A water washing and drawing device and process for graphene filament production

Abstract

The application relates to a water washing and drawing device for a graphene filament production process and belongs to the technical field of graphene processing equipment; the device comprises three-roller units and multiple five-roller units arranged in sequence along the graphene filament conveying direction, the five-roller units respectively comprise a first-stage drawing unit, a second-stage drawing unit and a third-stage drawing unit, a press roller is arranged above the roller shaft at the top of the output end of the third-stage drawing unit, and a first-stage water washing tank is arranged between the three-roller unit and the first-stage drawing unit; the water washing effect of the device is strengthened by adopting multistage water washing, increasing vibration and controlling the water washing liquid temperature, the cleanliness of the graphene filament and the product quality are ensured, multistage water distribution is adopted between the water washing tanks to guide overflow, an external pump body is connected to guide the flow direction of the whole water washing tank, meanwhile, multiple vibration devices arranged in the water washing tank make the water washing liquid fully contact with the filament bundle to ensure high water washing efficiency.

Description

Technical Field

[0001] This invention belongs to the technical field of graphene production equipment, specifically relating to a water washing and drawing equipment and process for the production of graphene precursor fibers. Background Technology

[0002] Graphene fiber is a two-dimensional material composed of a single layer of carbon atoms. It possesses excellent electrical conductivity, thermal conductivity, and mechanical strength. Furthermore, it can serve as a reinforcement, enhancing the mechanical and electrical properties of resins or metal composites. Therefore, it is commonly used in aerospace, flexible electronics, supercapacitors, and motors. Graphene precursor fibers are key intermediate materials in the graphene fiber preparation process. They are typically in the form of graphene oxide fibers or composite spinning solutions, and are converted into graphene fibers through reduction or carbonization.

[0003] In the drawing process, stretching causes the internal structure of the fiber, such as graphene sheets or molecular chains, to align in an orientation, which significantly affects the mechanical properties, conductivity, density, and defect distribution of the final graphene precursor. If the drawing rate is too fast or the drawing temperature is too high, the breakage rate of the graphene precursor will increase. If the drawing stress distribution is uneven, the uniformity of the fiber diameter cannot be guaranteed. Therefore, during the production process, it is necessary to clean the solvent remaining in the graphene precursor and ensure the temperature, rate, and ratio of the drawing process to obtain high-quality graphene precursor for subsequent processing. Summary of the Invention

[0004] The present invention mainly addresses the technical problems existing in the prior art, and provides a water washing and stretching equipment and process for the production of graphene precursor fibers.

[0005] The above-mentioned technical problems of the present invention are mainly solved by the following technical solution: a water washing and drawing equipment and process for graphene precursor production, comprising a three-roll mill and multiple five-roll mills arranged sequentially along the graphene precursor conveying direction, characterized in that: the five-roll mills respectively include a primary drawing mill, a secondary drawing mill, and a tertiary drawing mill; a pressure roller is arranged above the roller shaft at the top of the output end of the tertiary drawing mill; a primary water washing tank is arranged between the three-roll mill and the primary drawing mill; the primary water washing tank... The washing tank has primary water washing tank pipelines connected to both ends. A secondary water washing tank is set between the primary and secondary drawing units. The secondary water washing tank has secondary water washing tank pipelines connected to both ends. A tertiary water washing tank is set between the secondary and tertiary drawing units. The tertiary water washing tank has tertiary water washing tank pipelines connected to both ends. Pipelines are connected between the primary and secondary water washing tanks and between the secondary and tertiary water washing tanks. An external circulation pipeline is connected between the primary and tertiary water washing tanks.

[0006] Preferably, the housing structure of the three-roll mill and the multiple five-roll mills is exactly the same, all being hollow shells welded from plates, the difference being the number of rollers arranged.

[0007] Preferably, the primary, secondary, and tertiary washing tanks have identical tank structures, all being shells formed by bending and welding sheet metal. The primary washing tank includes a tank body, with temperature sensors installed on both the left and right sides of the middle section of the tank body. Vibration devices are installed on both the left and right sides of the middle section of the inner wall of the tank body. A heating coil is laid at the bottom of the inner wall of the tank body. A first overflow plate and a second overflow plate are respectively installed at both ends of the tank body cavity, and the coil is located between the first overflow plate and the second overflow plate.

[0008] Preferably, a first overflow cavity is formed between the first overflow plate and the side of the washing tank, and a second overflow cavity is formed between the second overflow plate and the washing tank. A liquid replenishment port and a pump suction port are respectively provided on both sides of the bottom of the first overflow cavity. A first drain port and a pump discharge port are respectively provided on both sides of the bottom of the washing tank. A connection port and a second drain port are respectively provided on both sides of the bottom of the second overflow cavity.

[0009] Preferably, the connection ports between the primary washing tank, the secondary washing tank, and the tertiary washing tank are interconnected by pipelines.

[0010] Preferably, the primary water washing tank pipeline, the secondary water washing tank pipeline, and the tertiary water washing tank pipeline are interconnected with the corresponding pump outlet and pump inlet, respectively.

[0011] Preferably, the height of the first overflow plate is lower than the height of the second overflow plate, and the difference between the two is 3-8mm.

[0012] The beneficial effects of this invention are as follows:

[0013] Washing effect: Multi-stage washing, increased vibration and control of washing liquid temperature are adopted to enhance the washing effect of the equipment, ensuring the cleanliness of graphene precursor and product quality. The washing tanks are divided into multiple sections for overflow guidance, and the external pump guides the flow direction of the entire washing tank. At the same time, multiple vibration devices are set inside the washing tank to ensure that the washing liquid and the fiber bundle are in full contact to ensure efficient washing effect.

[0014] Drafting effect: Multi-stage drafting is adopted, and the drafting rate and drafting ratio can be changed according to the application scenario of graphene precursor to improve the performance of graphene precursor fiber. At the same time, a five-roll mill with multiple washing tanks is used to better assist in the drafting of the cleaned filament bundle, so that the stretching force of the filament bundle can be more uniform. Attached Figure Description

[0015] Figure 1 This is a process flow diagram of the present invention;

[0016] Figure 2 This is a schematic diagram of the equipment structure layout according to the present invention;

[0017] Figure 3 This is a schematic diagram of the internal structure of a primary water washing tank according to the present invention.

[0018] In the diagram: 1. Three-roll mill; 11. First-stage drawing mill; 12. Second-stage drawing mill; 13. Third-stage drawing mill; 21. First-stage washing tank pipeline; 22. Second-stage washing tank pipeline; 23. Third-stage washing tank pipeline; 3. External circulation pipeline; 4. Pipeline; 5. Pressure roller; 61. First-stage washing tank; 62. Second-stage washing tank; 63. Third-stage washing tank; 6.1. Temperature sensor; 6.2. Coil; 6.3. Washing tank body; 6.4. Liquid inlet; 6.5. Pump inlet; 6.6. First drain outlet; 6.7. Pump outlet; 6.8. Connection port; 6.9. Second drain outlet; 6.10. Vibration device; 6.11. First overflow plate; 6.12. Second overflow plate. Detailed Implementation

[0019] The technical solution of the present invention will be further described in detail below through embodiments and in conjunction with the accompanying drawings.

[0020] Example 1: A water washing and drawing equipment and process for graphene precursor fiber production, such as... Figure 1 As shown, the entire water washing and drawing process includes the following steps: after the fiber bundle comes out of the coagulation bath, it undergoes multi-stage water washing and drawing, which includes: first-stage water washing, first-stage drawing, second-stage water washing, second-stage drawing, third-stage water washing, and third-stage drawing. After the water washing operation, the fiber bundle is then oiled and dried to finally become graphene precursor fiber.

[0021] Example 2: A water washing and drawing equipment and process for graphene precursor fiber production, such as... Figures 2-3As shown, the system includes a three-roll mill 1 and multiple five-roll mills arranged sequentially along the graphene precursor conveying direction. The three-roll mill 1 and the multiple five-roll mills have identical housing structures, both being hollow shells welded from plates. The difference lies in the number of rollers arranged. Each five-roll mill includes a primary drawing unit 11, a secondary drawing unit 12, and a tertiary drawing unit 13. A pressure roller 5 is installed above the roller at the top of the output end of the tertiary drawing unit 13. A primary washing tank 61 is installed between the three-roll mill 1 and the primary drawing unit 11, and both ends of the primary washing tank 61 are connected to a primary water... A secondary washing tank 62 is provided between the primary drawing unit 11 and the secondary drawing unit 12. The two ends of the secondary washing tank 62 are connected to the secondary washing tank pipeline 22. A tertiary washing tank 63 is provided between the secondary drawing unit 12 and the tertiary drawing unit 13. The two ends of the tertiary washing tank 63 are connected to the tertiary washing tank pipeline 23. Pipelines 4 are connected between the primary washing tank 61 and the secondary washing tank 62, and between the secondary washing tank 62 and the tertiary washing tank 63. An external circulation pipeline 3 is connected between the primary washing tank 61 and the tertiary washing tank 63.

[0022] The primary washing tank 61, secondary washing tank 62, and tertiary washing tank 63 have identical tank structures, all being shells formed by sheet metal bending and welding. The connection ports 6.8 between the primary washing tank 61, secondary washing tank 62, and tertiary washing tank 63 are interconnected via pipes 4. The primary washing tank 61 includes a washing tank body 6.3. Temperature sensors 6.1 are installed on both sides of the middle section of the washing tank body 6.3. Vibration devices 6.10 are installed on both sides of the middle section of the inner wall of the washing tank body 6.3. A heating coil 6.2 is laid at the bottom of the inner wall of the washing tank body 6.3. A first overflow plate 6.11 and a second overflow plate 6.12 are respectively installed at both ends of the cavity of the washing tank body 6.3. The height of the first overflow plate 6.11 is lower than the height of the second overflow plate 6.12. The two are 3-8mm apart. The coil 6.2 is located between the first overflow plate 6.11 and the second overflow plate 6.12. The first overflow plate 6.11 and the side of the water washing tank 6.3 form the first overflow cavity, and the second overflow plate 6.12 and the water washing tank 6.3 form the second overflow cavity. The bottom of the first overflow cavity is provided with a liquid replenishment port 6.4 and a pump suction port 6.5 on both sides. The bottom of the water washing tank 6.3 is provided with a first drain port 6.6 and a pump discharge port 6.7 on both sides. The bottom of the second overflow cavity is provided with a connection port 6.8 and a second drain port 6.9 on both sides. The first-stage water washing tank pipeline 21, the second-stage water washing tank pipeline 22, and the third-stage water washing tank pipeline 23 are respectively connected to the corresponding pump discharge port 6.7 and pump discharge inlet.

[0023] The principle of this invention: After the graphene raw solution comes out of the coagulation bath, it is first initially drawn through a three-roll mill 1, and then enters a primary washing tank 61 for washing. In the primary washing tank 61, the washing liquid in the washing tank is heated by a coil 6.2 and vibrated by a vibration device 6.10 to ensure that the washing liquid is in full contact with the fiber bundle to ensure a high-efficiency washing effect. Then, it is further washed and drawn through a primary drawing mill 11 and a secondary washing tank 62, and then through a secondary drawing mill 12 and a tertiary washing tank 63 for final washing and drawing. Finally, it reaches the tertiary drawing mill 13, and after drawing, the washing liquid that has penetrated into the graphene raw fiber is squeezed out by a pressure roller 5.

[0024] The key process parameters for the water washing and drawing equipment are as follows: the driving speed of the three-roll mill 11 is 2-10 m / min, the driving speed of the first-stage drawing mill 11 is 2-10 m / min, the driving speed of the second-stage drawing mill 12 is 2-10 m / min, and the driving speed of the third-stage drawing mill 13 is 3-15 m / min; each filament in the first-stage drawing mill 11 has a strength of 70 cN, a draw ratio of 2, and the filament is immersed in the liquid to a depth of 20-30 mm. The solvent concentration in washing tank 61 is 2%, and the washing liquid temperature is 60℃; each filament bundle in the secondary drawing unit 12 is 70cN, with a drawing ratio of 3 times, and the filament bundle is immersed in the liquid to a depth of 20~30mm; the solvent concentration in the secondary washing tank 62 is 2%, and the washing liquid temperature is 60℃; each filament bundle in the tertiary drawing unit 13 is 70cN, with a drawing ratio of 1.1 times, and the filament bundle is immersed in the liquid to a depth of 20~30mm; the solvent concentration in the tertiary washing tank 63 is 2%, and the washing liquid temperature is 60℃.

[0025] During the washing process, from an overall perspective, the washing liquid is replenished from the tertiary washing tank 63. When the liquid level reaches a certain height, it overflows into the secondary washing tank 62 through pipe 4. When the liquid level is constant, it overflows into the primary washing tank 61 through pipe 4. When the liquid level is constant, it is pumped back into the tertiary washing tank 63 through the external circulation pipe 3 and corresponding purification operations. From a local perspective, the washing liquid is first pumped into the washing tank 63 by the external pump unit through the replenishment port 6.4, and then the pump unit draws the washing liquid away through the pump suction port 6.5 and discharges it through the pump discharge port 6.7. This ensures that the flow direction of the washing liquid is consistent with the flow direction of the fiber bundle, which can prevent burrs from forming in the fiber bundle during the washing process. At this time, the coil 6.2 in the washing tank heats and keeps the washing liquid warm. The washing solution is kept at a constant temperature. Temperature sensor 6.1 monitors the temperature in real time; excessively high temperatures can cause thermal decomposition of the graphene precursor fibers, while excessively low temperatures will affect the washing effect. Vibration device 6.10 creates turbulent flow in the washing solution, increasing the contact time and intensity between the solution and the fiber bundle, thus improving the washing effect. When the washing solution reaches the first overflow plate 6.11, the overflowing solution mixes with the replenished solution and is pumped away through pump inlet 6.5 for recirculation. As the liquid level in the washing tank 6.3 increases, exceeding the second overflow plate 6.12, the overflowing solution, under gravity, is forced through connection port 6.8 and pipeline 4 into the secondary washing tank 62, and then enters the primary washing tank 61 under the same operation. When the washing and stretching equipment needs to be shut down for maintenance, the liquid in the washing tank can be drained through the first drain port 6.6 and the second drain port 6.9.

[0026] Finally, it should be noted that the above embodiments are merely representative examples of the present invention. Obviously, the present invention is not limited to the above embodiments and many variations are possible. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention should be considered within the protection scope of the present invention.

Claims

1. A water washing and drawing device for graphene precursor production, comprising a three-roll mill (1) and multiple five-roll mills arranged sequentially along the graphene precursor conveying direction, characterized in that: The five-roll mill unit includes a primary drawing mill unit (11), a secondary drawing mill unit (12), and a tertiary drawing mill unit (13). A pressure roller (5) is installed above the roller shaft at the top of the output end of the tertiary drawing mill unit (13). A primary washing tank (61) is installed between the three-roll mill unit (1) and the primary drawing mill unit (11). Primary washing tank pipelines (21) are connected to both ends of the primary washing tank (61). A secondary washing tank (62) is installed between the primary drawing mill unit (11) and the secondary drawing mill unit (12). Secondary washing tank pipelines (22) are connected to both ends of the secondary washing tank (62). The secondary drawing mill unit… (12) A three-stage washing tank (63) is provided between the three-stage drawing unit (13). The two ends of the three-stage washing tank (63) are connected to the three-stage washing tank pipeline (23). Pipelines (4) are connected between the first-stage washing tank (61) and the second-stage washing tank (62) and between the second-stage washing tank (62) and the three-stage washing tank (63). The tank structures of the first-stage washing tank (61), the second-stage washing tank (62) and the three-stage washing tank (63) are completely the same. The first-stage washing tank (61) includes a washing tank body (6.3). The two ends of the washing tank body (6.3) are respectively provided with a first overflow plate (6.11) and a second overflow plate. The first overflow plate (6.11) is lower than the height of the second overflow plate (6.12). The first overflow plate (6.11) and the side of the washing tank (6.3) form a first overflow cavity, and the second overflow plate (6.12) and the washing tank (6.3) form a second overflow cavity. The bottom sides of the first overflow cavity are respectively provided with a liquid replenishment port (6.4) and a pump suction port (6.5). The bottom sides of the washing tank (6.3) are respectively provided with a first drain port (6.6) and a pump discharge port (6.7). The bottom sides of the second overflow cavity are respectively provided with a connection port (6). 8) The second drain outlet (6.9) is connected to the first-stage washing tank (61) and the third-stage washing tank (63) by an external circulation pipe (3). The first-stage washing tank pipe (21), the second-stage washing tank pipe (22), and the third-stage washing tank pipe (23) are respectively connected to the corresponding pump outlet (6.7) and pump inlet (6.5). From a local perspective, the washing liquid is first pumped into the washing tank body (6.3) by the external pump group through the replenishment port (6.4), and then the washing liquid is drawn away by the pump group through the pump inlet (6.5) and discharged through the pump outlet (6.7), so that the flow direction of the washing liquid is consistent with the flow direction of the yarn bundle.

2. The water washing and drawing equipment for graphene precursor fiber production according to claim 1, characterized in that: The three-roll mill (1) and the multiple five-roll mills have the same box structure, which is a hollow shell made of welded plates. The difference lies in the number of rollers arranged.

3. The water washing and drawing equipment for graphene precursor fiber production according to claim 1, characterized in that: The primary washing tank (61), secondary washing tank (62), and tertiary washing tank (63) are all shells made of sheet metal by bending and welding. Temperature sensors (6.1) are installed on both the left and right sides of the middle section of the washing tank body (6.3). Vibration devices (6.10) are installed on both the left and right sides of the middle section of the inner wall of the washing tank body (6.3). A heating coil (6.2) is laid at the bottom of the inner wall of the washing tank body (6.3). The coil (6.2) is located between the first overflow plate (6.11) and the second overflow plate (6.12).

4. The water washing and drawing equipment for graphene precursor fiber production according to claim 1, characterized in that: The connection ports (6.8) between the primary water washing tank (61), the secondary water washing tank (62) and the tertiary water washing tank (63) are interconnected by pipes (4).

5. The water washing and drawing equipment for graphene precursor fiber production according to claim 1, characterized in that: The height of the first overflow plate (6.11) is set 3-8mm lower than the height of the second overflow plate (6.12).

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