Coating device for applying a viscous material and method for conveying viscous material onto a substrate

Abstract

The invention relates to a coating device (1) for applying a viscous material to a substrate, comprising a nozzle (2) through which the material can be conveyed from the coating device (1) to the substrate, and a line (3) through which the nozzle (2) is connected to a reservoir (4) in which the material can be stored, and a conveying device (5) arranged on the line (3) through which the material can be conveyed from the reservoir (4) via the line (3) to the nozzle (2), and a first filter device (7) comprising at least one filter (6), which is arranged in the line (3) upstream of the nozzle (2) in the conveying direction (8), wherein an intermediate storage reservoir (9) and a second filter device (10) are arranged in the line (3) between the conveying device (5) and the first filter device (7). The invention further relates to a method for conveying viscous material onto a substrate.

Description

[0001] The invention relates to a method for applying a viscous material to a substrate according to claim 1. Furthermore, the invention relates to a method for conveying viscous material onto a substrate by means of a coating device according to claim 10.

[0002] Coating devices can be used, for example, to apply electrode paste as a viscous material to a substrate, which can then form an electrode. Coating devices therefore play a role in the production of battery cells.

[0003] Battery cells can be used to form a traction battery for a motor vehicle. For maximum efficiency and / or durability of the vehicle, it is desirable to ensure the quality of the electrode paste prior to application, particularly with a slotted die, during the coating process to ensure a particularly high-quality battery.

[0004] US 10 566 603 B2 shows a battery module and an associated manufacturing method.

[0005] The object of the present invention is to provide a coating device for applying viscous material to a substrate and a corresponding method for applying the material, by means of which a particularly uniform application of the material is made possible.

[0006] This object is achieved according to the invention by the subject matter of the independent patent claims. Advantageous embodiments and further developments of the invention are specified in the dependent patent claims as well as in the description and the drawings.

[0007] A first aspect of the invention relates to a coating device for applying a viscous material, which may be in the form of a fluid, for example, to a substrate. The coating device has a nozzle, via which the material can be conveyed from the coating device to the substrate, and a line, via which the nozzle is connected to a reservoir, in particular a storage tank, in which the material can be stored, and a conveying device arranged on the line, by means of which the material can be conveyed from the reservoir via the line to the nozzle. Furthermore, the coating device has a first filter device having at least one filter, which is arranged in the line in the conveying direction, i.e. upstream of the nozzle.

[0008] The material can, for example, comprise an electrode paste and / or solvent. The conveying device is designed in particular as a pump and can be arranged directly in the line. Thus, the conveying device can convey material from the reservoir, in which the material is held, into a first part of the line to the conveying device or the pump and from there into the next part of the line and on to the nozzle, which is designed in particular as a slot nozzle. The conveying direction is the direction from the reservoir towards the nozzle and thus corresponds to the direction along which the pump conveys the material. The filter can, for example, be designed as a sieve and / or have a sponge-like or porous structure. The filter device comprises the filter and can, for example, furthermore have a housing for the filter, through which the filter can be arranged or inserted in the line.

[0009] In order to enable a particularly homogeneous application of the material to the substrate, the invention provides that an intermediate storage device is arranged between the conveying device and the filter device in the line and a second filter device having at least one filter is arranged upstream of this intermediate storage device in the conveying direction.

[0010] In other words, several filter stages are provided for the coating device in combination with a buffer storage between the filter stages, which can improve the material supply for the coating process. The last or final filter stage, which is arranged upstream of the nozzle and is formed by the first filter device, is provided so that its filter enables filtration for the target fineness of the material. The at least one second filter stage provided can have a coarser filter stage or also offer filtration according to the target fineness.

[0011] In practice, the use of electrode paste with conventional coating machines for the production of battery cells for motor vehicles has shown that when using only one filter or the first filter device, even if the electrode paste is homogenized or free of impurities, trouble-free conveyance of the latter is not possible, as the filter becomes clogged and a filter cake forms. This is accompanied by fluctuations in the differential pressure across the filter, i.e., different pressures occur in the line section upstream of the filter and in the line section downstream of the filter. Thus, it is impossible to find a suitable filter or the correct filter stage during normal operation, which subsequently leads to incorrect filter operation. This can, for example, lead to a complete interruption of the coating.This leads to a large amount of scrap, especially in pilot or series production systems in automotive production. Furthermore, due to the fact that conventional coating systems only have one filter installed, a filter change, especially due to an increase in differential pressure, always involves a production interruption.

[0012] The coating device presented can avoid the problems mentioned or prevent them from occurring.

[0013] It has proven advantageous for the coating device if the nozzle is designed as a slot nozzle, so that the coating, i.e., the application of the viscous material to the substrate, is a slot-die coating. In other words, the coating device is designed for slot-die coating, in which a thin layer of liquid or the material can be applied particularly advantageously to a slot-shaped substrate. This results in the advantage that the coating device can be used advantageously for forming particularly precise coatings.

[0014] In a further advantageous embodiment, in particular in order to be able to apply a particularly precise layer of material, a third filter device having at least one filter is arranged upstream of the second filter device in the conveying direction. In terms of their basic structure, both the second filter device and the third filter device are constructed analogously to the first filter device. The filter devices can only differ in the filter size of the respective filter. The filter size is the property of the respective filter to still allow particles of a certain size to pass through. It is particularly advantageous that the at least one filter of the third filter device, which is arranged upstream of the second filter device in the conveying direction, allows larger particles to pass through than the at least one filter thereof and / or the filter of the first filter device.By using several filter stages upstream of the intermediate storage, which can in particular be designed as an intermediate tank, a particularly good homogenization or filtering of the material can be achieved, so that a particularly advantageous coating is made possible.

[0015] In an advantageous embodiment, the conveying device is arranged between the reservoir and the second or third filter device, and a further conveying device is provided, which is arranged between the intermediate storage device and the first filter device. In other words, in addition to the first pump, a further pump is provided by which the material can be conveyed. The first pump serves to convey the material from the reservoir through the second or the second and third filter unit to the intermediate storage device. The further conveying device or pump finally serves to convey the material for the coating from the intermediate storage device via the first filter device through or to the nozzle, in particular the slot nozzle. This has the advantage that particularly homogeneous conveying of the material is possible.

[0016] In a further advantageous embodiment of the invention, a filter size of the at least one filter of the first filter device is the same as the filter size of the at least one filter of the second filter device and / or smaller than the at least one filter of the third filter device. In other words, the at least one filter of the first and second filter device is designed such that it each filters for the same particle size. In contrast, the at least one filter of the third filter device is designed such that it filters larger particles than the filters of the first and / or second filter device. This results in the advantage that, in particular, a differential pressure at the first filter device can be particularly low, thereby enabling a particularly high quality of the coating.

[0017] In a further advantageous embodiment of the invention, a pressure sensor is arranged upstream and / or downstream of at least one of the filter devices in the conveying direction, by means of which pressure sensor the pressure of the material acting in the line or in the line section can be measured. In other words, for at least one of the filter devices, the pressure upstream and downstream of the filter device is determined, so that a differential pressure of the filter device can be determined in a particularly advantageous manner. This makes it possible, for example, to determine the need for a filter replacement at an early stage. Advantageously, enough pressure sensors are arranged to determine the differential pressure of all three filter devices. Furthermore, it is advantageous if the respective pressure sensor is arranged as close as possible to the respective filter, i.e. at a particularly short distance upstream or downstream of the filter or the respective filter device.This allows, for example, the respective differential pressure to be determined with particular precision. Furthermore, the coating device can be operated and, in particular, maintained particularly advantageously.

[0018] In a further advantageous embodiment of the invention, the first filter device and / or the second filter device and / or the third filter device each have at least two filters arranged in parallel. In other words, instead of just one respective filter, at least one second filter is provided for the respective filter device. These at least two filters are connected in parallel, in particular depending on a particle or mass flow to be converted, i.e. the material can flow through them next to one another, rather than one after the other. The use of filters arranged in parallel for the respective filter device has the advantage of being able to respond to a required mass flow or volume flow in a particularly advantageous manner.In addition, the respective filter device has the advantage that at least one individual filter can be replaced and at least one other filter can still be operated or used.

[0019] For this purpose, in a further advantageous embodiment, an interruption unit, in particular in the form of a ball valve, is arranged upstream and downstream of the respective filter of the respective filter unit in the conveying direction. In other words, the at least one filter is decoupled from the flow of material without causing a leak in the line. This results in the advantage of enabling filter replacement in a particularly advantageous and simple manner.

[0020] In a further advantageous embodiment of the invention, the first filter device and / or the second filter device and / or the third filter device provides a connection device or connection option, in particular in the form of a blind flange, for an additional filter. In other words, the respective filter unit is designed such that, in particular depending on the mass flow requirement, an additional filter can be easily fitted into the filter device in parallel with the at least one existing filter. This results in the advantage that the coating device can be operated particularly advantageously, since flexible adaptation to the required mass flow of the material is possible.

[0021] A second aspect of the invention relates to a method for conveying viscous material onto a substrate by means of a coating device, wherein the material is conveyed from the coating device onto the substrate via a nozzle, and the nozzle is connected via a line to a reservoir in which the material can be stored, and a conveying device is arranged on the line, through which the material is conveyed from the reservoir via the line to the nozzle, wherein a first filter device having at least one filter is provided, which is arranged upstream of the nozzle in the line in the conveying direction, and an intermediate storage device is arranged between the conveying device and the filter device in the line and a second filter device having at least one filter is arranged upstream of this intermediate storage device in the conveying device.

[0022] Advantages, advantageous embodiments and further developments of the first aspect of the invention are to be regarded as advantages, advantageous embodiments and further developments of the second aspect of the invention and vice versa.

[0023] In an advantageous embodiment of the invention, the conveyed material used for the coating is a highly viscous, elastic material and / or an electrode paste. In other words, the material used for the coating process has a particularly high viscosity and, in addition, a particularly high elasticity. Additionally or furthermore, the material is suitable for forming an electrode on the substrate and is therefore designed as an electrode paste. This results in the advantage that the process can be used particularly advantageously for motor vehicle production.

[0024] Further features of the invention emerge from the claims, the figures, and the description of the figures. The features and combinations of features mentioned above in the description, as well as the features and combinations of features mentioned below in the description of the figures and / or shown alone in the figures, can be used not only in the respective specified combination, but also in other combinations or on their own.

[0025] The invention will now be explained in more detail using a preferred embodiment and with reference to the drawings. It shows: Fig. 1 shows a schematic view of a coating device according to the prior art; and Fig. 2 shows a schematic view of a coating device with several filter devices, pressure sensors and conveying devices for an advantageous application of a viscous material to a substrate.

[0026] The Fig. 1 shows a coating device according to the prior art, wherein the coating device is designed for applying viscous material to a substrate and has a nozzle 2 for this purpose, through which the material can be conveyed from the coating device to the substrate. The nozzle is connected to a reservoir 4 via a line 3, and a conveying device 5 is provided, through which the material can be conveyed from the reservoir to the nozzle 2. The coating device according to the prior art further has a filter 6, which serves to filter the material.

[0027] At least when using electrode paste as the material to be applied to the substrate, it has been shown in practice that with a conventional device according to Fig. 1, trouble-free conveyance of the electrode paste is hardly possible because the filter 6 becomes clogged and a filter cake forms, causing fluctuations in the differential pressure at the filter 6. The choice of filter 6 or the filter size, i.e. the properties of the filter as to how large the particles allowed to pass through, is irrelevant because the filter cake can form more or less independently of the filter size.

[0028] In order to avoid corresponding downtimes and to enable a particularly advantageous coating, a further development of the coating device 1 will now be presented below, which is shown very schematically in Fig. 2. In contrast to the device of the Fig. 1, the coating device 1 shows, instead of at least one filter 6, a first filter device 7 comprising or having this filter 6, which is arranged in the line 3 in the conveying direction 8 before, i.e. upstream of the nozzle 2.

[0029] In order to enable a particularly advantageous application of the viscous material to the substrate, the coating device 1 according to Fig. 2, it is provided that an intermediate storage device 9 is arranged between the conveying device 5 and the first filter device 7 in the line and, upstream of this in the conveying direction 8, a second filter device 10 having at least one filter 6 is arranged.

[0030] For a particular homogeneity of the material, it is further advantageous if a third filter device 12 having at least one filter 11 is arranged in front of the second filter device 10 in the conveying direction 8.

[0031] It is further advantageous, in particular with regard to a particularly low differential pressure at the first filter device 7, if a filter size of the at least one filter 6 of the first filter device 7 is the same as the filter size of the at least one filter 6 of the second filter device 10 and / or smaller than the at least one filter 11 of the third filter device 12. The filters 6 are therefore each a fine filter, and the filters 11 are each a coarse filter.

[0032] In other words, upstream of the last filter stage, the first filter device 7, a coarse filter stage formed by the filter devices 12 is formed in series with a filter device 10 designed analogously to the target filter size or filter stage in order to ensure a particularly advantageous filtration behavior and a suitable pressure difference at the filters 6 of the filter device 7.

[0033] How Fig. 2, both the first filter device 7 and the second filter device 10 and the third filter device 12 each have at least two filters 6 and 11 arranged in parallel. An interruption unit (not shown here), for example in the form of a ball valve, can be arranged downstream of the respective filter 6 or 11 in the conveying direction 8, so that the respective filter 6 or 11 can be easily replaced.

[0034] Furthermore, it is advantageous if a connection device for further filters 6 or 11 can be provided, which can be designed as a blind flange 13 in the respective filter device 7, 10 or 12.

[0035] Nozzle 2 is a slot nozzle, so that coating device 1 is designed to perform slot-nozzle coating and thus enables a method for conveying viscous material onto the substrate. The coating device 1 is advantageously designed such that a highly viscous elastic material and / or an electrode paste can be conveyed onto the substrate by means of this method.

[0036] The Fig. The coating device 1 presented in Figure 2 thus comprises a plurality of filter stages formed by the filter devices 7, 10 and 12 in combination with a buffer storage, the intermediate storage 9, which is designed as a tank, so that a particularly advantageous material supply of the coating process can be specified.

[0037] Any number of filters 6 or 11 can be connected in parallel, so that the number of filters 6 or 11 per filter stage 7, 10 or 12 can be added as required, depending on the volume flow or mass flow required for the slot die coating, in order to enable the operation of filters 6 or 11 with the appropriate differential pressure.

[0038] A design of the filters 6 and 11 that can be connected together in parallel can be given depending on the maximum volume flow that can be conveyed through the coating device 1.

[0039] The electron paste is filtered upstream of the intermediate storage 12 by the second filter device 11 in the same way as the first filter device 7, and thus as provided by the first filter device 7, so that a completely filtered electron paste is already present in the buffer storage or intermediate storage 9. Due to this filtration, no or very minimal pressure fluctuations in the differential pressure are to be expected in the first filtration unit 7, so that it serves only as a control, i.e., only stray contaminants are filtered out. In this context, one can speak of police filtration.

[0040] Thus, the filters 6 of the first filter unit 7 and the filters 6 of the second filter unit 10 have an identical filter fineness, so that no components of the electron paste are filtered out in the first filter unit 7 after the intermediate storage 9, which particularly advantageously ensures that the dosing accuracy at the nozzle 2 and the problem-free conveyance of the paste to the nozzle 2 are ensured. This results in the advantage that the coating device 1 can be used particularly advantageously for forming particularly homogeneous and high-quality material layers on the substrate. List of reference symbols 1 coating device 2 nozzles 3 Line 4 Reservoir 5 Conveyor system 6 filters 7 first filter device 8 Conveying direction 9 Cache 10 second filter device 11 filters 12 third filter device 13 Blind flange 14 Pressure sensor QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] US 10 566 603 B2

[0004]

Claims

[1] Coating device (1) for applying a viscous material to a substrate, comprising a nozzle (2) via which the material can be conveyed from the coating device (1) to the substrate, and a line (3) via which the nozzle (2) is connected to a reservoir (4) in which the material can be stored, and a conveying device (5) arranged on the line (3) through which the material can be conveyed from the reservoir (4) via the line (3) to the nozzle (2), and a first filter device (7) having at least one filter (6) which is arranged in the line (3) upstream of the nozzle (2) in the conveying direction (8), wherein an intermediate storage device (9) is arranged in the line (3) between the conveying device (5) and the first filter device (7), and a second filter device (10) having at least one filter (6) is arranged upstream of the intermediate storage device in the conveying direction (8). [2] Coating device (1) according to claim 1, characterized bythat the nozzle (2) is designed as a slot nozzle. [3] Coating device (1) according to claim 1 or 2, characterized by that in the conveying direction (8) upstream of the second filter device (10) a third filter device (12) having at least one filter (11) is arranged. [4] Coating device (1) according to one of the preceding claims, characterized by that the conveying device (8) is arranged between the reservoir (4) and the second filter device (10) or third filter device (12) and a further conveying device (5) is arranged between the intermediate storage device (9) and the first filter device (7). [5] Coating device (1) according to one of the preceding claims, characterized bythat a filter size of the at least one filter (6) of the first filter device (7) is equal to the filter size of the at least one filter (6) of the second filter device (10) and / or smaller than the at least one filter (11) of the third filter device (12). [6] Coating device (1) according to one of the preceding claims, characterized by that in the conveying direction (8) before and / or after at least one of the filter devices (7, 10, 12) a pressure sensor (14) is arranged, by means of which a pressure of the material acting in the line (3) can be measured. [7] Coating device (1) according to one of the preceding claims, characterized by that the first filter device (7) and / or the second filter device (10) and / or the third filter device (12) each have at least two filters (6, 11) arranged in parallel. [8] Coating device (1) according to one of the preceding claims, characterized bythat an interruption unit is arranged in the conveying direction (8) in front of and behind the respective filter (6, 11). [9] Coating device (1) according to one of the preceding claims, characterized by that the first filter device (7) and / or the second filter device (10) and / or the third filter device (12) each provide a connection device for a further filter (6, 11). [10] Method for conveying viscous material onto a substrate by means of a coating device (1), wherein the material is conveyed from the coating device (1) onto the substrate via a nozzle (2), and the nozzle (2) is connected via a line (3) to a reservoir (4) in which the material can be stored, and a conveying device (5) is arranged on the line (3), through which the material is conveyed from the reservoir via the line (3) to the nozzle (2), and with a first filter device (7) having at least one filter (6), which is arranged in the line (3) upstream of the nozzle (2) in the conveying direction (8), and between the conveying device (5) and the first filter device (7) in the line (3) an intermediate storage device (9) and upstream of this in the conveying direction (8) a second filter device (10) having at least one filter (6) is arranged. [11] Method according to claim 10, characterized bythat the material being conveyed is highly visco-elastic and / or an electrode paste.

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