Die pad and die for an extrusion coater

Abstract

The utility model belongs to lithium ion electric extrusion coating machine technical field, concretely relates to a die pad and die of extrusion coating machine. The die pad includes first fixed part and second fixed part, and the second fixed part is set in two ends of first fixed part in pairs and has the shape of extending towards the side where the coating lip is, the second fixed part is connected with the current limiting plate respectively, and the discharge port is formed between the two current limiting plates, the two current limiting plates all have the shape of extending towards the discharge port, the current limiting plate has the adjusting side towards the first fixed part, and the adjusting side is equipped with the deceleration runner of the thickness of being thinner than the current limiting plate main part, the first fixed part, the second fixed part and the current limiting plate cooperation form the slurry runner with the discharge port as the only outlet. The scheme sets the deceleration runner of the shape of being thin gradually on the discharge side of current limiting plate to make the greater flow resistance between the ladder structure and slurry, and the flow velocity, coating flow are also relatively smaller than the central region, avoid producing the thick edge phenomenon.

Description

Technical Field

[0001] This utility model belongs to the technical field of lithium-ion extrusion coating machine, specifically relating to a die head gasket and die head for an extrusion coating machine. Background Technology

[0002] The manufacturing process of lithium-ion electrode sheets includes slurry preparation, coating, and roll forming. The coating process involves applying the electrode slurry onto the current collector using a die of an extrusion coating machine. The die consists of an upper die, a die pad, and a lower die. The electrode slurry is extruded through a narrow slit between the upper and lower dies; the length of this slit is the coating width of the extrusion coating machine die. Due to the fluid properties of the electrode slurry, the coating tends to spontaneously accumulate at the edges, resulting in a "thick edge" phenomenon after coating. Utility Model Content

[0003] In view of this, the present invention aims to propose a die head gasket structure for an extrusion coating machine, which improves the thick edge phenomenon by adjusting the flow characteristics of the electrode slurry.

[0004] This utility model is achieved through the following technical solution:

[0005] A die head gasket for an extrusion coating machine, wherein the die head gasket cooperates with an upper die head and a lower die head to form a coating lip of the extrusion coating machine, characterized in that:

[0006] The die head pad includes a first fixing part and a second fixing part. The second fixing part is arranged in pairs at both ends of the first fixing part and has a shape that extends toward the side where the coating lip is located.

[0007] A flow-limiting plate is connected to a pair of second fixing parts, and a discharge port is formed between the two flow-limiting plates; both flow-limiting plates have a shape that extends toward the discharge port.

[0008] The flow limiting plate has an adjustment side facing the first fixing part, and the adjustment side is provided with a deceleration channel with a thickness thinner than the main body of the flow limiting plate;

[0009] The first fixing part, the second fixing part, and the flow limiting plate cooperate to form a slurry flow channel with the discharge port as the only outlet.

[0010] In the die head structure of the extrusion coating machine, the die head gasket is fixed to the lower die head by a first fixing part and a second fixing part. The area enclosed by the first fixing part and the second fixing part is the discharge chamber of the lower die head. The electrode slurry in the slurry tank flows into the die head through the discharge chamber, then flows through the second fixing part and the flow limiting plate in sequence, and finally flows out from the discharge port, and is coated onto the current collector through the coating lip. The coating lip is a narrow slit structure formed by the pressing of the upper and lower dies. Due to the fluid properties of the electrode slurry itself, the coating thickness at both ends of the coating lip is greater than the coating thickness in the middle area, forming a "thick edge" on the current collector, which greatly affects the electrode performance.

[0011] This invention optimizes the flow channel of the electrode slurry by slowing down the electrode slurry at both ends of the channel to control the outflow during coating. The design features a gradually thinning decelerating flow channel on the discharge side of the flow restrictor. This stepped structure provides a larger contact area with the slurry, resulting in greater flow resistance at the slurry edges and a lower flow velocity than in the central region. Consequently, the flow rate during coating is also relatively lower in the central region, preventing thick edges. The stepped structure also thins the slurry edges, reducing the flow volume in these areas.

[0012] Preferably, the deceleration channel includes a first deceleration step surface close to the flow restrictor and a second deceleration step surface away from the flow restrictor; the first deceleration step surface provides a deceleration stroke longer than the second deceleration step surface.

[0013] In the edge region of the flow channel, the slurry closer to the flow restrictor flows along the first deceleration step, with a longer deceleration stroke and a slower flow velocity compared to the slurry in the central region of the flow channel; the slurry slightly farther from the flow restrictor flows along the second deceleration step, also with a slightly slower flow velocity compared to the slurry in the central region of the flow channel. The deceleration flow channel further divides the slurry in the edge region of the flow channel into velocity gradients by setting the first and second steps.

[0014] Preferably, the second deceleration step has a shape that partially faces the discharge port.

[0015] The second deceleration step is positioned on the adjustment side of the flow limiting plate facing the first fixing part. Based on this, the second deceleration step has a shape that partially faces the discharge port, which can guide the electrode slurry to flow smoothly from the adjustment side of the flow limiting plate to the discharge port. Compared with the setting method that is completely facing the first fixing part, the second deceleration step in this solution is set at an angle, which can provide a larger deceleration stroke.

[0016] Preferably, the flow restrictor includes a discharge side facing the discharge port and a coating side facing the outside of the coating lip; the connection between the discharge side and the coating side has a shape that expands the width of the discharge port channel.

[0017] By widening the flow channel at the discharge point, the fluid volume is dispersed, resulting in a smaller fluid thickness per unit coating length.

[0018] Preferably, the connection between the discharge side and the coating side is provided with a first chamfer.

[0019] The electrode slurry is a non-Newtonian fluid. For the slurry channel, the corner here is an external angle, which may generate concentrated stress on the slurry fluid. By setting a chamfer, the stress caused by the widening of the channel can be avoided.

[0020] Preferably, the connection position between the second fixing part and the adjustment side is provided with a second chamfer.

[0021] The adjusting side and the second fixing part together form the edge of the slurry flow channel. The angle formed by the two is a concave angle, so there is a flow dead zone in the slurry. This solution eliminates the flow dead zone by setting a chamfer.

[0022] A die head for an extrusion coating machine includes a discharge chamber, characterized in that it further includes a die head gasket as described in any of the preceding claims; the discharge chamber and the die head gasket at least form a partial outline of a slurry flow channel.

[0023] Preferably, the flow restrictor is arranged adjacent to the discharge chamber.

[0024] After the slurry flows from the discharge chamber into the die head, it immediately enters the flow channel adjustment area defined by the flow restrictor, maximizing the adjustment effect.

[0025] Preferably, one end of the deceleration channel is disposed on the second fixing part.

[0026] Increasing the length of the deceleration channel extends the deceleration stroke of the slurry; at the same time, the width of the deceleration channel changes with the extension. The longer the step length, the greater the width gradient that the deceleration channel can form, providing a more distinct diversion effect to the edge area of ​​the slurry.

[0027] Preferably, one end of the deceleration channel is located on the discharge side.

[0028] The length of the deceleration channel is further increased, and the deceleration process is closely connected with the discharge process to prevent the slurry volume from re-aggregating during discharge.

[0029] This solution optimizes the flow channel structure of the electrode slurry on the die head gasket. By setting a deceleration channel on the adjustment side of the flow restrictor, the flow velocity in the edge region of the electrode slurry is reduced, eliminating the thick edge phenomenon during coating. The increased contact area between the deceleration channel and the slurry enhances the flow resistance in the edge region. The gradient of the deceleration stroke between the first and second deceleration steps of the deceleration channel further creates different levels of deceleration effect in the edge region of the slurry flow, resulting in a segmented reduction of the coating flow rate in the edge region and avoiding discontinuities in coating thickness due to abrupt elimination of the thick edge. In addition, this solution also incorporates chamfers at the bends of the flow channel to eliminate stress concentration and flow dead zones, reducing slurry particle agglomeration; the end of the flow channel has a gradually widening outlet, which enhances the thinning effect on the slurry volume and further improves the coating quality. Attached Figure Description

[0030] Figure 1 This is a top view of the die head gasket;

[0031] Figure 2 This is a schematic diagram of a current limiting plate;

[0032] Figure 3 Top view of the die head gasket and lower die head

[0033] Legend:

[0034] 1. Flow restrictor, 110 coating side, 120 adjustment side, 130 discharge side;

[0035] 2. Deceleration flow path, 210. First deceleration step surface, 220. Second deceleration step surface;

[0036] 3 lower die head, 310 discharge cavity;

[0037] 4. Apply to lips and mouth;

[0038] 5. Discharge port;

[0039] 6. Mold head gasket, 610. First fixing part, 620. Second fixing part, 630. First chamfer, 640. Second chamfer. Detailed Implementation

[0040] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. Those skilled in the art will be able to implement the present invention based on these descriptions. Furthermore, the embodiments of the present invention described below are generally only a part of the embodiments of the present invention, and not all of the embodiments. Therefore, all other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort should fall within the scope of protection of the present invention.

[0041] Example 1

[0042] This embodiment is a die head gasket for an extrusion coating machine.

[0043] To reduce the thick edge phenomenon during electrode slurry coating, this invention aims to design the gasket shape to change the flow channel of the electrode slurry, thereby slowing down the electrode slurry in the edge area and reducing the discharge flow rate in the edge area.

[0044] Please see Figure 1 The main body of the die head gasket 6 includes a first fixing part 610 and a second fixing part 620. The second fixing parts 620 are arranged in pairs at both ends of the first fixing part 610. The two pairs of second fixing parts 620 extend towards the side where the coating lip 4 is located, and a flow limiting plate 1 is provided at the end of the extension direction. The two flow limiting plates 1 have an extension direction that faces each other and approaches each other. A discharge port 5 is formed in the gap area between the two flow limiting plates 1. The first fixing part 610, the pair of second fixing parts 620, and the two flow limiting plates 1 enclose a unidirectional channel with the discharge port 5 as the only opening. The electrode slurry flows through the second fixing part 620 and the flow limiting plate 1 in sequence and then flows out from the coating lip 4.

[0045] Please see Figure 2 The side of the flow-limiting plate 1 facing the first fixing part 610 is the adjustment side 120, and a deceleration channel 2 is provided on the adjustment side 120. The deceleration channel 2 is stepped, extending outward from the flow-limiting plate 1, and the thickness of the stepped portion is thinner than the thickness of the main body of the flow-limiting plate 1. The stepped structure has a larger contact area with the electrode paste, which can create greater flow resistance in the edge areas of the paste, making the flow velocity at the edge of the paste lower than that in the center, and the aggregation velocity during coating is also relatively lower than that in the central area, avoiding the formation of thick edges. At the same time, the flow space in the edge area of ​​the paste channel is squeezed by the stepped structure, thus thinning the volume of the paste and correspondingly reducing the flow rate in the edge area during coating.

[0046] Please see Figure 2The flow restrictor 1 also includes a coating side 110 facing outwards from the coating lip and a discharge side 130 facing the discharge port 5. The connection between the coating side 110 and the discharge side 130 is at the very end of the slurry flow channel. The discharge sides 130 of the two flow restrictors 1 form the two side profiles of the discharge port 5, and the distance between the two discharge sides 130 forms the flow channel width of the discharge port 5. If the very end of the slurry flow channel is widened, when the electrode slurry flows to this point, its volume is dispersed by the flow channel width, the coating volume per unit length decreases, and the coating thickness becomes thinner. Therefore, the two discharge sides 130 have a recessed shape near the coating side 110 to widen the distance between the two discharge sides 130 and broaden the flow channel width of the discharge port 5. In some embodiments, the end of the discharge side (130) is a slope connecting the discharge side (130) and the coating side (110). In a preferred embodiment, a first chamfer 630 is provided at the connection position between the discharge side 130 and the coating side 110. The electrode slurry is a non-Newtonian fluid, and for the slurry flow channel, this corner is an external angle, which may generate concentrated stress on the slurry fluid; by setting the chamfer, the stress caused by the widening of the flow channel is avoided.

[0047] Please see Figure 1 A second chamfer 640 is provided at the connection position between the adjusting side 120 of the flow restrictor 1 and the second fixing part 620. The adjusting side 120 and the second fixing part 620 together form the edge of the slurry flow channel, and the angle formed by the two is a concave angle, so there is a flow dead zone in the slurry. This solution eliminates the flow dead zone by setting the chamfer.

[0048] Please see Figure 2 The deceleration channel 2 includes a first deceleration step surface 210 near the flow limiting plate 1 and a second deceleration step surface 220 away from the flow limiting plate 1. Both the first and second deceleration step surfaces 210 and 220 are vertically oriented. The first deceleration step surface 210 has a longer length than the second deceleration step surface 220, and the deceleration stroke provided by the first deceleration step surface 210 is also longer than that of the second deceleration step surface 220. The first deceleration step surface 210 is located at the outermost edge of the slurry channel, where the electrode slurry has the longest deceleration stroke. The second deceleration step surface 220 is located at the second outermost edge of the slurry channel, where the electrode slurry has a slightly shorter deceleration stroke than that of the first deceleration step surface 210. By setting the first and second deceleration step surfaces 210 and 220, the deceleration channel 2 further divides the slurry flow rate in the edge region of the channel, allowing the slurry flow rate in the edge region of the coating lip 4 to decrease smoothly, avoiding discontinuities in the coating thickness due to the sudden elimination of the thick edge.

[0049] In a preferred embodiment, the second deceleration step 220 partially faces the discharge port 5. The second deceleration step 220 is positioned on the adjustment side 120 of the flow limiting plate 1 facing the first fixing part 610. Based on this, the second deceleration step 220 has a shape that partially faces the discharge port 5, which can guide the electrode slurry to flow smoothly from the adjustment side 120 of the flow limiting plate 1 to the discharge port 5. Compared with the arrangement where it is completely facing the first fixing part 610, the second deceleration step 220 in this solution is obliquely arranged, which can provide a larger deceleration stroke.

[0050] Example 2

[0051] This embodiment is a die head structure for an extrusion coating machine, including an upper die head, a lower die head, and the die head gasket proposed in Embodiment 1. The lower die head is provided with a discharge cavity, through which electrode slurry from an external slurry tank enters the die head.

[0052] Please see Figure 2 The area enclosed by the first fixing part 610 and the second fixing part 620 is provided with a discharge cavity 310 for the lower die head 3; the electrode slurry in the slurry tank flows into the die head through the discharge cavity 310, then flows through the second fixing part 620 and the flow limiting plate 1 in sequence, and finally flows out from the discharge port 5, and is coated onto the current collector through the coating lip 4. The discharge cavity 310 and the die head gasket 6 form part of the outline of the slurry flow channel.

[0053] To maximize the adjustment effect of the die head gasket 6 on the electrode slurry, this embodiment further optimizes the die head gasket 6.

[0054] Please see 8910 Figure 1 The two ends of the deceleration channel 2 are located on the second fixing part 620 and the discharge side 130, respectively, making maximum use of the extension length of the flow restrictor 1. The first deceleration step surface 210 and the second deceleration step surface 220 can provide more adjustment stroke. The flow restrictor 1 is arranged adjacent to the discharge cavity 310. The slurry flow channel restricted by the flow restrictor 1 is closely connected to the discharge cavity 310. After the slurry flows into the die head from the discharge cavity 310, it can immediately enter the flow channel adjustment area defined by the flow restrictor 1 to start adjustment and eliminate thick coating edges.

Claims

1. A die head gasket for an extrusion coating machine, wherein the die head gasket (6) cooperates with the upper die head and the lower die head (3) to form the coating lip (4) of the extrusion coating machine, characterized in that: The die head pad (6) includes a first fixing part (610) and a second fixing part (620). The second fixing part (620) is arranged in pairs at both ends of the first fixing part (610) and has a shape that extends toward the side where the coating lip (4) is located. The second fixing part (620) is provided in pairs and is connected to flow limiting plates (1) respectively. A discharge port (5) is formed between the two flow limiting plates (1). Both flow limiting plates (1) have a shape that extends toward the discharge port (5). The flow limiting plate (1) has an adjustment side (120) facing the first fixing part (610), and the adjustment side (120) is provided with a deceleration channel (2) with a thickness thinner than the main body of the flow limiting plate (1); The first fixing part (610), the second fixing part (620) and the flow limiting plate (1) cooperate to form a slurry flow channel with the discharge port (5) as the only outlet.

2. The die head gasket according to claim 1, characterized in that, The deceleration channel (2) includes a first deceleration step surface (210) close to the flow restrictor (1) and a second deceleration step surface (220) away from the flow restrictor (1); the first deceleration step surface (210) provides a deceleration stroke longer than the second deceleration step surface (220).

3. The die head gasket according to claim 2, characterized in that, The second deceleration step surface (220) has a shape that partially faces the discharge port (5).

4. The die head gasket according to claim 1, characterized in that, The flow restrictor (1) includes a discharge side (130) facing the discharge port (5) and a coating side (110) facing the outside of the coating lip (4); the connection between the discharge side (130) and the coating side (110) has a shape that expands the width of the discharge port (5) channel.

5. The die head gasket according to claim 4, characterized in that, The connection between the discharge side (130) and the coating side (110) is provided with a first chamfer (630).

6. The die head gasket according to claim 1, characterized in that, The second fixing part (620) is provided with a second chamfer (640) at the connection position with the adjusting side (120).

7. A die head for an extrusion coating machine, comprising a discharge chamber (310), characterized in that, It also includes the die head gasket (6) as described in any one of claims 1 to 6; the discharge cavity (310) and the die head gasket (6) at least form a partial outline of the slurry flow channel.

8. The die head according to claim 7, characterized in that, The flow restrictor (1) is disposed adjacent to the discharge chamber (310).

9. The die head according to claim 7, characterized in that, One end of the deceleration channel (2) is disposed on the second fixing part (620).

10. The die head according to claim 7, characterized in that, One end of the deceleration channel (2) is disposed on the adjustment side (120).

Images