiece, wherein the blow-off device (4) has an air intake opening (14) through which additional air from outside the coating unit (2) can flow in during blowing using the blow-off nozzle (13) in order to generate an air flow between the workpiece and the negative pressure region (8) and to reduce unwanted deposits of coating medium on the workpiece.

Description

[0001] Device and method for coating a section, in particular a bevel and / or an end face, of a plate-shaped workpiece with a coating medium

[0002] The present invention relates to a device for coating a section, in particular a bevel and / or an end face, of a plate-shaped workpiece with a coating medium. Furthermore, the invention relates to a method for coating a section, in particular a bevel and / or an end face, of a plate-shaped workpiece with a coating medium.

[0003] Devices for coating bevels or end faces of panel-shaped workpieces, such as flooring elements or door panels, are known in the prior art. Such devices typically comprise a coating unit past which the workpiece to be coated is moved. In known coating units, the coating medium is conveyed into a nozzle. A vacuum is typically created in the area around the nozzle, which draws in the coating medium and thereby conveys it onto the workpiece. The coating thickness achieved on the workpiece can be adjusted by selecting the applied vacuum.

[0004] A disadvantage has proven to be that a relatively high vacuum is often required to achieve the desired layer thickness. However, high vacuum pressure imposes high shear stress on the coating medium, which can lead to poor-quality coatings on the workpiece.

[0005] Against this background, the task arises of reducing the shear stress on the coating medium.

[0006] To achieve the object, a device for coating a section, in particular a bevel and / or an end face, of a plate-shaped workpiece with a coating medium is proposed, comprising a coating unit which has an application device and a blow-off device which are arranged in such a way that the section of the workpiece to be coated can first be moved along the application device and then along the blow-off device, wherein a negative pressure can be generated in a negative pressure region of the coating unit, wherein the application device has a coating medium supply for supplying the coating medium to an application region in which the coating medium can be applied to the section of the workpiece by means of the negative pressure existing in the negative pressure region, wherein the blow-off device has at least one blow-off nozzle through which a gas, in particular air,can be blown onto the workpiece in order to blow off applied coating medium from the workpiece into the vacuum area and thereby adjust a layer thickness of the coating medium on the workpiece, wherein the blow-off device has an air intake opening through which additional air can flow in from outside the coating unit when blowing with the blow-off nozzle in order to create an air flow between the workpiece and the vacuum area and to reduce unwanted deposits of coating medium on the workpiece.

[0007] In the device according to the invention, in addition to the application device, a blow-off device is provided as part of the coating unit. This combination offers the advantage that the adjustment of the layer thickness of the coating medium on the workpiece does not have to be carried out by the negative pressure in the coating unit, but can be carried out by the blow-off device. As a result, the negative pressure in the negative pressure region of the coating unit can be reduced, so that the coating medium is subjected to less shear stress. Furthermore, a reduction in the negative pressure also makes it possible to reduce the volume of air sucked through the coating unit. Overall, this measure allows the entire device to be designed to be smaller and more compact than devices known in the prior art.The layer thickness of the coating medium on the workpiece can be adjusted by selecting the blowing pressure of the at least one blow-off nozzle. In this respect, the workpiece can be smoothed using the at least one blow-off nozzle. When the at least one blow-off nozzle is in operation, air can be sucked in from outside the coating unit through the air intake opening of the blow-off device. This can prevent coating medium that has accumulated in the negative pressure area from being sucked in by a Venturi effect triggered by the blow-off nozzle and depositing in undesired areas of the workpiece. The at least one blow-off nozzle of the blow-off device is, in particular, aligned such that the air expelled by the blow-off nozzle flows towards the negative pressure area of ​​the coating unit.Particularly preferably, the at least one blow-off nozzle is aligned such that the air expelled from the blow-off nozzle flows in a suction direction in which air is sucked out of the vacuum region. Preferably, the blow-off device comprises a plurality of blow-off nozzles through which a gas, in particular air, can be blown onto the workpiece in order to blow off applied coating medium from the workpiece into the vacuum region and thereby adjust the layer thickness of the coating medium on the workpiece. The plurality of blow-off nozzles are preferably arranged such that a workpiece moving along the coating unit passes through them one after the other. In this respect, the same area of ​​the workpiece can be sequentially exposed to compressed air by the plurality of blow-off nozzles.

[0008] According to an advantageous embodiment of the invention, the blow-off device comprises an air intake duct that extends into an interior of the coating unit, in particular into the vacuum region, and opens into the air intake opening. The duct can be used to determine the flow path of the air drawn in from outside the coating unit. Furthermore, the air intake duct can have a wall that additionally shields the workpiece from the vacuum region, thus further improving protection against unwanted suction of coating medium from the vacuum region of the coating unit.

[0009] According to an advantageous embodiment of the invention, the air intake duct forms a projection in the interior, particularly in the vacuum region. This projection allows for particularly good shielding against suctioned-in coating medium. Any suctioned-in coating medium can adhere to the projection and prevent it from reaching the workpiece.

[0010] According to an advantageous embodiment of the invention, the coating medium supply in the coating unit is arranged above the vacuum area. With such a configuration, the coating medium can be sucked downwards from the coating medium supply and thereby applied to the workpiece.

[0011] According to an advantageous embodiment of the invention, the coating medium supply in the coating unit is arranged below the vacuum region. With such a configuration, the coating medium can be sucked upwards from the coating medium supply and thereby applied to the workpiece. Preferably, the coating medium supply is arranged both above and below the vacuum region, thus combining the advantages of both variants of supplying the coating medium to the workpiece.

[0012] According to an advantageous embodiment of the invention, the coating medium supply comprises a plurality of supply channels that open into the application area. The plurality of supply channels can be arranged next to one another in such a way that a workpiece moving along the coating unit passes through them one after the other. Thus, the coating medium can be applied sequentially to the same area of ​​the workpiece through the plurality of supply channels.

[0013] The coating medium supply preferably has a nozzle. The nozzle can be a flat nozzle. Particularly preferably, the coating medium supply comprises several nozzles, for example, several flat nozzles. The nozzle can be arranged at the end of a supply channel.

[0014] According to an advantageous embodiment, it is provided that the coating medium supply has at least one supply channel which is designed as an upwardly open pocket in the application area, wherein the supply channel preferably extends to a front plate of the coating unit.

[0015] Preferably, the coating medium supply has a plurality of supply channels which are designed as upwardly open pockets in the application area, wherein the supply channels preferably extend to a front plate of the coating unit and are arranged next to one another.

[0016] According to an advantageous embodiment of the invention, the device comprises a transport means for transporting the workpiece along the coating unit, wherein the transport means is configured to move the workpiece first along the application device and then along the blow-off device. The transport means can be designed as a conveyor belt or a conveyor chain.

[0017] According to an advantageous embodiment of the invention, at least one wear element, in particular a wear plate, is arranged on an outer contour of the coating unit, which delimits the application area and is detachably connected to the outer contour. The at least one wear element can be removed from the coating unit if it is worn or worn out and replaced by another, in particular identically designed, wear element. Preferably, several wear elements are provided. During coating, the workpiece can be brought into contact with the at least one wear element, in particular guided along it. In this respect, the at least one wear element can act like a stop and contribute to several workpieces coated one after the other being provided with the coating medium in the same section of the respective workpiece.Preferably, the wear element is adapted to the contour of the workpiece to be coated. The at least one wear element can be made of hardened steel, a hard metal, or a ceramic. The at least one wear element can be manufactured using a machining or additive manufacturing process.

[0018] According to an advantageous embodiment of the invention, the coating unit has a wall in which a cooling channel for the passage of a cooling medium is arranged. The cooling channel can be used to control the temperature of the coating unit and / or the coating medium, in particular to cool it. This enables good processability of the coating medium and reduces the risk of undesired adhesion or drying of the coating medium within the coating unit.

[0019] To achieve the object mentioned above, a method for coating a section, in particular a bevel and / or an end face, of a plate-shaped workpiece with a coating medium is further proposed, wherein the section of the workpiece to be coated is first moved along an application device and then along a blow-off device of a coating unit, wherein a negative pressure is generated in a negative pressure region of the coating unit, wherein the coating medium is fed via a coating medium feed of the application device to an application region, in which the coating medium is applied to the section of the workpiece by means of the negative pressure existing in the negative pressure region, wherein a gas, in particular air, is blown onto the workpiece through at least one blow-off nozzle of the blow-off device,to blow applied coating medium from the workpiece into the vacuum area and thereby adjust a layer thickness of the coating medium on the workpiece, whereby additional air flows in from outside the coating unit through an air intake opening of the blow-off device when blowing with the blow-off nozzle in order to create an air flow between the workpiece and the vacuum area and to reduce unwanted deposits of coating medium on the workpiece.

[0020] The same effects and advantages can be achieved with the method according to the invention as have already been described in connection with the device according to the invention.

[0021] According to an advantageous embodiment of the method, the gas is blown through the blow-off nozzle onto the workpiece at a pressure in the range of 0.05 bar to 4 bar, preferably in the range of 0.1 bar to 1 bar. By adjusting the pressure of the blow-off nozzle, the layer thickness of the coating medium on the workpiece can be adjusted. The specified pressure range has proven advantageous for achieving technically relevant layer thicknesses.

[0022] According to an advantageous embodiment of the method, the gas, in particular the air, is humidified, in particular with a water mist, before being blown out of the blow-off nozzle. For example, the gas can be exposed to the water mist. Humidification can be carried out in a humidification device designed like a compressed air lubricator, with the difference that the gas is exposed to a water mist instead of an oil mist.

[0023] According to an advantageous embodiment of the method, the negative pressure in the coating unit is in the range of 10 mbar to 250 mbar, preferably in the range of 15 mbar to 40 mbar. The combination of the blow-off device and the application device in a common coating unit makes it possible to set the negative pressure in the coating unit to a lower level than the prior art while still applying thin, commercially available layer thicknesses. The aforementioned negative pressure ranges have proven advantageous in practice.

[0024] According to an advantageous embodiment of the method, the temperature of the coating unit is set to the dew point. Such a temperature setting is particularly advantageous when using a water-based coating medium to prevent unwanted adhesion or deposits of the coating medium within the coating unit.

[0025] According to an advantageous embodiment of the method, the ambient air surrounding the coating unit is humidified, in particular humidified to such an extent that the dew point is above a minimum processing temperature of the coating medium. Such humidification of the ambient air is particularly advantageous when using a water-based coating medium in order to prevent unwanted adhesion or deposits of the coating medium within the coating unit and / or in the area of ​​the coating medium supply of the application device.

[0026] Alternatively or in addition to the advantageous embodiments explained above, the advantageous embodiments and features explained in connection with the device according to the invention can be used in the method.

[0027] The device and method described above are particularly advantageously suited for coating floor elements, in particular floorboards. When coating floor elements, a decorative surface can preferably be oriented downward, while an end face and / or a bevel of the floor element is moved along the coating unit to coat the end face and / or the bevel.

[0028] Further details and advantages of the invention will be explained below with reference to the exemplary embodiments shown in the figures. Herein:

[0029] Fig. 1 shows a coating unit according to an embodiment of the invention in a first perspective view;

[0030] Fig. 2 the coating unit according to Fig. 1 in a second perspective

[0031] Depiction;

[0032] Fig. 3 the application device of the coating unit according to Fig. 1 in a

[0033] sectional view;

[0034] Fig. 4 shows the application device according to Fig. 3 in a perspective sectional view; side view; Fig. 5 shows the blow-off device of the coating unit according to Fig. 1 in a perspective sectional view; and

[0035] Fig. 6 shows an application device of a coating unit according to a further embodiment of the invention in a sectional view.

[0036] The illustration in Figs. 1 and 2 shows a device 1 for coating a section, in particular a bevel and / or an end face, of a plate-shaped workpiece with a coating medium according to a first exemplary embodiment of the invention. The device 1 has a coating unit 2. The workpieces to be coated are designed as floor elements, in particular floorboards. When coating floor elements, a decorative surface can preferably be oriented downwards, while an end face and / or a bevel of the floor element faces the coating unit and is moved along it in order to coat the end face and / or the bevel.

[0037] The coating unit 2 comprises an application device 3 and a blow-off device 4, which are arranged side by side. This arrangement allows the section of the workpiece to be coated to be moved first along the application device 3 and then along the blow-off device 4. Thus, coating medium can first be applied to the section of the workpiece and then blown off to achieve a desired layer thickness on the section of the workpiece.

[0038] The coating unit 2 comprises a common housing 5 for the application device 3 and a blow-off device 4. The housing 5 has walls through which one or more cooling channels pass. The cooling channels are fluidly connected to coolant connections 6, 7, through which coolant can be supplied to and removed from the cooling channels. A temperature of the coating unit 2 corresponding to the dew point is preferably set via the cooling channels.

[0039] Within the housing 5, a vacuum region 8 is provided, in which a vacuum is generated, for example by a vacuum pump arranged externally of the housing 5. For this purpose, the housing can have an opening to which a vacuum pump can be connected. This opening is arranged on the rear side of the housing 5 (not visible) in Figs. 1 and 2. The application device 3 of the coating unit 2 has a coating medium supply 9 for supplying the coating medium to an application region 10, in which the coating medium is applied to the section of the workpiece by means of the negative pressure existing in the vacuum region 8. In the embodiment according to Figs. 1 and 2, the coating medium supply 9 comprises two supply channels 11, which are fed by a coating medium inlet 12. The supply channels 11 are arranged within the housing 5 above the vacuum region 8.

[0040] In the exemplary embodiment, the feed channels 11 in the application area 10 are designed as upwardly open pockets which are arranged next to one another and extend to a front plate of the coating unit 2.

[0041] The blow-off device 4 comprises at least one, here two blow-off nozzles 13, through which a gas, in particular air, can be blown onto the workpiece in order to blow off applied coating medium from the workpiece into the vacuum region 8 and thereby adjust a layer thickness of the coating medium on the workpiece. The blow-off nozzles 13 are integrated into the outer contour of the coating unit 2 in such a way that the workpiece can first be provided with the coating medium in the application region 10 through the interaction of the coating medium supply 9 and the vacuum region 8, and then excess coating medium is blown off through the blow-off nozzles 13. The gas, in particular the air, is preferably blown onto the workpiece through the blow-off nozzle at a pressure in the range of 0.05 bar to 4 bar, preferably in the range of 0.3 bar to 2 bar, particularly preferably in the range of 0.1 bar to 1 bar. The gas can be humidified before being blown out.Alternatively or additionally, the ambient air of the coating unit 2 can be humidified, in particular such that the dew point is above a minimum processing temperature of the coating medium.

[0042] Furthermore, it is provided that the blow-off device 4 has an air intake opening 14, through which additional air can flow in from outside the coating unit 2 when blowing with the blow-off nozzles 13. This creates an air flow between the workpiece and the vacuum region 8 and undesired deposits of the coating medium on the workpiece are reduced or prevented. As shown in Figs. 1 and 2, the air intake opening 14 is located in the area below the two blow-off nozzles 13, so that the air flow is generated below the workpiece. In the exemplary embodiment, the air intake opening 14 is designed in the manner of an elongated hole. However, the air intake opening 14 can also have a different cross-section and / or several air intake openings can be provided.

[0043] The device 1 further comprises a transport means (not shown in the drawings) for transporting the workpiece along the coating unit 2. By means of the transport means, the workpiece can be moved first along the application device 3 and then along the blow-off device 4 in order to first apply the coating medium to the respective section of the workpiece and then smooth it or adjust the desired layer thickness. The transport means can be designed as a conveyor belt or a conveyor chain.

[0044] Furthermore, several wear elements 15, 16 are arranged on the outer contour of the coating unit 2. The wear elements 15, 16 are detachably mounted on the outer contour, for example, by means of screw connections, so that they can be removed and replaced if they become excessively worn or dirty. The detachable connection also makes it possible to attach wear elements 15, 16 to the coating unit 2, depending on the workpiece to be coated.

[0045] The illustrations in Fig. 3 and 4 show the application device 4 of the coating unit 2 in sectional views. It can be seen that the coating medium supply 9 in the coating unit 2 is arranged above the vacuum region 8, so that the coating medium is sucked downwards from the coating medium supply 9 and applied to the workpiece. In the exemplary embodiment, the coating medium supply 9 has two supply channels 11 which are arranged parallel to one another and run towards the application region 10. On a side of the supply channels opposite the application region 10, the latter are fluidically connected to a common coating medium inlet 12. The two supply channels 11 are thus arranged such that a workpiece moving along the coating unit 2 passes through them one after the other.In this respect, coating medium can be applied successively to the same area of ​​the workpiece through the two feed channels 11. The coating medium is introduced, in particular conveyed, into the coating unit 2 via the coating medium inlet 12. A pump, in particular an eccentric screw pump, a double diaphragm pump, or a peristaltic pump, can be provided outside the coating unit 2 to convey the coating medium. A pressure vessel and / or a pulsation damper is preferably arranged in a line between the pump and the coating medium inlet 12 in order to keep the flow rate as constant as possible. The end of the coating medium supply 9, in particular of the feed channels 11, facing the application area 10 is designed as a nozzle, in particular as a flat nozzle.

[0046] To generate the negative pressure in the negative pressure area 8, a vacuum pump is connected to the right side of the housing 5 shown in Fig. 3 and 4, which sucks air and excess coating medium out of the coating unit 2.

[0047] The illustrations in Fig. 3 and 4 also show a cooling channel 17 which is connected to the coolant connections 6, 7.

[0048] The illustration in Fig. 5 shows a sectional view of the blow-off device 4. It can be seen that the two blow-off nozzles 13 are aligned such that air can be blown toward the interior of the coating unit 2, i.e., toward the vacuum region 8. The workpiece moving along the coating unit 2 passes through the two blow-off nozzles 13 one after the other. The air intake opening 14 is arranged below the blow-off nozzles 13 in the wall of the housing 5 and allows for an additional air flow that separates the workpiece from the vacuum region 8 below the workpiece.

[0049] Within the housing 5, an air intake duct 18 is formed, starting from the air intake opening 14, which extends into the interior of the coating unit 2, in particular into the vacuum region. In the exemplary embodiment, this air intake duct 18, together with the air intake opening 14, has a substantially L-shaped course. An inner wall delimiting the air intake duct 18 forms a projection 19 within the vacuum region 8 in the housing 5. The air intake duct 18 determines the flow path of the air sucked in from outside the coating unit 2. The inner wall additionally shields the workpiece from the vacuum region, thus further improving protection against unwanted suction of coating medium from the vacuum region 8 of the coating unit 2.

[0050] Fig. 6 shows a further embodiment of an application device 3, which can be provided as part of a coating unit 2. In this embodiment, the coating medium supply 9 is arranged both above and below the vacuum region 8. With the devices 1 explained above, a method for coating a section, in particular a bevel and / or an end face, of a plate-shaped workpiece with a coating medium can be carried out, wherein the section of the workpiece to be coated is first moved along the application device 3 and then along the blow-off device 4 of the coating unit 2, wherein a vacuum is generated in the vacuum region 8 of the coating unit 2, wherein the coating medium is supplied to the application region 10 via the coating medium supply 9 of the application device 4.in which the coating medium is applied to the section of the workpiece by means of the negative pressure existing in the negative pressure region 8, wherein a gas, in particular air, is blown onto the workpiece through at least one blow-off nozzle 13 of the blow-off device 4 in order to blow off applied coating medium from the workpiece into the negative pressure region 8 and thereby adjust a layer thickness of the coating medium on the workpiece, wherein additional air flows in from outside the coating unit 2 through the air intake opening 14 of the blow-off device 4 during blowing with the blow-off nozzle 13 in order to generate an air flow between the workpiece and the negative pressure region 8 and to reduce unwanted deposits of coating medium on the workpiece.

[0051] 1 device for coating

[0052] 2 coating unit

[0053] 3 Order setup

[0054] 4 Blow-off device

[0055] 5 housings

[0056] 6 Coolant connection

[0057] 7 Coolant connection

[0058] 8 Negative pressure range

[0059] 9 Coating medium supply

[0060] 10 Order area

[0061] 11 Feed channel

[0062] 12 Coating medium inlet

[0063] 13 Blow-off nozzle

[0064] 14 Air intake opening

[0065] 15 Wear element

[0066] 16 Wear element

[0067] 17 Cooling channel

[0068] 18 Air intake duct

[0069] 19 lead

Claims

Device (1) for coating a section, in particular a chamfer and / or an end face, of a plate-shaped workpiece with a coating medium, comprising a coating unit (2) having an application device (3) and a blow-off device (4) arranged such that the section of the workpiece to be coated can first be moved along the application device (2) and then along the blow-off device (3), wherein a vacuum can be generated in a vacuum area (8) of the coating unit (2), wherein the application device (3) has a coating medium supply (9) for supplying the coating medium to an application area (10) in which the coating medium can be applied to the section of the workpiece by means of the vacuum existing in the vacuum area (8), wherein the blow-off device (4) has at least one blow-off nozzle (13) through which a gas, in particular air,The device (4) can be blown onto the workpiece to blow applied coating medium from the workpiece into the vacuum zone (8) and thereby adjust the coating medium layer thickness on the workpiece, wherein the blow-off device (4) has an air intake opening (14) through which, when blowing with the blow-off nozzle (13), additional air from outside the coating unit (2) can flow in to create an airflow between the workpiece and the vacuum zone (8) and to reduce unwanted coating medium deposits on the workpiece. Device according to claim 1, characterized in that the blow-off device (4) has an air intake channel (18) extending into an interior space of the coating unit (2), in particular into the vacuum zone (8), and opening into the air intake opening (14). Device according to claim 2, characterized in that the air intake channel (18) has a projection (19) in the interior space,especially in the low-pressure area (8), forms.

4. Device according to one of the preceding claims, characterized in that the coating medium supply (9) is arranged in the coating unit (2) above the vacuum area (8).

5. Device according to one of the preceding claims, characterized in that the coating medium supply (9) is arranged in the coating unit (2) below the vacuum area (8).

6. Device according to one of the preceding claims, characterized in that the coating medium supply (9) has several supply channels (11) which open into the application area (10).

7. Device according to one of claims 1 to 3, characterized in that the coating medium supply (9) has at least one supply channel (11) which is designed as an upwardly open pocket in the application area (10), wherein the supply channel (11) preferably extends to a front plate of the coating unit (2).

8. Device according to claim 7, characterized by several feed channels (11) which are designed as upwardly open pockets in the application area (10), wherein the feed channels (11) preferably extend to a front plate of the coating unit (2) and are arranged next to each other.

9. Device according to one of the preceding claims, characterized by a transport means for transporting the workpiece along the coating unit (2), wherein the transport means is configured to move the workpiece first along the application device (3) and then along the blow-off device (4).

10. Device according to one of the preceding claims, characterized in that at least one wear element (15, 16), in particular a wear plate, is arranged on an outer contour of the coating unit (2), which limits the application area (10) and is detachably connected to the outer contour.

11. Device according to one of the preceding claims, characterized in that the coating unit (2) has a wall in which a cooling channel (17) is arranged for conveying a cooling medium.

12. Method for coating a section, in particular a chamfer and / or an end face, of a plate-shaped workpiece with a coating medium, wherein the section of the workpiece to be coated is first moved along an application device (3) and then along a blow-off device (4) of a coating unit (2), wherein a vacuum is generated in a vacuum area of ​​the coating unit (2), wherein the coating medium is supplied via a coating medium feed (9) of the application device (4) to an application area (10) in which the coating medium is applied to the section of the workpiece by means of the vacuum existing in the vacuum area (8), wherein a gas, in particular air, is blown onto the workpiece through at least one blow-off nozzle (13) of the blow-off device (4),to blow applied coating medium from the workpiece into the vacuum area (8) and thereby adjust a layer thickness of the coating medium on the workpiece, wherein additional air from outside the coating unit (2) flows in through an air intake opening (14) of the blow-off device (4) when blowing with the blow-off nozzle (13) in order to create an airflow between the workpiece and the vacuum area (8) and to reduce unwanted deposits of coating medium on the workpiece.

13. Method according to claim 12, characterized in that the gas is blown onto the workpiece through the blow-off nozzle (13) at a pressure in the range of 0.05 bar to 4 bar, preferably in the range of 0.1 bar to 1 bar.

14. Method according to one of claims 12 or 13, characterized in that the gas is moistened before being blown out of the blow-off nozzle (13), in particular with a water mist.

15. Method according to one of claims 12 to 14, characterized in that the negative pressure in the coating unit (2) is in the range of 10 mbar to 250 mbar, preferably in the range of 15 mbar to 40 mbar.

16. Method according to one of claims 12 to 15, characterized in that the temperature of the coating unit (2) is adjusted to the dew point. Method according to one of claims 12 to 16, characterized in that the ambient air surrounding the coating unit (2) is humidified, in particular humidified in such a way that the dew point is above a minimum processing temperature of the coating medium.

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