A preparation system of high-temperature-resistant fiber and application thereof

Abstract

The application discloses a kind of preparation system of high-temperature-resistant fiber and application thereof, step one: the fiber base material after uncoiling is cleaned, and is dried after being washed with deionized water sufficiently;Step two: the fiber base material after step one is placed in drying cabinet, and first time beating treatment is carried out to fiber base material using airflow;Step three: the surface of fiber base material after once beating is sprayed with treatment liquid, then is sent into drying cabinet, and secondary beating treatment is carried out to fiber base material using airflow;Step four: the fiber base material after drying is assembled to silk separator fixed support, and is sent into sputtering reaction cavity;Step five: the fiber base material after sputtering treatment is treated with oil, and then is dried, shaped, to obtain high-temperature-resistant carbon fiber finished product.The application has the advantages compared with prior art: the application adopts multistage impurity removal process.Firstly, through propane flame short-time burning, oil stain, dust, organic impurities and surface weakly combined defect layer attached to the surface of fiber base material are quickly removed.

Description

Technical Field

[0001] This invention relates to the field of carbon fiber preparation, specifically a system for preparing high-temperature resistant fibers and its application. Background Technology

[0002] With the rapid development of aerospace, defense industry, and high-temperature engineering, the demand for high-performance, high-temperature resistant materials is increasing. Carbon fiber, due to its excellent mechanical properties, low density, and high modulus, has become an important reinforcing material for advanced composite materials. However, carbon fiber is prone to oxidation and thermal decomposition at high temperatures, limiting its application under extreme conditions. To address this issue, surface coating treatments of carbon fiber to improve its high-temperature resistance and oxidation resistance have become a research hotspot in materials science.

[0003] Silicon carbide, as an important ceramic material, possesses high hardness, high wear resistance, high thermal conductivity, and excellent oxidation resistance, and is widely used in high-temperature structural and functional materials. Using silicon carbide as a coating material, by forming a dense SiC coating on the surface of carbon fibers, can effectively isolate oxygen and moisture, preventing oxidation and thermal decomposition of the carbon fibers under high-temperature environments, thereby significantly improving the high-temperature resistance and service life of the carbon fibers.

[0004] Currently, the main technologies for coating SiC on carbon fiber surfaces include embedding, chemical vapor deposition (CVD), sputtering, and solution impregnation. Each of these methods has its own advantages and disadvantages regarding coating uniformity, density, and bonding strength. For example, CVD can achieve high-density and uniform SiC coatings, but the process is complex, costly, and requires demanding equipment; sputtering has a high deposition rate, but the coating uniformity and oxidation resistance are poor; solution impregnation and embedding methods suffer from poor coating uniformity and density, making it difficult to meet the stringent requirements of high-temperature environments. Summary of the Invention

[0005] The technical problem to be solved by this invention is to overcome the above-mentioned technical defects.

[0006] To solve the above problems, the technical solution of the present invention is: a high-temperature resistant fiber preparation system and its application, comprising the following steps; Step 1: Clean the unwound fiber substrate to remove impurities, rinse thoroughly with deionized water, and then dry it, controlling the moisture content of the fiber substrate to be 15wt%~18wt%; The unwound fiber substrate is clamped and fixed, then ignited with a propane flame for 30 seconds. After natural cooling, it is placed in a cleaning solution and immersed in a cleaning solution at 50-60℃ for 25-35 minutes. After removal, it is repeatedly rinsed with deionized water and dried until the moisture content of the fiber substrate is 15wt%-18wt%. Step 2: Place the fiber substrate treated in Step 1 into a drying oven, adjust the carbon monoxide concentration inside the drying oven to 16%-20%, and use airflow to perform the first beating treatment on the fiber substrate for 10-15 minutes, with a beating airflow force of 30-40 Pa / m. Step 3: Spray the treatment liquid onto the surface of the fiber substrate after the first beating, and then put it into the drying oven. Control the carbon monoxide mass concentration in the drying oven to 8%-12%. Use airflow to beat the fiber substrate a second time for 10-15 minutes, and the force of the beating airflow is 18-25 Pa / m. The treatment solution uses ethanol as a solvent, and the mass fractions of each component in the system are: tert-butyl glycidyl ether 3%-5%, triethoxyvinyl silane 2%-3%, and fatty alcohol polyoxyethylene ether 1.2%-1.5%. Step 4: Assemble the dried fiber substrate onto the fiber splitter fixing bracket and send it into the sputtering reaction chamber; first, evacuate the reaction chamber to a base vacuum, then introduce high-purity inert gas as the sputtering process gas, and use SiC or SiO2 target material for magnetron sputtering to deposit a high-temperature protective coating on the surface of the fiber substrate. The sputtering process parameters are as follows: SiC target sputtering: sputtering power 100-500W, sputtering time 10-30min; SiO2 target sputtering: sputtering power 60-120W, sputtering time 10-30min; The sputtering pressure was 0.5-5 Pa, and the process gas flow rate was 5-30 mL / min; the resulting protective coating thickness was 150 nm. Step 5: Apply oil to the sputtered fiber substrate, then dry and shape it to obtain the high-temperature resistant carbon fiber product.

[0007] Further: In step one, the cleaning solution is a neutral aqueous cleaning solution, and the immersion cleaning process involves continuous low-speed stirring.

[0008] Further: In step three, the preparation method of the treatment solution is as follows: under normal temperature and pressure, tert-butyl glycidyl ether, triethoxyvinyl silane, and fatty alcohol polyoxyethylene ether are added sequentially to ethanol solvent, and stirred at a constant speed for 20-30 minutes at a stirring speed of 60-80 r / min until all components are completely dissolved and the system is uniform and transparent.

[0009] Further: In step two, the drying chamber is a sealed inert protective drying chamber, and the temperature inside the chamber is maintained at 40-50℃. Carbon monoxide gas is mixed with nitrogen gas to form a protective atmosphere. After the gas is evenly mixed, the airflow beat-up treatment is carried out.

[0010] Further: In step three, the treatment liquid is sprayed using a high-pressure atomization spraying method with a spraying pressure of 0.2-0.4MPa and a spraying volume of 8-12mL / ㎡ to ensure that the surface of the fiber substrate is uniformly covered with liquid without any accumulation or missed spraying.

[0011] The advantages of this invention compared to existing technologies are: This invention employs a multi-stage impurity removal process consisting of "propane flame calcination + constant-temperature stirring chemical cleaning + precise humidity control drying". First, short-time propane flame calcination rapidly removes oil, dust, organic impurities, and weak bonding defects from the fiber substrate surface. Then, low-speed stirring and immersion in a medium-temperature neutral aqueous cleaning solution thoroughly removes residual impurities from substrate crevices, avoiding corrosive damage to the fiber body caused by strong alkali or acid cleaning. Finally, the substrate moisture content is precisely controlled within the range of 15wt% to 18wt%. This moisture content allows for the formation of a moderately active capillary structure on the fiber surface, preventing uneven adhesion of the subsequent modification solution and bubbling during drying due to excessive moisture content, while also preventing insufficient fiber surface activity and weak coating adhesion due to excessively low moisture content. This effectively improves the uniformity and stability of subsequent modification treatments and sputtered coating adhesion. Attached Figure Description

[0012] Figure 1 This is a flowchart of a high-temperature resistant fiber preparation system and its application according to the present invention. Detailed Implementation

[0013] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings. Identical components are indicated by the same reference numerals.

[0014] It should be noted that the terms “front,” “back,” “left,” “right,” “up,” and “down” used in the following description refer to the directions shown in the attached diagram, while the terms “inside” and “outside” refer to the directions toward or away from the geometric center of a specific component, respectively.

[0015] To make the content of this invention easier to understand, the technical solutions in the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings.

[0016] like Figure 1As shown, a system for preparing high-temperature resistant fibers and its application are described. Conventional carbon fiber is selected as the fiber substrate. The unwound fiber substrate is clamped and fixed, and then uniformly ignited with a propane flame for 30 seconds to remove surface oil, dust, and impurities. After ignition, the substrate is allowed to cool naturally to room temperature. The cooled fiber substrate is then immersed in a neutral aqueous cleaning solution at a cleaning temperature of 55°C, with continuous low-speed stirring and immersion cleaning for 30 minutes. After immersion, the fiber substrate is removed and repeatedly rinsed with deionized water to thoroughly remove any residual cleaning solution. The rinsed fiber substrate is then sent to a drying equipment for drying, with precise control of drying parameters to ensure a final moisture content of 16.5 wt%, ready for use.

[0017] The fiber substrate pretreated in step one was placed in a sealed, inert protective drying oven. A protective atmosphere was prepared beforehand, consisting of a mixture of carbon monoxide and nitrogen. The carbon monoxide concentration inside the oven was controlled to 18%, and the temperature was maintained at a constant 45°C. After the gases were uniformly mixed, the airflow beater was activated to perform the first beating treatment on the fiber substrate. The beating airflow force was set to 35 Pa / m, and the beating treatment was performed continuously for 12 minutes to complete the surface loosening and activation treatment of the fiber substrate.

[0018] Prepare the special treatment solution in advance: Under normal temperature and pressure, using anhydrous ethanol as solvent, add 4% by mass of tert-butyl glycidyl ether, 2.5% by mass of triethoxyvinyl silane, and 1.35% by mass of fatty alcohol polyoxyethylene ether in sequence. Set the stirring speed to 70 r / min and stir at a uniform speed for 25 min until all components are completely dissolved and the system is in a uniform and transparent state, thus obtaining a homogeneous treatment solution.

[0019] The fiber substrate was sprayed using a high-pressure atomization method after one beating, with the spraying pressure controlled at 0.3 MPa and the spraying volume at 10 mL / m², ensuring complete coverage of the fiber substrate surface without any missed areas or liquid accumulation. Immediately after spraying, the fiber substrate was placed in the original sealed drying oven, with the carbon monoxide concentration inside the oven controlled at 10% and the temperature maintained at a constant 45°C. The airflow beating parameters were adjusted, and the substrate was continuously beating with an airflow force of 22 Pa / m for 12 minutes to complete the fiber surface modification and adhesion treatment.

[0020] The modified fiber substrate, after secondary beating, was removed and assembled onto the fiber splitter's fixing bracket, then smoothly fed into the magnetron sputtering reaction chamber. The reaction chamber was closed and evacuated to a baseline vacuum. High-purity argon gas was then introduced as the sputtering process gas, with a flow rate controlled at 18 mL / min and a sputtering pressure maintained at 2.5 Pa. In this embodiment, a SiC target was used for magnetron sputtering, with a sputtering power of 300 W and a continuous sputtering time of 20 min, ultimately depositing a uniform 150 nm thick SiC high-temperature protective coating on the fiber substrate surface.

[0021] The fiber substrate with sputtered coating is subjected to conventional oiling treatment to eliminate static electricity on the fiber surface and improve fiber bundle properties. It is then sent to a setting and drying equipment for gradient heating drying and constant temperature setting. After cooling to room temperature, the finished high-temperature resistant carbon fiber is obtained.

[0022] For the pretreatment of substrate cleaning and impurity removal, the unwound fiber substrate is clamped and fixed, ignited with a propane flame for 30 seconds, and then naturally cooled to room temperature. It is then immersed in a neutral aqueous cleaning solution and cleaned for 35 minutes at a constant temperature of 50°C with low-speed stirring. After removal, it is thoroughly rinsed with deionized water, dried, and the moisture content of the fiber substrate is adjusted to 15 wt% for later use.

[0023] The first airflow beating modification treatment involves placing the pretreated fiber substrate in a sealed inert protective drying oven with a constant temperature of 40°C. A mixed protective atmosphere is prepared, and the carbon monoxide mass concentration is controlled at 16%. After the gas is mixed evenly, it is beaten with an airflow force of 30 Pa / m for 15 minutes to complete the first activation treatment.

[0024] Surface spraying treatment solution and secondary beating modification: The treatment solution was prepared by adding 3% tert-butyl glycidyl ether, 2% triethoxyvinyl silane, and 1.2% fatty alcohol polyoxyethylene ether to an ethanol solvent at room temperature and pressure, and stirring at 60 r / min for 30 min until the system was uniform and transparent. High-pressure atomization spraying at 0.2 MPa was used, with a spraying rate of 8 mL / m², ensuring uniform coating of the fiber surface. After spraying, the fiber was placed in a drying oven, with the carbon monoxide concentration controlled at 8% and the temperature maintained at 40℃. The fiber was then beaten with an airflow force of 18 Pa / m for 15 min.

[0025] A high-temperature protective coating was deposited by magnetron sputtering. The modified fiber substrate was fixed to a fiber splitter support and fed into the sputtering reaction chamber. After evacuation to a base vacuum, high-purity argon gas was introduced at a flow rate of 5 mL / min and a sputtering pressure of 0.5 Pa. A SiO2 target was used for magnetron sputtering, with a sputtering power of 60 W and a sputtering time of 30 min, resulting in a 150 nm thick SiO2 high-temperature protective coating.

[0026] Post-processing involves standardized oiling, drying, and shaping of the sputtered fiber substrate, followed by cooling to obtain the high-temperature resistant carbon fiber finished product.

[0027] The present invention and its embodiments have been described above. This description is not restrictive, and the accompanying drawings are only one embodiment of the present invention; the actual structure is not limited thereto. In conclusion, if those skilled in the art are inspired by this description and design similar structures and embodiments without departing from the spirit of the invention, such designs should fall within the protection scope of the present invention.

Claims

1. A system for preparing high-temperature resistant fibers and its application, characterized in that: Includes the following steps; Step 1: Clean the unwound fiber substrate to remove impurities, rinse thoroughly with deionized water, and then dry it, controlling the moisture content of the fiber substrate to be 15wt%~18wt%; The unwound fiber substrate is clamped and fixed, then ignited with a propane flame for 30 seconds. After natural cooling, it is placed in a cleaning solution and immersed in a cleaning solution at 50-60℃ for 25-35 minutes. After removal, it is repeatedly rinsed with deionized water and dried until the moisture content of the fiber substrate is 15wt%-18wt%. Step 2: Place the fiber substrate treated in Step 1 into a drying oven, adjust the carbon monoxide concentration inside the drying oven to 16%-20%, and use airflow to perform the first beating treatment on the fiber substrate for 10-15 minutes, with a beating airflow force of 30-40 Pa / m. Step 3: Spray the treatment liquid onto the surface of the fiber substrate after the first beating, and then put it into the drying oven. Control the carbon monoxide mass concentration in the drying oven to 8%-12%. Use airflow to beat the fiber substrate a second time for 10-15 minutes, and the force of the beating airflow is 18-25 Pa / m. The treatment solution uses ethanol as a solvent, and the mass fractions of each component in the system are: tert-butyl glycidyl ether 3%-5%, triethoxyvinyl silane 2%-3%, and fatty alcohol polyoxyethylene ether 1.2%-1.5%. Step 4: Assemble the dried fiber substrate onto the fiber splitter fixing bracket and send it into the sputtering reaction chamber; first, evacuate the reaction chamber to a base vacuum, then introduce high-purity inert gas as the sputtering process gas, and use SiC or SiO2 target material for magnetron sputtering to deposit a high-temperature protective coating on the surface of the fiber substrate. The sputtering process parameters are as follows: SiC target sputtering: sputtering power 100-500W, sputtering time 10-30min; SiO2 target sputtering: sputtering power 60-120W, sputtering time 10-30min; The sputtering pressure was 0.5-5 Pa, and the process gas flow rate was 5-30 mL / min; the resulting protective coating thickness was 150 nm. Step 5: Apply oil to the sputtered fiber substrate, then dry and shape it to obtain the high-temperature resistant carbon fiber product.

2. The high-temperature resistant fiber preparation system and its application according to claim 1, characterized in that: In step one, the cleaning solution is a neutral aqueous cleaning solution, and the immersion cleaning process involves continuous low-speed stirring.

3. The high-temperature resistant fiber preparation system and its application according to claim 1, characterized in that: In step three, the preparation method of the treatment solution is as follows: at room temperature and pressure, tert-butyl glycidyl ether, triethoxyvinyl silane, and fatty alcohol polyoxyethylene ether are added sequentially to ethanol solvent, and stirred at a constant speed for 20-30 minutes at a stirring speed of 60-80 r / min until all components are completely dissolved and the system is uniform and transparent.

4. The high-temperature resistant fiber preparation system and its application according to claim 1, characterized in that: In step two, the drying chamber is a sealed inert protective drying chamber, and the temperature inside the chamber is maintained at 40-50℃. Carbon monoxide gas is mixed with nitrogen gas to form a protective atmosphere. After the gas is evenly mixed, the airflow beat-up treatment is carried out.

5. The high-temperature resistant fiber preparation system and its application according to claim 1, characterized in that: In step three, the treatment liquid is sprayed using a high-pressure atomization spraying method with a spraying pressure of 0.2-0.4MPa and a spraying volume of 8-12mL / ㎡ to ensure that the surface of the fiber substrate is uniformly covered with liquid without any accumulation or missed spraying.

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