Coating device and method

Abstract

The invention relates to a coating device and a method for applying a coating medium to a running surface, comprising a coating head extending over the entire width of the running surface, in which a linear guide device is also provided, the linear guide extends in the width direction of the coating device, in particular parallel to the coating head, and is provided for mounting one or more cleaning elements for the coating head.

Description

[0001] The present invention relates to a coating device for applying a coating medium to a running surface as described in the preamble of claim 1 and a method for cleaning a coating head.

[0002] In the manufacture or processing of fibrous webs such as paper webs or cardboard webs, a coating medium is often applied to these webs in order to, for example, influence the surface properties, permeability or strength properties of the fibrous web.

[0003] Here, the coating medium can be applied directly to the running paper web or first to a running transfer surface (e.g., a transfer roller) and then transferred from there to the paper web.

[0004] There are various possibilities for the embodiment of the coating head for discharging the coating medium.

[0005] For example, from DE 10 2016 209 336 A1 and DE 103 59 120 A1, a coating head is known in which the coating medium is discharged from a slit nozzle in the form of a free-falling curtain onto the paper web or a coating roller.

[0006] The documents DE 20 2017 100 655 U1 and DE 20 2015 009 603 U1 show coating heads that apply the coating medium to the running surface through spray nozzles.

[0007] The applicant's later published patent application DE102022105510 shows a coating head that has both a slit nozzle and an air nozzle.

[0008] During the operation of these coating heads, the coating heads can be soiled by the coating medium itself or other contaminants. Here, for example, individual positions or areas of individual spray nozzles or slit nozzles may become blocked, thus affecting the application of the coating medium. Therefore, repeated maintenance and cleaning of these coating heads are essential.

[0009] DE 103 59 120 A1 proposes, for cleaning a curtain nozzle, to provide a closable cleaning opening at the end face of the nozzle.

[0010] It is also known from DE 20 2015 009 603 U1 that, during spray coating, a second spray coating device with a plurality of spray nozzles is provided such that there is always one group of nozzles in the coating position while the second group of nozzles is in the maintenance or cleaning position.

[0011] However, the actual cleaning of these coating heads is carried out completely manually using sponges, hoses, high-pressure cleaners. But this is both difficult and costly, especially when the coating head is installed in a machine where it is impossible or only limitedly possible to work in the narrow nozzle gaps.

[0012] For spray nozzles, it is usually also necessary to remove the second set of nozzles from the machine to ensure thorough cleaning, without interrupting the machine operation for too long.

[0013] The technical problem to be solved by the present invention is to achieve improved cleaning of the coating head and trouble-free operation of the coating device.

[0014] In addition, the technical problem to be solved by the present invention also lies in proposing a flexible system that can be applied to different types of coating heads.

[0015] This technical problem is solved according to the present invention by a coating device according to claim 1 and a method for cleaning a coating head according to claim 12. Other advantageous embodiments of the present invention can be found in the dependent claims.

[0016] A coating device for applying a coating medium to a running surface is proposed, including a coating head extending over the entire width of the running surface. According to the present invention, a linear guiding device is also provided, which extends in the width direction of the coating device and is provided for mounting one or more cleaning elements for the coating head.

[0017] The running surface can be a material web, in particular a paper web, a cardboard web or a pulp web. Alternatively, the running surface can also be a transfer surface, for example the surface of a transfer roller. The coating medium can be transferred from this transfer surface to the material web in a transfer nip.

[0018] If the coating head extends at least over the part of the surface provided for the coating, then the feature that the coating head extends over the entire width of the running surface should be considered to be satisfied here. Thus, for example, in indirect coating, the transfer roller may be slightly wider than the material web to be coated later. In this case, the coating head can also extend only over the width of the later material web. However, since these differences are in the order of a few centimeters, which is almost negligible compared to the width of a paper machine, which is usually about 10 m and wider, for the sake of easy reading, these linguistic distinctions are omitted in this application, and the term "entire width" is used instead.

[0019] The coating medium can be, for example, a starch solution, a pigment-containing coating color or a barrier medium.

[0020] Preferably, the linear guiding device can be provided on the coating head. Here, it can either be stipulated that the linear guiding device is fixed to the coating head. Alternatively, it can be stipulated that the coating head itself is shaped such that it directly serves as the linear guiding device. If the linear guiding device cannot or should not be directly fixed to the coating head, an equivalent solution is that the linear guiding device and the coating head are held by the same support device.

[0021] In a preferred embodiment, it can be provided that the coating device comprises at least one cleaning element which is mounted on a linear guide and is in particular detachably mounted.

[0022] Cleaning the coating head in a machine, such as a paper machine, is difficult for various reasons.

[0023] On the one hand, these devices are very wide. Widths of 10 m and more are common today. Therefore, the area of the coating head, especially in the middle of the web, is difficult to access.

[0024] In addition, the available installation space is very limited. This applies both to direct coating, where the coating head has to be positioned close to the paper web, and to indirect coating, since one or more transfer rollers described here take up a large amount of space.

[0025] In addition, the components and structures to be cleaned are relatively small, so precise positioning of the cleaning element is required.

[0026] The present invention now solves these problems by providing a linear guide in the coating device. This linear guide extends in the width direction of the running surface, like the coating head. In an advantageous embodiment, it can be provided that the linear guide extends parallel to the coating head.

[0027] Such a guide can be constructed relatively compactly, so that it can be inserted into the existing installation space. A suitable cleaning element can be mounted on this linear guide. If the cleaning element is detachably mounted, it is inserted into the machine only at the time of cleaning and removed again after cleaning is complete.

[0028] Particularly advantageously, the linear guide is arranged on the coating head itself as described above. This brings a series of advantages.

[0029] On the one hand, such a linear guide is easy to implement and can also be retrofitted into existing equipment very simply.

[0030] In addition, by mounting the linear guide on the coating head, it can be ensured by simple means that the relative position of the linear guide with respect to the coating head to be cleaned can be maintained very precisely.

[0031] In addition, the weight of the cleaning element is relatively light, so that the influence of the traversing cleaning element on the positioning of the coating head can be excluded.

[0032] The weight of a medium-sized cleaning element - including the drive - will be between 10 kg and 20 kg. Since a coating head of machine width usually weighs more than 100 kg / m and the support structure and crossbeam are designed to hold this weight in place, the additional weight of the cleaning element is not significant.

[0033] In addition, this embodiment eliminates the need for the linear guiding device to have its own crossbeam or bracket. As a result, the coating device can be realized very economically.

[0034] If the linear guiding device cannot or should not be directly fixed to the coating head, an equivalent solution is that the linear guiding device and the coating head are held by the same supporting device.

[0035] It is also possible to provide a plurality of cleaning elements. In particular, it may be advantageous to provide different types of cleaning elements that operate at different positions or by different cleaning methods. With this modular structure, the coating device according to various aspects of the present invention can be used very flexibly.

[0036] In a preferred embodiment, at least one cleaning element can be movable along the linear guiding device. In this way, the entire width of the coating head can be cleaned with a single, relatively compact cleaning element. In addition, it is significantly easier to install small, movable cleaning elements than rigid cleaning elements of the machine width.

[0037] The movement of the cleaning element can be carried out manually, electrically, pneumatically or hydraulically, for example. Manual movement can be achieved very simply and economically, for example by means of a pull cord. For simple cleaning elements, such as a sponge or the like that is directly pulled across the position to be cleaned, such as the coating head, this fully meets the requirements. For more complex and heavier cleaning elements, such as cleaning elements with cleaning nozzles, automatic or semi-automatic movement will be preferred.

[0038] It can be stipulated here that the linear guiding device itself has means for moving the cleaning element. The cleaning element is then fixed to the movable unit. As a result, the cleaning element can be held very simply. This may be particularly advantageous for mechanical cleaning elements (such as sponges, films, etc.). In addition, even if a plurality of different cleaning elements are used, only one moving unit is required.

[0039] Alternatively, the linear guiding device can be designed very simply and, for example, consist only of slats, tracks or the like. In this case, the moving means can be integrated into the cleaning element. The advantage of this is that the linear guiding device can be designed very simply and compactly.

[0040] In addition, the components of the moving unit are only installed in the machine during the cleaning process, so contamination of the moving unit during the operation of the coating device can be avoided. This solution may be particularly advantageous for more complex cleaning units, such as those including spray nozzles, etc.

[0041] It can be stipulated that the coating head has a slot nozzle, wherein the slot extends particularly in the entire width direction of the cleaning device.

[0042] Here, especially in curtain coating or in the combination slit and air nozzles of DE102022105510, the slit width of the slit nozzle is usually less than 2 mm, especially less than 1 mm.

[0043] Alternatively or additionally, it can be provided that the coating head has one or more spray nozzles, wherein, in particular, a plurality of spray nozzles are arranged along the width direction of the coating device.

[0044] In an advantageous embodiment, it can be provided that the cleaning element has mechanical cleaning means, in particular a cleaning film, a brush or a sponge.

[0045] The surface of the discharge head can be cleaned in particular by a sponge.

[0046] The surface of the coating head is also cleaned with a brush. If the brush is designed as a rotary brush, the cleaning effect can be improved.

[0047] A cleaning film can be particularly advantageous for slit nozzles. Since the gap width of the slit in these wide slit nozzles is very small, the risk of contamination here is relatively high. For cleaning, the cleaning film can be introduced into the nozzle gap, for example, on the operator side and then moved in the width direction.

[0048] The cleaning film can be made here, for example, of plastic, metal, CFK, GFK or other suitable materials.

[0049] Since gap widths of < 1 mm often occur, these cleaning films must be very thin but still resistant. Therefore, CFK and GFK films are particularly recommended here. Compared to thin polymer films of PVC or the like, such CFK or GFK films and metal films are rather shape-stable and are therefore easier to insert into the gap to be cleaned. Such shape-stable films can also be referred to as "sheets". For better readability, such sheets should also be included in the concept of "film" in this application.

[0050] Although the cleaning film itself is a wearing part, most of the cleaning element with the holder or the moving device of the film is always reusable. The cleaning tool holder for the quickly replaceable cleaning film can be constituted, for example, by a clamping device.

[0051] Alternatively or additionally, it can be provided that the cleaning element has one or more cleaning nozzles. In particular, it may be advantageous to arrange two or three cleaning nozzles side by side.

[0052] These cleaning nozzles can be loaded with a cleaning fluid such as air, water, etc., and the cleaning fluid can optionally also be admixed with a surfactant or other cleaning agent.

[0053] Depending on the setting and the pressure, the cleaning fluid can also penetrate into the coating head or can also remove, for example, the contamination inside the spray nozzles.

[0054] By moving a separate cleaning nozzle along the linear guide, the entire width of the coating head can be cleaned without having to fixedly lay a pipeline for the cleaning medium in the installation space. After cleaning, these pipelines and the remaining parts of the cleaning elements can be removed from the coating device again.

[0055] It can be provided that both the coating head and the linear guide are fixedly installed.

[0056] Alternatively, it can be provided that the coating head can be moved, in particular swung, from the working position to the maintenance position. Thus, cleaning can be carried out at a more favorable position, and if necessary, parts of the coating head that are inaccessible or difficult to reach in the working position, for example due to too small a distance from the transfer roller, can also be reached. This can be achieved, for example, as implemented in DE 20 2015 009 603 U1, by providing a second spray coating device with a plurality of spray nozzles during spray coating, such that always one group of nozzles is in the coating position while the second group of nozzles is in the maintenance or cleaning position. However, other implementation methods are also possible.

[0057] Alternatively or additionally, it can also be provided that the linear guide can be moved, in particular swung, from the parked position to the maintenance position. The parked position can be selected, for example, such that the linear guide affects the production process as little as possible there.

[0058] In a preferred embodiment, it can be provided that the cleaning element has an active and a passive state, and a device for switching the cleaning element from the active state to the passive state and / or from the passive state to the active state is provided.

[0059] One implementation of this feature can be that a mechanical cleaning element, such as a sponge, does not contact the surface to be cleaned in the passive state. In the active state, the sponge then adheres to, in particular swings to, the surface to be cleaned.

[0060] An alternative implementation of this feature can be that the cleaning nozzle is not opened in the passive state. Subsequently, the nozzle is switched to the active state by supplying the cleaning fluid.

[0061] Depending on the cleaning element, other embodiments can also be considered.

[0062] The advantage of this embodiment is that the movement and positioning of the cleaning element can be carried out independently of the cleaning process. Thus, individual positions in the width direction can be cleaned in a targeted manner. Therefore, the wear of the cleaning element or the consumption of the cleaning agent can be reduced.

[0063] For this purpose, it may be advantageous to arrange a sensor downstream of the coating device in the process direction, for example a high-resolution scanner with a web detection system, which can determine the location of a defect when a disturbance occurs, such as uncovered stripes in the fiber web. The cleaning element can then be moved precisely to this area - preferably in a passive state - and the disturbance can be eliminated in a targeted manner.

[0064] Furthermore, a method for cleaning a coating head is proposed, wherein the coating head is arranged in a coating device according to one aspect of the invention, and wherein the method comprises the following steps:

[0065] a) Mounting at least one cleaning element on a linear guiding device;

[0066] b) Moving the cleaning element along the linear guiding device in the width direction of the coating head.

[0067] It can be provided here that the cleaning element is in an active state during its movement along the linear guiding device. Thus, the coating head is cleaned during the entire movement.

[0068] Alternatively, it can also be provided that the cleaning element is moved to a first position in a passive state, where the cleaning element is switched from the passive state to the active state. The cleaning element can then clean in a targeted manner at this position. Subsequently, the cleaning element can be moved in particular to a second position.

[0069] It may be advantageous to arrange a sensor device downstream of the coating device in the web running direction for determining disturbances in the fiber web and to determine the first position based on these sensor values. For example, a high-resolution scanner can be arranged in particular within the scope of a web detection system, which detects disturbances such as uncovered stripes in the fiber web and determines their location (as the first position).

[0070] The cleaning element can then be moved - preferably in a passive state - to this first position and the coating head can be cleaned in a targeted manner at this position.

[0071] As the sensor device, a variety of sensors are suitable. Here, the sensor can be, for example, a scanner for determining the basis weight. Alternatively, in particular, it can also be a gloss sensor for determining the gloss of the paper surface.

[0072] Optical systems based on cameras are also commonly used.

[0073] However, it is also possible to determine the contamination location by the formation of individual thickened or thinned stripes at the winding point.

[0074] The list of possible sensor devices can also be extended.

[0075] The present invention will be described with reference to the accompanying drawings. The present invention is not limited to these embodiments herein. In the drawings in detail:

[0076] Figure 1 shows a coating device according to one aspect of the present invention

[0077] Figure 2 shows a coating device according to another aspect of the present invention

[0078] Figure 3a and Figure 3b shows a coating device according to a further aspect of the present invention

[0079] Figure 4 shows a coating device known from the prior art.

[0080] Figure 5 shows again a coating device according to one aspect of the present invention

[0081] Figure 6 shows a film press according to one aspect of the present invention

[0082] Figure 1 shows a side view of a coating device according to one aspect of the present invention. The coating head 1 is designed here as a slit nozzle of a curtain coating mechanism, which - entering the drawing plane - extends over the entire width of the running surface 10. The coating head 1 is connected here to the machine bed by a bracket (not shown). Furthermore, a linear guiding device 2 extending in the width direction is provided. In the embodiment shown here, the linear guiding device 2 is directly fixed to the coating head 1 and extends parallel thereto.

[0083] Furthermore, Figure 1 shows a cleaning element 3 for cleaning the coating head 1. Here, mechanical cleaning is carried out by a cleaning film 4a, which is introduced into the nozzle gap of the coating head 1. If the cleaning element 3 is moved along the linear guiding device 2, the cleaning film 4a is pulled through the nozzle gap, so that contaminants in the gap can be removed. Since gap widths of < 1 mm often occur, these cleaning films 4a should be very thin but still resistant. Therefore, especially shape-stable CFK and GFK films are recommended here.

[0084] Furthermore, a bracket 5 is provided. The bracket 5 can here be part of the cleaning element 3 and can be easily removed and inserted together with it. Alternatively, however, the bracket 5 can also be separated from the cleaning element 3, so that only the bracket of the cleaning film 4a is removed from the machine - for example for replacing the cleaning film 4a - while the bracket 5 remains permanently in the machine.

[0085] The movement of the cleaning element 3 along the linear guide can be carried out in various ways. One possibility is manual movement via a pull cord or a crank. However, this is only suitable for narrower machines. Usually, the movement will be carried out electrically, pneumatically or hydraulically. The device for moving the cleaning device can either be installed in the linear guide here. Alternatively, the device for movement - for example, a drive motor - can also be installed in the cleaning element 3 itself or in the support 5.

[0086] Figure 2 The illustrated embodiment differs from Figure 1 in that instead of mechanical cleaning by means of the cleaning film 4a, one or more cleaning nozzles 4b are provided. In particular, it may be advantageous to arrange two cleaning nozzles 4b side by side. It is also possible to use the cleaning film 4a and the cleaning nozzles 4b simultaneously in one cleaning element 3.

[0087] Figure 2 The embodiment of

[0088] Figure 3a and Figure 3b shows a coating device according to some aspects of the present invention. The coating head 1 is equipped with two groups of spray nozzles 1b, as known from DE 20 2015 009 603 U1, for applying a coating medium to the moving surface 10. One group of spray nozzles 1b is in the working position 6a, while the second group of spray nozzles 1b is in the maintenance or cleaning position 6b.

[0089] Here, a linear guide 2 extending in the width direction of the coating device is also provided. The linear guide 2 is installed on the coating head 1, or rather, the coating head 1 and the linear guide 2 are held by the same support device - the support 5.

[0090] Furthermore, a cleaning element 3 is provided, which is installed on the linear guide 2 and in particular is detachably installed on the linear guide 2. The linear guide 2 and the cleaning element 3 are installed in such a way that the spray nozzles 1b located in the cleaning position 6b can be cleaned, while the coating device can continue to operate with the remaining spray nozzles located in the working position 6a.

[0091] In Figure 3a the illustrated device, a cleaning sponge 4c is provided for cleaning. This may be advantageous because, unlike cleaning with the cleaning nozzles 4b, no spray is generated here that could affect the operation of the coating device.

[0092] Figure 3b shows a variant of the device. Different from Figure 3aThe difference is that the cleaning element 3 includes both a cleaning sponge 4c and a cleaning nozzle 4b. It can be stipulated here that both the cleaning nozzle 4b and the cleaning sponge 4c are in an active state when the cleaning element moves along the linear guiding device. However, it can also be stipulated that the cleaning nozzle 4b and / or the cleaning sponge 4c are in a passive state until the cleaning element 3 moves to the first position. This can be, for example, a severely contaminated spray nozzle 1b. Then it can be switched from the passive state to the active state, so that in particular the cleaning nozzle 4b is activated by supplying a cleaning fluid, and the contaminated spray nozzle 1b or the contaminated part of the coating head 1 is cleaned in a targeted manner.

[0093] Advantageously here, a suitable sensor is provided downstream of the coating unit in the process direction, which can identify the contamination location by the resulting web interference and transmit this contamination location to the control device of the cleaning element 3.

[0094] Figure 4 A coating device known from the prior art, in particular DE102022105510, is shown. The coating head 1 here includes both a slot nozzle 1a for discharging the coating medium and a spray nozzle 1b. The spray nozzle 1b is loaded with air so that the coating medium discharged from the slot nozzle 1a across the machine width is deposited in the form of a spray on the running surface 10.

[0095] For this coating head 1, both the slot nozzle 1a and the spray nozzle 1b can be contaminated. Therefore, it is particularly advantageous to clean the nozzles 1a, 1b simply and reliably.

[0096] Figure 5 An improvement to the Figure 4 device according to an aspect of the present invention is shown. Here again, a linear guiding device 2 for accommodating the cleaning element 3 is provided. Since the distance between the air nozzle 1b and the running surface 10 is usually very short, embodiments in which the linear guiding device 2 and / or the spray nozzle 1b and / or the slot nozzle 1a can be moved to, in particular swung to, a maintenance or cleaning position are particularly advantageous here.

[0097] In Figure 5 the illustrated embodiment, the cleaning element 3 has both a cleaning film 4a for cleaning the slot nozzle 1a and a cleaning nozzle 4b for cleaning the spray nozzle 1b. Various other embodiments can also be envisaged here. For example, a cleaning nozzle 4b can also be provided for cleaning the slot nozzle 1a. For example, a separate cleaning nozzle 4b can also be provided, the spray direction of which is set or can be set so that both the spray nozzle 1b and the slot nozzle 1a can be cleaned with this cleaning nozzle.

[0098] Figure 6Shows a size press for coating a starch solution on both sides of a fibrous web. Here, two transfer rollers 20 are provided, and these two transfer rollers are arranged such that they form a transfer nip 25, in which the starch solution is transferred from the surfaces of the transfer rollers 10, 20 to the paper web or cardboard web. A coating head 1 is provided on each transfer roller, and this coating head is similar to Figure 4 and respectively has a slot nozzle 1a and a spray nozzle 1b. Alternatively, only a slot nozzle 1a or only a spray nozzle 1b can also be provided.

[0099] To ensure good penetration of the starch solution into the fibrous web, it may be advantageous for both transfer rollers 20 to be provided with a hard surface. The hardness of the roller surface can be especially greater than 50 Shore D, or also greater than 60 Shore D.

[0100] In the film press, for each coating head 1, a linear guiding device 2 is respectively provided. Here, it is particularly advantageous that the two linear guiding devices 2 are designed identically. This can, for example, enable cleaning of the two coating heads 1 with a single cleaning element 3. This is especially advantageous when the cleaning element 3 is very complex and, for example, includes its own drive device and / or a device for supplying cleaning fluid to the cleaning nozzle 4b.

[0101] In Figure 6 the shown embodiment, the linear guiding devices 2 are respectively mounted on the spray nozzles 1b, or rather, both share a bracket 5. Alternatively or additionally, for example, it can also be stipulated that the linear guiding devices 2 are provided on the slot nozzles 1a.

[0102] Depending on the application, it may also be advantageous to provide linear guiding devices 2 on both the spray nozzles 1b and the slot nozzles 1a. In this way, cleaning elements 3 can be provided for the slot nozzles 1a and the spray nozzles 1b respectively, and these cleaning elements can clean the corresponding parts of the coating head 1 independently of each other.

[0103] List of reference numerals

[0104] 1 Coating head

[0105] 1a Slot nozzle

[0106] 1b Spray nozzle

[0107] 2 Linear guiding device

[0108] 3 Cleaning element

[0109] 4a Cleaning film

[0110] 4b Cleaning nozzle

[0111] 4c Cleaning sponge

[0112] 5 Bracket

[0113] 6a working position

[0114] 6b cleaning position

[0115] 10 running surface

[0116] 20 transfer roller

[0117] 25 transfer nip

Claims

1. A coating device for applying a coating medium to a running surface, comprising a coating head extending over the entire width of the running surface, characterized in that, A linear guiding device is also provided, which extends in the width direction of the coating device, in particular parallel to the coating head and is provided for mounting one or more cleaning elements for the coating head.

2. The coating device according to claim 1, wherein, The linear guiding device is arranged on the coating head, or the linear guiding device and the coating head are held by the same supporting device.

3. The coating device according to any one of the preceding claims, characterized in that, The coating device includes at least one cleaning element, which is mounted on the linear guiding device and is in particular detachably mounted.

4. The coating device according to claim 3, characterized in that, The at least one cleaning element is designed to be movable along the linear guiding device, wherein the movement is carried out in particular manually, electrically, pneumatically or hydraulically.

5. The coating device according to any one of the preceding claims, characterized in that, The cleaning element has mechanical cleaning means, in particular a cleaning film, preferably in the form of a CFK or GFK film, a sponge or a brush.

6. The coating device according to any one of the preceding claims, characterized in that, The cleaning element has one or more cleaning nozzles.

7. The coating device according to any one of the preceding claims, characterized in that, The coating head has a slot nozzle, wherein the slot extends in particular in the entire width direction of the cleaning device, and wherein the slot width of the slot nozzle is preferably less than 2 mm, particularly preferably less than 1 mm.

8. The coating device according to any one of the preceding claims, characterized in that, The coating head has one or more spray nozzles, wherein a plurality of spray nozzles are arranged in particular in the width direction of the coating device.

9. The coating device according to any one of the preceding claims, characterized in that, The coating head can be moved, in particular swung, from the working position to the maintenance position, and / or the linear guiding device can be moved, in particular swung, from the parked position to the maintenance position.

10. The coating device according to any one of the preceding claims, characterized in that, The cleaning element has an active state and a passive state, and is provided with means for switching the cleaning element from the active state to the passive state and / or from the passive state to the active state.

11. The coating device according to any one of the preceding claims, characterized in that, The coating device has a first coating head and a second coating head, the first coating head is equipped with a first linear guiding device, the second coating head is equipped with a second linear guiding device, and wherein the coating device also has a cleaning element that can be alternately mounted on the first linear guiding device and on the second linear guiding device.

12. A method for cleaning a coating head, wherein, The coating head is arranged in the coating device according to any one of the preceding claims, and wherein the method includes the following steps: a) mounting at least one cleaning element on the linear guiding device; b) moving the cleaning element along the linear guiding device in the width direction of the coating head.

13. The method according to claim 12, characterized in that, The cleaning element is in the active state during the movement along the linear guiding device.

14. The method according to claim 12, wherein The cleaning element is moved to a first position in the passive state, where the cleaning element is switched from the passive state to the active state.

15. The method according to claim 14, wherein A sensor device is arranged behind the coating device in the running direction of the web in order to determine disturbances of the fiber web, and the first position is determined based on the sensor values.

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