Carbon fiber pre-oxidation device and method

Abstract

The embodiment of the invention provides a carbon fiber pre-oxidation device and method, and belongs to the technical field of carbon fiber equipment. The carbon fiber pre-oxidation device comprises an oxidation furnace used for pre-oxidizing pre-oxidized fibers of carbon fibers; the traction machine is positioned at the inlet of the oxidation furnace and is used for pulling the pre-oxidized fiber into the oxidation furnace; the electrostatic elimination device is used for generating ionization airflow and blowing the ionization airflow to the surface of the pre-oxidized fiber; wherein the static electricity elimination device comprises a first static electricity eliminator and a second static electricity eliminator, the first static electricity eliminator is located at an outlet of the traction machine, and the second static electricity eliminator is located at an outlet of the oxidation furnace. The electrostatic effect in the carbon fiber pre-oxidation process can be solved, dispersion of pre-oxidized fibers is reduced, the consistency of the width of tows is kept, and the bundling performance of the tows is improved. The stability and safety of carbon fiber pre-oxidation operation can be improved, the discreteness of the strength of a carbon fiber finished product can be effectively reduced, and the quality of the carbon fiber is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of carbon fiber equipment, and in particular to a carbon fiber pre-oxidation device and method. Background Art

[0002] As a new type of fiber material with a carbon content of more than 90%, carbon fiber is widely used in military industry, aerospace and other high-tech fields due to its excellent properties such as high strength, light weight, high temperature resistance and radiation resistance. It is a high-tech product. In the past decade, carbon fiber and its composite materials have been widely demanded in the market, and the industrial production of carbon fiber has gradually attracted everyone's attention.

[0003] The carbon fiber production process is complicated. After the polyacrylonitrile precursor is unwound, it needs to go through pre-oxidation, carbonization, surface treatment, sizing and other processes to obtain carbon fiber. Not only does the polyacrylonitrile precursor itself have a certain amount of static electricity, but the tow is constantly in contact and friction with multiple rollers (roller rollers) from the beginning of unwinding, causing a large amount of static electricity to be generated on the surface of the tow. Among them, the reaction of the pre-oxidation process is the most complex and time-consuming, and plays a decisive role in the performance of the carbon fiber finished product, and the generation of static electricity during the pre-oxidation process is particularly obvious. Usually, during the pre-oxidation process, the pre-oxidation wire needs to pass through multiple furnace areas to complete the reaction. In order to increase the residence time of the tow and increase the reaction efficiency, the pre-oxidation wire needs to be operated in multiple layers in multiple oxidation furnaces. This means that the pre-oxidation wire needs to be pulled by dozens of rollers, and the friction is relatively frequent. Therefore, the reaction of the pre-oxidation wire in the oxidation furnace is complex and exothermic, and at the same time, it is rubbed by the blowing of the circulating air, which will cause a large amount of static electricity to be generated in the pre-oxidation wire.

[0004] The existence of the electrostatic effect will cause the internal parts of the filament bundle to repel each other, weaken the static friction resistance between the single filaments, resulting in poor bundle bunching and wider single filament diameter. The pre-oxidized filament itself has poor conductivity. These static electricity will continue to accumulate during the production process and are difficult to eliminate, which will cause the filament bundle to become fuzzy or break, and entangle on the roller surface to form a roller, which can easily cause the oxidation furnace to stop. In addition, the poor bundling of the pre-oxidized filament caused by static electricity may cause broken filaments when passing through the carbonization furnace section, making it difficult to pass through the carbonization furnace smoothly, which will not only reduce the yield of the finished carbon fiber, but also seriously affect the strength and other properties of the finished carbon fiber.

[0005] At present, in the production process of polyacrylonitrile precursor, some production processes mainly reduce the electrostatic effect of the precursor by oiling, but the precursor will still generate a lot of static electricity after friction after unwinding. For example, the prior art discloses a device for eliminating static electricity generated by the operation of carbon fiber precursor, including a seat body, a channel for the carbon fiber precursor to pass through, and at least one atomizing liquid inlet connected to the channel on the seat body, which can eliminate static electricity on the carbon fiber precursor. The above scheme mainly reduces the static electricity generation of the tow and reduces the drift of the tow by applying water mist to the surface of the tow. However, the device is mainly used in the unwinding area of ​​the precursor. After the reaction and friction of the subsequent process such as pre-oxidation, the surface of the precursor will still generate a lot of static electricity. The device will make the surface of the tow wet and there will be a lot of water. When the tow passes through the oxidation furnace for pre-oxidation reaction, a lot of water vapor will be generated. The accumulation of water vapor and heat in the furnace cavity is easy to cause flash explosion.

[0006] Some production processes also use the method of grounding the traction roller to eliminate static electricity. However, due to the poor conductivity of the pre-oxidized yarn, a large amount of static electricity still remains on its surface and cannot be eliminated. For example, the prior art discloses a static electricity removal device for a carbon fiber production line, which is provided with an electrostatic wool roller, and the wool roller is provided with an electrostatic wool strip, which is connected to the ground through the electrostatic wool roller. On the basis of conventional static electricity removal, this scheme achieves secondary static electricity in the carbon fiber production line by colliding with the wool roller. However, this static electricity removal device uses an electrostatic wool roller that directly contacts and collides with the fiber surface, which can easily cause fiber surface defects, increase the generation of fiber filaments, and affect the quality of the carbon fiber product. Summary of the invention

[0007] The purpose of the embodiments of the present invention is to provide a device and method that can solve the electrostatic effect in the process of pre-oxidation of carbon fiber, thereby reducing the discreteness of the pre-oxidation yarn, maintaining the consistency of the yarn bundle width, and improving the bundle bundling performance.

[0008] In order to achieve the above-mentioned purpose, an embodiment of the present invention provides a carbon fiber pre-oxidation device, which includes: an oxidation furnace, used to pre-oxidize the pre-oxidation filaments of the carbon fiber; a traction machine, located at the inlet of the oxidation furnace, used to pull the pre-oxidation filaments into the oxidation furnace; and an electrostatic eliminator, used to generate an ionized airflow and blow the ionized airflow to the surface of the pre-oxidation filaments; wherein the electrostatic eliminator includes a first electrostatic eliminator and a second electrostatic eliminator, the first electrostatic eliminator is located at the outlet of the traction machine, and the second electrostatic eliminator is located at the outlet of the oxidation furnace.

[0009] Optionally, the first static eliminator and the second static eliminator are arranged in the width direction of the wire surface of the pre-oxidation wire, the wire surface width of the pre-oxidation wire is smaller than the roller length in the oxidation furnace, and the wire surface width of the pre-oxidation wire is smaller than the length of the first static eliminator.

[0010] Optionally, the width of the pre-oxidized yarn is 1.5 to 3.5 m, the length of the roller in the oxidation furnace is 1.7 to 3.6 m, and the length of the first static eliminator and the second static eliminator is 1.7 to 3.6 m.

[0011] Optionally, the first static eliminator and the second static eliminator are located above the surface of the pre-oxidized yarn, wherein the distance between the first static eliminator and the second static eliminator and the surface of the pre-oxidized yarn is 50 to 2000 mm.

[0012] Optionally, the first static eliminator and the second static eliminator include: a nozzle vertically aligned with the yarn surface of the pre-oxidized yarn; and a compressed air interface.

[0013] Optionally, a plurality of electrode needles are arranged in the nozzle.

[0014] Optionally, the plurality of electrode needles include three electrode needles, and the three electrode needles are arranged in a triangle in the nozzle.

[0015] Optionally, the electrode needle is made of tungsten; and / or the first static eliminator and the second static eliminator further include a shell, the shell is made of polycarbonate plastic, and the surface of the shell is coated with polytetrafluoroethylene.

[0016] Optionally, the operating voltage of the first static eliminator and the second static eliminator is 24-36V.

[0017] On the other hand, the present invention provides a carbon fiber pre-oxidation method, which includes: pre-oxidizing the pre-oxidation filaments of the carbon fiber through an oxidation furnace; pulling the pre-oxidation filaments into the oxidation furnace through a traction machine, wherein the traction machine is located at the inlet of the oxidation furnace; and generating an ionized airflow through an electrostatic eliminator, and blowing the ionized airflow to the surface of the pre-oxidation filaments; wherein the electrostatic eliminator includes a first electrostatic eliminator and a second electrostatic eliminator, the first electrostatic eliminator is located at the outlet of the traction machine, and the second electrostatic eliminator is located at the outlet of the oxidation furnace.

[0018] Through the above technical solution, the present invention can solve the electrostatic effect in the process of carbon fiber pre-oxidation, reduce the discreteness of pre-oxidized filaments, maintain the consistency of filament bundle width, and improve the bundle bundling performance. At the same time, it can avoid the generation of broken filaments, reduce the entanglement of filament bundles on the roller surface, and avoid the occurrence of roller winding. It can not only improve the stability and safety of carbon fiber pre-oxidation operation, but also effectively reduce the discreteness of the strength of carbon fiber finished products and improve the quality of carbon fiber.

[0019] Other features and advantages of the embodiments of the present invention will be described in detail in the subsequent detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings are used to provide a further understanding of the embodiments of the present invention and constitute a part of the specification. Together with the following specific implementations, they are used to explain the embodiments of the present invention, but do not constitute a limitation on the embodiments of the present invention. In the accompanying drawings:

[0021] Figure 1 is a schematic diagram of a carbon fiber pre-oxidation device according to an embodiment of the present invention;

[0022] Figure 2 is a schematic diagram of a static eliminator according to an embodiment of the present invention;

[0023] Figure 3 is a schematic diagram of a carbon fiber pre-oxidation device according to an embodiment of the present invention;

[0024] Figure 4 The figure is a schematic flow chart of a carbon fiber pre-oxidation method according to an embodiment of the present invention.

[0025] Description of Reference Numerals

[0026] 100, oxidation furnace; 200, traction machine; 301, first static eliminator; 302, second static eliminator;

[0027] 1-3, oxidation furnace; 4-7, traction machine; 8-14, static eliminator;

[0028] 15. Nozzle; 16. Compressed air interface; 17. Power interface; 18. Shell. DETAILED DESCRIPTION

[0029] The specific implementation of the embodiment of the present invention is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described here is only used to illustrate and explain the embodiment of the present invention, and is not used to limit the embodiment of the present invention.

[0030] To achieve the above object, the present invention provides a carbon fiber preoxidation device, such as Figure 1 As shown, the carbon fiber preoxidation device may include: an oxidation furnace 100, used for preoxidation of preoxidized fibers of carbon fibers; a traction machine 200, located at the inlet of the oxidation furnace 100, used for traction of the preoxidized fibers into the oxidation furnace 100; and an electrostatic eliminator, used for generating an ionized airflow and blowing the ionized airflow toward the surface of the preoxidized fibers. The electrostatic eliminator may include a first electrostatic eliminator 301 and a second electrostatic eliminator 302, wherein the first electrostatic eliminator 301 may be located at the outlet of the traction machine 200, and the second electrostatic eliminator 302 may be located at the outlet of the oxidation furnace 100.

[0031] The carbon fiber preoxidation device of the present invention can not only effectively eliminate the static electricity generated by the friction of the rollers and the circulating wind in the oxidation furnace 100 on the surface of the preoxidation yarn online, but also reduce the discreteness of the yarn bundle, maintain the uniformity of the yarn bundle width, and reduce the strength discreteness of the carbon fiber finished product. At the same time, it can also reduce the generation of hairy and broken yarns, avoid the occurrence of roller winding, and increase the continuity and stability of carbon fiber preoxidation. The static electricity elimination method of the present invention is scientific and reasonable, has good static electricity elimination, and has a simple structure and is easy to install, and is particularly suitable for industrial production applications. While ensuring safe production operation, it can effectively reduce and improve continuous production efficiency.

[0032] In one embodiment, the carbon fiber preoxidation device of the present invention can be applied to carbon fiber preoxidation of various specifications and types. For example, the K number of the carbon fiber can range from 3 to 120K. The tow width D1 can range from 1.4 to 55 mm, and the preferred range can be 5.5 to 44 mm. The single-filament spacing D2 can range from 1.5 to 25 mm, and the preferred range can be 5 to 13 mm.

[0033] In one embodiment, the first static eliminator 301 and the second static eliminator 302 may be the same. The first static eliminator 301 will be described in detail below, and those skilled in the art may configure the structure and function of the second static eliminator 302 with reference to the first static eliminator 301 .

[0034] In one embodiment, the first static eliminator 301 may be arranged in the width direction of the wire surface of the pre-oxidized wire, the wire surface width L1 of the pre-oxidized wire may be smaller than the roller length L2 in the oxidation furnace 100, and the wire surface width L1 of the pre-oxidized wire may be smaller than the length L3 of the first static eliminator 301. For example, the wire surface width L1 of the pre-oxidized wire is 1.5 to 3.5 m, more preferably 2.6 to 3.4 m. The roller length L2 in the oxidation furnace 100 is 1.7 to 3.6 m, more preferably 2.8 to 3.5 m. The length L3 of the first static eliminator 301 is 1.7 to 3.6 m, more preferably 2.8 to 3.5 m. In a preferred embodiment, the roller length L2 in the oxidation furnace 100 may be the same as the length L3 of the first static eliminator 301.

[0035] In one embodiment, the first static eliminator 301 may be located above the surface of the pre-oxidized yarn, wherein the distance between the first static eliminator 301 and the surface of the pre-oxidized yarn is 50 to 2000 mm, preferably in the range of 100 to 1400 mm.

[0036] In one embodiment, if Figure 2 As shown, the first static eliminator 301 may include: a nozzle 15 , a compressed air interface 16 , a power interface 17 and a housing 18 .

[0037] In one embodiment, the nozzle 15 can be vertically aligned with the wire surface of the pre-oxidized wire. In another embodiment, the nozzle 15 can adopt a hexagonal cover. Among them, the hexagonal cover has a dust shielding effect and can keep the electrode needle clean. In another embodiment, a plurality of electrode needles can be arranged inside the nozzle 15, and the plurality of electrode needles can include three electrode needles, and the three electrode needles are arranged in a triangle in the nozzle 15. Among them, the electrode needles arranged in this triangular shape can maximize the 360° generation of ion air. In another embodiment, the material of the electrode needle can be selected as tungsten, and preferably high-density metal tungsten can be used, which can effectively reduce the wear of the electrode needle and maximize the ion production.

[0038] In one embodiment, the shell 18 may be made of polycarbonate plastic, and the surface of the shell 18 may be coated with polytetrafluoroethylene to achieve high temperature resistance and corrosion resistance.

[0039] In one embodiment, the first static eliminator 301 can be connected to compressed air of a set pressure (for example, 0.2-0.6MPa) through the compressed air interface 16, and connected to direct current through the power interface 17. The voltage of the direct current can be selected in different ranges according to actual needs, for example, the operating voltage can be 24-36V. Then, the connected voltage can generate high voltage (4-8KV) through the AC high-voltage generator, and then positive and negative voltages are alternately applied to each electrode needle in a pulsed manner, so that two polar ions can be produced on each electrode needle. At the same time, a super strong ionization field can be generated between the electrode needles, thereby ionizing the air molecules and generating a large number of positive and negative charges. When the surface of the pre-oxidation wire is positively charged, the pre-oxidation wire will attract negative charges in the airflow, and when the surface of the pre-oxidation wire is negatively charged, the pre-oxidation wire will attract positive charges in the airflow, so that the charge on the surface of the pre-oxidation wire is neutralized, thereby achieving the purpose of eliminating static electricity.

[0040] At the same time, the value of the operating voltage is related to the rotation speed of the traction machine 200. During the pre-oxidation production process, the traction machine 200 rotates so that the traction bundle runs continuously. The faster the traction speed, the greater the friction between the roller of the traction machine 200 and the bundle, and the more static electricity is generated. At the same time, the faster the operating speed, the more bundles pass through the first static eliminator 301 per unit time, and the elimination load of the first static eliminator 301 increases. The working efficiency of the first static eliminator 301 can be increased by increasing the voltage of the first static eliminator 301. In one embodiment, the operating speed of the traction machine 200 is 8 to 16 m / min, and the preferred range is 10 to 14 m / min. The operating voltage of the first static eliminator 301 is 24 to 36 V, and can be adaptively adjusted according to the operating speed of the traction machine 200.

[0041] In one embodiment, a plurality of oxidation furnaces may be provided, and the temperature zones of the plurality of oxidation furnaces may be distributed in a gradient. For example, the number of oxidation furnaces may range from 3 to 6, and preferably three oxidation furnaces may be provided. Figure 3 As shown, it includes oxidation furnace 1, oxidation furnace 2, and oxidation furnace 3, and different temperature ranges are set. For example, the temperature range of oxidation furnace 1 can be 220-225°C, the temperature range of oxidation furnace 2 can be 230-235°C, and the temperature range of oxidation furnace 3 can be 240-250°C.

[0042] In this case, the carbon fiber pre-oxidation device may also include a plurality of traction machines and a plurality of static elimination devices. Figure 3 As shown, it may include: traction machine 4, traction machine 5, traction machine 6, traction machine 7; static eliminator 8, static eliminator 9, static eliminator 10, static eliminator 11, static eliminator 12, static eliminator 13, static eliminator 14. Among them, traction machine 4 is located at the inlet of oxidation furnace 1, traction machine 5 is located at the outlet of oxidation furnace 1, traction machine 6 is located at the outlet of oxidation furnace 2, and traction machine 7 is located at the outlet of oxidation furnace 3. Static eliminator 8 is installed at the bottom of traction machine 4, static eliminator 9 is installed above oxidation furnace 1, static eliminator 10 is installed at the bottom of traction machine 5, static eliminator 11 is installed above oxidation furnace 2, static eliminator 12 is installed at the bottom of traction machine 6, static eliminator 13 is installed above oxidation furnace 3, and static eliminator 14 is installed at the bottom of traction machine 7.

[0043] In this case, the application method of the carbon fiber pre-oxidation device is as follows: after the original fiber is unwound, it is first pulled into the oxidation furnace 1 by the traction machine 4. The static eliminator 8 located at the bottom of the traction machine 4 can eliminate the static electricity generated by the friction of the filament bundle through the traction machine 4. After the filament bundle runs 6 layers in the oxidation furnace 1, it exits from the oxidation furnace 1 outlet. The static eliminator 9 located above the oxidation furnace 1 can eliminate the static electricity generated by the friction of the filament bundle through the roller and the circulating air friction in the oxidation furnace 1. The exiting filament bundle is pulled into the oxidation furnace 2 by the traction machine 5. The static eliminator 10 located at the bottom of the traction machine 5 can eliminate the static electricity generated by the friction of the traction machine 5. After the filament bundle runs 6 layers inside the oxidation furnace 2, it exits from the oxidation furnace 2 outlet. The static eliminator 11 located above the oxidation furnace 2 can eliminate the static electricity generated by the friction of the filament bundle through the roller and the circulating air inside the oxidation furnace 2. The tow from the oxidation furnace 2 is pulled into the oxidation furnace 3 by the traction machine 6. The static eliminator 12 located at the bottom of the traction machine 6 can eliminate the static electricity generated by the friction of the traction machine 6. After the tow runs 6 layers inside the oxidation furnace 3, it exits from the oxidation furnace 3 outlet. The static eliminator 13 located above the oxidation furnace 3 can eliminate the static electricity generated by the friction of the rollers and the circulating air friction inside the oxidation furnace 3. Finally, the tow is pulled into the subsequent section by the traction machine 7. The static eliminator 14 located at the bottom of the traction machine 7 can eliminate the static electricity generated by the friction of the traction machine 7.

[0044] The present invention also provides a carbon fiber preoxidation method, such as Figure 4 As shown, the carbon fiber pre-oxidation method includes: S1, pre-oxidizing the pre-oxidized fibers of the carbon fiber through an oxidation furnace; S2, pulling the pre-oxidized fibers into the oxidation furnace through a traction machine, wherein the traction machine is located at the inlet of the oxidation furnace; and S3, generating an ionized airflow through an electrostatic eliminator, and blowing the ionized airflow to the surface of the pre-oxidized fibers; wherein the electrostatic eliminator includes a first electrostatic eliminator and a second electrostatic eliminator, the first electrostatic eliminator is located at the outlet of the traction machine, and the second electrostatic eliminator is located at the outlet of the oxidation furnace.

[0045] For specific details and benefits of the carbon fiber pre-oxidation method provided in the embodiment of the present invention, please refer to the above description of the carbon fiber pre-oxidation device, which will not be repeated here.

[0046] In order to further illustrate the beneficial effects of the present invention, the following is a comparative example and six embodiments. Figure 3 The effect of the carbon fiber pre-oxidation device was tested.

[0047] Comparative Example 1: No static electricity elimination device was set in the oxidation furnace area, and 180 ingots of 12K carbon fiber were produced. The single filament width D1 is 5.5 mm, and the single filament spacing D2 is 5 mm. During production, the raw silk is unwound from the creel area and then pre-oxidized by traction machine 4, oxidation furnace 1, traction machine 5, oxidation furnace 2, traction machine 6, oxidation furnace 3, and traction machine 7 in sequence to obtain pre-oxidized silk. The pre-oxidized silk is subjected to carbonization, surface treatment, water washing, sizing, and winding processes to obtain the finished carbon fiber product. Among them, the single filament width deviation rate of the pre-oxidized silk is 30%, the discrete value of the wound carbon fiber strength is 15%, and the number of roller windings during a single batch production operation is 8 times.

[0048] Example 1: The carbon fiber pre-oxidation device proposed in the present invention is used, and the static eliminator is located in the traction machine and oxidation furnace area to produce 180 ingots of 12K carbon fiber. The single wire width D1 is 5.5mm, and the single wire spacing D2 is 5mm. During production, the raw silk is unwound from the creel area and then passed through the traction machine 4, oxidation furnace 1, traction machine 5, oxidation furnace 2, traction machine 6, oxidation furnace 3, and traction machine 7 in sequence for pre-oxidation to obtain pre-oxidized silk. The pre-oxidized silk is subjected to carbonization, surface treatment, water washing, sizing, and winding to obtain a finished carbon fiber product.

[0049] In this embodiment, the length of the wire surface is L1, which is 2.6 m, the length of the roller is L2, which is 2.8 m, the length of the static eliminator is L3, which is 2.8 m, the distance D3 between the static eliminator and the wire surface is 1400 mm, and the voltage U of the static eliminator is 24 V. Before starting operation, the static eliminator is connected to 0.4 MPa compressed air and a 24 V DC power supply. When the raw wire is unwound at a certain speed, it passes through the traction machine 4, the oxidation furnace 1, the traction machine 5, the oxidation furnace 2, the traction machine 6, the oxidation furnace 3, and the traction machine 7 in sequence. The static eliminator 8 installed at the bottom of the traction machine 4, the static eliminator 10 installed at the bottom of the traction machine 5, the static eliminator 12 installed at the bottom of the traction machine 6, and the static eliminator 14 installed at the bottom of the traction machine 7 can eliminate the static electricity generated by the friction of the traction roller on the surface of the pre-oxidized wire. The static eliminator 9 installed above the oxidation furnace 1, the static eliminator 11 installed above the oxidation furnace 2, and the static eliminator 13 installed above the oxidation furnace 3 can eliminate the static electricity generated by the friction of the circulating air in the furnace chamber of the oxidation furnace on the surface of the pre-oxidized wire. Finally, after the static electricity is eliminated, the pre-oxidized yarn enters the carbonization furnace, and then undergoes surface treatment, water washing, sizing, winding, etc., and finally the carbon fiber product is obtained.

[0050] After adopting the carbon fiber preoxidation device provided by the present invention, the deviation rate C1 of the single fiber width of the preoxidized yarn is 1.5%, the obtained carbon fiber strength discrete rate C2 is 0.8%, and 0 roller winding occurs during a single batch production operation.

[0051] In Examples 2 to 6, the carbon fiber preoxidation device and method are the same as those in Example 1, wherein the carbon fiber K number, the monofilament width D1, the monofilament spacing D2, the number of raw yarn spindles N, the yarn surface length L1, the roller length L2, the static eliminator length L3, the distance D3 between the static eliminator and the yarn surface, and the static eliminator voltage parameter U are different from those in Example 1. The specific parameters are shown in Table 1, and the generated operation results are shown in Table 2.

[0052] Table 1

[0053]

[0054] Table 2

[0055]

[0056]

[0057] From the operation results of various embodiments and comparative examples, the deviation rate C1 of the monofilament width of the preoxidized yarn ranges from 0.6 to 5.5%, and the carbon fiber strength discrete rate C2 ranges from 0.2 to 3%, which are much lower than the C1 value of 30% and the C2 value of 15% of the comparative example, and the number of roller windings in each embodiment is 0. It can be seen that the carbon fiber preoxidation device of the present invention can effectively eliminate the static electricity generated by the fiber, and at the same time, the influence of static electricity on the fiber performance is well reduced.

[0058] In another set of comparative examples and embodiments (1 comparative example and 6 embodiments), the carbon fiber preoxidation device and method are the same as in embodiment 1, and the above-mentioned embodiments 2 to 5 are adjusted. However, the difference is that the carbon fiber (12K) with the same K number as in embodiment 1 is set, and the speed parameters of different devices, that is, the static eliminator voltage U and the operating speed V are different, as shown in Table 3.

[0059] Table 3

[0060]

[0061] From the operation results of various embodiments and comparative examples, the deviation rate C1 of the monofilament width of the preoxidized yarn ranges from 1.3% to 2.0%, and the carbon fiber strength discrete rate C2 ranges from 0.5% to 1.3%, which are also much lower than the C1 value of 30% and the C2 value of 15% of the comparative example. At the same time, the number of roller windings in each embodiment is 0. It can be seen that as the operating speed increases, by increasing the voltage of the static eliminator, the carbon fiber preoxidation device of the present invention can still stably and effectively eliminate the static electricity generated by the fiber.

[0062] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0063] The above are only embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included within the scope of the claims of the present application.

Claims

1. A carbon fiber pre-oxidation device, characterized in that: The carbon fiber pre-oxidation device comprises: An oxidation furnace, used for pre-oxidizing the pre-oxidized fibers of the carbon fiber; a traction machine, located at the entrance of the oxidation furnace, for pulling the pre-oxidized wire into the oxidation furnace; and A static elimination device, used for generating an ionized airflow and blowing the ionized airflow toward the surface of the pre-oxidized yarn; The static eliminator includes a first static eliminator and a second static eliminator. The first static eliminator is located at the outlet of the traction machine, and the second static eliminator is located at the outlet of the oxidation furnace.

2. The carbon fiber pre-oxidation device according to claim 1, characterized in that: The first static eliminator and the second static eliminator are arranged in the width direction of the wire surface of the pre-oxidized wire, the wire surface width of the pre-oxidized wire is smaller than the roller length in the oxidation furnace, and the wire surface width of the pre-oxidized wire is smaller than the length of the first static eliminator.

3. The carbon fiber pre-oxidation device according to claim 2, characterized in that: The width of the pre-oxidized yarn is 1.5 to 3.5 m, the length of the roller in the oxidation furnace is 1.7 to 3.6 m, and the length of the first static eliminator and the second static eliminator is 1.7 to 3.6 m.

4. The carbon fiber pre-oxidation device according to claim 1, characterized in that: The first static eliminator and the second static eliminator are located above the surface of the pre-oxidized yarn, wherein the distance between the first static eliminator and the second static eliminator and the surface of the pre-oxidized yarn is 50 to 2000 mm.

5. The carbon fiber pre-oxidation device according to claim 1, characterized in that: The first static eliminator and the second static eliminator include: a nozzle vertically aligned with the yarn surface of the pre-oxidized yarn; and a compressed air interface.

6. The carbon fiber pre-oxidation device according to claim 5, characterized in that: A plurality of electrode needles are arranged in the nozzle.

7. The carbon fiber pre-oxidation device according to claim 6, characterized in that: The plurality of electrode needles include three electrode needles, and the three electrode needles are arranged in a triangle in the nozzle.

8. The carbon fiber pre-oxidation device according to claim 6 or 7, characterized in that: The electrode needle is made of tungsten; and / or The first static eliminator and the second static eliminator further include a shell, the shell is made of polycarbonate plastic, and the surface of the shell is coated with polytetrafluoroethylene coating.

9. The carbon fiber pre-oxidation device according to claim 1, characterized in that: The operating voltage of the first static eliminator and the second static eliminator is 24-36V.

10. A carbon fiber preoxidation method, characterized in that: The carbon fiber pre-oxidation method comprises: Pre-oxidizing the pre-oxidized fibers of the carbon fiber by an oxidation furnace; Pulling the pre-oxidized wire into the oxidation furnace by a traction machine, wherein the traction machine is located at the entrance of the oxidation furnace; and An ionized airflow is generated by a static eliminator, and the ionized airflow is blown toward the surface of the pre-oxidized yarn; The static eliminator includes a first static eliminator and a second static eliminator. The first static eliminator is located at the outlet of the traction machine, and the second static eliminator is located at the outlet of the oxidation furnace.

Images