DE102020126101A1 - Coating device for depositing a coating material on a substrate - Google Patents

Abstract

Coating apparatus (1) for depositing a coating material on a substrate (2), comprising a coating chamber (3) having an inlet passage (4) and an outlet passage (5), a coating channel (6) arranged within the coating chamber (3). and has an inlet opening (7) and an outlet opening (8), at least one feed line (9) which is connected to the coating channel (6) and has a feed opening (10), a primary suction line which is connected to the coating channel (6). (12) and a filter device (14), which is connected to the primary suction line (12), the filter device (14) being connected to the coating chamber (3) via a primary return line (15) designed to return the mixture cleaned of coating material. is connected, the primary return line (15) opening into the coating chamber (3) via a primary return orifice (16).

Description

The invention is directed to a coating device for depositing a coating material on a substrate, comprising a coating chamber which has an inlet passage and an outlet passage for bringing the substrate in and out, a coating channel designed for coating the substrate, which is arranged inside the coating chamber and which has an inlet opening and an outlet opening for introducing and removing the substrate, and at least one feed line designed for feeding in coating material, which is connected to the coating channel and has a feed opening opening into the coating channel. The substrate can be a steel strip, for example.

the WO 2016/042079 discloses a device for forming coatings on a substrate, which can be, for example, a strip-shaped material or a tool, with the device vaporizing the coating material by means of an arc and being transported to the substrate to be coated by means of a carrier gas stream. A disadvantage of this known device is that the excess coating material supplied in this way does not only condense on the substrate to be coated, but also at any other point in the coating chamber which has a temperature below the condensation temperature of the coating material and which at the WO 2016/042079 is designed as a vacuum chamber.

A coating device of the type mentioned in the introduction is, for example, from DE 10 2004 041 854 known, wherein in this coating device a coating channel or vaporization channel is arranged within the coating chamber designed as a vacuum chamber, which can be heated and which has a nozzle designed for coating the substrate, which is connected to a feed line designed for supplying coating material. The DE 10 2004 041 854 proposes that the coating channel is separated into an inner space and an outer space by inserting a hollow body, so that the substrate is protected in the inner space. In this way, the coating material flowing into the coating channel is not deposited on the substrate. Likewise, there is no uncontrolled coating of the substrate in the event of an accident. It is at the DE 10 2004 041 854 However, the disadvantage is that the amount of excess coating material that settles on the outside of the hollow body cannot be continuously removed, so that either complex changing devices or process interruptions including ventilation of the coating chamber or the vacuum chamber are necessary.

The object of the invention is to create a solution that provides an improved coating device, through which excess coating material can be continuously removed in a structurally simple manner and continuous operation of the coating device is possible without expensive changing devices. The task also includes that the coating device does not disturb or impede the actual application of the coating material and that only the excess portion of the coating material is removed, but not the vapors of the coating material, which could still condense on the material to be coated.

The object is achieved according to the invention by a coating device with the features according to claim 1.

The coating device according to the invention for depositing a coating material on a substrate has a coating chamber, which has an inlet passage and an outlet passage for introducing and removing the substrate, a coating channel designed for coating the substrate, which is arranged inside the coating chamber and which is used for introducing and removing of the substrate has an inlet opening and an outlet opening, and at least one feed line designed for feeding in coating material, which is connected to the coating channel and has a feed opening opening into the coating channel. Furthermore, the coating device according to the invention has a primary suction line designed to suck a mixture of carrier gas and coating material out of the coating channel and connected to the coating channel via a primary suction opening, and a filter device designed to clean the mixture sucked out of the coating channel, which is connected to the primary suction line connected, on. The filter device is connected to the coating chamber via a primary return line designed to return the mixture that has been cleaned of coating material feed line opens into the coating chamber via a primary return port.

Advantageous and expedient refinements and developments of the invention result from the dependent claims.

The invention provides a coating device which is characterized by a simple construction and which prevents the excess coating material from escaping into the free volume of the coating chamber, i.e. into areas outside the coating channel, which in turn prevents the occurrence of Stray layers, which can flake off the substrate and lead to quality problems in the end product, are avoided.

In order to actually remove only excess coating material from the coating channel, a preferred embodiment provides that the primary suction opening is arranged lying between the feed opening and the outlet passage with respect to a conveying direction of the substrate.

It is advantageous here if the primary suction opening and the outlet opening are arranged lying in a common plane. Because at the outlet opening there is the greatest risk in the coating channel that excess coating material will condense and block the outlet opening for the substrate.

Alternatively, in one embodiment of the invention, however, it is also sufficient if the primary suction opening is arranged lying between the feed opening and the outlet opening with respect to a conveying direction of the substrate.

The primary suction opening is preferably arranged lying in a plane which extends parallel to a conveying direction of the substrate.

It is particularly advantageous in an embodiment of the invention if a secondary suction line designed to suck the mixture of carrier gas and coating material out of the coating channel and connected to the coating channel is connected to the filter device, with the secondary suction line being connected to the filter device via a secondary suction opening Coating channel is connected.

With a clever arrangement of the primary suction line or the primary suction opening and the secondary suction line or the secondary suction opening, excess coating material can be suctioned out of the coating channel particularly effectively without adversely affecting the main coating process. Such an advantageous arrangement is given in an embodiment of the invention in that, with respect to a conveying direction of the substrate, the secondary suction opening is arranged lying between the inlet opening and the feed opening.

It is also advantageous in a further embodiment if the secondary suction opening is arranged lying in a plane which extends parallel to a conveying direction of the substrate.

In a further advantageous embodiment, the invention provides that the secondary suction line consists of a high-temperature-resistant material, preferably graphite or ceramic.

So that the coating material sucked off by the secondary suction line first condenses in the filter device, the invention also provides in an embodiment that the secondary suction line is designed to be heatable.

In a further embodiment, the invention provides that a secondary return line designed to return the mixture cleaned of coating material is connected to the filter device, the secondary return line being connected to the coating chamber and having a secondary return orifice.

It is of particular advantage here if the secondary return orifice is arranged at the inlet opening and outside of the coating channel. This arrangement prevents the coating material supplied to the coating channel from escaping from the inlet opening of the coating channel into the coating chamber.

In an embodiment of the invention, this advantageous effect can be increased in that the secondary return orifice is designed to be aligned with the inlet opening.

Furthermore, it is advantageous in an embodiment of the invention if the primary return orifice is arranged at the outlet opening and outside of the coating channel. Because this arrangement prevents the coating material supplied to the coating channel and/or excess coating material from escaping from the outlet opening of the coating channel into the coating chamber.

In this case, too--as in the case of the secondary return opening--the above-mentioned advantageous effect can be increased in the embodiment of the invention by the primary return opening being designed to be aligned with the outlet opening.

According to a further advantageous embodiment of the invention, it is provided that the primary suction line consists of a high-temperature-resistant material, preferably graphite or ceramic.

So that the coating material sucked off by the primary suction line first condenses in the filter device, the invention provides in an embodiment that the primary suction line is designed to be heatable.

In order to lower the vaporization temperature and also the temperature inside the coating channel, it is finally advantageous in an embodiment of the invention if the coating chamber is designed as a vacuum chamber in which a negative pressure prevails.

It goes without saying that the features mentioned above and those that are still to be explained below can be used not only in the combination specified in each case, but also in other combinations or on their own, without departing from the scope of the present invention. The scope of the invention is defined only by the claims.

Further details, features and advantages of the subject of the invention result from the following description in connection with the drawing, in which exemplary and preferred exemplary embodiments of the invention are shown.

• 1 eine schematische Darstellung einer erfindungsgemäßen Beschichtungsvorrichtung gemäß einer ersten Ausführungsform,
• 2 eine schematische Darstellung einer erfindungsgemäßen Beschichtungsvorrichtung gemäß einer zweiten Ausführungsform und
• 3 eine schematische Darstellung einer erfindungsgemäßen Beschichtungsvorrichtung gemäß einer dritten Ausführungsform.

In the drawing shows:

• 1 a schematic representation of a coating device according to the invention according to a first embodiment,
• 2 a schematic representation of a coating device according to the invention according to a second embodiment and
• 3 a schematic representation of a coating device according to the invention according to a third embodiment.

the 1 , 2 and 3 12 show different embodiments of a coating device 1 according to the invention for depositing a coating material on a substrate 2, wherein the substrate 2 can be, for example, a steel strip to be coated. In all three embodiments, the coating device 1 has a coating chamber 3 , the coating chamber 3 having an inlet passage 4 for introducing the substrate 2 into the coating chamber 3 and an outlet passage 5 for removing the substrate 2 from the coating chamber 3 . In order to reduce the vaporization temperature and also the temperature inside the coating chamber, the coating chamber 3 can be designed as a vacuum chamber in the embodiments shown, which also prevents the ambient air from reacting with the coating material. Furthermore, in all three embodiments, the substrate 2 is coated in a coating channel 6 designed for coating the substrate 2. The coating channel 6 is arranged within the coating chamber 3, the coating channel 6 for introducing the substrate 2 into the coating channel 6 having an inlet opening 7 and Ejection of the substrate 2 from the coating channel 6 has an outlet opening 8 . The coating channel 6 is designed to be heatable in that the coating channel 6 is provided, for example, with a heating device not shown in detail in the figures over its entire circumference. In order to coat the substrate 2 with coating material, the coating device 1 in all three embodiments has a feed line 9 designed for feeding in coating material, it also being possible for more than one feed line 9 to be provided as an alternative. The feed line 9 is connected to the coating channel 6 and has a feed opening 10 opening into the coating channel 6 . In this case, the feed opening 10 for introducing the coating material into the coating channel 6 can be designed in the form of a nozzle, it being possible for the feed opening, which is designed in the form of a nozzle, to be aligned with the substrate 2 accordingly.

Furthermore, the in the 1 until 3 The coating device 1 shown has a primary suction opening 11 in all three embodiments, which is formed in the wall of the coating channel 6 . The coating device 1 has a primary suction line 12 designed to suck a mixture of carrier gas and coating material out of the coating channel 6 and connected to the coating channel 6 via the primary suction opening 11 .

Finally, in all three embodiments, the coating device 1 according to the invention has a filter device 14 designed to clean the mixture sucked out of the coating channel 6 . The filter device 14 in the 1 until 3 is indicated only schematically, is connected to the primary suction line 12 . Like the 1 until 3 further to be taken , the filter device 14 in all three illustrated embodiments is connected to the coating chamber 3 via a primary return line 15 designed to return the mixture that has been cleaned of coating material. In all three embodiments of the coating device 1, the primary return line 15 opens into the coating chamber 3 via a primary return orifice 16.

In all three embodiments in the 1 until 3 1, the primary suction opening 11 is arranged lying between the supply opening 10 and the discharge passage 5 with respect to a conveying direction 17 of the substrate 2 . The primary suction of the mixture of carrier gas and coating material from the coating channel 6 therefore takes place with reference to the conveying direction 17 after the supply of the coating material via the supply line 9 or supply opening 10.

The primary suction line 12 and the primary suction port 11 can in all three embodiments, which in the 1 until 3 are shown, be designed to be heatable, with the primary suction line 12 made of a high-temperature-resistant material, preferably made of graphite or ceramics. To heat the primary suction opening 11 and the primary suction line 12, a temperature is preferably selected which is above the condensation temperature of the coating material to be suctioned off. This temperature should be as slightly as possible above the condensation temperature. Because this ensures that the extracted coating material loses temperature up to the filter device 14 , which is a circuit filter in each of the three embodiments, whereby the extracted coating material condenses as desired only inside the filter device 14 . However, on the other hand, the temperature for heating the primary suction opening 11 and the primary suction line 12 is selected so high that the temperature of the coating material that has been cooled in the filter device 14 and returned is still above the temperature of the preheated substrate 2 that is fed to the coating device 1. in order to cool the substrate 2 as little as possible when the filtered coating material is fed back in.

The features described above for the coating device 1 according to the invention relate to all three embodiments. In the following, the differences between the individual embodiments will mainly be discussed, with a repetition of the features already described above being largely dispensed with.

In 1 a first embodiment of the coating device 1 according to the invention is shown. In the first embodiment of the coating device 1, the primary suction opening 11 and the outlet opening 8 are in a common plane 18 (see dashed line in 1 ) arranged horizontally. Thus, the primary suction opening 11 formed in an end wall of the coating channel 6 is offset parallel to the outlet opening 8 formed in the end wall of the coating channel 6, with the primary suction line 12 also extending parallel to the conveying direction 17 of the substrate 2 in the exemplary embodiment shown , wherein a parallelism of the conveying direction 17 and the extension of the primary suction line 12 is not absolutely necessary. The primary suction line 12 runs in sections within the coating chamber 3, with another section of the primary suction line 12 extending further outside the coating chamber 3 to the filter device 14, to which the primary return line 15 is connected. The other end of the primary return line 15 is also connected to the coating chamber 3 and opens into the coating chamber 3 via the primary return orifice 16.

the 2 shows a second embodiment of the coating device 1 according to the invention. In contrast to the first embodiment, the second embodiment of the coating device has a secondary suction line 19 . The secondary suction line 19 is designed to suck the mixture of carrier gas and coating material out of the coating channel 6 and is also connected to the coating channel 6 at one of its two ends. The other end of the secondary suction line 19 is connected to the filter device 14 as shown in FIG 2 is evident. The mixture of carrier gas and coating material is sucked out of the coating channel 6 into the secondary suction line 19 via a secondary suction opening 20 and conducted to the filter device 14 via the secondary suction line 19 . In the second embodiment, both the mixture conveyed via the primary suction line 12 and the mixture conveyed via the secondary suction line 19 are then cleaned and filtered in the filter device 14 . The mixture cleaned of coating material in the filter device 14 is then conveyed from the filter device 14 via the primary return line 15 into the coating chamber 3 . Alternatively, it is also conceivable in the second embodiment that the filtering and cleaning of the extracted Mixing of carrier gas and coating material takes place in separate filter devices, so that two filter devices are provided, in which case the primary suction line 12 is connected to a first filter device and the secondary suction line 19 is connected to a second filter device. In this alternative, the mixture cleaned or filtered from the coating material would then be fed to the primary return line, via which the cleaned or filtered mixture would then be conveyed into the coating chamber 3 .

From the 2 it can also be seen for the second embodiment of the coating device 1 according to the invention that the primary suction opening 11 is arranged lying between the feed opening 10 and the outlet opening 8 with respect to the conveying direction 17 of the substrate 2, whereas the secondary suction opening 20 is between the inlet opening 7 and the feed opening 10 is arranged lying. In addition, the primary suction opening 11 and the secondary suction opening 20 are in one plane 21 (see dashed line in 2 ) arranged lying, which extends parallel to the conveying direction 17 of the substrate 2.

In the second embodiment according to 2 If necessary, the secondary suction line 19, like the primary suction line 12, can also consist of a high-temperature-resistant material, preferably graphite or ceramic. In the second embodiment, the primary suction line 12 and/or the secondary suction line 19 can be designed to be heatable. In the event that the secondary suction line 19 is designed to be heatable, the secondary suction line 19 can thus be set to a temperature which is as little as possible above the condensation temperature of the coating material to be suctioned off, whereby the suctioned coating material reaches the filter device 14 Loses temperature and only condenses within the filter device 14. According to the above statements, it is characteristic of the second embodiment that at least one suction opening, i.e. the primary suction opening 11, is arranged behind the supply opening 10, viewed in the direction of transport 17, and that at least one suction opening, i.e. the secondary suction opening 20, is arranged in the direction of transport 17 is arranged in front of the feed opening 10.

In 3 Finally, a third embodiment of the coating device 1 according to the invention is shown. As before in the second embodiment, a secondary suction line 19 with a secondary suction opening 20 is also present in the third embodiment. The secondary suction line 19 is also designed to suck the mixture of carrier gas and coating material out of the coating channel 6 and is connected to the coating channel 6 via the secondary suction opening 20 . Furthermore, the secondary suction opening 20 is arranged between the inlet opening 7 and the feed opening 10 when viewed in the conveying direction 17 , whereas the primary suction opening 11 is arranged between the feed opening 10 and the outlet opening 8 when viewed in the conveying direction 17 . In the third embodiment, too, the primary suction line 12 and the secondary suction line 19 are connected to the filter device 14 in order to clean the mixture of carrier gas and coating material sucked out of the coating channel 6 . Alternatively, two filter devices can also be provided, which separately clean the mixture sucked out of the coating channel 6 through the primary suction line 12 and the mixture sucked out of the coating channel 6 through the secondary suction line 19 .

In contrast to the second embodiment, in which only the primary return line 15 is provided, in the third embodiment the coating device 1 has a secondary return line 22 designed to return the mixture cleaned of coating material, which is provided in addition to the primary return line 15 is. The secondary return line 22 is connected to the filter device 14 and returns the cleaned mixture to the coating chamber 3 , with the primary return line 15 also leading part of the cleaned mixture into the coating chamber 3 . The secondary return line 22 opens into the coating chamber 3 via a secondary return orifice 23.

In the third embodiment of the coating device 1, the primary return port 16 is arranged at the outlet opening 8 and outside of the coating channel 6, wherein the secondary return port 23 - as shown in FIG 3 can be seen - is arranged at the inlet opening 7 and outside of the coating channel 6 . In the case of the third embodiment of the coating device 1, it has proven to be advantageous that the filtered or cleaned mixture is fed back into the front-side openings of the coating channel 6 on both sides. Accordingly, the secondary return orifice 23 is designed to be aligned with the inlet opening 7 of the coating channel 6 , whereas the primary return orifice 16 is designed to be aligned with the outlet opening 8 of the coating channel 6 . As a result, the filtered mixture is further heated before the filtered or cleaned Mixture reaches the area of the feed opening 10, where the unheated and filtered mixture would otherwise unnecessarily cool down the coating material supplied via the feed opening 10. On the other hand, the targeted flow into the coating channel 6 ensures that the vaporous coating material does not exit via the front inlet opening 7 and the front outlet opening 8 of the coating channel 6, i.e. through the necessary inlet and outlet openings 7 and 8 for introducing and removing the Substrate 2 is largely avoided.

In summary, the coating device 1 according to the invention is characterized in that at least one high-temperature-resistant suction opening (primary suction opening 11) is integrated in the area of the hot coating channel 6, to which a high-temperature-resistant and optionally actively heatable piping in the form of the primary suction line 12 is connected. The primary suction line 12 is connected to the input side of the filter device 14, which can be a circuit filter. The output side of the filter device 14 is in turn connected to the coating chamber 3 in order to feed the cleaned or filtered mixture of carrier gas and coating material back into the coating chamber 3, with the cleaned mixture then only containing the carrier gas.

The invention described is of course not limited to the embodiments described and illustrated. It is evident that numerous modifications can be made to the embodiments shown in the drawing, which would be obvious to a person skilled in the art, depending on the intended application, without thereby departing from the scope of the invention. For example, more than one primary suction opening and thus correspondingly more than one primary suction line can also be provided, with more than one secondary suction opening and thus correspondingly more than one secondary suction line being able to be provided. The invention includes everything that is contained in the description and/or shown in the drawing, including that which differs from the specific exemplary embodiments and is obvious to the person skilled in the art.

Reference List

1

coating device

2

substrate

3

coating chamber

4

entry passage

5

exit passage

6

coating channel

7

entry opening

8th

exit port

9

supply line

10

feed opening

11

Primary suction port

12

Primary suction line

14

filter device

15

primary return line

16

Primary Return Orifice

17

direction of transport

18

common level

19

Secondary suction line

20

Secondary suction port

21

level

22

secondary return line

23

Secondary Return Orifice

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• WO 2016/042079 [0002]
• DE 102004041854 [0003]

Claims (18)

Coating device (1) for depositing a coating material on a substrate (2), comprising - a coating chamber (3) which has an inlet passage (4) and an outlet passage (5) for introducing and removing the substrate (2), - a coating channel (6) designed for coating the substrate (2), which is arranged inside the coating chamber (3) and which has an inlet opening (7) and an outlet opening (8) for introducing and removing the substrate (2), - at least one feed line (9) designed for feeding in coating material, which is connected to the coating channel (6) and has a feed opening (10) opening into the coating channel (6), - a primary suction line (12) designed to suck a mixture of carrier gas and coating material out of the coating channel (6) and connected to the coating channel (6) via a primary suction opening (11) and - a filter device (14) designed to clean the mixture sucked out of the coating channel (6), which is connected to the primary suction line (12), the filter device (14) having a primary return line designed to return the mixture cleaned of coating material (15) is connected to the coating chamber (3), the primary return line (15) opening into the coating chamber (3) via a primary return orifice (16). Coating device (1) after claim 1 wherein the primary suction opening (11) is arranged lying between the supply opening (10) and the discharge passage (5) with respect to a conveying direction (17) of the substrate (2). Coating device (1) after claim 1 or 2 , wherein the primary suction opening (11) and the outlet opening (8) are arranged lying in a common plane (18). Coating device (1) after claim 1 , wherein the primary suction opening (11) is arranged lying between the feed opening (10) and the outlet opening (8) with respect to a conveying direction (17) of the substrate (2). Coating device (1) after claim 1 or 4 , wherein the primary suction opening (11) is arranged lying in a plane (21) which extends parallel to a conveying direction (17) of the substrate (2). Coating device (1) according to one of the preceding claims, wherein a secondary suction line (19) designed to suck off the mixture of carrier gas and coating material from the coating channel (6) and connected to the coating channel (6) is connected to the filter device (14), the secondary suction line (19) being connected to the coating channel (6) via a secondary suction opening (20). Coating device (1) after claim 6 , wherein the secondary suction opening (20) is arranged lying between the inlet opening (7) and the feed opening (10). Coating device (1) after claim 6 or 7 , wherein the secondary suction opening (20) is arranged lying in a plane (21) which extends parallel to a conveying direction (17) of the substrate (2). Coating device (1) according to one of Claims 6 until 8th , wherein the secondary suction line (19) consists of a high-temperature-resistant material, preferably graphite or ceramic. Coating device (1) according to one of Claims 6 until 9 , wherein the secondary suction line (19) is heatable. Coating device (1) according to one of the preceding claims, wherein a secondary return line (22) designed to return the mixture cleaned of coating material is connected to the filter device (14), the secondary return line (22) being connected to the coating chamber (3). and having a secondary return port (23). Coating device (1) after claim 11 , wherein the secondary return orifice (23) is arranged at the inlet opening (7) and outside of the coating channel (6). Coating device (1) after claim 11 or 12 wherein the secondary return port (23) is formed aligned with the inlet port (7). Coating device (1) according to one of the preceding claims, in which the primary return orifice (16) is arranged at the outlet opening (8) and outside the coating channel (6). Coating device (1) according to one of the preceding claims, wherein the primary Return mouth (16) is aligned with the outlet opening (8). Coating device (1) according to one of the preceding claims, in which the primary suction line (12) consists of a high-temperature-resistant material, preferably graphite or ceramic. Coating device (1) according to one of the preceding claims, in which the primary suction line (12) is designed to be heatable. Coating device (1) according to one of the preceding claims, wherein the coating chamber (3) is designed as a vacuum chamber.

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