Coating device and extrusion type coating equipment

Abstract

The utility model relates to the technical field of coating processing, and discloses a coating device and extrusion type coating equipment, the coating device comprises a coating die head assembly and a feeding system; the coating die head assembly is provided with a plurality of groups of uniform pressure cavities, each group of uniform pressure cavities is communicated with a group of coating lips, and the coating lips are used for spraying slurry to a target base material; the feeding system extends outwards to form a plurality of groups of feeding slurry paths; each group of slurry supply paths is connected with a material supply pump, and each group of slurry supply paths is alternatively communicated with one group of pressure equalizing cavities and is used for pressurizing and conveying slurry into the pressure equalizing cavities at intervals. The device has the beneficial effects that a grouping independent feeding design is adopted, so that independent buffering and pressure balancing of each group of slurry in the respective uniform pressure cavity can be ensured, transverse flowing of the slurry in a single large uniform pressure cavity is avoided, the supply quantity and pressure intensity of each group of slurry can be accurately controlled, and the production efficiency is improved. Therefore, the accurate adjustment of the longitudinal surface density of each group of coating banners is realized.

Description

TECHNICAL FIELD

[0001] The utility model relates to coating processing technical field especially relates to a kind of coating device and extrusion coating equipment. BACKGROUND

[0002] Lithium ion battery has been widely used in consumer electronics and power battery and many other fields due to its high operating voltage, high energy density, small size, large capacity and long cycle life, and no memory effect. In order to further improve the performance of lithium ion battery, a specific slurry is usually coated on the battery pole piece of lithium ion battery. At present, the coating process technology of lithium ion battery pole piece has gradually evolved from the traditional and slow transfer coating (roll coating) method to the high-speed and efficient extrusion coating (spraying) method. The detailed process flow of extrusion coating includes: first, mix various substances in the storage tank according to a specific ratio and stir them into slurry, then use a pump to deliver the slurry in the storage tank to the coating die through the pipeline. The coating die and the coating roller maintain a small distance, the gap type lip at one end of the coating die extrudes and discharges the slurry, which is coated on the foil transported by the coating roller, and then the foil is dried and cut, finally forming the battery pole piece.

[0003] To improve the production efficiency of the same type of pole piece or adapt to the production needs of various types of lithium batteries, some existing extrusion coating equipment adopts multi-width coating design, that is, a plurality of gap type lips with the same or different widths are arranged on the coating die, so that the coating die can coat at least two coating widths on the surface of the foil at the same time in one coating process.

[0004] However, the existing multi-width coating design of extrusion coating equipment has the following technical problems in application: the extrusion coating equipment with multi-width coating design usually uses a single feeding pump to supply the coating die, the coating die gasket separates the coating flow channel arranged at the front end of the coating die to form a plurality of discharge lips, and the slurry discharged from each discharge lip constitutes a group of coating widths. During the coating process, the rotational speed of the feeding pump can be adjusted to change the pressure of the slurry entering the coating die, thereby adjusting the longitudinal surface density of each group of coating widths. However, after the slurry enters the die, it needs to flow horizontally to reach each discharge lip, which affects the adjustment amount of the longitudinal surface density of each coating width and makes it uneven. The above uneven situation is particularly obvious when the coating speed is high or the number of coating widths is greater than or equal to 4. SUMMARY

[0005] To solve the above technical problems, the utility model is realized by the following technical scheme:

[0006] To solve the above technical problems, the utility model is realized by the following technical scheme:

[0007] In one aspect, the utility model provides a kind of coating device, comprising: coating die head assembly and feed system;The coating die head assembly has several groups of uniform pressure cavity, each group of uniform pressure cavity is communicated with a group of coating lip, and the coating lip is used to spray slurry to target substrate;The feed system is outwardly extended and formed with several groups of feed slurry path;Each group of the feed slurry path is connected with feed pump, and each group of feed slurry path is selectively communicated with a group of the uniform pressure cavity, for the internal pressure of the uniform pressure cavity Interval boost delivery slurry.

[0008] Further, the feed system includes a storage tank and a flow distribution assembly;The storage tank is used to store slurry;The flow distribution assembly includes a main flow pipe, one end of the main flow pipe is communicated with the bottom of the storage tank, and the other end is provided with at least two groups of flow distribution pipes by flow distribution variable diameter, each group of the flow distribution pipe extends to form a group of the feed slurry path.

[0009] Further, the feed system further includes a uniform flow pump;The input end of the uniform flow pump is communicated with the bottom of the storage tank, and the output end is communicated with the input end of the main flow pipe.

[0010] Further, the flow regulating valve is provided on the feed slurry path, and the flow regulating valve is arranged upstream of the feed pump and connected with the input end of the feed pump.

[0011] Further, the feed pump is a screw pump, and the total output flow of all feed pumps is less than the maximum feed flow of the main flow pipe.

[0012] Further, an iron removal filter and a slurry filter are provided on each group of the feed slurry path to filter impurities in the slurry.

[0013] On the other hand, the utility model provides a kind of extrusion coating equipment, which includes the coating device as described above.

[0014] Compared with the prior art, the utility model has at least the following beneficial effects:

[0015] The group feed design can ensure that each group of slurry is independently buffered and balanced in the respective uniform pressure cavity, avoiding the horizontal flow of slurry in a single large uniform pressure cavity. In addition, each group of feed slurry path is provided with a group of feed pump, and is selectively communicated with a group of uniform pressure cavity, so that the independent feed system can accurately control the supply amount and pressure of each group of slurry, thereby realizing accurate adjustment of the longitudinal surface density of each coating strip. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 System diagram of coating device provided for example one Figure 1 ;

[0017] Figure 2 System schematic of the coating device provided for example one Figure 2

[0018] Figure 3 Structure schematic of the feed system of the coating device provided for example one

[0019] In the drawings:

[0020] Reference numerals: 1, coating die assembly; 11, coating lip; 12, barrier structure; 13, pressure equalizing chamber; 2, feed system; 21, feed pump; 22, storage tank; 23, flow splitting assembly; 231, main flow pipe; 232, flow splitting pipe; 24, flow equalizing pump; 25, flow regulating valve; 26, iron removal filter; 27, slurry filter; 3, movable carriage; 31, roller. DETAILED DESCRIPTION

[0021] The embodiments of the present application are described in detail below, examples of which are shown in the drawings. The embodiments described below by reference to the drawings are exemplary and are intended to explain the present application, and should not be understood as limiting the present application.

[0022] In the present application, the orientation terms such as "center", "longitudinal", "transverse" are based on the drawings shown, for description and simplification, and do not limit the actual orientation of the device or element. The terms "first", "second" are only used for distinction, and do not represent the specific meaning of importance or quantity, and the features containing these terms contain at least one. And "multiple" means at least two. For the terms "mounting", "connecting", etc., should be understood in a broad sense, which can be fixed, detachable, mechanical, electrical or communication connection, directly or indirectly connected through a medium, indicating internal communication or interaction, unless otherwise limited. Those skilled in the art can understand the specific application of the above terms in the present application.

[0023] The present application is further described in detail below in conjunction with the drawings:

[0024] Example one

[0025] Reference Figures 1-3 A coating device, like the coating device applied to the existing multi-width extrusion coating equipment, comprises a coating die assembly 1 for extruding and spraying slurry and a feed system 2 for feeding and supplying slurry to the coating die assembly 1. The coating die assembly 1 has a pressure equalizing chamber 13 connected to the feed system 2, and a coating lip 11 connected to the pressure equalizing chamber 13, which is used to spray slurry to the target substrate.

[0026] ​In operation, the battery pole piece slurry prepared in advance can be delivered by the feeding system 2 to the pressure equalizing cavity 13 of the coating die head, and then discharged through the coating lip 11 after buffering and equalizing pressure in the pressure equalizing cavity 13, and sprayed on the target substrate.

[0027] To solve the problem of uneven longitudinal surface density of each coating strip due to the transverse flow of slurry in the pressure equalizing cavity 13 during multi-width coating in the prior art, the improvement of the present application is that:

[0028] The coating die head assembly 1 has a plurality of groups (at least two groups) of pressure equalizing cavities 13 and a plurality of groups of coating lips 11, each group of coating lips 11 is selectively and correspondingly connected to one group of coating lips 11, and the feeding system 2 extends outwardly to form a plurality of groups of feeding slurry paths, each group of feeding slurry paths is independently provided with a group of feeding pumps 21, and each group of feeding slurry paths is selectively and correspondingly connected to one group of pressure equalizing cavities 13 and can deliver slurry to the inside of the pressure equalizing cavity 13 under the action of the respective feeding pump 21 to increase the pressure. By the above technical solution, the coating die head assembly 1 is designed to have a plurality of groups of pressure equalizing cavities 13 and a plurality of groups of coating lips 11, and each group of coating lips 11 is correspondingly connected to one group of pressure equalizing cavities 13. This group feeding design can ensure that each group of slurry independently buffers and equalizes pressure in the respective pressure equalizing cavity 13, avoiding the transverse flow of slurry in a single large pressure equalizing cavity 13. In addition, each group of feeding slurry paths is independently provided with a group of feeding pumps 21, and is selectively and correspondingly connected to one group of pressure equalizing cavities 13. This independent feeding system 2 can accurately control the supply amount and pressure of each group of slurry, thereby realizing accurate adjustment of the longitudinal surface density of each coating strip.

[0029] The implementation structure of the coating die head assembly 1 having a plurality of groups of pressure equalizing cavities 13 and a plurality of groups of coating lips 11 has diversity, and the present embodiment provides two specific implementation structures: referring to Figure 1 , the first implementation structure, the coating die head assembly 1 includes a plurality of coating die head monomers, each of which forms a group of pressure equalizing cavities 13 and a coating lip 11 connected to the pressure equalizing cavity 13.

[0030] Referring to Figure 2 , the second implementation structure, the coating die head assembly 1 is a single structure, and a group of pressure equalizing cavities 13 is formed inside the coating die head assembly 1. The pressure equalizing cavity 13 is provided with a barrier structure 12, and the barrier structure 12 divides the pressure equalizing cavity 13 into a plurality of groups of pressure equalizing cavities 13. One end of each group of pressure equalizing cavities 13 is selectively and correspondingly connected to one group of coating lips 11, and the other end is selectively and correspondingly connected to one group of feeding slurry paths.

[0031] The barrier structure 12 can adopt various forms, such as a partition plate, a partition strip, etc. The specific form should be determined according to the structure of the coating die head, the properties of the slurry, and the requirements of the coating process.

[0032] To make up for the insufficient uniform pressure effect of the single group of uniform pressure cavities 13 that may be caused by the above-mentioned group feeding design, in the embodiment, the top end of the inner wall of each uniform pressure cavity 13 extends downward to form a uniform pressure surface. The uniform pressure surface, as part of the inner wall of the uniform pressure cavity 13, is designed to change the flow path and velocity distribution of the slurry in the uniform pressure cavity 13, so that the slurry achieves a more uniform pressure and flow distribution before reaching the coating lip 11. For example, the uniform pressure surface can be designed as an arched curved surface structure to guide the flow of the slurry, which helps to reduce the turbulence and vortex phenomenon of the slurry in the uniform pressure cavity 13, making the flow of the slurry more stable. Specifically, the shape, size and position of the uniform pressure surface can be customized according to the requirements of the coating process to achieve the best uniform pressure effect.

[0033] It should be noted that the attached drawings of the embodiment Figure 1 、 2 For illustrative purposes, the coating lip 11 and the corresponding number of feeding slurry paths are set to two groups, while the Figure 3 The structure diagram of the feeding system 2 of a practical application case of the utility model is shown in FIG. 6, and the number of feeding slurry paths thereon is six groups.

[0034] In the embodiment, the feeding system 2 includes a storage tank 22 and a flow splitting assembly 23. The main function of the storage tank 22 is to store the slurry required by the battery pole piece. The slurry can maintain a certain temperature and stirring state in the storage tank 22 to ensure its stability and uniformity. The flow splitting assembly 23 includes a main flow pipe 231, one end of which is in communication with the bottom of the storage tank 22, and the other end is provided with at least two groups of flow splitting pipes 232 through flow splitting variable diameter, each group of flow splitting pipes 232 extends to form a group of feeding slurry paths. When coating is needed, the slurry flows into the flow splitting assembly 23 through the main flow pipe 231, and in the flow splitting assembly 23, the slurry is uniformly distributed into each flow splitting pipe 232 through the flow splitting variable diameter structure, the flow splitting pipe 232 delivers the slurry to the uniform pressure cavity 13 of the coating die assembly 1, and then sprays it on the target substrate through the coating lip 11.

[0035] Through the above-mentioned flow splitting feeding design, the feeding system 2 can uniformly distribute the slurry from a single storage tank 22 to multiple flow splitting pipes 232, thereby forming multiple feeding slurry paths, which not only simplifies the storage and management of the slurry, but also improves the utilization efficiency of resources.

[0036] Generally, each branch pipe 232 is connected with a feeding pump 21, and during coating, the feeding pump 21 of each group of feeding slurry paths can generate suction to suck the slurry from the storage tank 22 and into the corresponding branch pipe 232 along the main pipe 231. However, since the slurry is passively sucked into the branch pipe 232 by the feeding pump 21, and the slurry itself has thick and viscous characteristics, under high-speed coating conditions, the slurry is prone to vacuum flow interruption at the branch diameter where the main pipe 231 is connected with each group of branch pipes 232 due to the large suction. This leads to uneven slurry flow into each branch pipe 232, affecting the uniformity of subsequent coating.

[0037] To ensure that the slurry can be evenly distributed into each branch pipe 232 after entering the main pipe 231 from the storage tank 22, in the present embodiment, the feeding system 2 further comprises a uniform flow pump 24, the input end of which is in communication with the bottom of the storage tank 22, and the output end of which is in communication with the input end of the main pipe 231. The uniform flow pump 24 can provide a stable and uniform initial pressure for the slurry, which can ensure that the slurry has a stable flow rate and pressure distribution when flowing out of the storage tank 22. The stable pressure enables the slurry to flow more uniformly along the main pipe 231. When the slurry reaches the branch diameter, the risk of vacuum flow interruption is reduced due to the uniform pressure distribution. This enables the slurry to enter each branch pipe 232 more uniformly, thereby helping to improve the uniformity and quality of subsequent coating and reducing defects and waste during the coating process.

[0038] Each group of feeding slurry paths, i.e., the slurry flow path of each group of branch pipes 232, is provided with a flow regulating valve 25, which is arranged upstream of the feeding pump 21 of each group of branch pipes 232 and connected with the input end of the feeding pump 21. When it is necessary to replace the process and clean the slurry in the feeding pump 21 and each branch pipe 232, the flow regulating valve 25 can be used to adjust and block the connection between the main pipe 231 and each branch pipe 232, so that the slurry in the storage tank 22 does not flow out, and the cleaning work of the feeding pump 21 and the branch pipe 232 can be safely performed, avoiding waste and cross contamination of the slurry. The flow regulating valve 25 is preferably a ball valve, which has the advantages of simple structure, easy operation, good sealing performance, etc., and is very suitable for flow regulation of the relatively thick and viscous medium such as battery slurry.

[0039] Each group of feeding slurry paths is provided with a flow regulating valve 25, which is arranged upstream of the feeding pump 21 and connected with the input end of the feeding pump 21. The flow regulating valve 25 is used to adjust the flow of the slurry, so that the supply amount of the slurry for each group of coating lips 11 can be accurately adjusted as needed, thereby ensuring the uniformity of the longitudinal area density of the coating swath.

[0040] The feed pump 21 is a screw pump, which can push the medium from one end to the other end in the pump body through a pair or several pairs of intermeshing screws rotating in the pump body, and can transport the medium with high viscosity, containing solid particles or fibers, which is very suitable for the slurry which is thick and may contain impurities. In addition, the screw pump has a certain self-suction capacity, which can reduce the pressure loss of the suction port to a certain extent, and helps the smooth suction of the slurry. Further, in the embodiment, the total output flow of all feed pumps 21 is less than the maximum feed flow of the main flow pipe 231. This design ensures that the slurry has a certain amount of surplus in the main flow pipe 231, so as to be evenly distributed to each group of feed slurry paths. When the slurry enters the distribution pipe 232 from the main flow pipe 231, due to the small total output flow of the feed pump 21, the distribution of the slurry in the distribution pipe 232 will be more uniform, avoiding the problem of uneven coating caused by insufficient feeding.

[0041] An iron removal filter 26 and a slurry filter 27 are arranged on each group of feed slurry paths, which are used to filter the impurities in the slurry. The iron removal filter 26 can remove the metal impurities in the slurry, and the slurry filter 27 further filters the particulate matter in the slurry to ensure the coating quality.

[0042] In addition, in the embodiment, the coating device further comprises a movable frame 3, the bottom of the movable frame 3 is connected with a roller 31 for movement, and the feed system 2 is installed on the movable frame 3. Since the feed system 2 is installed on the movable frame 3, its position can be easily adjusted to adapt to the needs of different coating processes, which is beneficial to the material replacement in the multi-width coating process. In addition, when it is necessary to clean, inspect or replace the feed pump 21, the pipe or the pressure equalizing chamber 13, the entire feed system 2 can be easily moved to the maintenance area without complicated disassembly and reinstallation process.

[0043] Embodiment two

[0044] An extrusion coating device comprising the coating device in the above embodiment one.

[0045] The above only describes the specific embodiments of the present application, but the technical features of the present application are not limited to this. Any changes or modifications made by those skilled in the art within the scope of the present application are covered by the patent scope of the present application.

Claims

1. A coating apparatus, characterized in that: include: Coating die assembly (1) and feeding system (2); The coating die assembly (1) has several sets of pressure equalization chambers (13), each set of pressure equalization chambers (13) is connected to a set of coating lips (11), the coating lips (11) are used to spray the slurry onto the target substrate; The feeding system (2) extends outward to form several sets of feeding slurry paths; each set of feeding slurry paths is connected to a feeding pump (21), and each set of feeding slurry paths is selectively connected to a set of pressure equalization chambers (13) for intermittently pressurizing and conveying slurry into the pressure equalization chambers (13).

2. The coating apparatus as described in claim 1, characterized in that: The feeding system (2) includes a storage tank (22) and a diversion component (23); the storage tank (22) is used to store slurry; the diversion component (23) includes a main pipe (231), one end of which is connected to the bottom of the storage tank (22), and the other end is provided with at least two diversion pipes (232) through a diversion and diameter change, each diversion pipe (232) extending to form a set of feeding slurry paths.

3. The coating apparatus as described in claim 2, characterized in that: The feeding system (2) also includes a flow equalizer (24); the input end of the flow equalizer (24) is connected to the bottom of the storage tank (22), and its output end is connected to the input end of the main flow pipe (231).

4. The coating apparatus as described in claim 2, characterized in that: A flow regulating valve (25) is connected to the feed slurry line. The flow regulating valve (25) is located upstream of the feed pump (21) and connected to the input end of the feed pump (21).

5. The coating apparatus as described in claim 2, characterized in that: The feed pump (21) is a screw pump, and the total output flow of all feed pumps (21) is less than the maximum feed flow of the main flow pipe (231).

6. The coating apparatus as described in claim 1, characterized in that: Each feed slurry path is equipped with an iron removal filter (26) and a slurry filter (27) to filter impurities in the slurry.

7. The coating apparatus as claimed in claim 1, characterized in that: It also includes a movable frame (3), the bottom of which is connected to rollers (31) for movement, and the feeding system (2) is mounted on the movable frame (3).

8. An extrusion coating apparatus, characterized in that: Includes the coating apparatus as described in any one of claims 1 to 7.

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