Coating mold and testing method

Abstract

The invention relates to a coating mold and a testing method in the technical field of coating, the coating mold comprises a mold head structure and a feeding assembly, a discharging seam and a feeding opening which are connected with each other are formed in the two sides of the mold head structure respectively, and the feeding assembly comprises a feeding barrel installed on one side of the mold head structure; the feeding barrel is connected with the feeding port, and a connector used for being connected with the outside is arranged on the feeding barrel. The design that the feeding barrel is integrally arranged on one side of the die head structure not only simplifies the complexity of a traditional feeding system, but also improves the flexibility and efficiency of testing, the feeding barrel is used as a buffer tank, no additional feeding equipment is needed for cooperation in the coating process, and the complexity and cost of small-batch production testing in a laboratory are greatly reduced. And the coating mold is miniaturized, so that the coating mold is more compact and is easy to operate and store. In addition, the design is also convenient to clean and maintain, the durability of the equipment is improved, and the service life of the equipment is prolonged.

Description

Technical Field

[0001] The present invention relates to the technical field of coating, and particularly relates to a coating die and a testing method. Background Art

[0002] At present, lithium batteries have developed rapidly in the new energy industry, from the initial mobile phone lithium batteries to the current power batteries for new energy vehicles. Most power batteries are manufactured by the slit extrusion method. As a precise wet coating technology, the working principle of slit extrusion coating is that the coating slurry is extruded and ejected along the slit of the coating die under a certain pressure and a certain flow rate and then transferred to the substrate. Slit extrusion coating has the advantages of high speed, high precision, uniform wet thickness, a closed coating system, which can prevent pollutants from entering during the coating process, high slurry utilization rate, can maintain the stability of the slurry properties, and can adapt to different slurry viscosities and solid content ranges, and has stronger practicability compared with other coating processes.

[0003] In the current stage of testing coating slurries in the laboratory, slit extrusion coating dies are mainly used for coating operations. Such dies have the advantages of high coating speed, high precision, and uniform wet thickness. However, they require an independent and complete feeding system (including a stirring tank, a buffer tank, and their related pipelines) to achieve stable output of the slurry. For small-batch test production in the laboratory, this coating method is too complex, resulting in difficulty in further improving the testing efficiency. In view of this, the present invention provides a coating die and a testing method dedicated to testing coating slurries. Summary of the Invention

[0004] The present invention provides a coating die and a testing method to solve the problems mentioned in the above background art.

[0005] The object of the present invention is achieved in the following way:

[0006] A coating die includes a die head structure and a feeding component. On both sides of the die head structure, there are respectively arranged a discharge slit and a feeding port which are connected to each other. The feeding component includes a feeding barrel installed on one side of the die head structure. The feeding barrel is connected to the feeding port, and an interface for connecting to the outside is arranged on the feeding barrel.

[0007] Further, the discharge slit and the feeding port are connected through a valve port channel, and a valve structure for cooperating with the valve port channel is arranged on the die head structure.

[0008] Further, the valve structure includes a valve rod arranged on the die head structure and a sealing valve body slidably arranged in the valve port channel. One end of the valve rod is connected to the sealing valve body.

[0009] Further, the die head structure includes an upper die cover, a lower die base and a forming gasket. A discharge slit is formed between the upper die cover and the lower die base, and the lower die base is connected to the feed barrel.

[0010] Further, the feeding assembly further includes a driver and a feeding piston disposed in the feed barrel. A notch communicating with the outside is provided on one side of the feed barrel away from the die head structure, and the driver passes through the notch to push the feeding piston to move in the feed barrel.

[0011] Further, a sealing ring for interference fit with the feeding piston is provided on one side of the feed barrel close to the notch.

[0012] Further, a cylindrical storage cavity is provided in the feed barrel, and limiting planes for cooperating with the feeding piston are arranged in parallel on both sides of the storage cavity.

[0013] Further, buckles are provided on both sides of the lower die base, and clamping grooves for clamping cooperation with the buckles are provided on both sides of the feeding piston.

[0014] A testing method for a coating die includes the following steps:

[0015] Step 1: Inject several groups of slurries to be tested with different ratios into several coating dies respectively to obtain several groups of task test sets, and each group of task test sets includes at least one coating die;

[0016] Step 2: Concentrate each group of task test sets side by side on a test line to synchronously perform coating test operations to obtain the slurry performance parameters of each group of task test sets;

[0017] Step 3: Take the average value of the slurry performance parameters of each group of task test sets, and compare and analyze the average values of the slurry performance parameters of each group of task test sets to determine the slurry with the optimal slurry performance parameters.

[0018] Further, it further includes: Step 4: Based on the current standard coating thickness, intercept the front and back thickness range intervals of the benchmark, and equally spaced select at least three test nodes within this interval. Each group of slurries to be tested is tested according to the thickness data of the test nodes, and the above Steps 1 to 3 are repeated for each group of slurries.

[0019] The beneficial effects of the present invention:

[0020] First, the present invention integrates and arranges a feeding bucket on one side of the die head structure, which not only simplifies the complexity of the traditional feeding system but also improves the flexibility and efficiency of testing. In traditional coating tests, the buffer tank is set independently, requiring additional space and pipeline connections. This not only increases the volume and cost of the equipment but also causes waste and pollution of the slurry during transmission. In contrast, the present invention directly integrates a feeding bucket on one side of the die head structure and uses it directly as a buffer tank, eliminating the need for additional feeding equipment and significantly reducing the complexity and cost of small-batch production tests in the laboratory. Moreover, the arrangement of miniaturizing the coating die makes it more compact, easy to operate and store. In addition, this design is also convenient for cleaning and maintenance, improving the durability and service life of the equipment.

[0021] Second, the present invention combines a highly integrated coating die with a testing method, enabling efficient testing of slurries with different ratios, thereby quickly obtaining the optimal performance parameters of different slurries, significantly improving the testing efficiency in the laboratory, and accelerating the optimization process of the slurry. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is the first structural schematic diagram of a coating die of the present invention;

[0023] Figure 2 is the second structural schematic diagram of a coating die of the present invention;

[0024] Figure 3 is the exploded schematic diagram of a coating die of the present invention;

[0025] Figure 4 is the first cross-sectional view of a coating die of the present invention;

[0026] Figure 5 is the second cross-sectional view of a coating die of the present invention;

[0027] Figure 6 is Figure 5 the enlarged schematic diagram of A in

[0028] The reference numerals in the drawings are respectively: 1 - die head structure, 2 - feeding bucket, 3 - valve structure, 4 - driver, 5 - feeding piston, 6 - fixed bracket, 7 - pressure wrench, 8 - positioning pin, 10 - discharging slit, 11 - feeding port, 12 - interface, 13 - valve port channel, 14 - sealing cover, 15 - valve rod, 16 - sealing valve body, 17 - upper die cover, 18 - lower die base, 19 - forming gasket, 20 - notch, 21 - sealing ring, 22 - storage cavity, 23 - buckle. DETAILED DESCRIPTION OF THE INVENTION

[0029] The present invention will be further described in detail below in conjunction with the drawings and the specific embodiments.

[0030] In this embodiment, referring to Figures 1 to 6 , a coating die for its specific implementation includes a die head structure 1 and a feeding assembly. On both sides of the die head structure 1, there are respectively arranged a discharge slit 10 and a feeding port 11 which are connected to each other. The feeding assembly includes a feeding barrel 2 installed on one side of the die head structure 1. The feeding barrel 2 is connected to the feeding port 11. An interface 12 for connecting to the outside is arranged on the feeding barrel 2, and a detachable sealing cover 14 is arranged on the interface 12, which is convenient for adding slurry into the feeding barrel 2.

[0031] In this embodiment, the discharge slit 10 and the feeding port 11 are connected through a valve port channel 13. A valve structure 3 for cooperating with the valve port channel 13 is arranged on the die head structure 1. The setting of the valve structure 3 can prevent the slurry from leaking from the discharge slit 10, thereby improving the safety during the transfer of the coating die to the test line, and at the same time avoiding the slurry in the feeding barrel 2 from being polluted by the external environment.

[0032] The valve structure 3 includes a valve rod 15 arranged on the die head structure 1 and a sealing valve body 16 slidably arranged in the valve port channel 13. One end of the valve rod 15 is connected to the sealing valve body 16. The simple and ingenious design of this valve structure 3 can not only quickly close when needed to ensure the stability and safety of the slurry to prevent the slurry from leaking during the transfer process. At the same time, the simple structure design also reduces the difficulty of cleaning in the subsequent test process.

[0033] In this embodiment, the valve rod 15 is threadedly connected to the die head structure 1, and an internal hexagonal groove is arranged at one end of the valve rod 15 away from the sealing valve body 16, so as to facilitate driving the movement of the valve rod 15 through an external wrench.

[0034] In this embodiment, the die head structure 1 includes an upper die cover 17, a lower die base 18 and a forming gasket 19. The discharge slit 10 is formed at the lip between the upper die cover 17 and the lower die base 18, and the lower die base 18 is connected to the feeding barrel 2. During the actual process of testing the coating output of the slurry, the width and thickness of the discharge slit 10 can be changed according to the specifications of the forming gasket 19. Specifically, since the forming gasket 19 is directly arranged between the upper die cover 17 and the lower die base 18, the thickness of the discharge slit 10 will change due to the thickness of the forming gasket 19, and the width of the discharge slit 10 will also be changed by the shape and size of the internal slot 20 of the forming gasket 19. In this embodiment, the width range of the lip is preferably 50 - 200 mm.

[0035] In this embodiment, the feeding assembly further includes a driver 4 and a feeding piston 5 disposed in the feeding barrel 2. A notch 20 communicating with the outside is provided on one side of the feeding barrel 2 away from the die head structure 1, and the driver 4 passes through the notch 20 to push the feeding piston 5 to move in the feeding barrel 2. The driver 4 is preferably a servo electric cylinder. In the actual application process, the user can adjust the driving speed of the driver 4 according to actual needs, and then directly control the moving speed of the feeding piston 5 in the feeding barrel 2 to achieve precise control of the slurry extrusion amount and ensure precise matching with the moving speed of the coil on the test line.

[0036] As Figure 6 shown, the feeding piston 5 is in clearance fit with the inner wall of the feeding barrel 2. While achieving a certain sealing performance, it does not affect the movement of the feeding piston 5 in the feeding barrel 2. Moreover, a sealing ring 21 for interference fit with the feeding piston 5 is provided on one side of the feeding barrel 2 close to the notch 20. During the process of injecting slurry into the feeding barrel 2, the closely cooperating feeding piston 5 and sealing ring 21 further improve the sealing performance of the feeding barrel 2 and effectively avoid slurry leakage.

[0037] Furthermore, a cylindrical storage cavity 22 is provided in the feeding barrel 2, and limiting planes for cooperating with the feeding piston 5 are arranged in parallel on both sides of the storage cavity 22. When the feeding piston 5 moves in the storage cavity 22, the limiting planes can guide the feeding piston 5, enabling the feeding piston 5 to move smoothly in the feeding barrel 2, avoiding the situation of shaking or jamming during the movement of the feeding piston 5, and thus ensuring the stability and precision of the coating die. The setting of the limiting planes also makes the cooperation between the feeding piston 5 and the storage cavity 22 closer, further improving the sealing performance of the feeding barrel 2.

[0038] Furthermore, buckles 23 are provided on both sides of the lower die base 18, and clamping grooves for clamping and cooperating with the buckles 23 are provided on both sides of the feeding piston 5. In actual application, when the feeding piston 5 moves to the end position of the feeding barrel 2 (the clamping grooves on both sides of the feeding piston 5 are synchronously clamped and cooperated with the buckles 23 on both sides of the lower die base 18), the slurry in the feeding barrel 2 has been basically completely discharged. In the subsequent cleaning and maintenance stage, through the coordinated action of the buckles 23 and the clamping grooves, while separating the lower die base 18 from the feeding barrel 2, the feeding piston 5 inside the feeding barrel 2 can be synchronously disassembled, thereby reducing the complexity of disassembling the feeding piston 5 and improving the efficiency of cleaning and maintenance work.

[0039] In the embodiment, the material of the feeding barrel 2 is preferably ceramic, which has good wear resistance, corrosion resistance and high temperature resistance, and can effectively extend the service life of the feeding barrel 2.

[0040] Furthermore, the feed barrel 2 is installed on the test line through a quick-release structure, and the quick-release structure includes a fixed bracket 6 and a pressure wrench 7 and a positioning pin 8 respectively arranged on both sides of the fixed bracket 6. The head and tail ends of the feed barrel 2 are respectively provided with positions and holes for cooperating with the pressure wrench 7 and the positioning pin 8. In specific implementation, the pressure wrench 7 is used to apply pressure to tightly fix the feed barrel 2 on the fixed bracket 6, while the positioning pin 8 ensures the precise positioning of the feed barrel 2 during the disassembly and assembly process, avoiding the tediousness and time consumption that may be caused by the traditional bolt fixing method. The design of using the pressure wrench 7 and the positioning pin 8 is not only convenient for quick disassembly and assembly, but also ensures the stability and reliability of the feed barrel 2 after installation, further improving the overall working efficiency of the coating mold.

[0041] The method for using the coating mold described in this embodiment includes the following steps:

[0042] Step 1: preferably, an external hydraulic device or other pressure device is used to place the feed piston 5 at one end of the feed barrel 2, so that the feed piston 5 and the sealing ring 21 are interference-fitted, and then the valve structure 3 is opened;

[0043] Step 2: inject the mixed slurry into the storage cavity 22 of the feed barrel 2 from the interface 12. After the storage cavity 22 is filled with slurry, close the valve structure 3 and the interface 12. During the injection of slurry, the air in the storage cavity 22 passes through the feed inlet 11 and the valve port channel 13 in sequence, and is finally discharged to the outside from the discharge slit 10.

[0044] Step three: The coating mold is transferred and installed to the test line through the quick-release structure. At that time, the feed piston 5 can be pushed into the feed barrel 2 by the driver 4, so that the slurry passes through the feed port 11 and the valve port channel 13 in turn from the feed barrel 2, and is finally evenly output from the discharge slot 10 to the coil on the external test line.

[0045] The present invention integrates the design of the feed barrel 2 on one side of the die structure 1, which not only simplifies the complexity of the traditional feeding system, but also improves the flexibility and efficiency of the test. In traditional coating tests, the buffer tank is set up independently, requiring additional space and pipeline connections, which not only increases the volume and cost of the equipment, but also causes waste and pollution of the slurry during the transmission process. The present invention directly integrates the feed barrel 2 on one side of the die structure 1 and uses it directly as a buffer tank, without the need for additional feeding equipment, which greatly reduces the complexity and cost of small-batch production tests in laboratories.

[0046] The arrangement for miniaturizing the coating die not only makes it more compact, easier to operate and store, but also facilitates cleaning and maintenance, improving the durability and service life of the equipment. Further, the design of the miniaturized coating die enables it to be easily integrated into external equipment. For example, it can be placed in a temperature control device for temperature-controlled coating to adapt to slurries with special ratios, thereby significantly reducing the testing difficulty of coating and improving the stability of coating tests.

[0047] In addition, as a buffer tank, the feeding bucket 2 can effectively control the flow rate and pressure of the slurry, ensuring the stability and uniformity of the slurry during the coating process. During use, by adjusting the moving speed of the feeding piston 5, the coating thickness can be precisely controlled to meet different testing requirements. The design of the feeding bucket 2 of the present invention not only simplifies the equipment configuration for coating tests, improves the flexibility and efficiency of testing, but also ensures the stability and uniformity of the slurry during the coating process, providing strong support for the research and development and production of new energy products such as lithium batteries.

[0048] A testing method for a coating die includes the following steps:

[0049] Step 1: Inject multiple groups of slurries to be tested with different ratios into several coating dies respectively to obtain multiple groups of task test sets, and each group of task test sets includes at least one coating die;

[0050] Step 2: Arrange and concentrate each group of task test sets side by side on a single test line to synchronously perform coating test operations to obtain the slurry performance parameters of each group of task test sets;

[0051] Step 3: Take the average value of the slurry performance parameters of each group of task test sets, and compare and analyze the average values of the slurry performance parameters of each group of task test sets to determine the slurry with the optimal slurry performance parameters.

[0052] In the test line of this embodiment, nine coating dies can be installed side by side for each round of testing. During the testing process, to reduce errors, every three coating dies are combined into a group of task test sets, and each group of task test sets tests a slurry with a specific ratio to ensure the accuracy and reliability of the test results. Before the test starts, all coating dies need to be preheated and calibrated to ensure the consistency of the test conditions. During the test process, by precisely controlling the moving speed of the feeding piston 5 of the coating die, the accurate control of the slurry extrusion amount can be achieved, thereby ensuring the accuracy of the test results. At the same time, high-precision sensors are used to monitor and record the key parameters during the coating process for subsequent data analysis and processing.

[0053] The test method of this embodiment is to select steps 1 to 3 for investigation in order to quickly screen the slurry with the appropriate ratio. However, according to the ratio of different coating slurries, the applicable coating thickness will also be adjusted accordingly. Currently, the coating slurry thickness range of the positive electrode is generally 80-180 μm (surface density 16-28 mg / cm 2 ), and the coating slurry thickness range of the negative electrode is generally 70-120 μm (surface density 8-15 mg / cm 2 ). It can be seen that the range of the slurry coating thickness has a large span. If investigated one by one according to this range, it is difficult to further improve the test efficiency. Therefore, in order to avoid some slurries missing the appropriate coating thickness, the screening of the coating slurry thickness in this embodiment further includes the following steps:

[0054] Step 4: Set the coating thickness of the current standard as the benchmark, intercept the thickness range intervals before and after the benchmark, and equally spaced select at least three test nodes within this interval. Each group of slurries to be tested repeats steps 1 to 3 according to the thickness data of the test nodes to test each group of slurries; by comparing the slurry performance parameters at each test node, the screening range of the slurry ratio can be further narrowed, and the test efficiency can be improved. Specifically, if the slurry performance parameters at a certain test node are excellent, more detailed tests can be carried out on the slurry ratios near this node in order to find the optimal slurry ratio.

[0055] In the embodiment, the coating thickness of the current standard can be set according to actual application requirements. For example, in the application of the positive electrode coating slurry, the coating thickness of the current standard can be set to 120 μm (surface density 22 mg / cm 2 ). According to step 4, intercept 90-150 μm as the thickness range interval, and equally spaced select 90 μm, 120 μm, and 150 μm as the test nodes within this interval. Each group of slurries to be tested repeats steps 1 to 3 according to the thickness data of the above three test nodes to test each group of slurries.

[0056] In the application of the negative electrode coating slurry, the coating thickness of the current standard can be set to 95 μm (surface density 11.5 mg / cm 2 ). According to step 4, intercept 65-125 μm as the thickness range interval, and equally spaced select 65 μm, 95 μm, and 125 μm as the test nodes within this interval. Each group of slurries to be tested repeats steps 1 to 3 according to the thickness data of the above three test nodes to test each group of slurries.

[0057] Of course, the above coating thickness standard is not absolute and can be adjusted according to specific circumstances.

[0058] In step 4, by taking the current standard coating thickness as a reference and equally spacing at least three test nodes within the thickness range before and after this reference, the test range can be further refined, improving the accuracy and reliability of the test. This method is not only applicable to small-batch test production in the laboratory, but also can provide strong data support for large-scale industrial production, helping to optimize the coating process, improve product quality and production efficiency. The way of combining a highly integrated coating die with a test method in the present invention can efficiently test slurries with different ratios, thereby quickly obtaining the optimal performance parameters of different slurries, significantly improving the test efficiency in the laboratory and accelerating the optimization process of the slurries.

[0059] The above are only preferred embodiments of the present invention and do not impose any form of limitation on the present invention. Although the present invention is disclosed above in preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art, without departing from the scope of the technical solution of the present invention, when making some changes or modifications using the above-disclosed technical content into equivalent embodiments of equivalent changes, but as long as they do not depart from the content of the technical solution of the present invention, any simple modification, equivalent change and modification made to the above embodiments according to the technical means of the present invention shall fall within the scope of the technical solution of the present invention.

Claims

1. A coating die, characterized in that, It includes a die head structure (1) and a feeding component. On both sides of the die head structure (1), there are respectively arranged a discharge slit (10) and a feeding port (11) which are connected to each other. The feeding component includes a feeding barrel (2) installed on one side of the die head structure (1). The feeding barrel (2) is connected to the feeding port (11), and an interface (12) for connecting to the outside is arranged on the feeding barrel (2).

2. The coating die according to claim 1, wherein: The discharge slit (10) and the feeding port (11) are connected through a valve port channel (13), and a valve structure (3) for cooperating with the valve port channel (13) is arranged on the die head structure (1).

3. The coating die according to claim 2, wherein: The valve structure (3) includes a valve rod (15) arranged on the die head structure (1) and a sealing valve body (16) slidably arranged in the valve port channel (13). One end of the valve rod (15) is connected to the sealing valve body (16).

4. The coating die according to any one of claims 1 to 3, characterized in that: The die head structure (1) includes an upper die cover (17), a lower die base (18) and a forming gasket (19). The discharge slit (10) is formed between the upper die cover (17) and the lower die base (18), and the lower die base (18) is connected to the feeding barrel (2).

5. The coating die according to claim 4, wherein: The feeding component further includes a driver (4) and a feeding piston (5) arranged in the feeding barrel (2). A notch (20) communicating with the outside is arranged on one side of the feeding barrel (2) away from the die head structure (1), and the driver (4) passes through the notch (20) to push the feeding piston (5) to move in the feeding barrel (2).

6. The coating die according to claim 5, wherein: A sealing ring (21) for interference fit with the feeding piston (5) is arranged on one side of the feeding barrel (2) close to the notch (20).

7. The coating die according to claim 5 or 6, characterized in that: A cylindrical storage cavity (22) is arranged in the feeding barrel (2), and limiting planes for cooperating with the feeding piston (5) are arranged in parallel on both sides of the storage cavity (22).

8. The coating die according to claim 7, wherein: Clasps (23) are arranged on both sides of the lower die base (18), and clamping grooves for clamping and cooperating with the clasps (23) are arranged on both sides of the feeding piston (5).

9. The testing method of a coating die according to any one of claims 1-8, characterized in that It includes the following steps: Step 1: Inject multiple groups of test slurries with different ratios into several coating molds respectively to obtain multiple groups of task test sets. Each group of task test sets includes at least one coating mold; Step 2: Arrange and concentrate each group of task test sets side by side on a test line to synchronously perform coating test operations to obtain the slurry performance parameters of each group of task test sets; Step 3: Take the average value of the slurry performance parameters of each group of task test sets, and compare and analyze the average values of the slurry performance parameters of each group of task test sets to determine the slurry with the optimal slurry performance parameters.

10. The test method for a coating die according to claim 9, characterized in that, It further includes: Step 4: Based on the current standard coating thickness, intercept the front and back thickness range intervals of the benchmark, and equally spaced select at least three test nodes within this interval. Each group of test slurries is tested according to the thickness data of the test nodes, and the above Steps 1 to 3 are repeated for each group of slurries.

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