Ultraviolet crosslinking device for polycarbosilane fibers

Abstract

The utility model discloses an ultraviolet cross-linking device of polycarbosilane fiber, including air intake system, ultraviolet cross-linking and heat treatment system and control system, air intake system includes air intake chamber, air intake chamber is communicated with a plurality of air intake channels, air intake chamber is provided with a plurality of groups of first automatic heater, ultraviolet cross-linking and heat treatment system includes airtight processing chamber, and the airtight processing chamber is provided with a plurality of groups of second automatic heater. An air outlet channel is communicated between the air inlet chamber and the closed treatment chamber, the closed treatment chamber comprises a first cavity and a second cavity, a treatment platform for placing polycarbosilane fiber bundles is arranged in the first cavity, a plurality of groups of second automatic heaters are arranged in the first cavity, and a plurality of ultraviolet lamps are further arranged in the closed treatment chamber. According to the ultraviolet cross-linking device for the polycarbosilane fibers, ultraviolet radiation cross-linking is combined with thermal cross-linking, the cross-linking time is shortened, the cross-linking efficiency is improved, and the polycarbosilane fibers treated by the ultraviolet cross-linking device have good thermal stability, mechanical performance and chemical stability.

Description

Technical Field

[0001] This utility model relates to the field of fiber crosslinking technology, specifically to an ultraviolet crosslinking device for polycarbosilane fibers. Background Technology

[0002] Polycarbosilanes, as an important class of polymeric compounds, occupy a core position in the preparation of high-performance ceramic materials, especially silicon carbide (SiC) fibers. In traditional processes, polycarbosilanes are transformed into high-performance SiC fibers through steps such as melt spinning, non-melting treatment, pyrolysis, and final sintering. Among these, the non-melting treatment is a key step to ensure that the fibers maintain their morphology during the subsequent high-temperature pyrolysis process.

[0003] Currently, the non-melting treatment of polycarbosilane fibers mainly employs methods such as thermal oxidation, electron beam irradiation crosslinking, and chemical vapor deposition, among which:

[0004] 1. Thermal oxidation is a commonly used non-melting treatment method, but it introduces a large amount of oxygen, which is detrimental to the high-temperature performance of the final ceramic fibers. For example, existing silicon carbide fibers, due to the use of air non-melting treatment, introduce a certain amount (10) oxygen into the fibers. wt %~20 wt The presence of oxygen (%) severely affects the high-temperature mechanical properties of the fiber;

[0005] 2. Electron beam irradiation or gamma ray irradiation in an inert atmosphere can achieve non-melting and produce ceramic fibers with low oxygen content. However, this method requires huge initial investment in equipment and high dosage for non-melting treatment, leading to increased costs. At the same time, conventional irradiation processing is difficult, further increasing the manufacturing cost of fibers and reducing the production efficiency of polycarbosilane fibers.

[0006] 3. Chemical vapor phase non-melting methods, such as the oxygen-free non-melting method for polycarbosilane fibers, have advantages such as avoiding the introduction of oxygen, achieving non-melting of polycarbosilane fibers at lower temperatures, uniform active atmosphere flow field, and uniform heating of fibers at different positions through axial heating. However, they have high requirements for reaction conditions. On the one hand, the process is relatively complex, involving the use and control of chemical gases, which increases the difficulty and complexity of the process. On the other hand, the emission of chemical gases may have adverse effects on the environment, resulting in poor environmental protection. In addition, in the non-melting treatment of polycarbosilane and other fibers, the unsaturated hydrocarbon vapors used in chemical vapor phase crosslinking are toxic and harmful, and the process takes a long time, which is not conducive to large-scale production and application. Utility Model Content

[0007] The purpose of this invention is to provide an ultraviolet crosslinking device for polycarbosilane fibers. By combining ultraviolet radiation crosslinking with thermal crosslinking, the crosslinking time is reduced and the crosslinking efficiency is improved. Furthermore, the polycarbosilane fibers treated by this invention have better thermal stability, mechanical properties, and chemical stability, and can meet more demanding usage conditions.

[0008] To achieve the above objectives, the solution of this utility model is:

[0009] A UV crosslinking device for polysilane fibers includes an air intake system, a UV crosslinking and heat treatment system, and a control system. The air intake system includes an air intake chamber with several air intake channels. Several sets of first automatic heaters are installed within the air intake chamber. The UV crosslinking and heat treatment system includes a sealed treatment chamber. An air outlet channel connects the air intake chamber and the sealed treatment chamber. The sealed treatment chamber includes a first cavity and a second cavity that are isolated from each other and arranged side-by-side, separated by a heat insulation plate. A processing platform for placing polysilane fiber bundles is installed within the first cavity. The processing platform is equipped with a rotating bracket for supporting the polysilane fiber bundles and a first driving mechanism for driving the polysilane fiber bundles to rotate. Several sets of second automatic heaters are arranged around the processing platform on the inner wall of the first cavity. Several UV lamps are installed within the sealed treatment chamber, and several sets of heaters for supplying each UV lamp are also installed within the sealed treatment chamber. A second drive mechanism moves the external lamp between the first cavity and the second cavity. Each second drive mechanism is located above the processing platform. The heat insulation plate is provided with several through holes for the ultraviolet lamp to pass through and for gas to flow. Each ultraviolet lamp has a heat insulation plug at both ends for sealing each through hole. The sealed processing chamber is provided with multiple gas outlets connected to the vacuum processing system at positions corresponding to the first cavity and the second cavity. The sealed processing chamber is provided with a three-way exhaust valve at the position corresponding to the first cavity. One exhaust port of the three-way exhaust valve is connected to the outside, and the other exhaust port of the three-way exhaust valve is connected to the second cavity. The sealed processing chamber is provided with a two-way exhaust valve at the position corresponding to the second cavity, which is connected to the outside. The sealed processing chamber is covered with an ultraviolet shielding layer. The control system is connected to the first drive mechanism, the second drive mechanism, the first automatic heater, the second automatic heater, the ultraviolet lamp, the vacuum processing system, the three-way exhaust valve, and the two-way exhaust valve.

[0010] Temperature sensors connected to the control system are respectively installed in the air inlet chamber and the first cavity, and the vacuum processing system is a vacuum pump.

[0011] Each of the aforementioned air intake channels is equipped with a flow valve, and the flow valve is connected to the control system.

[0012] The sealed processing chamber is provided with a material outlet at one end corresponding to the first cavity. A sealing valve cover is provided in the sealed processing chamber at the position corresponding to the material outlet. The inner surface of the sealing valve cover is fixedly connected to the processing platform. A sliding frame is provided on the outer surface of the sealing valve cover. The sealed processing chamber is fixed on the fixed frame, and the sliding frame is slidably connected to the fixed frame. A slide rail is also provided in the first cavity to slide and cooperate with the processing platform.

[0013] Each of the second drive mechanisms includes a lead screw motor and a lead screw nut that cooperates with the lead screw of the lead screw motor. The bottom of each ultraviolet lamp is provided with a fixed base that is fixedly connected to the corresponding lead screw nut. Each lead screw motor is located at one end of the sealed treatment chamber corresponding to the second cavity. One end of the lead screw of each lead screw motor passes through the space between the first cavity and the second cavity and extends towards the end of the sealed treatment chamber corresponding to the first cavity. The heat insulation plugs at both ends of the ultraviolet lamp are located on both sides of the heat insulation plate.

[0014] The sliding frame is provided with a third driving mechanism for driving the sliding frame to slide, and the third driving mechanism is controlled and connected to the control system.

[0015] With the above structure, the ultraviolet crosslinking device for polycarbosilane fibers of this invention has the following advantages:

[0016] 1. A rotating support is installed on the processing platform. The rotation of the support enables all-round ultraviolet radiation to the polycarbonate silane fibers, ensuring that each fiber achieves a uniform cross-linking effect and improving product quality. The air intake system, vacuum exhaust system, three-way exhaust valve and two-way exhaust valve realize the circulation of protective gas, remove oxygen, reduce oxidation reaction and optimize the cross-linking environment. By controlling the second automatic heater, the temperature of the cross-linking area is precisely controlled and kept within the optimal cross-linking temperature range of the fiber, which promotes the cross-linking reaction and avoids fiber damage.

[0017] 2. First, a high-efficiency and stable ultraviolet lamp is used, which can emit ultraviolet light of a specific wavelength to effectively stimulate the active groups on the surface of polysilane fiber and promote the cross-linking reaction. Then, thermal cross-linking treatment is carried out in an oxygen-free environment, and the heating rate and holding time are precisely controlled. Finally, post-treatment is carried out in an inert atmosphere to reduce the oxygen content and consolidate the cross-linking structure.

[0018] 3. Ultraviolet crosslinking mainly forms a crosslinking layer on the surface of polysilane filaments, while thermal crosslinking further consolidates and improves the crosslinking structure from the inside. The combination of the two can make polysilane filaments form a more uniform and dense three-dimensional network structure, effectively improving the overall stability and performance of the fiber.

[0019] 4. Polycarbosilane fibers treated with joint crosslinking have good thermal stability, mechanical properties and chemical stability. Under high temperature environment, they can maintain good shape and structural integrity, withstand higher tensile stress, and have greatly improved resistance to chemical reagents, which can meet more demanding use conditions.

[0020] 5. No chemical crosslinking agent is required, thus avoiding the environmental pollution and impact on material properties that chemical crosslinking agents may cause;

[0021] 6. Since ultraviolet lamps cannot withstand high temperatures, when thermal cross-linking of polysilane fiber bundles is required, each ultraviolet lamp needs to be moved into the second cavity 33 by the second drive mechanism to avoid damage to the ultraviolet lamps due to high temperature heating.

[0022] Furthermore, the sliding frame is equipped with a third drive mechanism to drive the sliding frame to slide, realizing automated assisted feeding and unloading, which saves more effort, improves production efficiency, and reduces the difficulty of operation. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the structure of a UV crosslinking device for polycarbosilane fibers according to the present invention;

[0024] Figure 2 This is a top view of the air intake system and the ultraviolet cross-linking and heat treatment system in this utility model;

[0025] Figure 3 This is a side view of the ultraviolet crosslinking and heat treatment system in this utility model;

[0026] Figure 4 The image shows an electron microscope image of silicon carbide fibers obtained by post-processing the polycarbosilane fibers in Example 2.

[0027] Figure 5 The image shows an electron microscope image of silicon carbide fibers obtained by post-processing the polycarbosilane fibers in Example 3.

[0028] In the picture:

[0029] Air intake chamber 1; Air intake passage 11;

[0030] Flow valve 12; First automatic heater 2;

[0031] Sealed processing chamber 3; First cavity 31;

[0032] Second automatic heater 311; slide rail 312;

[0033] Second cavity 32; sealing valve cover 33;

[0034] UV lamp 34; heat insulation plug 341;

[0035] Three-way exhaust valve 35; Two-way exhaust valve 36;

[0036] Processing platform 4; Rotating support 41;

[0037] Rotating shaft 411; crossbar 412;

[0038] First drive mechanism 42; lead screw motor 51;

[0039] Lead screw 511; Lead screw nut 52;

[0040] Sliding frame 6; pulley 61;

[0041] Third drive mechanism 62; Fixing frame 7;

[0042] Guide rail 71; Air outlet channel 8;

[0043] Vacuum processing system 9; Control system 10;

[0044] Roller 1a. Detailed Implementation

[0045] To further explain the technical solution of this utility model, the following detailed description is provided through specific embodiments.

[0046] Example 1

[0047] A UV crosslinking device for polycarbonyl silane fibers, such as Figures 1-3 As shown, it includes an air intake system, an ultraviolet cross-linking and heat treatment system, and a control system. The air intake system includes an air intake chamber 1, which is connected to several air intake channels 11 for introducing protective gas. Each air intake channel 11 is equipped with a flow valve 12.

[0048] The intake chamber 1 is equipped with several sets of first automatic heaters 2. Each set of first automatic heaters 2 is arranged axially around the inner wall of the intake chamber 1. The first automatic heater 2 is a heating rod or a heating tube.

[0049] The ultraviolet crosslinking and heat treatment system includes a sealed treatment chamber 3, which includes a first cavity 31 and a second cavity 32 that are isolated from each other. The first cavity 31 and the second cavity 32 are arranged side by side and separated by a heat insulation plate. The heat insulation plate is made of a known heat insulation material, such as a board wrapped with heat insulation cotton with aluminum foil.

[0050] The sealed processing chamber 3 is provided with a material outlet at one end corresponding to the first cavity 31. A sealing valve cover 33 is provided at the position of the material outlet in the sealed processing chamber 3. A processing platform 4 for placing polycarbosilane fiber bundles is provided inside the first cavity 31. A rotating bracket 41 for supporting the polycarbosilane fiber bundles and a first driving mechanism 42 for driving the polycarbosilane fiber bundles to rotate are provided on the processing platform 4. The inner surface of the sealing valve cover 33 is fixedly connected to one end of the processing platform 4. Polycarbosilane fiber bundles are typically wound around roller 1a. The rotating support 41 includes a rotating shaft 411 passing through the center of roller 1a. The rotating support 41 also includes several crossbars 412 mounted on the processing platform 4. The rotating shaft 411 and the crossbars 412 are on the same horizontal plane. These crossbars 412 also pass through roller 1a. The output end of the first drive mechanism 42 is connected to the rotating shaft 411. The first drive mechanism 42 is a drive mechanism known in the art. If a drive motor is used, the first drive mechanism 42 drives the rotating shaft 411 to rotate, thereby causing roller 1a to rotate around the rotating shaft 411.

[0051] Several sets of second automatic heaters 311, which are heating rods or heating tubes, are arranged around the processing platform 4 on the inner wall of the first cavity 31. Several ultraviolet lamps 34 are also arranged above the processing platform 4 in the sealed processing chamber 3. Several sets of second driving mechanisms are also arranged in the sealed processing chamber 3 to move each ultraviolet lamp 34 between the first cavity 31 and the second cavity 32. The second driving mechanisms are located above the processing platform 4, so that when the ultraviolet lamps 34 slide into the first cavity 31, they are positioned above the processing platform 4 to perform ultraviolet crosslinking treatment on the polycarbosilane fiber bundles. Since the ultraviolet lamps 34 cannot withstand high temperatures, when thermal crosslinking of the polycarbosilane fiber bundles is required, the second driving mechanisms need to move each ultraviolet lamp 34 into the second cavity 33 to avoid damage to the ultraviolet lamps 34 due to high-temperature heating.

[0052] The heat insulation plate is provided with several through holes for the ultraviolet lamps 34 to pass through and for gas to flow, so that the ultraviolet lamps 34 can move back and forth between the first cavity 31 and the second cavity 32. Preferably, there are two ultraviolet lamps 34, which are symmetrically arranged on both sides above the processing platform 4. Correspondingly, there are also two second drive mechanisms and two through holes.

[0053] Each ultraviolet lamp 34 has a heat-insulating plug 341 at both ends for sealing each through hole, located on both sides of the heat insulation plate. One heat-insulating plug 341 is always located inside the first cavity 31, and the other heat-insulating plug 341 is always located inside the second cavity 32. When each ultraviolet lamp 34 is completely inside the second cavity 32, the heat-insulating plug 341 of the ultraviolet lamp 34 in the first cavity 31 is engaged in the through hole, preventing hot air from entering the second cavity 32. Preferably, when each ultraviolet lamp 34 is completely inside the first cavity 31, the heat-insulating plug 341 of the ultraviolet lamp 34 in the second cavity 32 is engaged in the through hole. Preferably, when each ultraviolet lamp 34 is completely inside the second cavity 32, it is positioned directly above the processing platform 4.

[0054] The second drive mechanism is a drive mechanism known in the art. For example, each second drive mechanism includes a lead screw motor 51 and a lead screw nut 52 that cooperates with the lead screw 511 of the lead screw motor 51. The bottom of each ultraviolet lamp 34 is fixedly connected to the corresponding lead screw nut 52, or it can be fixedly connected to the lead screw nut 52 through a fixing seat. Each lead screw motor 51 is located outside one end of the sealed processing chamber 3 corresponding to the second cavity 32. One end of the lead screw 511 of each lead screw motor 51 passes between the first cavity 31 and the second cavity 32 and extends towards the end of the sealed processing chamber 3 corresponding to the first cavity 31. By rotating the lead screw 511 of the lead screw motor 51, the lead screw nut 52 is driven to move on the lead screw 51, thereby realizing the horizontal movement of each ultraviolet lamp 34.

[0055] A three-way exhaust valve 35 is installed in the sealed processing chamber 3 at the position corresponding to the first cavity 31. One exhaust port of the three-way exhaust valve 35 is connected to the outside, and the other exhaust port of the three-way exhaust valve 35 is connected to the second cavity 32. A two-way exhaust valve 36 is installed in the sealed processing chamber 3 at the position corresponding to the second cavity 32, which is connected to the outside. This arrangement ensures that the atmosphere and air pressure in the first cavity 31 and the second cavity 32 are kept consistent, thus ensuring the normal operation of the second drive mechanism.

[0056] A sliding frame 6 is provided on the outer surface of the sealing valve cover 33. The sealed processing chamber 3 is fixed on a fixed frame 7. Pulleys 61 are symmetrically arranged on both sides of the lower end of the sliding frame 6. Guide rails 71 are provided on both sides of the fixed frame 7 to slide and cooperate with each pulley 61, so that the sliding frame 6 and the fixed frame 7 are slidably connected. A slide rail 312 that slides and cooperates with the processing platform 4 is also provided in the first cavity 31. A third drive mechanism 62 for driving the sliding frame 6 to slide is symmetrically arranged on the sliding frame 6. The third drive mechanism 62 is a drive mechanism known in the art. For example, a stepper motor is used. The output shaft of the third drive mechanism 62 is connected to the corresponding pulley 61 for transmission. This arrangement allows the processing platform 4 to slide automatically relative to the sealed processing chamber 3, making feeding and discharging more convenient and labor-saving.

[0057] The sealed processing chamber 3 is covered with an ultraviolet shielding layer, which is a known coating in the art that can block ultraviolet rays, such as a coating formed by applying KINGCELA rare earth ultraviolet shielding agent.

[0058] An exhaust channel 8 connects the inlet chamber 1 and the sealed processing chamber 3, allowing protective gas to enter the sealed processing chamber 3. The sealed processing chamber 3 has multiple gas outlets connected to the vacuum processing system 9 at positions corresponding to the first cavity 31 and the second cavity 32. Specifically, there are two gas outlets at each of the first cavity 31 and the second cavity 32. The vacuum processing system 9 is a vacuum pump.

[0059] Preferably, the sealed processing chamber 3 is provided with an inspection port at the position corresponding to the second cavity 32.

[0060] (Not shown in the diagram), for easy maintenance.

[0061] The ultraviolet crosslinking device also includes a control system 10, which is connected to the flow valve 12, the first drive mechanism 42, the second drive mechanism, the third drive mechanism 62, the first automatic heater 2, the second automatic heater 311, the ultraviolet lamp 34, the vacuum pump, the three-way exhaust valve 35, and the two-way exhaust valve 36. The control system 10 is also a system known in the art, such as a PLC control system, and the control method is also a control method known in the art.

[0062] Temperature sensors (not shown in the figure) connected to the control system 10 are respectively installed in the air intake chamber 1 and the sealed processing chamber 3, so as to achieve precise control of the temperature in the air intake chamber 1 and the sealed processing chamber 3.

[0063] Example 2

[0064] The crosslinking method using the ultraviolet crosslinking device for polycarbosilane fibers described in Example 1 includes the following steps:

[0065] Step 1: First, place the polycarbosilane fiber bundle with a diameter of 12~13 μm on the processing platform 4. Then, turn on the third drive mechanism 62 to send the polycarbosilane fiber bundle into the sealed processing chamber 3. Use a vacuum pump to evacuate the chamber. Then, introduce helium into the sealed processing chamber 3 through the outlet channel 8 of the inlet chamber 1. Control the flow rate of helium to 50 mL / min through the flow valve 12. At this time, the three-way exhaust valve 35 is connected to the second chamber 32 to ensure that the atmosphere and pressure of the first chamber 31 and the second chamber 32 are the same.

[0066] Step 2: Then, control the second drive mechanism to send each UV lamp 34 from the second cavity 32 into the first cavity 31. Control the UV wavelength, intensity, and irradiation time of the UV lamp 34, where the UV wavelength is 365 nm, the UV lamp intensity is 10 mW / cm, and the irradiation time is 30 min. Open the first drive mechanism 42 to make the roller 1a rotate for all-round UV crosslinking treatment. After the treatment is completed, control the second drive mechanism again to send each UV lamp 34 from the first cavity 31 back into the second cavity 32.

[0067] Step 3: Then control the heating rate, heating temperature and time of the second automatic heater 311, wherein the heating rate is 2℃ / min, the heating temperature is 180℃ and the heating time is 6 h, to perform thermal crosslinking treatment on the polycarbonyl silane fiber bundles.

[0068] Step 4: Finally, control the heating rate, heating temperature and time of the second automatic heater 311, wherein the heating rate is 2℃ / min, the heating temperature is 340℃ and the heating time is 30 min, to perform post-treatment on the polycarbonate silane fiber bundles, so that the fiber molecules are transformed into a non-melting network structure, and the gas in the sealed treatment chamber 3 is released through the three-way exhaust valve 35 and the two-way exhaust valve 36.

[0069] In step 1, the heating temperature of the first automatic heater 2 can also be controlled to control the temperature of the protective gas. The heating temperature is kept consistent with that of the second automatic heater 311 to reduce the heat loss caused by the gas entering and thus reduce fluctuations in the performance of the polycarbonate fiber.

[0070] Example 3

[0071] The crosslinking method using the ultraviolet crosslinking device for polycarbosilane fibers described in Example 1 includes the following steps:

[0072] Step 1: First, place the polycarbosilane fiber bundle with a diameter of 15~16 μm on the processing platform 4. Then, turn on the third drive mechanism 62 to send the polycarbosilane fiber bundle into the sealed processing chamber 3. Use a vacuum pump to evacuate the chamber. Then, introduce helium into the sealed processing chamber 3 through the outlet channel 8 of the inlet chamber 1. Control the flow rate of helium to 150 mL / min through the flow valve 12. At this time, the three-way exhaust valve 35 is connected to the second chamber 32 to ensure that the atmosphere and pressure of the first chamber 31 and the second chamber 32 are the same.

[0073] Step 2: Then, control the second drive mechanism to send each UV lamp 34 from the second cavity 32 into the first cavity 31. Control the UV wavelength, intensity, and irradiation time of the UV lamp 34, where the UV wavelength is 400 nm, the UV lamp intensity is 30 mW / cm, and the irradiation time is 3 h. Open the first drive mechanism 42 to make the roller 1a rotate for all-round UV crosslinking treatment. After the treatment is completed, control the second drive mechanism again to send each UV lamp from the first cavity 31 back into the second cavity 32.

[0074] Step 3: Then control the heating rate, heating temperature and time of the second automatic heater 311, wherein the heating rate is 2℃ / min, the heating temperature is 250℃ and the heating time is 8h, to perform thermal crosslinking treatment on the polycarbonyl silane fiber bundles.

[0075] Step 4: Finally, control the heating rate, heating temperature and time of the second automatic heater 311, wherein the heating rate is 2℃ / min, the heating temperature is 350℃ and the heating time is 35 min, to perform post-treatment on the polycarbonyl silane fiber bundles, so that the fiber molecules are transformed into a non-melting network structure, and the gas in the sealed treatment chamber 3 is released through the three-way exhaust valve 35 and the two-way exhaust valve 36.

[0076] The terms "first," "second," etc., used in the specification and claims of this utility model are used to distinguish different objects, rather than to distinguish a specific order.

[0077] Performance testing

[0078] 1. Morphology of silicon carbide fibers

[0079] The polycarbosilane crosslinked fibers obtained in Examples 2 and 3 were converted into high-performance SiC fibers through hydrogen pyrolysis at 1250°C and final calcination at 1600°C. The morphology of the silicon carbide fibers is as follows: Figure 4 and Figure 5 As shown, its diameter is shown in Table 1.

[0080] Table 1 Single fiber diameter

[0081]

[0082] The single fiber in Example 2 has a diameter of 10.6 μm. This relatively fine diameter offers advantages in certain applications. For example, in the preparation of high-performance composites, finer fibers can be more uniformly dispersed in the matrix, enhancing the overall performance of the material. Simultaneously, the smaller diameter may also make the fiber easier to apply in confined spaces or situations with strict requirements on material thickness. The single fiber diameter Cv is 7.25%, indicating good fiber diameter consistency, which helps ensure the stability and reliability of material properties. In practical applications, the uniformity of fiber diameter is crucial for product quality control.

[0083] The single fiber diameter in Example 3 is 12.5 μm. A larger diameter may offer unique advantages in certain applications. For example, in situations requiring greater external force or higher abrasion resistance, a larger diameter fiber can provide stronger load-bearing capacity and better durability. Furthermore, larger fibers may be easier to handle during processing and treatment, reducing production complexity. The single fiber diameter Cv is 7.85%, also demonstrating good diameter consistency. This helps ensure the performance stability of the fiber during use and reduces quality problems caused by diameter variations.

[0084] 2. Tensile property test

[0085] Table 2 Tensile property test results

[0086]

[0087] The mechanical properties of SiC fibers are one of the important indicators for determining whether they can work for a long time in high-temperature environments. The silicon carbide fiber corresponding to Example 2 has a tensile strength as high as 2.8 GPa, demonstrating strong tensile strength. This allows the silicon carbide fiber of Example 2 to withstand large external forces without breaking when used as a structural reinforcement material, providing reliable mechanical support for the product. Its tensile modulus of elasticity reaches 346 GPa, exhibiting high stiffness. This means that the silicon carbide fiber deforms less under stress, maintaining structural stability. The tensile strength of the silicon carbide fiber corresponding to Example 3 is 2.6 GPa, slightly lower than that of Example 2, but still at a high level. This indicates that the silicon carbide fiber of Example 3 has good performance in withstanding tensile loads and can meet the requirements of most structural materials.

[0088] 3. High-temperature strength retention rate

[0089] (1) Silicon carbide fibers obtained from Example 2

[0090] Table 3 High-Temperature Strength Retention Rate of Silicon Carbide Fibers

[0091]

[0092] In an air atmosphere, the silicon carbide fibers corresponding to Example 2 exhibited high high-temperature strength retention rates at various temperatures. For example, under air conditions of -1300°C to 2000s, the high-temperature strength retention rate was 82.9%, indicating that even in relatively high-temperature and oxygen-rich environments, the fibers can still retain most of their initial strength. As the temperature increased to 1400°C and 1500°C, although the high-temperature strength retention rate decreased, it still remained at 58.6% and 58.2%, respectively. This demonstrates that the fibers still possess a certain strength retention capacity at higher temperatures, reflecting their adaptability over a wide temperature range. For applications that may face temperature fluctuations, this characteristic ensures that the material can function effectively under different temperature conditions, reducing performance instability caused by temperature changes.

[0093] Under an argon atmosphere, the high-temperature strength retention rate of the silicon carbide fiber corresponding to Example 2 was further improved. Under Ar-1300℃-2000s conditions, the high-temperature strength retention rate reached as high as 87.5%, significantly higher than under the same temperature conditions in an air atmosphere. This is because the inertness of argon effectively protects the fiber from oxidation and other chemical reactions, thus better maintaining its strength. When the temperature increased to 1400℃ and 1500℃, the high-temperature strength retention rates were 62.9% and 59.3%, respectively, showing a slight decrease but still remaining at a high level. This indicates that under argon protection, the fiber can maintain good strength at higher temperatures, providing more possibilities for applications in high-temperature environments.

[0094] Test data under different temperatures and atmospheres show that the high-temperature strength retention rate of the silicon carbide fiber corresponding to Example 2 is relatively stable with a small fluctuation range. This indicates that the silicon carbide fiber has good performance consistency under different environments, providing reliable performance assurance for practical applications. Whether in air or argon atmospheres, and at lower or higher temperatures, the fiber maintains a certain strength, reducing the risks associated with performance instability.

[0095] (2) Silicon carbide fibers obtained from Example 3

[0096] Table 4 High-Temperature Strength Retention Rate of Silicon Carbide Fibers

[0097]

[0098] The silicon carbide fiber corresponding to Example 3 exhibited a certain degree of high-temperature strength retention under both air and argon atmospheres. Under air - 1300℃ - 2000s conditions, the high-temperature strength retention rate was 81.5%, slightly lower than that of Example 2, but still at a relatively high level. This indicates that the fiber can resist the effects of high temperatures to a certain extent in air, making it suitable for applications requiring high-temperature resistance. As the temperature increased to 1400℃ and 1500℃, the high-temperature strength retention rates were 58.8% and 54.6%, respectively. Although the strength decreased slightly, it still maintained a certain level of strength, demonstrating the fiber's adaptability to higher temperatures. For industrial applications that may face high-temperature challenges, this characteristic can provide more possibilities for material selection.

[0099] Under an argon atmosphere, the high-temperature strength retention rate of the silicon carbide fiber corresponding to Example 3 was also improved. Under Ar-1300℃-2000s conditions, the high-temperature strength retention rate was 84.2%, higher than under the same temperature conditions in an air atmosphere. This indicates that the inert environment of argon played a positive role in the retention of the fiber's high-temperature strength. When the temperature increased to 1400℃ and 1500℃, the high-temperature strength retention rates were 63.5% and 58.1%, respectively, showing a slight decrease but still remaining at a relatively high level. This demonstrates that under argon protection, the fiber can maintain good strength at higher temperatures, providing a certain guarantee for applications in high-temperature environments.

[0100] The above embodiments and figures are not intended to limit the product form and style of this utility model. Any appropriate changes or modifications made by those skilled in the art should be considered as not departing from the patent scope of this utility model.

Claims

1. A UV crosslinking device for polycarbosilane fibers, comprising an air intake system, a UV crosslinking and heat treatment system, and a control system, characterized in that: The air intake system includes an air intake chamber connected to several air intake channels. Several sets of first automatic heaters are installed within the air intake chamber. The UV crosslinking and heat treatment system includes a sealed treatment chamber. An air outlet channel connects the air intake chamber and the sealed treatment chamber. The sealed treatment chamber includes a first cavity and a second cavity that are isolated from each other. The first cavity and the second cavity are arranged side-by-side and separated by a heat insulation plate. A processing platform for placing polycarbonate silane fiber bundles is installed within the first cavity. The processing platform is equipped with a rotating bracket for supporting the polycarbonate silane fiber bundles and a first driving mechanism for driving the polycarbonate silane fiber bundles to rotate. Several sets of second automatic heaters distributed around the processing platform are installed on the inner wall of the first cavity. Several UV lamps are installed within the sealed treatment chamber. Several sets of UV lamps are also installed within the sealed treatment chamber to allow each UV lamp to move between the first cavity and the second cavity. The second drive mechanism is located above the processing platform. The heat insulation plate has several through holes for the ultraviolet lamps to pass through and for gas flow. Each ultraviolet lamp has heat-insulating plugs at both ends to seal the through holes. The sealed processing chamber has multiple gas outlets connected to the vacuum processing system at positions corresponding to the first and second cavities. A three-way exhaust valve is located in the sealed processing chamber corresponding to the first cavity, with one exhaust port connected to the outside and the other exhaust port connected to the second cavity. A two-way exhaust valve is located in the sealed processing chamber corresponding to the second cavity and connected to the outside. The sealed processing chamber is covered with an ultraviolet shielding layer. The control system is connected to the first drive mechanism, the second drive mechanism, the first automatic heater, the second automatic heater, the ultraviolet lamps, the vacuum processing system, the three-way exhaust valve, and the two-way exhaust valve.

2. The ultraviolet crosslinking device for polycarbosilane fibers according to claim 1, characterized in that: Temperature sensors connected to the control system are respectively installed in the air inlet chamber and the first cavity, and the vacuum processing system is a vacuum pump.

3. The ultraviolet crosslinking device for polycarbosilane fibers according to claim 1, characterized in that: Each of the aforementioned air intake channels is equipped with a flow valve, and the flow valve is connected to the control system.

4. The ultraviolet crosslinking device for polycarbosilane fibers according to claim 1, characterized in that: Each of the second drive mechanisms includes a lead screw motor and a lead screw nut that cooperates with the lead screw of the lead screw motor. The bottom of each ultraviolet lamp is provided with a fixed base that is fixedly connected to the corresponding lead screw nut. Each lead screw motor is located at one end of the sealed treatment chamber corresponding to the second cavity. One end of the lead screw of each lead screw motor passes through the space between the first cavity and the second cavity and extends towards the end of the sealed treatment chamber corresponding to the first cavity. The heat insulation plugs at both ends of the ultraviolet lamp are located on both sides of the heat insulation plate.

5. The ultraviolet crosslinking device for polycarbosilane fibers according to claim 1, characterized in that: The sealed processing chamber is provided with a material outlet at one end corresponding to the first cavity. A sealing valve cover is provided in the sealed processing chamber at the position corresponding to the material outlet. The inner surface of the sealing valve cover is fixedly connected to the processing platform. A sliding frame is provided on the outer surface of the sealing valve cover. The sealed processing chamber is fixed on the fixed frame, and the sliding frame is slidably connected to the fixed frame. A slide rail is also provided in the first cavity to slide and cooperate with the processing platform.

6. The ultraviolet crosslinking device for polycarbosilane fibers according to claim 5, characterized in that: The sliding frame is provided with a third driving mechanism for driving the sliding frame to slide, and the third driving mechanism is controlled and connected to the control system.

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