A multi-layer slit coating head

Abstract

The present invention discloses a multi-layer slit coating head, which belongs to the field of coating heads. It solves the problem that the thickness of each part of the coating formed at the coating head outlet is difficult to be consistent and the orientation degree of the graphene film is low. The technical solution to this problem mainly includes a shell, a feed channel and a flow channel are provided in the shell, and a discharge port is provided at the front end of the shell. The feed channel runs horizontally through the shell, and the flow channel includes a first channel, a storage channel, and a second channel. The bottom end of the first channel is connected to the feed channel, the top end of the first channel is connected to the top end of the storage channel, and the storage channel is connected to the discharge port through the second channel. The top end of the storage channel is higher than the discharge port in the height direction. The second channel forms a plurality of narrow flow channels, and the narrow flow channels are distributed at intervals. The present invention is mainly used to make the density of the graphene oxide slurry more uniform after passing through the storage channel and the second channel to obtain a highly oriented graphene film.

Description

Technical Field

[0001] The invention discloses a multi-layer slit coating head, belonging to the technical field of coating heads. Background Art

[0002] The graphite oxide film is obtained by passing the graphene oxide slurry through a flat coating head to form a coating that meets the thickness requirements on the coating base tape. During the production process, the graphene oxide slurry passes through the flat coating head and accumulates between the coating head and the coating base tape. When the coating base tape moves forward, the graphene oxide slurry is scraped to the required thickness by a comma scraper to form a graphite oxide coating on the coating base tape. After drying, the graphite oxide film is obtained.

[0003] However, in the prior art, a feed channel and a flow channel are provided inside the coating head. The flow channel is a straight connection between the feed channel and the outlet of the coating head. The feed channel forms inlets on both sides of the coating head, and the graphene oxide slurry is filled into the feed channel from the two inlets at the same time. Since the graphene oxide slurry is a non-Newtonian fluid, the viscosity of the slurry is high and the self-leveling property is poor. Therefore, the closer to the inlet of the feed channel, the greater the pressure of the graphene oxide slurry, that is, the pressure of the graphene oxide slurry in the flow channel is uneven, and the thickness of the coating formed by the graphene oxide slurry at the outlet of the coating head is difficult to be consistent at different parts, and the orientation degree of the graphene film is low, which ultimately affects the performance of the finished graphene film. Summary of the Invention

[0004] The purpose of the present invention is to solve the problem that the thickness of each part of the coating formed at the outlet of the coating head is difficult to be consistent and the orientation degree of the graphene film is low. For this purpose, a multi-layer slit coating head is provided. After the graphene oxide slurry passes through the storage channel and the second channel, the pressure of the graphene oxide slurry can be made more uniform, and the shear rate of the graphene slurry is increased through the multi-layer slits, so that the graphene sheets in the slurry are arranged parallel to the flow direction, and overlap at the outlet to form a coating layer of the required thickness. After drying, a highly oriented graphene film is obtained.

[0005] To solve the above technical problems, the present invention adopts the following technical solutions:

[0006] A multi-layer slit coating head includes a shell, a feed channel and a flow channel are provided in the shell, and a discharge port is provided at the front end of the shell. The feed channel passes through the shell horizontally and forms a feed port on both sides of the shell. The flow channel includes a first channel, a storage channel and a second channel. The bottom end of the first channel is connected to the feed channel, the top end of the first channel is connected to the top end of the storage channel, and the storage channel is connected to the discharge port through the second channel. The top end of the storage channel is higher than the discharge port in the height direction. Several narrow flow channels are formed at one end of the second channel close to the discharge port, and the narrow flow channels are distributed at intervals along the height direction.

[0007] The beneficial effects of the present invention are:

[0008] The flow channel of the present invention includes a first channel, a storage channel and a second channel. The bottom end of the first channel is connected to the feed channel, the top end of the first channel is connected to the top end of the storage channel, and the storage channel is connected to the discharge port through the second channel. That is, the first channel is higher than the feed channel as a whole. Therefore, when the slurry enters the feed channel from the feed port, the slurry first needs to fill the feed channel fully before it can gradually spread to the first channel. As the slurry is continuously filled, under the action of gravity, the slurry will fully fill the feed channel, making the distribution of the slurry in the feed channel more uniform. The slurry also spreads from low to high in the first channel. Therefore, the slurry pressure in the first channel can be evenly distributed, and the subsequent flow of the slurry in the storage channel and the second channel is not likely to affect the distribution of the slurry, thereby forming a coating with uniform thickness distribution at the discharge port, thereby obtaining a finished graphene film with better thickness consistency; in addition, when the slurry passes through a narrow channel, the shear rate during flow can be greatly increased, thereby causing shear thinning and decreasing the viscosity, so that the graphene wafers in the slurry are better arranged parallel to the flow direction under the action of the shear force, and the slurry overlaps in multiple layers at the discharge port to form a graphene film with high orientation and consistent thickness.

[0009] Preferably, the shell includes a coating bottom plate and a coating top plate that are spliced ​​together, the feed channel is arranged on the coating bottom plate, the second channel and the discharge port are formed between the coating bottom plate and the coating top plate, and the top end of the first channel and the storage channel is formed in the coating top plate. By adopting the above technical solution, the shell is divided into the coating bottom plate and the coating top plate, making the structure of the coating head more modular, facilitating the disassembly and installation of the coating head. When the coating head needs to be cleaned, repaired or replaced with parts, the operation can be carried out more conveniently. At the same time, each part can also be replaced or upgraded separately, which helps to reduce maintenance costs and extend the service life of the coating head.

[0010] Preferably, the coating bottom plate and the coating top plate are sandwiched with a first partition plate and a second partition plate that are stacked in an interlaced manner, and a narrow channel is formed between two adjacent first partition plates in the second channel, and the second channel is connected to the discharge port through the narrow channel. With the above-mentioned technical solution, the interlaced stacking of the first partition plate and the second partition plate can form a more stable support for each other, which can effectively reduce the possibility of deformation or breakage of the first partition plate and the second partition plate, thereby ensuring that the thickness of each narrow channel can be kept consistent, so that a coating with the same thickness and uniform distribution can be obtained; in addition, the interlaced stacking of the first partition plate and the second partition plate provides a means of regulating the thickness of the coating, and the thickness and quantity of the coating can be adjusted by adjusting the thickness and quantity of the first partition plate and the second partition plate, thereby accurately controlling the thickness and quantity of the coating, making the coating process more controllable, and meeting different application scenarios according to different coating requirements, so that the coating head has a wider range of applications.

[0011] Preferably, the first partition plate and the second partition plate are both provided with a first notch for avoiding the first channel, and the first partition plate is provided with a second notch for avoiding the storage channel.

[0012] Preferably, the second baffle is provided with a plurality of supports at one end near the discharge port, spaced apart in the transverse direction of the shell, extending through the storage channel and into the second channel. The aforementioned technical solution allows the supports to provide a stable support for the first baffle, thereby reducing the possibility of deformation or collapse of the first baffle, which could cause deformation of the narrow channel. This allows the thickness of the narrow channel to remain consistent, so that after the slurry passes through the narrow channel, a coating of uniform thickness is formed at all locations, thereby improving the quality of the coating.

[0013] Preferably, the width of the support gradually decreases as it approaches the discharge port, with a narrow channel formed at the front of the support. This technical solution avoids the problem of partial loss or uneven distribution of the coating due to the support, allowing for more uniform distribution of the slurry within the narrow channel, thereby forming a coating with consistent thickness across all areas, resulting in a finished graphene film with improved performance.

[0014] Preferably, a covering body corresponding to the supporting body is provided in the second notch, and the vertical projections of the covering body and the supporting body overlap. With the above technical solution, the covering body can provide a stable support for the supporting body, preventing the supporting body from deformation or breakage.

[0015] Preferably, both sides of the first partition and the second partition are provided with connecting parts, the front end of the connecting part extends into the second channel, a connecting plate is provided between the connecting parts on both sides of the first partition, a third gap is formed between the connecting parts on both sides of the second partition, and the narrow channel is formed between the two adjacent connecting plates.

[0016] Preferably, the bottom end of the storage channel is lower than the discharge port in height direction.

[0017] Other features and advantages of the present invention will be disclosed in detail in the following specific embodiments and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The present invention will be further described below with reference to the accompanying drawings:

[0019] Figure 1 This is a schematic structural diagram of a multi-layer slit coating head of the present invention;

[0020] Figure 2 A cross-sectional view of a multi-layer slit coating head of the present invention

[0021] Figure 3This is a schematic structural diagram of a multi-layer slit coating head of the present invention with the coating top plate removed;

[0022] Figure 4 This is a schematic structural diagram of a coating base plate in a multi-layer slit coating head of the present invention;

[0023] Figure 5 This is a schematic structural diagram of a flow channel top plate in a multi-layer slit coating head of the present invention;

[0024] Figure 6 This is a schematic structural diagram of a first partition and a second partition in a multi-layer slit coating head of the present invention;

[0025] Figure 7 for Figure 6 A partial enlarged view of part A;

[0026] Figure 8 This is a schematic structural diagram of the first partition in a multi-layer slit coating head of the present invention;

[0027] Figure 9 This is a schematic structural diagram of the second partition in a multi-layer slit coating head of the present invention.

[0028] Figure 10 This is the SAXS characterization of the highly oriented graphene oxide film obtained by extrusion according to the present invention.

[0029] Figure numerals: 11, coating top plate; 111, flow channel top plate; 112, pressing plate; 12, coating bottom plate; 121, flow channel bottom plate; 122, feeding bottom plate; 21, feeding channel; 211, feeding port; 22, first channel; 23, storage channel; 24, second channel; 25, discharge port; 31, first partition; 311, connecting plate; 312, covering body; 32, second partition; 321, supporting body; 322, third notch; 33, first notch; 34, second notch; 35, connecting part; 36, narrow channel. DETAILED DESCRIPTION

[0030] The following is an explanation and description of the technical solutions of the embodiments of the present invention in conjunction with the drawings of the embodiments of the present invention. However, the following embodiments are only preferred embodiments of the present invention and are not exhaustive. Based on the embodiments in the implementation manner, other embodiments obtained by those skilled in the art without creative work are all within the scope of protection of the present invention.

[0031] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "clockwise", "counterclockwise" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0032] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referenced. Thus, features identified with "first" or "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, "plurality" means two or more, unless expressly limited otherwise.

[0033] In the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connect," "fixed," etc. should be understood broadly. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediary; or internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0034] like Figures 1 to 9 As shown, this embodiment shows a multi-layer slit coating head, including a shell, in which a feed channel 21 and a flow channel are provided, and a discharge port 25 is provided at the front end of the shell, the feed channel 21 passes through the shell horizontally and forms a feed port 211 on both sides of the shell, the flow channel includes a first channel 22, a storage channel 23 and a second channel 24, the bottom end of the first channel 22 is connected to the feed channel 21, the top of the first channel 22 is connected to the top of the storage channel 23, the storage channel 23 is connected to the discharge port 25 through the second channel 24, the top of the storage channel 23 is higher than the discharge port 25 in the height direction, the second channel 24 is horizontally arranged, and a plurality of narrow flow channels 36 are formed at one end of the second channel 24 close to the discharge port 25, and the narrow flow channels 36 are spaced apart along the height direction.

[0035] The flow channel in this embodiment includes a first channel 22, a storage channel 23 and a second channel 24. The bottom end of the first channel 22 is connected to the feed channel 21, the top end of the first channel 22 is connected to the top end of the storage channel 23, and the storage channel 23 is connected to the discharge port 25 through the second channel 24. That is, the first channel 22 is higher than the feed channel 21 as a whole. Therefore, when the slurry enters the feed channel 21 from the feed port 211, the slurry first needs to fill the feed channel 21 fully before it can gradually spread to the first channel 22. As the slurry is continuously filled, under the action of gravity, the slurry will fully fill the feed channel 21, so that the distribution of the slurry in the feed channel 21 is more uniform, and the slurry is The slurry pressure in the first channel 22 also spreads from low to high, so the slurry pressure in the first channel 22 can be evenly distributed, and then the flow of the slurry in the storage channel 23 and the second channel 24 is not likely to affect the distribution of the slurry, and thus a coating with uniform thickness distribution can be formed at the discharge port 25, thereby obtaining a finished graphene film with better thickness consistency; in addition, when the slurry passes through the narrow channel 36, the shear rate during flow can be greatly increased, thereby causing shear thinning and a decrease in viscosity, so that the graphene wafers in the slurry are better arranged parallel to the flow direction under the action of shear force, and the slurry overlaps in multiple layers at the discharge port 25 to form a graphene film with high orientation and consistent thickness.

[0036] like Figure 1 and Figure 2As shown, the shell in this embodiment includes a coating bottom plate 12 and a coating top plate 11 spliced ​​with each other, the coating top plate 11 is covered on the upper side of the coating bottom plate 12, the coating bottom plate 12 includes a feed bottom plate 122 and a flow channel bottom plate 121, the coating top plate 11 includes a feed top plate and a flow channel top plate 111, the feed channel 21 passes through the feed bottom plate 122 horizontally, and forms a feed port 211 on both sides of the feed bottom plate 122, the flow channel bottom plate 121 is covered on the upper side of the feed bottom plate 122, the first channel 22 is partially located in the flow channel bottom plate 121, the bottom end of the first channel 22 is connected to the top of the feed channel 21, the flow channel top plate 111 is covered on the flow channel bottom plate 121, the flow channel top plate 111 has another part of the first channel 22 and a storage channel 23, the first channel 22 and the storage channel 23 are at the top of the flow channel top plate 111 The first channel 22 and the material storage channel 23 are connected, that is, the first channel 22 and the material storage channel 23 form an inverted U shape in the flow channel top plate 111. After the flow channel top plate 111 and the flow channel bottom plate 121 are installed, a second channel 24 is formed between the flow channel top plate 111 and the flow channel bottom plate 121 on the right side of the material storage channel 23. The material storage channel 23 is connected with the discharge port 25 through the second channel 24. The pressure plate 112 is installed on the upper side of the flow channel top plate 111 and seals the first channel 22 and the material storage channel 23. The shell is divided into a coating bottom plate 12 and a coating top plate 11, so that the structure of the coating head is more modular, which is convenient for the disassembly and installation of the coating head. When the coating head needs to be cleaned, repaired or replaced with parts, the operation can be carried out more conveniently. At the same time, each part can also be replaced or upgraded separately, which helps to reduce maintenance costs and extend the service life of the coating head.

[0037] like Figure 4 and Figure 5 As shown, in this embodiment, the first channel 22 and the storage channel 23 are both arranged vertically, and the second channel 24 is arranged horizontally. Such an arrangement can make the production of the coating bottom plate 12 and the coating top plate 11 simpler, and can ensure that after the coating bottom plate 12 and the coating top plate 11 are spliced, the feed channel 21 and the flow channel can be accurately connected and docked. At the same time, it can also simplify the sealing difficulty of the coating bottom plate 12 and the coating top plate 11, reduce the possibility of slurry leakage in the coating head, and enable the slurry to maintain a higher pressure in the coating head, thereby making the slurry more evenly distributed in the feed channel 21, so as to form a coating with uniform thickness distribution at the discharge port 25, thereby obtaining a finished graphene film with better performance.

[0038] In addition, the upper surface of the flow channel bottom plate 121 in this embodiment is provided with a groove, which is aligned with the discharge channel. After the flow channel bottom plate 121 and the flow channel top plate 111 are spliced, the groove forms the bottom end of the discharge channel, that is, the bottom end of the storage channel 23 is lower than the discharge port 25 in the height direction. In addition, the second channel 24 is formed between the upper surface of the flow channel bottom plate 121 and the lower surface of the flow channel top plate 111, so the bottom end of the storage channel 23 is also lower than the second channel 24. When the slurry flows from the first channel 22 into the storage channel 23, the slurry will fall to the upper surface of the flow channel bottom plate 121 under the action of gravity, and the groove The setting of the groove can make part of the slurry stay in the storage channel 23, reducing the slurry directly entering the second channel 24. Therefore, the flow rate from the first channel 22 to the storage channel 23 will be greater than the flow rate from the storage channel 23 to the second channel 24, that is, the slurry in the storage channel 23 will continue to increase until the slurry can fill the storage channel 23, so that the slurry in the storage channel 23 can be squeezed toward the second channel 24 under the action of pressure. The slurry enters the second channel 24 through squeezing, which can make the slurry in the second channel 24 more substantial, avoiding the problem of vacancies or uneven distribution of slurry.

[0039] like Figure 6 and Figure 7 As shown, in this embodiment, the coating bottom plate 12 and the coating top plate 11 are sandwiched between the first partition plate 31 and the second partition plate 32 stacked in an interlaced manner, and the first partition plate 31 and the second partition plate 32 are both provided with a first notch 33 for avoiding the first channel 22, and the first partition plate 31 is provided with a second notch 34 for avoiding the storage channel 23. Both sides of the first partition plate 31 and the second partition plate 32 are provided with a connecting portion 35, and the front end of the connecting portion 35 extends into the second channel 24. A connecting plate 311 is provided between the connecting portions 35 on both sides of the first partition plate 31, and a third notch 322 is formed between the connecting portions 35 on both sides of the second partition plate 32. A narrow channel 36 is formed between the two adjacent first partition plates 31 in the second channel 24, and the second channel 24 is connected to the narrow channel 36 through the narrow channel 36. The discharge port 25 is connected, and the staggered stacking of the first partition 31 and the second partition 32 can form a more stable support for each other, which can effectively reduce the possibility of deformation or breakage of the first partition 31 and the second partition 32, thereby ensuring that the thickness of each narrow channel 36 can be kept consistent, so that a coating with the same thickness and uniform distribution can be obtained; in addition, the staggered stacking of the first partition 31 and the second partition 32 provides a means of regulating the thickness of the coating. By adjusting the thickness and number of the first partition 31 and the second partition 32, the thickness and number of the coating can be accurately controlled, making the coating process more controllable, and can meet different application scenarios according to different coating requirements, so that the coating head has a wider range of applications. Generally speaking, the thickness of the first partition 31 and the second partition 32 can be set at 0.1~1mm.

[0040] like Figure 8 and Figure 9 As shown, in this embodiment, a plurality of support bodies 321 are provided at one end of the second partition 32 close to the discharge port 25, and the support bodies 321 are spaced apart in the transverse direction of the shell. The support bodies 321 pass through the storage channel 23 and extend into the second channel 24. The width of the support body 321 gradually decreases as it approaches the discharge port 25. A narrow channel 36 is formed on the front side of the support body 321. A covering body 312 corresponding to the support body 321 is provided in the second notch 34. The covering body 312 and the supporting body 321 are overlapped in the vertical direction. The supporting body 321 can form a stable support for the first partition 31, thereby reducing the deformation or collapse of the first partition 31. The possibility of deformation of the narrow channel 36 caused by the collapse of the narrow channel 36 is reduced, so that the thickness of the narrow channel 36 can be kept consistent, so that a coating with uniform thickness is formed in each part after the slurry passes through the narrow channel 36, which helps to improve the quality of the coating; in addition, the width of the support body 321 gradually decreases as it approaches the discharge port 25, which can avoid the problem of partial loss or uneven distribution of the coating caused by the support body 321, and make the slurry more evenly distributed in the narrow channel 36, so as to form a coating with uniform thickness in each part, thereby obtaining a finished graphene film with better performance; secondly, the covering body 312 can form a stable support for the support body 321, so as to avoid deformation or breakage of the support body 321.

[0041] During use, a graphene oxide aqueous solution (graphene oxide slurry) with a concentration of 1 mg / ml is injected into the multi-layer slit coating head of the present invention through the feed ports 211 on both sides. The graphene oxide slurry passes through the first channel 22, the storage channel 23, and the second channel 24, and finally passes through the narrow flow channel 36 for horizontal shear orientation to form a multi-layer graphene oxide gel film. At the moment of extrusion, the upper and lower graphene oxide films fuse with each other at the interface, thereby obtaining a highly oriented graphene oxide thick film, such as Figure 10 As shown, according to Figure 10 We can confirm that the graphene oxide film is almost entirely horizontally oriented.

[0042] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Those skilled in the art will understand that the present invention includes, but is not limited to, the contents described in the drawings and the above specific embodiments. Any modifications that do not deviate from the functional and structural principles of the present invention are intended to be included within the scope of the claims.

Claims

1. A multi-layer slit coating head, characterized by: The invention comprises a shell, wherein a feed channel and a flow channel are provided in the shell, and a discharge port is provided at the front end of the shell, wherein the feed channel passes through the shell transversely and forms a feed port on both sides of the shell, and the flow channel comprises a first channel, a storage channel, and a second channel, wherein the bottom end of the first channel is connected to the feed channel, the top end of the first channel is connected to the top end of the storage channel, the storage channel is connected to the discharge port through the second channel, the top end of the storage channel is higher than the discharge port in the height direction, and a plurality of narrow flow channels are formed at one end of the second channel close to the discharge port, and the narrow flow channels are spaced apart along the height direction; The shell includes a coating bottom plate and a coating top plate spliced ​​with each other, the feed channel is arranged on the coating bottom plate, the second channel and the discharge port are formed between the coating bottom plate and the coating top plate, and the top end of the first channel and the storage channel are formed in the coating top plate; the coating bottom plate and the coating top plate are sandwiched with first and second partitions stacked in an interlaced manner, and a narrow flow channel is formed between two adjacent first partitions in the second channel, and the second channel is connected with the discharge port through the narrow flow channel; both sides of the first partition and the second partition are provided with connecting parts, and the front end of the connecting part extends into the second channel, and there is a connecting plate between the connecting parts on both sides of the first partition, and a third notch is formed between the connecting parts on both sides of the second partition, and the narrow flow channel is formed between two adjacent connecting plates.

2. The multi-layer slit coating head according to claim 1, characterized in that: The first partition plate and the second partition plate are both provided with a first notch for avoiding the first channel, and the first partition plate is provided with a second notch for avoiding the storage channel.

3. The multi-layer slot coating head according to claim 2, characterized in that: A plurality of supporting bodies are provided at one end of the second partition close to the discharge port. The supporting bodies are distributed at intervals in the transverse direction of the shell. The supporting bodies pass through the storage channel and extend into the second channel.

4. The multi-layer slit coating head according to claim 3, characterized in that: The width of the support body gradually decreases as it approaches the discharge port, and a narrow flow channel is formed on the front side of the support body.

5. The multi-layer slot coating head according to claim 3, characterized in that: A covering body corresponding to the supporting body is provided in the second notch, and the orthographic projections of the covering body and the supporting body in the vertical direction overlap with each other.

6. The multi-layer slot coating head according to claim 1, characterized in that: The bottom end of the material storage channel is lower than the discharge port in the height direction.

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