Coated gasket

Abstract

The utility model relates to the technical field of coating, and provides a coating gasket which is suitable for slit coating equipment and comprises a gasket body clamped between an upper mold and a lower mold, a through groove and two second runners are formed in the gasket body, and a first runner is defined by the upper mold, the through groove and the lower mold; the two second flow channels are located on the two sides, in the length direction of the gasket body, of the first flow channel correspondingly. The first flow channel is communicated with the two second flow channels, a liquid outlet face is formed on one side of the gasket body in the width direction of the gasket body, and projection parts of a first outlet, in the liquid outlet face, of the first flow channel and projection parts of second outlets, in the liquid outlet face, of the second flow channels in the thickness direction of the gasket body coincide. And the depth of the first flow channel in the thickness direction of the gasket body is greater than that of the second flow channel in the thickness direction of the gasket body. According to the coating gasket provided by the embodiment of the invention, when the second surface of the to-be-coated piece for turn-back type slit coating is coated, thick edges can be effectively prevented from being formed on the two sides of the coating layer on the second surface of the to-be-coated piece.

Description

Technical Field

[0001] The present application relates to the field of coating technology, and in particular to a coating gasket. Background Art

[0002] Slit coating is a wet coating method that presses the coating liquid out along the gap of the mold under a certain pressure and transfers it to the moving substrate. It has the advantages of fast coating speed and wide coating window. In the battery production process, the battery pole piece needs to be coated with material layers such as active material layer or insulation layer.

[0003] The folding slit coating coats the front and back sides of the battery pole piece. The slit coating equipment coats the first side of the battery pole piece first, and then coats the second side of the battery pole piece. In the related art, the slit coating equipment uses the same coating pad when coating the first side and the second side, resulting in a thick edge at the edge of the coating layer on the second side of the battery pole piece. Utility Model Content

[0004] In order to solve the above technical problems or at least partially solve the above technical problems, the present application provides a coated gasket.

[0005] The embodiment of the present application provides a coating gasket, which is suitable for a slit coating device, wherein the slit coating device comprises an upper die and a lower die, and the coating gasket comprises a gasket body sandwiched between the upper die and the lower die, a through groove and two second flow channels are formed on the gasket body, the upper die, the through groove and the lower die surround a first flow channel, and the two second flow channels are respectively located on both sides of the first flow channel in the length direction of the gasket body;

[0006] Wherein, the first flow channel is connected with two second flow channels respectively, a liquid outlet surface is formed on one side of the gasket body along its width direction, a first outlet of the first flow channel on the liquid outlet surface and a projection of the second outlet of the second flow channel on the liquid outlet surface in the thickness direction of the gasket body overlap, and a depth of the first flow channel in the thickness direction of the gasket body is greater than a depth of the second flow channel in the thickness direction of the gasket body.

[0007] Optionally, the first outlet and the second outlet are connected to form a common outlet.

[0008] Optionally, a side of the second flow channel facing the first flow channel is connected to the first flow channel.

[0009] Optionally, the second outlet extends along a side away from the first outlet to form a first chamfer.

[0010] Optionally, each of the second flow channels is further provided with a third flow channel on a side away from the first flow channel, and a third outlet of the third flow channel on the liquid outlet surface overlaps with a projection of the second outlet of the second flow channel on the liquid outlet surface in the thickness direction of the gasket body.

[0011] Optionally, the direction from the inlet to the outlet of the third flow channel includes a first section, a second section and a third section connected in sequence, the inner diameter of the second section gradually decreases from one end connected to the first section to the other end connected to the third section, and the inner diameter of the third section is consistent with the inner diameter of the other end of the second section.

[0012] Optionally, the outlet of the third flow channel on the liquid outlet surface is recessed along the length direction of the gasket body to form a second chamfer on both side walls thereof.

[0013] Optionally, the thickness of the portion of the gasket body without the flow channel is 0.8 mm-1.2 mm.

[0014] Optionally, a depth of the second flow channel in the thickness direction of the gasket body is 0.3 mm-0.7 mm.

[0015] Optionally, a positioning hole is also provided on the gasket body.

[0016] Compared with the prior art, the technical solution provided by the embodiments of the present application has the following advantages:

[0017] The coating gasket provided in the embodiment of the present application forms a through groove on the gasket body, so that when the gasket body is sandwiched between the upper mold and the lower mold, the upper mold, the through groove and the lower mold surround the first flow channel. By forming two second flow channels on the gasket body, which are respectively located on both sides of the first flow channel in the length direction of the gasket body, and respectively communicating with the two second flow channels through the first flow channel, the feeding die head in the upper mold or the lower mold conveys the fluid coating to the first flow channel, and the fluid coating entering the first flow channel fills the first flow channel and enters the second flow channel respectively. By setting the first outlet of the first flow channel on the liquid outlet surface and the second outlet of the second flow channel on the liquid outlet surface to overlap in the thickness direction of the gasket body, the first coating layer formed when the fluid coating flowing out of the first outlet is coated on the pole piece and the second coating layer formed when the fluid coating flowing out of the second outlet is coated on the pole piece are connected in the length direction of the gasket body to form an integral coating layer. By setting the depth of the first flow channel in the thickness direction of the gasket body to be greater than the depth of the second flow channel in the thickness direction of the gasket body, the thickness of the first coating layer formed on the pole piece will not be less than the thickness of the second coating layer on both sides of the first coating layer.

[0018] When coating the second side of the coated piece by the folding slit coating, it is possible to effectively avoid the formation of thick edges on both sides of the coating layer on the second side of the coated piece, so that the edge thickness of the coating layer on the first side and the second side of the coated piece is as similar as possible. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0020] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0021] Figure 1 This is a schematic diagram of the structure of the slit coating device described in the embodiment of the present application;

[0022] Figure 2 This is a schematic diagram of the structure of the coating gasket described in the embodiment of the present application;

[0023] Figure 3 for Figure 2 A partial enlarged view of the middle A;

[0024] Figure 4 A schematic cross-sectional view in the thickness direction of the coating gasket described in an embodiment of the present application;

[0025] Figure 5 This is a schematic cross-sectional view in the thickness direction of a coating gasket according to another embodiment of the present application.

[0026] Among them, 1. gasket body; 11. through groove; 12. liquid outlet surface; 2. first flow channel;

[0027] 21. First outlet; 3. Second flow channel; 31. Second outlet; 32. First chamfer;

[0028] 4. third flow channel; 41. first section; 42. second section; 43. third section;

[0029] 44. Second chamfer; 5. Positioning hole; 6. Upper die; 7. Lower die;

[0030] 8. pole piece; 81. first side; 82. second side; 9. convex part. DETAILED DESCRIPTION

[0031] In order to more clearly understand the above-mentioned purposes, features and advantages of the present application, the scheme of the present application will be further described below. It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

[0032] In the following description, many specific details are set forth to facilitate a full understanding of the present application, but the present application may also be implemented in other ways different from those described herein; obviously, the embodiments in the specification are only part of the embodiments of the present application, rather than all of the embodiments.

[0033] like Figure 1 As shown, the slit coating equipment includes an upper die 6, a lower die 7 and a coating gasket sandwiched between the upper die 6 and the lower die 7. The return slit coating is used to coat the front and back sides of the battery pole piece 8. The slit coating equipment first coats the first side 81 of the battery pole piece 8, and then coats the second side 82 of the battery pole piece 8. When the slit coating equipment first coats the first side 81 of the battery pole piece 8, the slit coating equipment uses the same coating gasket when coating the first side 81 and the second side 82, resulting in a thick edge at the edge of the coating layer of the second side 82 of the battery pole piece 8.

[0034] The inventors found that since the pole piece 8 is wound around the outer circumference of the roller, Figure 1 As shown, due to the thinning characteristics of the coating gasket, the edges on both sides of the coating layer on the pole piece 8 are thinner after the first side 81 of the pole piece 8 is coated. When the pole piece 8 is folded back to fit the first side 81 onto the outer peripheral surface of the roller for coating the second side 82, there is a gap between the thin edges on both sides of the coating layer on the first side 81 and the surface of the roller. When the slit coating equipment coats the second side 82 of the pole piece 8, the edge of the coating layer on the second side 82 will "collapse" due to the above gap, and excess fluid coating will accumulate at the "collapsed" edge of the second side 82, resulting in the formation of thick edges on the edge of the coating layer on the second side 82 after the slit coating equipment coats the second side 82 of the pole piece 8.

[0035] Reference Figures 1 to 4 As shown, this embodiment provides a coating gasket suitable for a slit coating device, the slit coating device includes an upper mold 6 and a lower mold 7, the coating gasket includes a gasket body 1 clamped between the upper mold 6 and the lower mold 7, a through groove 11 and two second flow channels 3 are formed on the gasket body 1, the upper mold 6, the through groove 11 and the lower mold 7 surround a first flow channel 2, and the two second flow channels 3 are respectively located on both sides of the first flow channel 2 in the length direction of the gasket body 1.

[0036] The first flow channel 2 is connected to the two second flow channels 3 respectively, and the feeding die head in the upper mold 6 or the lower mold 7 conveys the fluid coating to the first flow channel 2. The fluid coating entering the first flow channel 2 fills the first flow channel 2 and then enters the second flow channels 3 respectively. A liquid outlet 12 is formed on one side of the gasket body 1 along its width direction, and the first outlet 21 of the first flow channel 2 on the liquid outlet surface 12 and the second outlet 31 of the second flow channel 3 on the liquid outlet surface 12 overlap in the thickness direction of the gasket body 1. The fluid coating flowing out through the first outlet 21 forms a first coating layer when applied on the pole piece 8, and the fluid coating flowing out through the second outlet 31 forms a second coating layer when applied on the pole piece 8, so that the first coating layer and the second coating layer are connected in the length direction of the gasket body 1 to form an integral coating layer. And the depth of the first flow channel 2 in the thickness direction of the gasket body 1 is greater than the depth of the second flow channel 3 in the thickness direction of the gasket body 1, that is, the thickness of the fluid coating in the first flow channel 2 is greater than the thickness of the fluid coating in the second flow channel 3, reducing the fluid coating flowing out of the second outlet 31 and accumulating at the "collapse" of the edge of the second surface 82 of the pole piece 8. When the slit coating equipment coats the surface of the pole piece 8, the fluid coating flowing out of the first outlet 21 will flow toward both sides when it flows to the surface of the pole piece 8. In addition, the thickness of the fluid coating flowing out of the second outlet 31 is thinned, so that the thickness of the first coating layer formed on the pole piece 8 will not be less than the thickness of the second coating layer on both sides of the first coating layer, thereby avoiding the formation of thick-edged coating layers on both sides.

[0037] In specific implementation, it is required that the thickness of the edges on both sides of the coating layer on the pole piece 8 cannot be greater than the thickness of the middle main body of the coating layer. Thinning the edges on both sides of the coating layer on the pole piece 8 is more conducive to the next cutting process or other processes of the pole piece 8 after the coating layer is formed. The first flow channel 2 is the main discharge area of ​​the fluid coating during coating. The length of the first flow channel 2 in the length direction of the gasket body 1 is set according to the width requirement of the coating on the pole piece 8, and can meet the coatings of different widths.

[0038] The coating gasket provided in the embodiment of the present application can effectively avoid the formation of thick edges on both sides of the coating layer on the second surface 82 of the workpiece to be coated when coating the second surface 82 of the workpiece to be coated in the return slit coating, so that the edge thickness of the coating layer on the first surface 81 and the second surface 82 of the workpiece to be coated is as similar as possible.

[0039] Because the pressure of the fluid coating in the second flow channel 3 is lower than the pressure of the fluid coating in the first flow channel 2, when the pressure of the fluid coating in the second flow channel 3 is too small, the fluid coating in the second flow channel 3 flowing out from the second outlet 31 will be disconnected in the length direction of the gasket body 1, resulting in gaps in the second coating formed on the pole piece 8.

[0040] Therefore, in some embodiments, the first outlet 21 and the second outlet 31 are connected to form a common outlet. That is, the first outlet 21 and the second outlet 31 on the liquid outlet surface 12 of the gasket body 1 are connected to form a common outlet, and the pressure of the fluid coating at the first flow channel 2 near the first outlet 21 will compensate for the pressure of the fluid coating at the second flow channel 3 near the second outlet 31.

[0041] Further, in some embodiments, the second flow channel 3 is connected to the first flow channel 2 on one side thereof facing the first flow channel 2. Figure 4 and Figure 5 As shown, the side of the second flow channel 3 on the gasket body 1 facing the groove is open, that is, the side of the half-milled groove facing the through groove 11 along the length direction of the gasket body 1 is connected to the through groove 11. The fluid coating entering the groove is filled into the second flow channel 3 through the opening, further increasing the pressure of the fluid coating in the second flow channel 3.

[0042] In specific implementation, in order to facilitate the processing of the second flow channel 3 on the gasket body 1, as Figure 4 As shown, the gasket body 1 is recessed along its thickness direction to form a through groove 11, and the through groove 11 penetrates the gasket body 1 along the thickness direction of the gasket body 1. Half milling grooves are processed on both sides of the through groove 11 along the length direction of the gasket body 1. The half milling groove can be understood as: the gasket body 1 is recessed along its thickness direction to form a half milling groove, and the recessed depth is half of the thickness of the gasket body 1. The side of the second flow channel 3 on the gasket body 1 facing the groove is open, that is, the half milling groove is connected to the through groove 11 along the length direction of the gasket body 1. At this time, the upper mold 6 and the groove (half milling groove) form the second flow channel 3, and the side of the second flow channel 3 facing the first flow channel 2 is directly connected to the first flow channel 2.

[0043] In some embodiments, the second outlet 31 extends along a side away from the first outlet 21 to form a first chamfer 32, so that the second coating formed on the pole piece 8 by the fluid coating flowing out of the second outlet 31 becomes thinner on the side away from the first coating, thereby facilitating the processing of the pole piece 8 in the next process of the pole piece 8.

[0044] In some embodiments, a third flow channel 4 is further provided on the side of each second flow channel 3 away from the first flow channel 2, and the third outlet of the third flow channel 4 on the liquid outlet surface 12 partially overlaps with the projection of the second outlet 31 of the second flow channel 3 on the liquid outlet surface 12 in the thickness direction of the gasket body 1. The third flow channel 4 is used as a white glue flow channel (boehmite material), which is used to coat the electrode 8 to form a boehmite white material layer (diaphragm layer) to facilitate the subsequent cutting and processing, and does not play any role. Because the positive and negative electrodes in the battery are stacked one by one, and the negative electrode is wider than the positive electrode, the coating of boehmite can prevent the positive and negative electrodes from short-circuiting. If there is no boehmite white material layer, the negative electrode may directly overlap with the positive electrode, causing a short circuit or even a fire.

[0045] In some embodiments, the third flow channel 4 includes a first section 41, a second section 42 and a third section 43 which are connected in sequence from the inlet to the outlet, the inner diameter of the second section 42 gradually decreases from one end connected to the first section 41 to the other end connected to the third section 43, and the inner diameter of the third section 43 is consistent with the inner diameter of the other end of the second section 42. Since the feed port of the third flow channel 4 is a separate feed port, the pressure of the feed port is unstable, and the third flow channel 4 configured in this way can make the fluid pressure at the third outlet of the third flow channel 4 on the liquid outlet surface 12 sufficient for the continuous and stable outflow of the fluid coating.

[0046] In some embodiments, the outlet of the third flow channel 4 on the liquid outlet surface 12 is recessed along the length direction of the gasket body 1 on both side walls to form a second chamfer 44, so that the fluid coating flowing out of the third outlet and the fluid coating flowing out of the second outlet 31 form a connected third coating and a second coating on the pole piece 8, and the thickness of the third coating becomes thinner on the side away from the second coating.

[0047] In some embodiments, the thickness of the portion of the gasket body 1 without the flow channel is 0.8 mm to 1.2 mm, which is set according to the requirements of the slit coating equipment.

[0048] In some embodiments, the depth of the second flow channel 3 in the thickness direction of the gasket body 1 is 0.3mm-0.7mm. Exemplarily, the depth of the second flow channel 3 in the thickness direction of the gasket body 1 is 0.3mm, 0.5mm, 0.6mm and 0.7mm, which can meet the thinner thickness requirements of the coating edges on the pole pieces 8 of various specifications, and at the same time, the pressure of the fluid coating in the second flow channel 3 can meet the continuous and stable flow of the fluid coating. If the depth of the second flow channel 3 in the thickness direction of the gasket body 1 is less than 0.3mm, the fluid coating overflowing from the first flow channel 2 is not easy to enter the second flow channel 3. If the depth of the second flow channel 3 in the thickness direction of the gasket body 1 is 0.7mm-1.2mm, it is easy to cause thick edges on both sides of the coating on the second surface of the pole piece 8.

[0049] In some embodiments, a positioning hole 5 is further provided on the gasket body 1 to facilitate the positioning of the slit coating gasket on the die head cavity of the upper die 6 and the lower die 7 for installation and use.

[0050] In some embodiments, a side surface of the gasket body 1 opposite to the liquid outlet surface 12 extends along the width direction of the gasket body 1 to form a protrusion 9, and the protrusion 9 is used to set a gasket marking business card, and the gasket marking business card records the model information of the coated gasket. The model information includes but is not limited to the above-mentioned various specification information of the gasket thickness, gasket length, the first flow channel and the second flow channel.

[0051] It should be noted that, in this article, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0052] The above description is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments described herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A coating gasket, suitable for a slit coating device, the slit coating device comprising an upper die (6) and a lower die (7), characterized in that: The coating gasket comprises a gasket body (1) sandwiched between the upper die (6) and the lower die (7); a through groove (11) and two second flow channels (3) are formed on the gasket body (1); the upper die (6), the through groove (11) and the lower die (7) surround a first flow channel (2); and the two second flow channels (3) are respectively located on both sides of the first flow channel (2) in the length direction of the gasket body (1); The first flow channel (2) is connected to two of the second flow channels (3) respectively, a liquid outlet surface (12) is formed on one side of the gasket body (1) along its width direction, a first outlet (21) of the first flow channel (2) on the liquid outlet surface (12) and a second outlet (31) of the second flow channel (3) on the liquid outlet surface (12) are partially overlapped in the thickness direction of the gasket body (1), and a depth of the first flow channel (2) in the thickness direction of the gasket body (1) is greater than a depth of the second flow channel (3) in the thickness direction of the gasket body (1).

2. The coated gasket according to claim 1, characterized in that: The first outlet (21) and the second outlet (31) are communicated with each other to form a common outlet.

3. The coated gasket according to claim 2, characterized in that: The second flow channel (3) is connected to the first flow channel (2) on the side facing the first flow channel (2).

4. The coated gasket according to claim 3, characterized in that: The second outlet (31) extends along a side away from the first outlet (21) to form a first chamfer (32).

5. The coated gasket according to claim 2, characterized in that: A third flow channel (4) is also provided on a side of each second flow channel (3) away from the first flow channel (2), and a third outlet of the third flow channel (4) on the liquid outlet surface (12) overlaps with a projection of a second outlet (31) of the second flow channel (3) on the liquid outlet surface (12) in the thickness direction of the gasket body (1).

6. The coated gasket according to claim 5, characterized in that: The third flow channel (4) comprises a first section (41), a second section (42) and a third section (43) which are connected in sequence from the inlet to the outlet, the inner diameter of the second section (42) gradually decreases from one end connected to the first section (41) to the other end connected to the third section (43), and the inner diameter of the third section (43) is consistent with the inner diameter of the other end of the second section (42).

7. The coated gasket according to claim 5, characterized in that: The outlet of the third flow channel (4) on the liquid outlet surface (12) is formed with a second chamfer (44) on both side walls in the length direction of the gasket body (1) which are recessed along the length direction of the gasket body (1).

8. The coated gasket according to claim 1, characterized in that: The thickness of the portion of the gasket body (1) without a flow channel is 0.8 mm to 1.2 mm.

9. The coated gasket according to claim 8, characterized in that: The depth of the second flow channel (3) in the thickness direction of the gasket body (1) is 0.3 mm-0.7 mm.

10. The coated gasket according to claim 1, characterized in that: The gasket body (1) is also provided with a positioning hole (5).

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