Carbon fiber anodizing surface treatment device and surface treatment method

Abstract

The invention discloses a carbon fiber anodized surface treatment device and a surface treatment method, the device includes an electrolysis unit for carbon fiber anodized surface treatment and a post-electrolysis waste gas treatment unit. The device can flexibly adjust the spacing of the impregnation rollers in the electrolytic cell, control the electrolysis time, oxidize each single filament evenly, and have a good electrolytic oxidation treatment effect. Active functional groups such as oxygen and nitrogen are introduced into the surface of the carbon fiber, and the interlayer shear strength of the carbon fiber composite material is significantly improved; the equipment manufacturing cost is low; the operation is simple, and it is easy to process a large number of carbon fiber bundles, which is suitable for batch production; the electrolysis device is equipped with an inlet suction hood, an outlet suction hood, and a movable cover plate, and a fan is used to extract the ammonia waste gas generated by the electrolysis device to the post-electrolysis waste gas treatment device equipped with a foldable cover plate to produce an acid-base reaction, effectively blocking the escape of waste gas, reducing environmental pollution, avoiding harm to the health of operators during operation, and ensuring safe production.

Description

Technical Field

[0001] The invention relates to carbon fiber technology, and in particular to a carbon fiber anodizing surface treatment device and a surface treatment method. Background Art

[0002] The performance of carbon fiber reinforced thermosetting resin composites depends not only on the composition of the material, but also on the interface quality between the constituent materials, the surface properties of the carbon fiber, and the transmission mode of the interfacial stress between the carbon fiber and the matrix. The quality of the interfacial bonding directly affects the stress transfer effect between the reinforcement and the matrix, thereby affecting the macroscopic mechanical properties of the composite material. If the interfacial bonding is too weak, the composite material is prone to interfacial debonding under stress, and the carbon fiber cannot fully play its reinforcing role. If the carbon fiber surface is properly modified, the interlaminar shear strength of the composite material can be improved. If the interfacial bonding is too strong, under stress, the growing cracks in the material destruction process are easy to spread to the interface, directly impact the reinforcement material and show brittle failure. This requires appropriate adjustment of the interfacial bonding strength so that the cracks of the reinforcement material can expand along the interface, forming a tortuous path, dissipating more energy, and thus improving the toughness of the composite material.

[0003] Carbon fiber is mainly used as a reinforcement material. The main purpose of its surface treatment is to improve the interfacial adhesion between carbon fiber and matrix resin, while avoiding excessive loss of carbon fiber tensile strength, thereby improving and enhancing the mechanical properties of carbon fiber composites.

[0004] In order to solve the above problems, it is necessary to treat the surface of carbon fiber, enhance the interfacial bonding performance between carbon fiber and resin matrix, and improve the interlayer shear strength of carbon fiber. There are many methods for carbon fiber surface treatment, such as gas phase oxidation method, liquid phase oxidation method, gas-liquid dual effect method, surface grafting method, vapor deposition method, and surface coating method. Among them, the anodic electrolytic oxidation method in the liquid phase oxidation method has mild oxidation, easy to control the degree of oxidation on the surface of carbon fiber, easy to operate, and realizes uniform oxidation of single strands. Active functional groups such as oxygen and nitrogen are introduced on the surface of each carbon fiber strand to improve the interlayer shear strength of carbon fiber. It is widely used by carbon fiber manufacturers at home and abroad.

[0005] In the industrial production of carbon fiber, the anodic electrolytic oxidation method is adopted. When the electrolytic oxidation surface treatment device is used, ammonium salts such as diammonium phosphate, triammonium phosphate, ammonium phosphate and ammonium bicarbonate are used as alkaline electrolyte aqueous solutions. The most widely used electrolyte is ammonium bicarbonate aqueous solution. Carbon fiber is used as anode and graphite is used as cathode. When current passes through the ammonium bicarbonate electrolyte, the active oxygen atoms react with the carbon rings of the carbon fiber to undergo oxidation. Under the action of electrochemical oxidation, the active carbon atoms on the surface of the carbon fiber adsorb OH- in the alkaline solution and are oxidized to form hydroxyl groups. The generated hydroxyl groups continue to be oxidized by active oxygen to form carbonyl groups. Finally, oxidation continues to oxidize the carbonyl groups to form carboxyl groups. Since the carboxyl group is not very stable in the violent exothermic reaction, it is easy to release carbon dioxide.

[0006] During the electrolysis process, ammonium salts such as diammonium phosphate, triammonium phosphate, ammonium phosphate and ammonium bicarbonate are used as ammonia molecules in the alkaline electrolyte aqueous solution to be adsorbed by unsaturated carbon atoms on the surface of the carbon fiber, and then amino and imino groups are generated under electrochemical conditions. After electrochemical oxidation treatment, a large number of oxygen-containing functional groups and nitrogen-containing functional groups are introduced to the surface of the carbon fiber. Due to the increase of these functional groups, its surface polarity is improved, which improves the wettability and reactivity of the carbon fiber with the epoxy resin, and is beneficial to improve the mechanical properties of the carbon fiber reinforced thermosetting resin composite material. However, during the surface treatment of the carbon fiber, carbon dioxide and ammonia will be generated. Ammonia has a pungent smell and floats in the air, which does not meet the "Emission Standards for Malodor Pollutants", pollutes the operating environment, and harms the health of operators.

[0007] The single-filament fiber surface treatment device disclosed in Chinese utility model patent CN202164492U is applied to fiber surface treatment. A plasma generator power supply and a cyclone fan are fixed at the lower part of the bracket. A low-temperature plasma generator under normal pressure is used to treat the fiber surface to directly realize continuous production, reduce the fiber surface treatment steps, simplify the treatment process, and improve the efficiency of fiber surface treatment. Only electricity and air are required during the entire operation, achieving clean and pollution-free processing. However, when the plasma liquid is emitted from the low-temperature plasma generator to the carbon fiber surface, there is a certain distance between the nozzles of the spray gun group, and it is difficult to control the amount of plasma liquid sprayed on the carbon fiber surface to remain the same. There are differences, which affect the uniformity and consistency of the interlaminar shear strength of the carbon fiber reinforced thermosetting resin composite material.

[0008] Chinese invention patent CN101660185B discloses a method for strong carbon fiber anodization surface treatment, which accelerates the oxidation process by anodizing the carbon fiber in an external magnetic field with an intensity of 5-50mT. It can speed up the surface treatment of carbon fiber and reduce the amount of electrolyte used, but it still does not solve the problem of direct emission of gas generated during electrolyte electrolysis into the air, making it difficult to meet the pollutant emission requirements in the production operation area and not meeting the green environmental protection requirements of industrialized production of carbon fiber.

[0009] Therefore, there is an urgent need for a green and environmentally friendly carbon fiber processing system that consumes less materials and is pollution-free. Summary of the invention

[0010] In order to overcome the deficiencies of the prior art, the object of the present invention is to provide a carbon fiber anodizing surface treatment device and a surface treatment method, which can solve the above problems.

[0011] The purpose of the present invention is achieved by the following technical solutions:

[0012] A carbon fiber anodizing surface treatment device belongs to anodizing surface treatment technology for online production of carbon fiber, and the device includes an electrolysis unit and an exhaust gas treatment unit. The electrolysis unit includes an electrolyte feed tank, an electrolyte feeding pump, an electrolytic cell, a DC power supply, a first conductive anode roller, a first impregnation roller, a second impregnation roller, a second conductive anode roller, a graphite cathode plate, a first circulation pump, a movable cover, an inlet suction hood, and an outlet suction hood. The electrolyte feed tank supplies electrolyte to the electrolytic cell through the electrolyte feeding pump. The electrolytic cell circulates the electrode liquid in the cell through the first circulation pump. The first conductive anode roller, the first impregnation roller, the second impregnation roller, the second conductive anode roller, and the graphite cathode plate are arranged in the electrolytic cell, and the first impregnation roller, the second impregnation roller, and the graphite cathode plate are immersed in the electrolyte. The first conductive anode roller, the first impregnation roller, the second impregnation roller, and the graphite cathode plate are sequentially connected from the feed port to the discharge port of the electrolytic cell to transport and immerse the carbon fiber. The DC power supply is electrically connected to the first conductive anode roller, the second conductive anode roller and the graphite cathode plate for power supply. An inlet air suction hood is arranged at the top of the feed port side of the electrolytic cell, and an outlet air suction hood is arranged at the top of the discharge port side of the electrolytic cell, and the movable cover is arranged between the inlet air suction hood and the outlet air suction hood. Wherein, the waste gas treatment unit after electrolysis includes a blower, an acidification tank, a folding cover, a second circulation pump, an acid feeding pump, and an acid supply tank. The folding cover is arranged on the top surface of the acidification tank. The upstream of the blower is connected to the vent holes of the inlet air suction hood and the outlet air suction hood above the electrolytic cell, and the downstream of the blower is connected to the acidification tank. The acid supply tank supplies acid to the acidification tank through the acid feeding pump. The second circulation pump is connected to the bottom wall and the side wall of the acidification tank to realize the acid circulation in the acidification tank.

[0013] Preferably, the carbon fiber tow N running in the electrolytic cell 1 Ply, each strand width W 2 , the spacing between two adjacent carbon fiber tows W 3 , electrolytic cell width W 1 W 1 =N 1 *W 2 +(N 1 +40)*W 3 , electrolytic cell length L 1 For L 1 =L 4 +L 6 +L 8 .

[0014] Preferably, the two ends of the first and second dipping rollers are mounted on the wall of the electrolytic cell through roller bearing seats, and a waist-shaped hole is provided on both sides of the roller bearing seats to enable them to move horizontally left and right. The maximum adjustable distance of the first dipping roller horizontally left and right is the roller diameter D of the first dipping roller. 1 The maximum adjustable distance of the second dipping roller horizontally moving left and right is the second dipping roller diameter D 2 By moving the horizontal positions of the first dipping roller and the second dipping roller, the maximum distance L between the first dipping roller and the second dipping roller is adjusted. 2 For L 2 =L 4 +5*D 2 , thereby controlling the electrolysis time of the carbon fiber tow in the electrolytic cell.

[0015] Preferably, the movable cover includes N 2 A single cover plate, a cover plate frame, and a sliding track, each single cover plate includes a transparent window, and driving wheels and guide wheels are arranged at the front and rear ends of each single cover plate. The single cover plate slides on the sliding track through the driving wheels and guide wheels at both ends.

[0016] Preferably, the inlet suction hood is fixedly installed above the first conductive anode roller and the first impregnation roller at the feed inlet of the electrolytic cell. There is a glass side door on each side of the inlet suction hood that can be opened up and down to facilitate the threading production operation. The width of the inlet suction hood is the same as the width of the electrolytic cell.

[0017] Preferably, the outlet suction hood is fixedly installed above the second conductive anode roller and the second impregnation roller at the discharge port of the electrolytic cell. There is a glass side door on each side of the outlet suction hood that can be opened up and down to facilitate the threading production operation. The width of the outlet suction hood is the same as the width of the electrolytic cell.

[0018] Preferably, the cover plates of the foldable cover plate are connected by hinges, a cylinder is arranged on the inner side of the cover plate, a cylinder rod is arranged on the outer side of the cover plate, and the cylinder is driven by a cylinder solenoid valve to perform opening and closing operations.

[0019] Preferably, the acid used in the acidification tank is hydrochloric acid, sulfuric acid, nitric acid, acetic acid, or phosphoric acid, and the acid concentration is 1 to 15%.

[0020] Preferably, a pH detector and a liquid level meter are provided in the acidification tank to control the pH value and liquid level of the solution in the acidification tank, and to control the pH value of the solution to be ≤7.

[0021] At the same time, a method for surface treatment of carbon fiber using the device is provided, and the method comprises the following steps.

[0022] S1 Preparation before operation: close the glass side doors on both sides of the inlet suction hood and the glass side doors on both sides of the outlet suction hood, open the valve at the bottom of the electrolyte feed tank, start the electrolyte feeding pump, add 10% ammonium bicarbonate aqueous solution to the electrolytic cell, when the ammonium bicarbonate aqueous solution level in the electrolytic cell reaches 80% of the depth of the electrolytic cell, turn off the electrolyte feeding pump, and start the first circulation pump. Turn on the cylinder control button of the acidification tank, lower the cylinder rod, and close the folding cover. Add 7% nitric acid solution to the acid feed tank, open the valve at the bottom of the acid feed tank, start the acid feeding pump, add 7% nitric acid solution to the acidification tank, when the nitric acid solution level reaches 80% of the depth of the acidification tank, turn off the acid feeding pump, start the second circulation pump, turn on the fan, and the inlet suction hood and outlet suction hood of the electrolytic cell extract the exhaust gas escaping from the electrolytic cell and pass it into the acidification tank.

[0023] S2 starts production operation. First, open the glass side doors on both sides of the inlet suction hood and the glass side doors on both sides of the outlet suction hood, and move the cover plates to move each two adjacent single cover plates to both sides, so that the top of the electrolytic cell is in an open state. The carbon fiber tow at the outlet of the high-temperature carbonization furnace passes through the vertical five-roller traction machine, and the threading operation passes through the first conductive anode roller, the first impregnation roller, the second impregnation roller, and the second conductive anode roller. Then, close the glass side doors on both sides of the inlet suction hood and the glass side doors on both sides of the outlet suction hood, and move the cover plates to keep the top of the electrolytic cell in a closed state.

[0024] S3 The first conductive anode roller, the second conductive anode roller, and the graphite cathode plate are connected to the DC power supply, and the DC power supply voltage is controlled to be 12 V. When the carbon fiber tow is running in the electrolytic cell, the conductivity of the electrolyte in the electrolytic cell is monitored to be 98±2μs / cm, and the pH value of the solution in the acidification tank is monitored to be ≤7.

[0025] The filament bundle at the outlet of the second conductive anode roller S4 is subjected to the production processes of washing, sizing, drying and winding to produce 12K carbon fiber.

[0026] Compared with the prior art, the beneficial effects of the present invention are as follows: the carbon fiber anodizing surface treatment device provided by the present invention has the advantages of flexible utilization of adjusting the spacing between the impregnation rollers in the electrolytic cell, controlling the electrolysis time, uniform oxidation of each single filament, good electrolytic oxidation treatment effect, introduction of oxygen-containing, nitrogen-containing and other active functional groups on the surface of the carbon fiber, and significant improvement of the interlayer shear strength of the carbon fiber composite material; the equipment manufacturing cost is low; the operation is simple, and it is easy to handle the anodic electrolytic oxidation of a large number of carbon fiber bundles, which is suitable for the industrial production of carbon fiber; the electrolytic device for the anodizing surface treatment of carbon fiber is equipped with an inlet suction hood, an outlet suction hood, and a movable cover plate, and a fan is used to extract the ammonia waste gas generated by the electrolytic device to the post-electrolysis waste gas treatment device equipped with a folding cover plate for acid-base reaction, which effectively blocks the escape of waste gas, reduces environmental pollution, avoids harm to the health of operators during operation, and ensures safe production. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic structural diagram of a carbon fiber anodizing surface treatment device of the present invention;

[0028] Figure 2 Schematic diagram of the structure of a movable cover, wherein (a) is a top plan view of the movable cover, (b) is a stereoscopic view of the movable cover, (c) is a stereoscopic view of a driving wheel of the movable cover, and (d) is a stereoscopic view of a guide wheel of the movable cover;

[0029] Figure 3 1 is a schematic diagram of the structure of the inlet air suction hood, wherein (a) is a stereoscopic diagram of the inlet air suction hood with the side door closed, and (b) is a stereoscopic diagram of the inlet air suction hood with the side door open;

[0030] Figure 4 1 is a schematic diagram of the structure of the outlet air suction hood, wherein (a) is a stereoscopic diagram of the outlet air suction hood with the side door closed, and (b) is a stereoscopic diagram of the outlet air suction hood with the side door opened;

[0031] Figure 5 Schematic diagram of the foldable cover structure of the acidizing tank, wherein (a) is a front view of the foldable cover, (b) is a side view of the foldable cover, and (c) is a top view of the stacked cover;

[0032] Figure 6 Schematic diagram of the roller bearing seat structure, including (a) a stereoscopic diagram of the roller bearing seat and the base plate, and (b) a stereoscopic diagram of the roller bearing seat and the impregnation roller.

[0033] In the figure: 1, electrolyte feed tank; 2, electrolyte feed pump; 3, electrolytic tank; 4, DC power supply; 5, first conductive anode roller; 6, first impregnation roller; 7, second impregnation roller; 8, second conductive anode roller; 9, graphite cathode plate; 10, first circulation pump; 11, movable cover; 12, inlet suction hood; 13, outlet suction hood; 14, fan; 15, acidification tank; 16, folding cover; 17, second circulation pump; 18, acid feed pump; 19, acid feed tank; 20, transparent window; 21, drive wheel; 22, guide wheel; 23, bearing; 24, Step shaft; 25. Positioning washer; 26. Washer; 27. Pin; 28. Bracket; 29. ​​Bearing; 30. Step shaft; 31. Positioning washer; 32. Washer; 33. Pin; 34. Bracket; 35. Glass side door; 36. Tow inlet end face; 37. Tow outlet end face; 38. Glass side door; 39. Tow inlet end face; 40. Tow outlet end face; 41. Cylinder; 42. Cylinder rod; 43. Roller bearing seat; 44. Waist-shaped hole; 45. Waist-shaped hole; 46. Bolt; 47. Bolt; 48. Bolt; 49. Bolt; 50. Bearing seat bottom plate. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] Comparative Example 1: When 250 strands of 12K carbon fiber were subjected to surface treatment for industrial production, a commonly used carbon fiber surface treatment device was used. The width of each strand of fiber is 0.007 meters, the spacing between two adjacent strands of carbon fiber fiber is 0.005 meters, the width of the electrolytic cell is 3.04 meters, and the length of the electrolytic cell is 15 meters. The spacing between the first impregnation roller and the second impregnation roller cannot be adjusted, and the inlet suction hood is not installed above the first conductive roller and the first impregnation roller at the inlet of the electrolytic cell, and the outlet suction hood is not installed above the second conductive roller and the second impregnation roller at the outlet of the electrolytic cell. There is no cover plate installed on the electrolytic cell. The commonly used carbon fiber surface treatment device is not equipped with an acidification tank with a cover plate.

[0036] When the commonly used carbon fiber surface treatment device is in operation, the DC power supply voltage is 12 V. The first conductive anode roller and the second conductive anode roller are connected to the positive electrode of the DC power supply, and the graphite cathode plate is connected to the negative electrode of the DC power supply. A 10% ammonium bicarbonate aqueous solution is added to the electrolytic cell.

[0037] The carbon fiber running speed is 6.8 meters per minute, and the electrolysis time is 120 seconds. The tow at the outlet of the high-temperature carbonization furnace passes through a vertical five-roller traction machine, and then passes through the first conductive roller, the first impregnation roller, the second impregnation roller, and the second conductive roller of the electrolytic cell in turn for carbon fiber anode surface treatment. After the surface treatment, the carbon fiber goes through the production processes of washing, sizing, drying, and winding to produce 12K carbon fiber.

[0038] Example 1: The carbon fiber anodizing surface treatment device and surface treatment method proposed in the present invention are used to carry out industrial production of surface treatment of 250 strands of 12K carbon fiber.

[0039] Please refer to Figure 1 , Figure 1 It is a structural schematic diagram of the carbon fiber anodizing surface treatment device and surface treatment method of the present invention. As can be seen from the figure, the carbon fiber anodizing surface treatment device and surface treatment method of the present invention include an electrolytic unit for carbon fiber anodizing surface treatment and a post-electrolysis waste gas treatment unit. Specifically, the electrolytic device for carbon fiber anodizing surface treatment includes an electrolyte feed tank 1, an electrolyte feeding pump 2, an electrolytic tank 3, a DC power supply 4, a first conductive anode roller 5, a first impregnation roller 6, a second impregnation roller 7, a second conductive anode roller 8, a graphite cathode plate 9, a first circulation pump 10, a movable cover 11, an inlet suction hood 12, and an outlet suction hood 13. The post-electrolysis waste gas treatment device includes a fan 14, an acidification tank 15, a folding cover 16, a second circulation pump 17, an acid feeding pump 18, and an acid feed tank 19.

[0040] 250 strands of 12K carbon fiber tow are run in the electrolytic cell, each strand has a width of W 2 0.007 meters, the distance between two adjacent carbon fiber tows W 3 0.005m, electrolytic cell width W 1 3.20 meters, electrolytic cell length L 1 20.81 meters.

[0041] The first conductive anode roller 5 and the second conductive anode roller 8 are made of 304 stainless steel. The first conductive anode roller 5 and the second conductive anode roller 8 are connected to the positive electrode of the DC power supply 4, and the graphite cathode plate 9 is connected to the negative electrode of the DC power supply 4. The first dipping roller 6 and the second dipping roller 7 are both rubber rollers, which serve as insulating guide passive rollers. The first dipping roller 6 and the second dipping roller 7 guide the carbon fiber tow into the electrolyte for dipping.

[0042] The first impregnation roller 6 and the second impregnation roller 7 are respectively mounted on the roller bearing seat 43. There are two waist-shaped holes 44 and 45 on both sides of the roller bearing seat 43, which can move horizontally left and right. 1 0.275m, diameter of the second dipping roller D 20.275 meters, the maximum adjustable distance of the first dipping roller horizontally moving left and right is 0.55 meters, and the maximum adjustable distance of the second dipping roller horizontally moving left and right is 0.55 meters. The distance L between the tow outlet end face of the inlet suction hood and the tow inlet end face of the outlet suction hood 4 16 meters. By moving the horizontal positions of the first and second dipping rollers, the maximum distance L between the first and second dipping rollers can be adjusted. 2 17.375 meters.

[0043] The movable cover plate 11 is a push-pull cover plate installed on the electrolytic cell 3 to prevent the exhaust gas from overflowing. The movable cover plate 11 is composed of 16 mutually intertwined cover plates equipped with rollers. The cover plate frame is made of stainless steel. Each cover plate has two transparent windows 20 made of colorless transparent organic glass, and rubber sealing strips are wrapped around the transparent windows 20. Four rollers are fixedly installed at the front and rear ends of each cover plate. When the cover plate moves on the sliding track, the two driving wheels 21 on the outer sides of the front and rear ends play a sliding role, and the two guide wheels 22 in the middle play a fixed guiding role. The bearing 23 of the driving wheel 21 is sleeved on the step shaft 24. The two ends of the bearing 23 are respectively provided with positioning washers 25 and washers 26 to fix the position of the bearing 23, and the pin 27 fixes the step shaft 24. The bearing seat of the driving wheel 21 is installed on the bracket 28, and the base of the bracket 28 is parallel to the end face of the bearing 23. The bearing 29 of the guide wheel 22 is sleeved on the stepped shaft 30. Positioning washers 31 and washers 32 are respectively added at both ends of the bearing 29 to fix the position of the bearing 29. The pin 33 fixes the stepped shaft 30. The bearing seat of the guide wheel 22 is installed on the bracket 34. The base of the bracket 34 is perpendicular to the end face of the bearing 29. The distance L between the tow outlet end face 37 of the inlet suction hood 12 and the tow inlet end face 39 of the outlet suction hood 13 4 Similarly, the distance between the inlet end face 36 of the inlet suction hood 12 and the outlet end face 40 of the inlet suction hood 13 is also L 4 16 meters. Length of each cover plate L 3 1 meter. Width of each cover plate W 4 3.20 meters.

[0044] The inlet suction hood 12 is fixedly installed at the inlet of the electrolytic cell 3, and is installed above the first conductive anode roller 5 and the first impregnation roller 6. There is a glass side door 35 on each side of the inlet suction hood 12 that can be opened up and down to facilitate the threading production operation. The roller diameter D of the first conductive anode roller 5 3 0.275m, diameter D of the first impregnation roller 6 1 0.275 m, the distance L between the first conductive anode roller 5 and the first impregnation roller 6 5 1.375 meters. Imported suction hood 12 length L 6 2.41 meters, imported air hood 12 width W 5 3.20 meters.

[0045] The outlet suction hood 13 is fixedly installed at the outlet of the electrolytic cell 3, and is installed above the second conductive anode roller 8 and the second impregnation roller 7. There is a glass side door 38 on each side of the outlet suction hood 13 that can be opened up and down, which is convenient for the threading production operation. The roller diameter D of the second conductive anode roller 8 4 0.275m, diameter D of the second impregnation roller 7 2 0.275 m, the distance L between the second conductive anode roller 8 and the second impregnation roller 7 7 1.375 m. Length of outlet hood 13L 8 2.41 meters, outlet suction hood 13 width W 6 3.20 meters.

[0046] The foldable cover plate 16 is installed on the acidification tank 15 and can be folded and lifted to prevent the exhaust gas from overflowing. The covers are connected by hinges and opened and closed by an external cylinder. A cylinder 41 is arranged on the inner side of the cover plate, and a cylinder rod 42 is arranged on the outer side of the cover plate. The cylinder 41 is driven by a cylinder solenoid valve to open and close.

[0047] The carbon fiber running speed is 6.8 m / min, and the electrolysis time is 153 seconds. First, loosen the bolts 46 and 47 on both sides of the bottom plate of the roller bearing seat 43. The first dipping roller 6 and the second dipping roller 7 are respectively installed on the roller bearing seat 43. There is a waist-shaped hole 44 and a waist-shaped hole 45 on both sides of the roller bearing seat 43. Bolts are installed in the waist-shaped holes 44 and 45 of the roller bearing seat 43. Move the horizontal position of the first dipping roller 6 and the second dipping roller 7 left and right, determine the installation position of the bolts 48 and 49 in the waist-shaped holes 44 and 45, tighten the bolts 48 and 49, and then tighten the bolts 46 and 47 on both sides of the roller bearing seat bottom plate 50 to fix the position of the roller bearing seat.

[0048] Then push each cover plate of the movable cover plate 11 left and right, and each cover plate has a length L 3 1.0m, width W 4 3.20 meters. Two driving wheels 21 are installed on the outer sides of the front and rear ends of each cover plate, and two guide wheels 22 are installed in the middle. The driving wheel 21 acts as a sliding cover plate, and the guide wheel 22 acts as a fixed guide to ensure that each cover plate moves horizontally along the sliding track. 16 cover plates that are intertwined and equipped with rollers are used to cover the groove surface between the tow outlet end face 37 of the inlet suction hood 12 and the tow inlet end face 39 of the outlet suction hood 13.

[0049] Close the glass side doors 35 on both sides of the inlet suction hood 12 and the glass side doors 38 on both sides of the outlet suction hood 13, open the bottom valve of the electrolyte feed tank 1, start the electrolyte feed pump 2, add a 10% ammonium bicarbonate aqueous solution to the electrolytic tank 3, and when the ammonium bicarbonate aqueous solution level in the electrolytic tank 3 reaches 80% of the depth of the electrolytic tank 3, close the electrolyte feed pump 2 and start the first circulation pump 10. Turn on the control button of the cylinder 41 of the acidification tank 15, put down the cylinder rod 42, and close the foldable cover 16. Add a 7% nitric acid solution to the acid feed tank 19, open the bottom valve of the acid feed tank 19, and start the acid feed pump 18. A nitric acid solution with a concentration of 7% is added to the acidification tank 15. When the liquid level of the nitric acid solution reaches 80% of the depth of the acidification tank 15, the acid feeding pump 18 is turned off, the second circulation pump 17 is turned on, the fan 14 is turned on, and the inlet suction hood 12 and the outlet suction hood 13 of the electrolytic cell 3 extract the exhaust gas escaping from the electrolytic cell 3 and pass it into the acidification tank 15.

[0050] After the preparations for start-up are completed, production operation begins. First, open the glass side doors 35 on both sides of the inlet suction hood 12 and the glass side doors 38 on both sides of the outlet suction hood 13. Move the two adjacent covers of the movable cover 11 to both sides so that the top of the electrolytic cell is in an open state. The carbon fiber tow at the outlet of the high-temperature carbonization furnace passes through the vertical five-roller traction machine, and the threading operation passes through the first conductive anode roller 5, the first impregnation roller 6, the second impregnation roller 7, and the second conductive anode roller 8. Then, close the glass side doors 35 on both sides of the inlet suction hood 12 and the glass side doors 38 on both sides of the outlet suction hood 13. Move the two adjacent covers of the movable cover 11 to the middle so that the top of the electrolytic cell is in a closed state.

[0051] The first conductive anode roller 5 and the second conductive anode roller 8 are connected to the positive electrode of the DC power supply 4, and the graphite cathode plate 9 is connected to the negative electrode of the DC power supply 4. Connect the DC power supply and control the DC power supply voltage to 12V. When the carbon fiber tow is running in the electrolytic cell, the conductivity of the electrolyte in the electrolytic cell 3 is monitored to be 98±2μs / cm. When the conductivity is lower than 96μs / cm, the electrolyte feed pump 2 is turned on to add an aqueous solution of ammonium bicarbonate with a concentration of 10%. When the conductivity is higher than 100μs / cm, the electrolyte feed pump 2 is turned off.

[0052] During the carbon fiber production operation, the pH value of the solution in the acidification tank 15 is monitored to be ≤7. When the pH value is >7, the acid feeding pump 18 is turned on, and the feeding pump is used to add 7% concentration nitric acid solution to the acidification tank 15. When the pH value of the solution in the acidification tank 15 is ≤7, the acid feeding pump 18 is turned off.

[0053] During the anodizing surface treatment of carbon fiber, waste gases such as ammonia and carbon dioxide escaping from the electrolytic cell 3 are sealed in the electrolytic cell 3 by the movable cover 11. At the same time, by turning on the fan 14, the waste gas is promptly extracted into the acidification tank 15 through the inlet suction hood 12 and the outlet suction hood 13 of the electrolytic cell 3 to prevent the waste gas from escaping into the operating environment.

[0054] The filament bundle at the outlet of the second conductive anode roller 8 is subjected to the production processes of washing, sizing, drying and winding to produce 12K carbon fiber.

[0055] Embodiments 2 to 6: Using the carbon fiber anodizing surface treatment device and surface treatment method proposed by the present invention, the surface treatment industrial production of carbon fibers with different strands and different K numbers is carried out. The carbon fiber surface treatment anodizing surface treatment device and method are the same as those in Embodiment 1, wherein the width and length of the electrolytic cell of the carbon fiber surface treatment anodizing surface treatment device, the maximum adjustable distance of the waist-shaped hole, the spacing between the tow outlet end face of the inlet suction hood and the tow inlet end face of the outlet suction hood, the maximum spacing between the first dipping roller and the second dipping roller, the length and width of the movable cover plate, the number of movable covers, the first conductive anode roller diameter, the first dipping roller diameter, the spacing between the first conductive anode roller and the first dipping roller, the second conductive anode roller diameter, the second dipping roller diameter, the spacing between the second conductive anode roller and the second dipping roller, the length and width of the inlet suction hood, the length and width of the outlet suction hood, and the voltage, electrolyte name and concentration, acid type and concentration process parameters, and the effect after implementation are different from those in Embodiment 1.

[0056] The width and length of the electrolytic device for anodizing the surface of carbon fiber are shown in Table 1. The main equipment parameters of the adjustable spacing between the impregnation rollers and the movable cover are shown in Table 2. The main equipment parameters of the first conductive anode roller, the first impregnation roller, and the inlet suction hood are shown in Table 3. The main equipment parameters of the second conductive anode roller, the second impregnation roller, and the outlet suction hood are shown in Table 4. The main process parameters and the effects after implementation of the carbon fiber anodizing surface treatment device during use are shown in Table 5.

[0057] Table 1 Width and length of electrolytic device for anodized surface treatment of carbon fiber

[0058]

[0059]

[0060] Table 2 Adjustable spacing between impregnation rollers and main equipment parameters of movable cover

[0061]

[0062] Table 3 Main equipment parameters of the first conductive anode roller, the first impregnation roller and the imported suction hood

[0063]

[0064] Table 4 Main equipment parameters of the second conductive anode roller, the second impregnation roller and the outlet suction hood

[0065]

[0066] Table 5 Main process parameters and effects after implementation during the use of carbon fiber anodizing surface treatment device

[0067]

[0068] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A carbon fiber anodizing surface treatment device, characterized in that: The device includes an electrolysis unit and an exhaust gas treatment unit; The electrolysis unit comprises an electrolyte feed tank (1), an electrolyte feed pump (2), an electrolytic cell (3), a DC power supply (4), a first conductive anode roller (5), a first impregnation roller (6), a second impregnation roller (7), a second conductive anode roller (8), a graphite cathode plate (9), a first circulation pump (10), a movable cover plate (11), an inlet air suction hood (12), and an outlet air suction hood (13); The electrolyte supply tank (1) supplies electrolyte to the electrolytic tank (3) via an electrolyte feeding pump (2); the electrolytic tank (3) allows the electrode solution in the tank to circulate via a first circulation pump (10); the first conductive anode roller (5), the first impregnation roller (6), the second impregnation roller (7), the second conductive anode roller (8), and the graphite cathode plate (9) are arranged in the electrolytic tank (3), and the first impregnation roller (6), the second impregnation roller (7), and the graphite cathode plate (9) are immersed in the electrolyte; the first conductive anode roller (5), ... the second impregnation roller (8), and the graphite cathode plate (9) are immersed in the electrolyte; the first conductive anode roller (5), the first impregnation roller (6), the second impregnation roller (7), the second impregnation roller (8), and the graphite cathode plate (9) are immersed in the electrolyte; the first conductive anode roller (5), the first impregnation roller (6), the second impregnation roller (7), the second impregnation roller (8), and the graphite cathode plate (9) are immersed in the electrolyte; the first conductive anode roller ( The soaking roller (7) and the second conductive anode roller (8) are sequentially connected in a transmission manner from the feed port to the discharge port of the electrolytic cell (3) to convey and immerse the carbon fiber; the DC power supply (4) is electrically connected to the first conductive anode roller (5), the second conductive anode roller (8) and the graphite cathode plate (9) to supply power; an inlet air suction hood (12) is arranged at the top of the feed port side of the electrolytic cell (3), an outlet air suction hood (13) is arranged at the top of the discharge port side of the electrolytic cell (3), and the movable cover plate (11) is arranged between the inlet air suction hood (12) and the outlet air suction hood (13); The waste gas treatment unit after electrolysis comprises a fan (14), an acidification tank (15), a foldable cover plate (16), a second circulation pump (17), an acid feed pump (18) and an acid feed tank (19); The foldable cover plate (16) is arranged on the top surface of the acidification tank (15); the upstream of the fan (14) is connected to the vent holes of the inlet suction hood (12) and the outlet suction hood (13) above the electrolytic tank (3), and the downstream of the fan (14) is connected to the acidification tank (15); the acid supply tank (19) supplies acid to the acidification tank (15) through the acid feeding pump (18); the second circulation pump (17) is connected to the bottom wall and the side wall of the acidification tank (15) to realize the acid circulation in the acidification tank; There are N1 strands of carbon fiber tows running in the electrolytic cell (3), each strand has a width of W2, and the spacing between two adjacent strands of carbon fiber tows is W3. The width W1 of the electrolytic cell is W1=N1*W2+(N1+40)*W3, and the length L1 of the electrolytic cell is L1=L4+L6+L8; The two ends of the first dipping roller (6) and the second dipping roller (7) are mounted on the wall of the electrolytic cell (3) via a roller bearing seat (43); a waist-shaped hole (44) and a waist-shaped hole (45) are respectively provided on both sides of the roller bearing seat (43) to enable the roller to be horizontally moved left and right for positioning; the maximum adjustable distance of the first dipping roller (6) for horizontal movement left and right is twice the roller diameter D1 of the first dipping roller (6); the maximum adjustable distance of the second dipping roller (7) for horizontal movement left and right is twice the roller diameter D2 of the second dipping roller (7); by moving the horizontal positions of the first dipping roller (6) and the second dipping roller (7), the maximum distance L2 between the first dipping roller (6) and the second dipping roller (7) is adjusted to L2=L4+5*D2, thereby controlling the electrolysis time of the carbon fiber tow in the electrolytic cell (3).

2. The device according to claim 1, characterized in that: The movable cover plate (11) comprises N2 single cover plates, a cover plate frame, and a sliding track, each single cover plate comprises a transparent window (20), a driving wheel (21) and a guide wheel (22) are arranged at the front and rear ends of each single cover plate, and the single cover plate slides on the sliding track via the driving wheels (21) and the guide wheels (22) at the two ends.

3. The device according to claim 1, characterized in that: The inlet air suction hood (12) is fixedly mounted above the first conductive anode roller (5) and the first impregnation roller (6) at the feed inlet of the electrolytic cell (3); a glass side door (35) which can be opened up and down is provided on both sides of the inlet air suction hood (12) to facilitate the threading production operation; the width of the inlet air suction hood (12) is the same as the width of the electrolytic cell (3).

4. The device according to claim 3, characterized in that: The outlet air suction hood (13) is fixedly mounted directly above the second conductive anode roller (8) and the second impregnation roller (7) at the discharge port of the electrolytic cell (3); a glass side door (38) which can be opened up and down is provided on both sides of the outlet air suction hood (13) to facilitate the threading production operation; the width of the outlet air suction hood (13) is the same as the width of the electrolytic cell (3).

5. The device according to claim 4, characterized in that: The cover plates of the foldable cover plate (16) are connected by hinges, a cylinder (41) is arranged on the inner side of the cover plate, and a cylinder rod (42) is arranged on the outer side of the cover plate. The cylinder (41) is driven by a cylinder solenoid valve to perform opening and closing operations.

6. The device according to claim 1, characterized in that: The acid used in the acidification tank (15) is hydrochloric acid, sulfuric acid, nitric acid, acetic acid, or phosphoric acid, and the acid concentration is 1 to 15%.

7. The device according to claim 1, characterized in that: A pH detector and a liquid level meter are arranged in the acidification tank (15) to control the pH value and liquid level of the solution in the acidification tank (15), and to control the pH value of the solution to be ≤7.

8. A method for surface treatment of carbon fiber using the device according to claim 5, characterized in that: The method comprises the following steps: S1 Preparation before operation: close the glass side doors (35) on both sides of the inlet suction hood (12) and the glass side doors (38) on both sides of the outlet suction hood (13), open the valve at the bottom of the electrolyte feed tank (1), start the electrolyte feed pump (2), add 10% ammonium bicarbonate aqueous solution to the electrolytic tank (3), and when the ammonium bicarbonate aqueous solution level in the electrolytic tank (3) reaches 80% of the depth of the electrolytic tank (3), close the electrolyte feed pump (2) and start the first circulation pump (10); turn on the control button of the cylinder (41) of the acidification tank (15), and lower the cylinder rod (42). , close the foldable cover (16); add a nitric acid solution with a concentration of 7% to the acid feed tank (19), open the bottom valve of the acid feed tank (19), start the acid feed pump (18), add the nitric acid solution with a concentration of 7% to the acidification tank (15), and when the nitric acid solution level reaches 80% of the depth of the acidification tank (15), close the acid feed pump (18), start the second circulation pump (17), start the fan (14), and use the inlet suction hood (12) and the outlet suction hood (13) of the electrolytic tank (3) to extract the exhaust gas escaping from the electrolytic tank (3) and pass it into the acidification tank (15); S2 starts production operation, firstly opens the glass side doors (35) on both sides of the inlet suction hood (12) and the glass side doors (38) on both sides of the outlet suction hood (13), and moves each two adjacent single cover plates of the movable cover plate (11) to both sides, so that the top of the electrolytic cell (3) is in an open state; the carbon fiber tow at the outlet of the high-temperature carbonization furnace passes through the vertical five-roller traction machine, and the threading operation passes through the first conductive anode roller (5), the first impregnation roller (6), the second impregnation roller (7), and the second conductive anode roller (8); then, closes the glass side doors (35) on both sides of the inlet suction hood (12) and the glass side doors (38) on both sides of the outlet suction hood (13), and moves the cover plate (11) so that the top of the electrolytic cell (3) is in a closed state; S3 The first conductive anode roller (5), the second conductive anode roller (8), and the graphite cathode plate (9) are connected to the DC power supply (4) and the DC power supply voltage is controlled to be 12V; when the carbon fiber tow is running in the electrolytic cell (3), the conductivity of the electrolyte in the electrolytic cell (3) is monitored to be 98±2 µs / cm, and the pH value of the solution in the acidification cell (15) is monitored to be ≤7; S4 The tow at the outlet of the second conductive anode roller (8) is subjected to the production processes of washing, sizing, drying and winding to produce 12K carbon fiber.

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