EDGE COATING OF A PANEL WITH A COATING MEDIUM

Description

Technical field

[0001] The invention relates to a coating device for a coating system for edge coating of a panel with a coating medium.

[0002] The present invention also relates to a coating system for edge coating of a panel with a coating medium. Background of the invention

[0003] A coating system for vacuum edge coating of flat workpieces is known, for example, from German patent application DE 40 21 174 A1. The flat workpieces are moved by conveyors and guided through edge coating chambers, with several edge coating chambers arranged as needed on the conveyors at any desired distance from a single base machine. The base machine is divided into separate individual units, which are positioned in any desired position relative to each other below the conveyor's transport level. Automatic color changes, automatic cleaning, uninterrupted filter changes or cleaning, and emergency safety devices are implemented by means of valves, controls, and regulators. Another coating system of the same type is known from US patent 5,298,072 A.

[0004] Coating systems are generally known to use a pumped coating medium into a pressure vessel. The pressure of the vessel then forces the medium to a coating head. First, the supply line must be vented. Next, the medium is forced through a ball valve at a constant pressure to the nozzle of the coating head. Finally, the medium must be drawn off the nozzle using a constant vacuum applied to the coating head. This creates a flow of the medium at the nozzle. In such systems, the flow rate of the coating medium is manually adjustable and complex. Description of the invention

[0005] Based on this situation, it is an object of the present invention to enable an improved coating of panels. In particular, the effort required for coating should be reduced, while at the same time the quality of the coating should be improved.

[0006] The object of the invention is achieved by the features of the independent main claim. Advantageous embodiments are specified in the dependent claims. Where technically feasible, the teachings of the dependent claims can be combined arbitrarily with the teachings of the main and dependent claims.

[0007] Accordingly, the problem is solved by a coating device for edge-coating a panel with a coating medium. The device comprises: at least one medium line for guiding a coating medium, with an inlet and an outlet, wherein the medium line has a recess for introducing a panel into a coating medium flow, and wherein the medium line and the recess are designed such that the coating medium can be applied to the edge of the panel by means of suction in the direction of medium flow.

[0008] The coating device according to the invention is part of a coating system for edge coating a panel with a coating medium. The system comprises: a medium piping system for conveying a coating medium; a pumping system connected to the medium piping system for conveying the coating medium; and at least one coating device connected to the medium piping system according to the invention or according to at least one of the modified embodiments of the invention.

[0009] The coating system can employ one or more coating devices. For example, it can be advantageous to use two coating devices spaced apart from each other on the coating system, with the coating devices being spaced apart from each other on a conveyor line for the panel. The coating devices can, for example, be arranged on the conveyor line such that the panel is first coated at its edge by a first coating device and then coated again with a further layer by a second coating device, which lies on top of the first layer.

[0010] A coating process for edge-coating a panel with a coating medium is also disclosed. The process comprises the following steps: Introducing an edge of the panel into a coating medium flow via a recess of a coating device according to the invention or according to at least one of the modified embodiments of the invention. Conveying the coating medium to the inlet of the coating device by means of a pump arranged upstream of an inlet of the coating device in the direction of medium flow. The pump is configured according to at least one of the modified embodiments of the invention. Conveying a coating medium within the coating device by means of a vacuum device arranged downstream of an outlet of the coating device in the direction of medium flow. The vacuum device is configured according to at least one of the modified embodiments of the invention.

[0011] The disclosed method may include process steps corresponding to features of the coating system according to the invention or according to at least one of the modified embodiments of the invention.

[0012] The process steps are carried out in a sequence corresponding to the direction of medium flow. It is preferred that the sequence of process steps can be varied unless a specific sequence is technically required. However, the sequence of process steps described above is particularly preferred.

[0013] The following sections explain aspects of the claimed subject matter of the invention, and subsequently describe preferred modified embodiments of the invention. Explanations, particularly regarding advantages and definitions of features, are essentially descriptive and preferred examples, but not limiting ones. If an explanation is limiting, this will be expressly stated. Where value ranges are mentioned, these apply including the stated values.

[0014] One aspect of the present invention is therefore to draw the coating medium through the coating device towards the base machine. This advantageously reduces the complexity of the coating system and improves the quality of the coating on the panel.

[0015] In other words, the significant advantage of drawing the medium through the coating device using a vacuum is a homogeneous coating. The device itself, due to its design, offers the benefit of minimal drying of the medium and low turbulence, resulting in a gentle and energy-efficient coating process. Furthermore, the device is less susceptible to dust and dirt, which is particularly relevant when coating a double-end profiler. Additionally, the device significantly reduces or prevents the clogging and soiling of conveyor belts, chains, chain plates, and cams when applying paints, thereby considerably reducing or eliminating the need for costly cleaning and maintenance.

[0016] The simpler design also results in less susceptibility to errors. Maintenance and cleaning are also less demanding. The simple design of the coating device without a nozzle is less prone to clogging. This also facilitates easier cleaning and maintenance. Furthermore, the coating device can be designed more compactly. For example, a coating head width of 15 to 20 cm can be avoided. Replacing or upgrading existing systems is therefore very easy.

[0017] Finally, the coating device itself offers the advantage of a more space-saving design for the entire coating system. Smaller pipe cross-sections than 50 mm to 60 mm can be used in the vacuum-operated conveying circuit, thus reducing the drying out of the coating medium in the pipes. Smaller batches can also be produced with less waste. Furthermore, there is no need for a complex and error-prone low-pulsation conveying system. Maintaining a constant pressure in the coating system's conveying circuit is also less critical, and many sensors can be omitted.

[0018] The vacuum device is preferably a side-channel compressor. The preferred side-channel compressor is a special type of compressor. It serves to compress or extract air or other gases. By way of example, and not as a limiting factor, a channel is arranged laterally around almost the entire circumference of a bladed impeller. The gas can flow from the areas of the impeller separated by the blades to the channel and back again. Air is drawn in by a rapidly rotating impeller and then forced outwards by centrifugal force, thus creating compression. The air then flows back inwards via the side channel and is accelerated again between two further blades and compressed outwards. These multiple compressions allow for the generation of higher differential pressures compared to a fan.However, similar systems can also be designed as a side-channel blower acting as a vacuum device.

[0019] According to a modified embodiment of the invention, the panel is a conveyed panel. The conveying direction of the panel can be arbitrary. The panel can, for example, be a wooden plank. The conveying speed is adapted, for example, to the characteristics of a coating system, the properties of the coating medium, and the speed of the medium flow.

[0020] According to a modified embodiment of the invention, the medium line and the recess are designed such that, at a medium pressure at the recess in the range of 3.5 x 10^3 Pa to 5.5 x 10^3 Pa, preferably at a medium pressure of 5 x 10^3 Pa, the coating medium can be applied to the edge of the panel. This has proven to enable a particularly homogeneous coating of the panel. For this purpose, it is preferred that the coating medium is conveyed into the inlet of the coating device at an inlet pressure of 10^4 Pa to 2 x 10^4 Pa. Such a low inlet pressure reduces the risk of the coating medium unintentionally being drawn onto the panel to be coated by suction.Nevertheless, this advantageous inlet pressure is sufficient to convey the coating medium through the coating device by means of suction in such a way that a panel can be coated as desired.

[0021] In other words, 3.5 x 10^3 Pascals is equivalent to 35 millibars. 5.5 x 10^3 Pascals is equivalent to 55 millibars. 5 x 10^3 Pascals is equivalent to 50 millibars. 10^4 Pascals is equivalent to 0.1 bar. 2 x 10^4 Pascals is equivalent to 0.2 bar.

[0022] According to a modified embodiment of the invention, the recess and the cross-section of the medium conduit have an aspect ratio such that the medium conduit is directed towards each other, and the medium conduit is routed such that the coating medium can be applied to the edge of the panel by means of suction in the direction of medium flow, in particular that the coating medium can be applied to the edge of the panel at a medium pressure in the range of 3.5 x 10^3 Pa to 5.5 x 10^3 Pa, preferably at a medium pressure of 5 x 10^3 Pa. These are further features that promote a particularly homogeneous coating.

[0023] According to a modified embodiment of the invention, the recess is arranged on an outer bend of an arc-shaped or kinked section of the medium line. This allows the panel to be easily conveyed past the opening in the recess of the coating device and simultaneously facilitates the controlled application of coating medium to the panel.

[0024] According to a modified embodiment of the invention, the arc-shaped or angled section of the medium line has an acute internal angle, with an inlet section extending from the inlet to the recess extending vertically when the medium line is connected via the inlet. This advantageously reduces leakage of the coating medium from the coating device.

[0025] According to a modified embodiment of the invention, the medium line is U-shaped with two legs, wherein the inlet section is a first leg and the outlet section, extending in the direction of medium flow from the recess to the outlet, is a second leg. Such a U-shaped design, in which the inlet is, for example, vertical or at least ascending to a certain height up to the recess, facilitates good control of the medium flow and pressure. At the same time, this design particularly facilitates the outflow of the coating medium in the direction of medium flow. Furthermore, the installation of such a coating device in a coating system is simpler.In other words, the shape of the coating device, which can be combined with a higher mounting position relative to other components of the coating system, allows the coating medium to easily flow back into the base machine. This function is similar to that of an overflow.

[0026] According to a modified embodiment of the invention, the edge profile of the recess is designed to fit the edge of the panel in a form-fitting manner, and in particular, the edge profile of the recess is designed to match a profile of the edge of the panel. This promotes a more uniform coating of the panel, while simultaneously reducing or preventing the medium from escaping the recess.

[0027] According to a modified embodiment of the invention, two medium lines are provided for conveying the coating medium. This can be advantageous for coating larger areas of the panel simultaneously, while keeping the cross-section of one line smaller to achieve a more controlled medium flow.

[0028] According to a modified embodiment of the invention, the pump system includes a vacuum device located downstream of the outlet in the direction of medium flow. This vacuum device, and in particular a cross-sectional area of ​​the medium line system, is designed to generate a vacuum, i.e., suction, at the outlet. The aforementioned feature, combined with the preferred coating device, offers advantages for installation on a profiling machine, i.e., a conveyor belt system: In the coating device, the medium is forced in at the bottom with virtually no pressure and then drawn through by the vacuum. This makes the system splash-free, meaning no coating medium can spray out of the recess. The prevention of splashing coating medium can be ensured even if the vacuum fails due to a malfunction.By drawing the medium through the coating device under negative pressure, the advantage is that the coating is homogeneous. Furthermore, there is no dependence on a low-pulsation conveying technology, which is complex and prone to failure.

[0029] According to a modified embodiment of the invention, a separation system is interposed between the vacuum device and the outlet in the direction of medium flow, wherein the separation system is designed to separate the gas supplied to the vacuum device from the coating medium. The separation system improves the quality of the coating medium in the conveying circuit of the coating system.

[0030] According to a modified embodiment of the invention, the separation system comprises a sieve system for filtering the coating medium from the gas. This is a simple and cost-effective way to separate the coating medium from the gas. Furthermore, a sieve system is easier to clean and maintain.

[0031] According to a modified embodiment of the invention, the separation system has a cover for accessing it. For example, the cover can be made of acrylic glass. Such a cover allows inspection of the system during operation and also facilitates easy cleaning of the separation system.

[0032] According to a modified embodiment of the invention, a pump of the pumping system is interposed between the separation system and the inlet in the direction of medium flow. This pump is designed for metered delivery of the coating medium to the inlet. The pump enables gentle conveying of the medium for coating. Very small quantities can also be conveyed continuously. Both of these advantages of the pump prevent foaming of the medium and ensure that the coating process produces a homogeneous, high-quality coating. Maintenance and cleaning of the entire system are also improved and / or simplified.

[0033] According to a modified embodiment of the invention, the pump is a shear-free pump. Preferably, but not necessarily limitingly, the pump is a peristaltic pump, wherein the peristaltic pump particularly comprises a hose made of chlorosulfonated polyethylene (CSM). A peristaltic pump is one possible embodiment of a shear-free pump, offering the advantages described in connection with the previously described embodiment. The hose made of CSM, or comprising CSM, has proven advantageous in exhibiting particularly high resistance to the coating medium. A shear-free pump has the advantage that the coating medium does not foam, thus improving the coating quality.

[0034] However, other pumps are also possible in principle, for example a double diaphragm pump or similarly functioning pumps.

[0035] According to a modified embodiment of the invention, the pump, and in particular a medium line cross-section of the medium line system, is designed to convey the coating medium such that the inlet is supplied with the coating medium at an inlet pressure greater than or equal to the medium pressure at the recess, preferably with an inlet pressure greater than or equal to 3.5 x 10^3 Pa, and particularly preferably with an inlet pressure of 10^4 Pa to 2 x 10^4 Pa. The volumetric flow rate of the coating medium is adjusted, for example by the line dimensioning, such that the coating medium is drawn out faster in the effective area of ​​the recess than it is supplied in the effective area of ​​the inlet, in order to prevent the coating medium from being introduced into the coating device too quickly.The cross-sectional area of ​​the medium lines can be dimensioned taking into account that the coating medium foams less with smaller cross-sectional areas. Gentler conveyance is also preferable. Furthermore, smaller quantities can be conveyed within the system, for example, for smaller batches. Another advantage is that the coating medium is forced into the coating device at virtually no pressure. This, in turn, allows for better control of the medium flow in the area of ​​the recess due to the generated suction.

[0036] According to a modified embodiment of the invention, a heater is interposed between the separation system, particularly between the pump, and the inlet in the direction of medium flow. The heater is designed to heat the coating medium to a temperature in the range of 30 °C to 45 °C. Within this temperature range, foaming of the coating medium is significantly reduced or prevented, thereby considerably improving the function of the coating system and preventing failures. Furthermore, the advantage is that homogeneous coating can always be achieved with a constant application quantity, regardless of the ambient temperature. Brief description of the drawings

[0037] The invention is explained in more detail below with reference to the accompanying drawings and preferred embodiments. The term "figure" is abbreviated as "Fig." in the drawings.

[0038] The drawings show Figure 1 is a schematic view of the coating device according to a preferred embodiment of the invention; Figure 2 is another schematic view of the coating device according to the preferred embodiment of the invention; Figure 3 is a schematic view of a coating system according to a preferred embodiment of the invention; Figure 4 is a schematic view of a coating system according to the prior art; and Figure 5 is a flowchart of an exemplary coating process. Detailed description of the implementation examples

[0039] The described embodiments are merely examples that can be modified and / or supplemented in various ways within the scope of the claims. Each feature described for a particular embodiment can be used independently or in combination with other features in any other embodiment. Each feature described for an embodiment of a particular claim category can also be used accordingly in an embodiment of a different claim category.

[0040] Figure 1 Figure 1 shows a schematic view of the coating device 1 according to a preferred embodiment of the invention. The coating device 1 is suitable for edge coating of a panel 2 with a coating medium B. The panel 2 is conveyed in a transport direction during the coating process (see Figure 1). Fig. 3The direction and speed of transport can be adjusted to match the speed of the medium flow of the coating medium B.

[0041] The coating device 1 according to the exemplary embodiment has: two medium lines 3, each designed to carry the coating medium B, and each provided with an inlet 3a and an outlet 3b. The inlet 3a and outlet 3b are connected to a coating medium circuit of a coating system 100 (see Fig. 3The coating medium B flows through each of the medium lines 3 in a medium flow direction M. The medium lines 3 can be connected to the coating medium circuit individually or together, for example via a Y-shaped connector. The coating device 1 can, for example, have a total width of 20 mm. The line diameter in the area of ​​the outlet 3b or the outlet piece 3B can be 19 mm for the medium lines 3.

[0042] Each of the medium lines 3 has a recess 3c for introducing the panel 2 into a coating medium stream. According to the exemplary embodiment, the panel 2 is introduced into the coating medium stream of the coating medium B with one edge facing the other. The coating medium B flows past the edge of the panel 2 and wets a surface of the panel 2 in the region of this edge.

[0043] The medium line 3 and the recess 3c are designed such that the coating medium B can be applied to the edge 2a of the panel 2 by means of a suction in the direction of medium flow M. The edge 2a comprises the edge described above. A profile of the recess 3c is designed to fit snugly against the edge 2a of the panel 2. Fig. 1 It is evident that the edge profile of the recess 3c is designed to match the profile of the edge 2a of the panel 2. The aforementioned suction in the direction of medium flow M promotes a uniform medium flow and bubble-free conveying and coating of the panel 2.

[0044] The medium line 3 and the recess 3c are designed such that a suction-like medium pressure is generated at the recess 3c in a range of 3.5 x 10^3 Pa to 5.5 x 10^3 Pa for the coating medium B at the edge 2a of the panel 2. A medium pressure of 5 x 10^3 Pa is particularly preferred. The desired medium pressure is achieved through the aspect ratio of the recess 2a and the cross-sectional area of ​​the medium line, as well as the design of the medium line 3.

[0045] It is preferred that the coating medium B is conveyed into the inlet 3a of the coating device 1 at an inlet pressure of 10⁴ Pa to 2 x 10⁴ Pa. Such a low inlet pressure reduces the risk of the coating medium B unintentionally coming into contact with the panel 2 to be coated by suction in a coating-like manner. Nevertheless, this advantageous inlet pressure is sufficient to convey the coating medium B through the coating device 1 by means of suction in such a way that a panel 2 can be coated as desired.

[0046] The recess 3c is located on an external bend of a kinked section of the medium line. The kinked section of the medium line has an acute internal angle (alpha), which is enclosed by a drain piece 3B and an inlet piece 3A. The inlet piece 3A, which extends from the inlet 3a to the recess 3c, extends vertically when the medium line 3 is connected via the inlet 3a. The inlet 3a is then connected to the coating system 100 of the Fig. 3 connected.

[0047] The medium line 3 according to the embodiment is U-shaped with two legs, wherein the inlet piece 3A is a first leg and the outlet piece 3B, which extends in the medium flow direction M from the recess 3c to the outlet 3b, is a second leg.

[0048] Figure 2Figure 1 shows another schematic view of the coating device 1 according to the preferred embodiment of the invention. Here, the two medium lines 3 can be viewed from a different perspective.

[0049] Figure 3 Figure 1 shows a schematic view of a coating system 100 according to a preferred embodiment of the invention.

[0050] The coating system 100 comprises: a medium piping system 30 for conveying the coating medium B; a pumping system connected to the medium piping system 30 for transporting the coating medium B; and a coating device 1 connected to the medium piping system 30 as previously described. The medium piping system 30 has several valves 80. A coating medium container 90, filled with the coating medium B, is also part of the medium piping system 30.

[0051] The pump system has a vacuum device 40 downstream of the outlet in the medium flow direction M, wherein the vacuum device 40 and a medium line cross-section of the medium line system 30 are designed to generate a vacuum at the outlet 3b, i.e. to generate the suction behind the recess 3c.

[0052] In the direction of medium flow M, between the vacuum device 40 and the outlet 3b, a separation system 50 is interposed. The separation system 50 is designed to separate the gas supplied to the vacuum device 40 from the coating medium B. The separation system 50 includes a sieve system 51 for filtering the coating medium B from the gas. The separation system 50 also has a cover 52 made of acrylic glass, which is part of a housing 53 of the separation system 50. The cover 52 can be opened to clean the separation system 50 or to observe a production process within the separation system 50. Furthermore, the separation system 50 has a guide wall 54, which is designed to guide the gas-coating medium mixture to the sieve system 51.

[0053] In the medium flow direction M between the separation system 50 and the inlet 3a, a pump 60 of the pumping system, designed as an exemplary shear-free pump 60, is interposed, wherein the shear-free pump 60 is designed for metered conveyance of the coating medium B up to the inlet 3a. The shear-free pump 60 is a peristaltic pump, wherein the peristaltic pump has a hose made of chlorosulfonated polyethylene (CSM). In principle, other pumps are also possible.

[0054] The shear-free pump 60 and a medium line cross-section of the medium line system 30 are designed to convey the coating medium B in such a way that the inlet 3a is supplied with the coating medium B at an inlet pressure greater than or equal to the medium pressure at the recess 3c, for example with an inlet pressure greater than 10^4 Pa.

[0055] In the direction of medium flow M, between the separation system 50, i.e., between the shear-free pump 60, and the inlet 3a, a heater 70 is interposed. The heater 70 is designed to heat the coating medium B to a temperature in the range of 30 °C to 45 °C.

[0056] Figure 4Figure 1 shows a schematic view of a coating system according to the prior art. The coating system includes a medium reservoir 1400 in its medium piping system, which supplies the circuit with the medium for coating a panel 2. Several valves 1700 are provided as part of the medium piping system, with valves with special functions described in more detail below. In the coating system according to the prior art, the medium is drawn from a base machine 1100 by a vacuum device 1200 designed as a double diaphragm pump through a filter designed as a medium filter 1300. The medium is then pumped into a pressure vessel by a pump 1500, which is a pulsation dampener 1600. The medium is then conveyed to a coating head 1000 by the pressure of the pressure vessel. The line for conveying the medium must first be vented.The medium is then forced at a constant pressure through a ball valve 1800, which is designed as a metering valve, to the nozzle on the coating head 1000. Subsequently, the medium must be drawn off using a constant vacuum applied to the coating head 1000. This creates a flow of medium at the nozzle of the coating head 1000. The coating system then operates in a steady state. The medium is pumped in a closed loop within the coating system. The base unit 1100 separates the medium for coating the panel 2 from a gas held under vacuum, which is required for coating and for the cycle. When a panel 2 passes the coating head 1000, the vacuum in a coating area of ​​the coating head 1000, i.e., the nozzle, no longer draws off the medium, and the panel 2 is coated, i.e., painted.The excess medium is extracted and returned to the circuit. The flow rate is manually adjustable and complex. The medium pressure in the coating head 1000 is between 15 x 10^4 Pa and 20 x 10^4 Pa to ensure that panel 2 is sprayed and coated with the coating medium without any breaks. Depending on the amount of foaming caused by the spraying process, the coating on panel 2 may be uneven.

[0057] Figure 5 shows a flowchart of an exemplary coating process.

[0058] According to a process step with the reference number "S100", an edge 2a of the panel 2 is introduced into a coating medium stream via a recess 3c of the coating device 1.

[0059] According to a process step with the reference number "S200", the coating medium B is conveyed to the inlet 3a of the coating device 1 by means of a shear-free pump 60, which is arranged upstream of an inlet of the coating device 1 in the medium flow direction M. The medium is drawn from the separation system 50 by a peristaltic pump and pumped through the heater 70, which is designed as a flow heater, to the coating device 1. The coating medium B is pumped almost without pressure to the inlet 3a of the coating device 1.

[0060] According to a process step with the reference number "S300", the coating medium B is conveyed within the coating device 1 by means of a vacuum device 40 located downstream of a drain of the coating device 1 in the medium flow direction M. In other words, the coating medium B is drawn through the coating device 1 towards the separation system 50 under vacuum.

[0061] Subsequently, according to step "S400", the coating medium B is separated from a gas under negative pressure by the separation system 50. The medium can be gently filtered by the sieve system 51, which is designed as a sieve basket, and conveyed in the circuit of the coating system 100.

[0062] During operation of coating system 100, an air-medium mixture is created at recess 3c of coating device 1, which is designed with a counter-profile to the coating area of ​​panel 2. When a panel 2 passes by coating device 1 – regardless of its direction of travel – the panel 2 is coated, i.e., painted, in its coating area by the air-medium mixture flowing onto it. The excess medium is extracted and returned to the circuit of coating system 100. The quantity control of the coating medium is fully automated. Reference symbol list

[0063] 1 Coating device 2 Panel 2a Edge of panel 3 Medium line 3a Inlet 3A Inlet section 3b Outlet 3B Outlet section 3c Recess 30 Medium piping system 40 Vacuum device 50 Separation system 51 Sieve system 52 Cover 53 Housing 54 Guide wall 60 Pump 70 Heater 80 Valve 90 Coating medium container 100 Coating system 1000 Coating head 1100 Base machine 1200 Vacuum device 1300 Medium filter 1400 Medium container 1500 Pump 1600 Pulsation damper 1700 Valve 1800 Ball valve B Coating medium M Medium flow direction α, alpha angle S100Introducing an edge of the panel into a coating medium stream via a recess of a coating device. S200Conveying the coating medium to the inlet of the coating device by means of a pump arranged upstream of an inlet of the coating device in the direction of medium flow. S300Conveying a coating medium within the coating device by means of a vacuum device arranged downstream of an outlet of the coating device in the direction of medium flow. S400Meeting the coating medium in the separation system of a gas under vacuum.

Claims

1. Coating device (1) for a coating installation (100), wherein the coating installation (100) is configured for edge coating of a panel (2) with a coating medium (B) and wherein the coating device (1) comprises at least one medium line (3) for guiding the coating medium (B), having an inlet (3a) and an outlet (3b), wherein the medium line (3) has a recess (3c) for introducing the panel (2) into a coating medium flow, and wherein the medium line (3) and the recess (3c) are configured such that the coating medium (B) can be applied to the edge (2a) of the panel (2) by means of suction in the medium flow direction (M), wherein the coating installation (100) comprises: a medium line system (30) for guiding the coating medium (B); a pump system connected to the medium line system (30) for conveying the coating medium (B), wherein the coating device (1) is connectable to the medium line system (30), wherein the pump system comprises a negative pressure device (40) arranged downstream of the outlet in the medium flow direction (M), wherein the negative pressure device (40), and in particular a medium line cross-section of the medium line system (30), is configured to generate a negative pressure at the outlet (3b).

2. Coating device (1) according to claim 1, wherein the medium line (3) and the recess (3c) are configured such that the coating medium (B) can be applied to the edge (2a) of the panel (2) at a medium pressure at the recess (3c) in a range of 3.5 × 103 Pa to 5.5 × 103 Pa, preferably at a medium pressure of 5 × 103 Pa.

3. Coating device (1) according to at least one of the preceding claims, wherein the recess (3c) and a medium line cross-section have an aspect ratio relative to one another and the medium line (3) is routed such that the coating medium (B) can be applied to the edge (2a) of the panel (2) by means of suction in the medium flow direction (M), in particular such that the coating medium (B) can be applied to the edge (2a) of the panel (2) at a medium pressure in a range of 3.5 × 103 Pa to 5.5 × 103 Pa, preferably at a medium pressure of 5 × 103 Pa.

4. Coating device (1) according to at least one of the preceding claims, wherein the recess (3c) is arranged at an outer bend of an arcuate or angled medium line section, wherein in particular the arcuate or angled medium line section has an acute interior angle (Alpha), wherein in particular an inlet piece (3A), which extends from the inlet (3a) to the recess (3c), extends vertically when the medium line (3) is connected via the inlet (3a).

5. Coating device (1) according to at least one of the preceding claims, wherein the medium line (3) is U-shaped with two legs, wherein in particular the inlet piece (3A) is a first leg and an outlet piece (3B) extending in the medium flow direction (M) from the recess (3c) to the outlet (3b) is a second leg.

6. Coating device (1) according to at least one of the preceding claims, wherein an edge profile of the recess (3c) is configured to be form-fittingly adapted to the edge (2a) of the panel (2), wherein in particular the edge profile of the recess (3c) is configured as a counter-profile adapted to a profile of the edge (2a) of the panel (2).