Die head

Abstract

A disclosed die head (10) comprises: a first block (30) having a manifold (33) to which a coating liquid is supplied; a second block (40); and a shim (52) disposed between the first block (30) and the second block (40) and forming a flow path corresponding to the manifold (33). An air vent groove (52b) that connects the manifold (33) with the outside is formed on at least one of the surface of the first block (30) facing the shim (52) and the surface of the shim (52) facing the first block (30).

Description

Die Head

[0001] The present disclosure relates to a die head.

[0002] Die heads used for applying a coating liquid have been known (for example, Patent Document 1). Patent Document 1 discloses "a die for discharging a coating liquid from a front end thereof onto a web being conveyed in a vertical direction to coat the web, the die comprising: a first body having a flat lower surface; a second body disposed opposite the lower surface of the first body; a sheet-like shim sandwiched between the first body and the second body; a liquid reservoir provided on the upper surface of the second body; a discharge passage formed by the shim between the upper surface of the second body and the lower surface of the first body; a slit-like discharge opening provided at the front end of the discharge passage; and a pair of left and right air vent holes on both sides of the second body that penetrate the liquid reservoir."

[0003] JP 2016-73950 A

[0004] In the die (or die head) of Patent Document 1, air remaining in the liquid reservoir (or manifold) can be released through the air release holes, but there is still room for improvement in this air release function. In this situation, one of the objects of the present disclosure is to sufficiently release air from within the manifold.

[0005] One aspect of the present disclosure relates to a die head including a first block having a manifold to which a coating liquid is supplied, a second block, and a shim disposed between the first block and the second block and forming a flow path corresponding to the manifold, wherein an air vent groove that connects the manifold to the outside is formed on at least one of a surface of the first block facing the shim and a surface of the shim facing the first block.

[0006] According to the present disclosure, air inside the manifold can be sufficiently removed.

[0007] 1 is a perspective view schematically illustrating an example of a die head according to the present disclosure, an exploded perspective view schematically illustrating the die head, in which the upper block is oriented so that its internal structure can be seen, and a plan view schematically illustrating a lower block and a second shim.

[0008] The following describes an embodiment of a die head according to the present disclosure. However, the present disclosure is not limited to the following examples. While the following description may use specific numerical values ​​and materials, other numerical values ​​and materials may be used as long as the effects of the present disclosure are achieved.

[0009] The die head according to the present disclosure is an apparatus for applying a coating liquid (e.g., electrode mixture slurry) to a strip-shaped substrate (e.g., a current collector for a battery or a metal foil), and is generally referred to as a die coater. The type of coating liquid is not particularly limited, but if the coating liquid is an electrode mixture slurry, the die head according to the present disclosure can also be referred to as a die head for electrode mixture slurry. The die head according to the present disclosure includes a first block, a second block, and a shim. The die head may be a horizontal die head or a vertical die head. The die head may be a single-layer die head or a multi-layer die head.

[0010] The first block has a manifold to which the coating liquid is supplied. The coating liquid may be supplied to the manifold intermittently or continuously. In the former case, the coating liquid can be intermittently applied to the substrate, and in the latter case, the coating liquid can be continuously applied to the substrate. The first block may have a flat surface facing the second block. The manifold may be formed on the flat surface. The first block may be formed in a generally rectangular prism shape. The first block may have a discharge lip for discharging the coating liquid. The first block may be a lower block in a horizontal die head. The first block may be made of a metal material such as stainless steel. Here, the manifold refers to a groove-shaped space extending in the width direction of the die head (the direction in which the discharge lip extends).

[0011] The second block may have a flat surface opposite to the flat surface of the first block. The second block may be a middle block in a horizontal multi-layer die head or an upper block in a horizontal single-layer die head. In the former case, the second block may be formed in a generally triangular prism shape, and in the latter case, the second block may be formed in a generally quadrangular prism shape. The second block may be made of a metal material such as stainless steel. The material of the second block may be the same as or different from the material of the first block.

[0012] The shim is disposed between the first block and the second block. The shim forms a flow path corresponding to the manifold. The shim may have at least one hollow portion for forming the flow path. The shim may be made of a metal material such as stainless steel. The material of the shim may be the same as or different from the material of each block.

[0013] A characteristic feature of the die head according to the present disclosure is that an air vent groove is formed on at least one of the surface of the first block facing the shim and the surface of the shim facing the first block, connecting the manifold to the outside. Air within the manifold can be discharged to the outside of the die head via the air vent groove. Furthermore, because the air vent groove is formed in the first block and / or the shim, there is no need to provide a separate component for this air vent function. Furthermore, air venting from the manifold via the air vent groove can be performed simultaneously with the application of the coating liquid by the die head, eliminating the need for additional time for air venting apart from the application of the coating liquid. The outside may be the space surrounding the die head. The air vent groove may have a flow path cross-sectional area that allows air to pass through but not the coating liquid. The flow path cross-sectional shape of the air vent groove is not particularly limited and may be, for example, rectangular, triangular, or semicircular. The maximum depth of the air vent groove may be smaller or larger than the maximum width of the air vent groove.

[0014] The air vent groove may connect the space on the flow path side of the manifold (or the discharge port side of the die head) to the outside. As a result of extensive research, it has been found that air tends to remain in the space on the flow path side of the manifold. Therefore, by forming the air vent groove so that the space on the flow path side of the manifold is connected to the outside, the air vent function of the air vent groove can be further improved. Note that the space on the flow path side of the manifold refers to half of the space on the flow path side when the manifold is divided into two equal parts: the flow path side and the opposite side.

[0015] The cross-sectional area of ​​the air vent groove is 1000 μm 2 More than 3000 μm 2 By setting the flow path cross-sectional area of ​​the air vent groove within this range, it is possible to achieve at a high level both that the air in the manifold can be smoothly released via the air vent groove and that the coating liquid in the manifold does not flow through the air vent groove. 2 Above, 2500μm 2 It may be 1800 μm or less, 2 Above, 2300μm 2 The maximum depth of the air release groove may be, for example, 20 μm or more and 40 μm or less, and the maximum width of the air release groove may be, for example, 60 μm or more and 90 μm or less.

[0016] The air vent groove may extend from the manifold to the outlet of the flow path. In this case, air in the manifold can flow through the air vent groove in accordance with the flow of the coating liquid in the flow path. Therefore, air can be vented more smoothly via the air vent groove. Furthermore, even if the coating liquid in the manifold flows out through the air vent groove, the coating liquid flows out from the outlet of the flow path or its vicinity, so the flowed-out coating liquid only adheres to the substrate, and the periphery of the die head and peripheral equipment are hardly contaminated by the coating liquid. The outlet of the flow path can also be referred to as the discharge port of the die head. Note that the air vent groove may extend from the manifold to a location other than the outlet of the flow path, as long as it connects the manifold to the outside.

[0017] The air vent groove may extend along the flow direction of the coating liquid in the flow channel. In this case, the air in the manifold can flow more smoothly through the air vent groove in accordance with the flow of the coating liquid in the flow channel. Therefore, air can be vented more smoothly via the air vent groove. The air vent groove may extend linearly along the flow direction, or may extend in a curved or serpentine manner along the flow direction.

[0018] The air release groove may be formed only in the shim. The shim is a smaller component than the first block. Therefore, forming an air release groove in the shim is easier than forming an air release groove in the first block. Furthermore, the dimensions of the air release groove may be changed as appropriate depending on the application of the die head. Even in such a case, the die head can be adapted to the application simply by replacing it with a shim having a different type of air release groove. This is easier than replacing the first block. However, the air release groove may be formed only in the first block, or may be formed in both the first block and the shim.

[0019] The shim may have a plurality of flow paths extending parallel to one another. The air vent groove may be formed at least between a pair of adjacent flow paths. The plurality of flow paths may be arranged side by side in the width direction of the die head. With this configuration, air can be vented from a wide range of the manifold. In other words, the air vent function of the air vent groove can be further enhanced.

[0020] The length L1 of each flow path and the length L2 of the air vent groove may satisfy the relationship 0.8≦L1 / L2≦1.2. By setting the ratio of lengths L1 and L2 within this range, the air vent groove can be properly connected to the manifold, thereby enabling the air vent function to be fully exerted. Here, the length of a flow path refers to the length of the hollow portion provided in the shim to form the flow path in the direction of flow of the coating liquid. Furthermore, the length of the air vent groove refers to the length of the air vent groove in a direction parallel to the direction of flow of the coating liquid.

[0021] As described above, according to the present disclosure, by providing the air vent groove in the first block and / or the shim, it is possible to sufficiently vent air from within the manifold. Furthermore, according to the present disclosure, such air venting can be performed simultaneously with the application of the coating liquid.

[0022] An example of a die head according to the present disclosure will be specifically described below with reference to the drawings. The components described above can be applied to the components of the die head of the example described below. The components of the die head of the example described below can be modified based on the above description. Furthermore, the matters described below may be applied to the above embodiment. Among the components of the die head of the example described below, components that are not essential to the die head according to the present disclosure may be omitted. Note that the diagrams shown below are schematic and do not accurately reflect the shapes and numbers of actual components.

[0023] 1 to 3, the die head 10 of this embodiment is configured as a horizontal multi-layer die head, but is not limited to this. The die head 10 includes an upper block 20, a lower block 30, a middle block 40, a first shim 51, and a second shim 52.

[0024] The upper block 20 is disposed on one side (the upper side in FIGS. 1 and 2 ) in the vertical direction (the Z direction in each figure). The upper block 20 is formed in a generally rectangular prism shape extending in a first horizontal direction (the X direction in each figure). The upper block 20 has a first flat surface 22 for forming a slit-shaped first flow path (not shown). The upper block 20 has a discharge lip 21 for discharging the coating liquid (not shown) in a second horizontal direction (the Y direction in each figure). The upper block 20 has a first manifold 23 to which the coating liquid is supplied. In this embodiment, the coating liquid is continuously supplied to the first manifold 23 from a supply means (not shown) via a supply path (not shown), but this is not limited thereto. The upper block 20 is made of a metal material. The upper block 20 is an example of a third block.

[0025] The lower block 30 is disposed on the other side in the vertical direction (the lower side in FIGS. 1 and 2 ). The lower block 30 is formed in a generally rectangular prism shape extending in the first horizontal direction. The lower block 30 has a second flat surface 32 for forming a slit-shaped second flow path (not shown). The lower block 30 has a discharge lip 31 for discharging the coating liquid in the second horizontal direction. The lower block 30 has a second manifold 33 to which the coating liquid is supplied. In this embodiment, the coating liquid is intermittently supplied to the second manifold 33 from a supply means (not shown) via a supply path (not shown), but this is not limited to this. The type of coating liquid supplied to the second manifold 33 may be the same as or different from the type of coating liquid supplied to the first manifold 23 of the upper block 20. The lower block 30 is made of a metal material. The lower block 30 is an example of a first block. The second manifold 33 is an example of a manifold.

[0026] The middle block 40 is disposed between the upper block 20 and the lower block 30. The middle block 40 is formed in a generally triangular prism shape extending in the first horizontal direction. The middle block 40 has a third flat surface 41 facing the first flat surface 22 of the upper block 20 and a fourth flat surface 42 facing the second flat surface 32 of the lower block 30. The middle block 40 is made of a metal material. The middle block 40 is an example of a second block.

[0027] The first shim 51 is disposed between the upper block 20 and the middle block 40. The first shim 51 is formed in the shape of a thin plate. The first shim 51 communicates with the first manifold 23 of the upper block 20 and has at least one (four in this example) first hollow portion 51a that forms a first flow path through which the coating liquid supplied to the first manifold 23 flows. The first shim 51 is made of a metal material.

[0028] The second shim 52 is disposed between the lower block 30 and the middle block 40. The second shim 52 is formed in a thin plate shape. The second shim 52 is connected to the second manifold 33 of the lower block 30 and has at least one (four in this example) second hollow portion 52a that forms a second flow path through which the coating liquid supplied to the second manifold 33 flows. The second hollow portions 52a extend parallel to one another, and thus the second shim 52 forms a plurality of second flow paths that extend parallel to one another. The second hollow portion 52a is disposed at a position that overlaps with the first hollow portion 51a of the first shim 51 in the vertical direction. The second shim 52 is an example of a shim. The second flow path is an example of a flow path.

[0029] A plurality of air vent grooves 52b are formed on the surface of the second shim 52 facing the lower block 30 (the lower surface in this example), which connects the second manifold 33 of the lower block 30 with the outside (see FIG. 3). In this embodiment, the plurality of air vent grooves 52b are formed only on the second shim 52, but this is not limited to this. The plurality of air vent grooves 52b are arranged side by side in the first horizontal direction. The air vent grooves 52b are formed at least between a pair of second hollow portions 52a (or second flow paths) adjacent to each other in the first horizontal direction. Between the second hollow portions 52a adjacent to each other in the first horizontal direction, the plurality of air vent grooves 52b extend linearly and parallel to each other. Each air vent groove 52b extends linearly along the second horizontal direction, i.e., along the flow direction of the coating liquid in the second flow path. The flow path cross-sectional area of ​​each air vent groove 52b is 1000 μm 2 More than 3000 μm 2 The plurality of air vent grooves 52b extend from the second manifold 33 to the outlet of the second flow path (or the tip of the discharge lip 31 of the lower block 30). The length L1 of each second flow path and the length L2 of the air vent groove 52b satisfy the relationship 0.8≦L1 / L2≦1.2. Note that, although the plurality of air vent grooves 52b are shown by solid lines in FIG. 3, the air vent grooves 52b are formed on the lower surface of the second shim 52 (the surface at the back of the page in FIG. 3).

[0030] <<Supplementary Note>> The above description of the embodiments discloses the following techniques. (Technology 1) A die head comprising: a first block having a manifold to which a coating liquid is supplied; a second block; and a shim disposed between the first block and the second block and forming a flow path corresponding to the manifold, wherein an air vent groove that connects the manifold to the outside is formed on at least one of a surface of the first block facing the shim and a surface of the shim facing the first block. (Technology 2) The flow path cross-sectional area of ​​the air vent groove is 1000 μm 2 More than 3000 μm 2 A die head according to Technology 1, which is as follows: (Technology 3) A die head according to Technology 1 or 2, wherein the air vent groove extends from the manifold to an outlet of the flow path. (Technology 4) A die head according to Technology 3, wherein the air vent groove extends along the flow direction of the coating liquid in the flow path. (Technology 5) A die head according to any one of Technology 1 to 4, wherein the air vent groove is formed only in the shim. (Technology 6) A die head according to any one of Technology 1 to 5, wherein the shim forms a plurality of the flow paths extending parallel to each other, and the air vent groove is formed at least between a pair of adjacent flow paths. (Technology 7) A die head according to any one of Technology 1 to 6, wherein the length L1 of each of the flow paths and the length L2 of the air vent groove satisfy 0.8≦L1 / L2≦1.2.

[0031] The present invention can be embodied in various other forms without departing from its spirit or main features. Therefore, the above-described embodiments are merely illustrative in all respects and should not be interpreted as limiting. The scope of the present invention is defined by the claims and is not limited to the text of the specification. Furthermore, all modifications and variations within the equivalent range of the claims are within the scope of the present invention.

[0032] This application claims priority from Japanese Patent Application No. 2024-011095, filed on January 29, 2024, the contents of which are incorporated herein by reference. In addition, all documents cited herein are specifically incorporated herein by reference in their entirety.

[0033] The present disclosure can be used in die heads.

[0034] 10: Die head 20: Upper block (third block) 21: Discharge lip 22: First flat surface 23: First manifold 30: Lower block (first block) 31: Discharge lip 32: Second flat surface 33: Second manifold (manifold) 40: Middle block (second block) 41: Third flat surface 42: Fourth flat surface 51: First shim 51a: First hollow portion 52: Second shim (shim) 52a: Second hollow portion 52b: Air vent groove

Claims

1. A die head comprising: a first block having a manifold to which a coating liquid is supplied; a second block; and a shim disposed between the first block and the second block and forming a flow path corresponding to the manifold, wherein an air vent groove that connects the manifold to the outside is formed on at least one of the surface of the first block facing the shim and the surface of the shim facing the first block.

2. The cross-sectional area of the air vent groove is 1000 μm 2 More than 3000μm 2 2. The die head of claim 1, wherein:

3. A die head according to claim 1 or 2, wherein the air vent groove extends from the manifold to the outlet of the flow path.

4. The die head according to claim 3, wherein the air vent groove extends along the direction in which the coating liquid flows in the flow path.

5. A die head according to claim 1 or 2, wherein the air release groove is formed only in the shim.

6. A die head as described in claim 1 or 2, wherein the shim forms a plurality of the flow paths extending parallel to one another, and the air vent groove is formed at least between a pair of adjacent flow paths.

7. A die head according to claim 1 or 2, wherein the length L1 of each flow path and the length L2 of the air release groove satisfy the relationship 0.8≦L1 / L2≦1.2.

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