Device and method for modifying glass fiber by microwave plasma

Abstract

The invention discloses a device and a method for modifying glass fibers by microwave plasmas, and relates to the technical field of glass fiber modification. The device is composed of a single-mode electrodeless microwave plasma torch and a transmission production workbench, the single-mode electrodeless microwave plasma torch comprises a high-temperature-resistant wave-transparent quartz reaction chamber, a compression waveguide, a nitrogen inlet and the like, and the transmission production workbench is provided with a plurality of microwave plasma torch combination devices and a glass fiber conveying mechanism. According to the method, 10L / min-30L / min nitrogen is adopted as an excitation medium, a 1500W-3000W variable-frequency microwave power supply is matched with a water-cooled magnetron to generate 2.45 GHz microwaves, the microwaves are concentrated through a compression waveguide and then act with the nitrogen to generate plasmas, glass fibers to be treated are modified for 30s-90s, and the glass fibers are repeatedly treated after being turned over. The device realizes normal-pressure operation, has no electrode loss, improves the industrial treatment capacity, and meets the large-scale glass fiber modification requirement.

Description

Technical Field

[0001] This invention relates to the field of glass fiber modification technology, and more specifically, to an apparatus and method for microwave plasma modification of glass fibers. Background Technology

[0002] Glass fiber is an inorganic non-metallic material with silicon dioxide as its main component. It possesses excellent properties such as lightweight, high strength, corrosion resistance, and insulation, and is widely used in construction and infrastructure, transportation, wind power, electronics, and environmental protection. China, as a major glass fiber producer, accounts for more than half of the global production capacity, while the United States and Europe hold an advantage in high-end applications. Currently, my country's glass fiber industry needs to leverage technological advancements to drive industry upgrading, modifying glass fiber through new methods to improve the performance of glass fiber products, in order to meet the development needs of high-precision industries.

[0003] Existing glass fiber modification methods mainly fall into three categories: chemical modification, surface treatment, and physical modification. Among these, plasma modification has attracted widespread attention due to its advantages of high activity and rapid reaction. Plasma is a fourth state of matter, distinct from solids, liquids, and gases. Common types of plasma include dielectric barrier discharge plasma, sliding arc discharge plasma, glow discharge plasma, and microwave plasma. Microwave plasma is currently a popular application. As a special wave, each molecule in microwaves has its own unique energy absorption band, and microwave plasma has a short path of freedom, enabling repeated re-excitation of neutral particles and generating more active substances. Existing academic research has proven that using microwave plasma to modify glass fibers can significantly improve the surface properties of glass fibers, achieving both physical and chemical modification.

[0004] However, current devices and methods for modifying fiber products using glow discharge plasma or low-temperature plasma have several shortcomings: First, the modification process requires vacuum equipment, making it impossible to operate at atmospheric pressure, resulting in high equipment costs; second, the plasma generation process requires electrodes to produce a strong electric field, leading to electrode wear and frequent electrode replacement; third, the working medium flow rate for exciting the plasma is low (<0.3 L / min), resulting in insufficient industrial processing capacity. Therefore, there is an urgent need to develop a glass fiber modification device and method that can operate at atmospheric pressure, has no electrode wear, and possesses high industrial processing capacity. Summary of the Invention

[0005] In view of the shortcomings of the existing technology, the purpose of this invention is to provide a device and method for microwave plasma modification of glass fiber, which solves the problems of existing glass fiber plasma modification technology, such as inability to operate at normal pressure, high electrode loss, and insufficient industrial processing capacity.

[0006] One of the above-mentioned objectives of this invention is achieved through the following technical solution: A device for modifying glass fiber by microwave plasma, characterized in that it includes a single-mode electrodeless microwave plasma torch 13 and a transmission production workbench 14. The single-mode electrodeless microwave plasma torch 13 includes a high-temperature resistant transparent quartz reaction chamber 1, a compressed waveguide 2, a nitrogen inlet 3, a leak-proof sealing plate 4, a water-cooled magnetron 5, a cooling water inlet 6, a cooling water outlet 7, and an excitation chamber 8. The high-temperature resistant, microwave-transparent quartz reaction chamber 1 is resistant to 1600℃ and is connected to the compression waveguide 2 via a flange and a sealing gasket, while also being directly connected to the nitrogen inlet 3. The compression waveguide 2 and the nitrogen inlet 3 are connected via internal threads. The compression waveguide 2 has a specific convergence angle and can be used to transmit 2.45GHz microwaves below 3000W. The compression waveguide 2 and the excitation cavity 8 are connected via a leak-proof sealing plate 4 and screws. The water-cooled magnetron 5 is connected to the excitation cavity 8. The cooling water inlet 6 and the cooling water outlet 7 are connected to the water-cooled magnetron 5. The transmission production workbench 14 includes a microwave plasma torch assembly device 9, a fiberglass conveyor belt 10, a transmission shaft 11, and a workbench support frame 12. Five microwave plasma torch connection devices 9 are provided for connecting single-mode electrodeless microwave plasma torches 13; the glass fiber conveyor belt 10 is connected to the drive shaft 11 for transmission, and the workbench support frame 12 is used to support the glass fiber conveyor belt 10 and adjust its height.

[0007] By adopting the above technical solution, the single-mode electrodeless microwave plasma torch 13 eliminates the electrode structure in traditional plasma devices, fundamentally avoiding the problem of electrode wear and eliminating the need for periodic electrode replacement, thus reducing equipment maintenance costs and downtime. The high-temperature resistant, microwave-transparent quartz reaction chamber 1 can withstand temperatures up to 1600℃, enabling it to withstand the high-temperature environment generated by microwave plasma and ensuring long-term stable operation of the device. The five microwave plasma torch combination device 9 can simultaneously connect five single-mode electrodeless microwave plasma torches 13, and with the continuous transmission of the glass fiber conveyor belt 10, realize the assembly line modification treatment of glass fiber, significantly improving industrial processing capacity. Moreover, the entire device does not rely on vacuum equipment and can operate under normal pressure, simplifying the equipment structure and reducing initial investment costs.

[0008] Furthermore, the specific convergence angle of the compressed waveguide 2 is adapted to the centralized transmission requirements of 2.45GHz microwaves below 3000W.

[0009] By adopting the above technical solution, the compressed waveguide 2 with a specific convergence angle can concentrate the transmission of the 2.45GHz microwave generated by the water-cooled magnetron 5, reduce microwave energy loss, make the microwave energy act more concentrated on the nitrogen, improve the plasma excitation efficiency, and thus enhance the modification effect on the glass fiber, ensuring a uniform improvement in the surface properties of the glass fiber.

[0010] Furthermore, the height of the glass fiber conveyor belt 10 of the transmission production workbench 14 is adjusted so that the microwave plasma can directly contact the glass fiber.

[0011] By adopting the above technical solution, the height of the glass fiber conveyor belt 10 can be adjusted by the worktable support frame 12 according to the length of the microwave plasma tail flame, so as to ensure that the microwave plasma can directly and fully contact the glass fiber surface, avoid the weakening of the modification effect due to too far distance, or damage to the glass fiber due to too close distance, and ensure that the modification process is stable and efficient.

[0012] Further: A method for microwave plasma modification of glass fiber using any one of the devices of claims 1-3, characterized by comprising the following steps: S1: Nitrogen gas is generated through a gas cylinder and delivered to nitrogen inlet 3 via a silicone tube. The nitrogen flow rate is controlled between 10L / min and 30L / min. S2: Turn on the 1500W-3000W frequency conversion microwave power supply to power the water-cooled magnetron 5. At the same time, cooling water is introduced through the cooling water inlet 6 and flows out from the cooling water outlet 7 to ensure that the water-cooled magnetron 5 operates at a suitable temperature. S3: The water-cooled magnetron 5 generates microwaves in the excitation cavity 8. After being concentrated and transmitted through the compressed waveguide 2, the microwaves react with nitrogen gas through the high-temperature resistant transparent quartz reaction chamber 1, ionizing the nitrogen gas to form microwave plasma. S4: Spread the glass fiber to be treated on the glass fiber conveyor belt 10, start the drive shaft 11, drive the glass fiber conveyor belt 10 to move, so that the glass fiber passes through the plasma action area of ​​the single-mode electrodeless microwave plasma torch 13 connected by 5 microwave plasma torch combination devices 9 in sequence, and perform 30s-90s modification treatment. S5: The glass fiber processed in step S4 is flipped 180° and transported again to the plasma interaction area via the glass fiber conveyor belt 10 for repeated modification treatment.

[0013] By adopting the above technical solution, using high-flow-rate nitrogen gas (10L / min-30L / min) as the excitation medium, compared to the flow rate of less than 0.3L / min in existing technologies, a sufficient gas source can be provided for the stable generation of plasma, while meeting the needs of continuous and efficient modification of glass fibers in large-scale industrial production. The cooling circulation design of the water-cooled magnetron 5 can effectively control the operating temperature of the magnetron, avoiding equipment damage due to high temperature and extending the service life of the equipment. The glass fiber undergoes two plasma treatments, ensuring that both sides are fully modified, further enhancing surface activity and improving the bonding performance with subsequent substrates. Moreover, the assembly line-style transport method enables continuous production, significantly improving production efficiency.

[0014] Furthermore: In step S3, the microwave frequency is 2.45 GHz.

[0015] By adopting the above technical solution, 2.45GHz is a commonly used microwave frequency in the industrial field. The microwave frequency at this frequency matches the resonant absorption characteristics of nitrogen molecules, which can efficiently excite nitrogen to ionize and form plasma. At the same time, microwave equipment at this frequency is mature and cost-controllable, which is convenient for industrial promotion and application. It can ensure the stable generation of plasma and the consistency of modification effect, and avoid the problem of low plasma excitation efficiency or unstable modification effect due to unsuitable frequency.

[0016] Further: In step S4, five single-mode electrodeless microwave plasma torches 13 operate simultaneously to perform a streamlined modification process on the glass fiber.

[0017] By adopting the above technical solution, the simultaneous operation of five plasma torches can form a continuous plasma treatment area on the conveyor belt. The glass fiber can continuously receive plasma treatment as it moves with the conveyor belt, without the need for frequent equipment start-ups and shutdowns or transmission interruptions. This significantly shortens the total time of a single modification treatment and increases the glass fiber processing capacity per unit time. At the same time, the coordinated operation of multiple torches can ensure that the glass fiber is subjected to uniform plasma treatment along the transmission path, avoiding insufficient local modification and ensuring the consistency of glass fiber performance in batch processing.

[0018] In summary, the present invention has at least one of the following beneficial technical effects: This invention uses microwave plasma to modify glass fibers. Microwave plasma has the characteristics of high activity and short modification time. The device combines a plasma torch and a transmission worktable to achieve continuous modification of glass fibers, which greatly improves industrial efficiency and solves the problem of insufficient industrial processing capacity in the prior art.

[0019] The electrodeless design of the single-mode microwave plasma torch of the present invention avoids electrode loss, eliminates the need for periodic electrode replacement, reduces operating costs, and solves the problems of high electrode loss and high cost in the prior art.

[0020] This invention eliminates the need for vacuum equipment, operates under normal pressure, simplifies the equipment structure, reduces equipment costs, and solves the problems of high costs and the need for vacuum equipment in existing technologies.

[0021] In this invention, the nitrogen flow rate is controlled at 10L / min-30L / min, which significantly increases the working medium flow rate compared to the less than 0.3L / min working medium flow rate in the prior art, further enhancing the industrial processing capacity and meeting the needs of large-scale glass fiber modification production.

[0022] This invention further enhances the modification effect of glass fibers by flipping the treated glass fibers 180° and repeating the modification treatment. When the modified glass fibers are combined with organic substrates such as resins, the bonding strength is greatly improved, thus improving the performance of glass fiber products. Attached Figure Description

[0023] Figure 1 This is a three-dimensional schematic diagram of an electrodeless single-mode microwave plasma torch; Figure 2 This is a 3D schematic diagram of the transmission production workbench; Figure 3 A three-dimensional schematic diagram of the entire invention.

[0024] In the diagram, 1. High-temperature resistant, wave-transparent quartz reaction chamber; 2. Compressed waveguide; 3. Nitrogen inlet; 4. Leak-proof sealing plate; 5. Water-cooled magnetron; 6. Cooling water inlet; 7. Cooling water outlet; 8. Excitation chamber; 9. Microwave plasma torch assembly; 10. Fiberglass conveyor belt; 11. Drive shaft; 12. Workbench support frame; 13. Single-mode electrodeless microwave plasma torch; 14. Drive production workbench. Detailed Implementation

[0025] The present invention will be further described in detail below with reference to the accompanying drawings.

[0026] Reference Figures 1-3 A device for modifying glass fiber by microwave plasma, characterized in that it includes a single-mode electrodeless microwave plasma torch 13 and a transmission production workbench 14. The single-mode electrodeless microwave plasma torch 13 includes a high-temperature resistant transparent quartz reaction chamber 1, a compressed waveguide 2, a nitrogen inlet 3, a leak-proof sealing plate 4, a water-cooled magnetron 5, a cooling water inlet 6, a cooling water outlet 7, and an excitation chamber 8. The high-temperature resistant, microwave-transparent quartz reaction chamber 1 is resistant to 1600℃ and is connected to the compression waveguide 2 via a flange and a sealing gasket, while also being directly connected to the nitrogen inlet 3. The compression waveguide 2 and the nitrogen inlet 3 are connected via internal threads. The compression waveguide 2 has a specific convergence angle and can be used to transmit 2.45GHz microwaves below 3000W. The compression waveguide 2 and the excitation cavity 8 are connected via a leak-proof sealing plate 4 and screws. The water-cooled magnetron 5 is connected to the excitation cavity 8. The cooling water inlet 6 and the cooling water outlet 7 are connected to the water-cooled magnetron 5. The transmission production workbench 14 includes a microwave plasma torch assembly device 9, a fiberglass conveyor belt 10, a transmission shaft 11, and a workbench support frame 12. Five microwave plasma torch connection devices 9 are provided for connecting single-mode electrodeless microwave plasma torches 13; the glass fiber conveyor belt 10 is connected to the drive shaft 11 for transmission, and the workbench support frame 12 is used to support the glass fiber conveyor belt 10 and adjust its height.

[0027] A method for microwave plasma modification of glass fibers using the above-described apparatus, characterized by comprising the following steps: S1: Nitrogen gas is generated through a gas cylinder and delivered to nitrogen inlet 3 via a silicone tube. The nitrogen flow rate is controlled between 10L / min and 30L / min. S2: Turn on the 1500W-3000W frequency conversion microwave power supply to power the water-cooled magnetron 5. At the same time, cooling water is introduced through the cooling water inlet 6 and flows out from the cooling water outlet 7 to ensure that the water-cooled magnetron 5 operates at a suitable temperature. S3: The water-cooled magnetron 5 generates microwaves in the excitation cavity 8. After being concentrated and transmitted through the compressed waveguide 2, the microwaves react with nitrogen gas through the high-temperature resistant transparent quartz reaction chamber 1, ionizing the nitrogen gas to form microwave plasma. S4: Spread the glass fiber to be treated on the glass fiber conveyor belt 10, start the drive shaft 11, drive the glass fiber conveyor belt 10 to move, so that the glass fiber passes through the plasma action area of ​​the single-mode electrodeless microwave plasma torch 13 connected by 5 microwave plasma torch combination devices 9 in sequence, and perform 30s-90s modification treatment. S5: The glass fiber processed in step S4 is flipped 180° and transported again to the plasma interaction area via the glass fiber conveyor belt 10 for repeated modification treatment.

[0028] In step S3, the microwave frequency is 2.45 GHz. In step S4, five single-mode electrodeless microwave plasma torches 13 work simultaneously to perform a production line modification process on the glass fiber.

[0029] The implementation principle of this embodiment is as follows: The device and method of the present invention achieve efficient modification of glass fiber through equipment coordination and process optimization. The working process is as follows: The preparation phase requires component assembly and debugging: connect the five single-mode electrodeless microwave plasma torches to the transmission production workbench through the microwave plasma torch connecting device, adjust the workbench support frame to make the height of the glass fiber conveyor belt adapt to the requirements of direct plasma contact; check the nitrogen and silicone pipeline, frequency conversion microwave power supply and water-cooled magnetron cooling water circuit connection to ensure the system is unobstructed.

[0030] After startup, supply nitrogen first: Nitrogen is supplied from a gas cylinder and delivered through a silicone tube to the nitrogen inlet of the plasma torch, with a flow rate controlled at 10L / min-30L / min, to ensure sufficient medium for plasma generation. Then start the microwave and cooling system: Turn on the 1500W-3000W inverter microwave power supply to power the water-cooled magnetron, and simultaneously circulate cooling water (inlet and outlet) to ensure the magnetron operates at room temperature.

[0031] Plasma generation stage: The water-cooled magnetron generates 2.45 GHz microwaves in the excitation cavity, which are concentrated and transmitted through a compressed waveguide with a specific convergence angle. The microwaves then pass through a quartz reaction chamber that can withstand 1600°C, where they react with nitrogen gas to ionize the nitrogen gas into microwave plasma.

[0032] The modification process consists of two steps: First, the glass fiber to be treated is laid on a conveyor belt, and the drive shaft drives the conveyor belt to move. The fiber passes through five plasma torches that work simultaneously and is modified for 30-90 seconds. Second, the fiber is flipped 180° and sent back to the plasma torches for repeated treatment to ensure that both sides are fully modified.

[0033] The entire process operates at atmospheric pressure with no electrode loss. High-flow nitrogen and automated production line operations enhance industrial processing capacity and meet the needs of large-scale modification.

[0034] The embodiments described herein are preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Therefore, all equivalent changes made in accordance with the structure, shape, and principle of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A device for microwave plasma modification of glass fibers, characterized in that, Includes a single-mode electrodeless microwave plasma torch (13) and a transmission production workbench (14). The single-mode electrodeless microwave plasma torch (13) includes a high-temperature resistant transparent quartz reaction chamber (1), a compressed waveguide (2), a nitrogen inlet (3), a leak-proof sealing plate (4), a water-cooled magnetron (5), a cooling water inlet (6), a cooling water outlet (7), and an excitation chamber (8). The high-temperature resistant transparent quartz reaction chamber (1) is resistant to 1600℃ and is connected to the compression waveguide (2) through a flange and a sealing gasket, and is also directly connected to the nitrogen inlet (3); the compression waveguide (2) and the nitrogen inlet (3) are connected by internal threads; the compression waveguide (2) and the excitation chamber (8) are connected by screws through the anti-leakage sealing plate (4); the water-cooled magnetron (5) is connected to the excitation chamber (8); the cooling water inlet (6) and the cooling water outlet (7) are connected to the water-cooled magnetron (5); The transmission production workbench (14) includes a microwave plasma torch assembly device (9), a glass fiber conveyor belt (10), a transmission shaft (11), and a workbench support frame (12). The microwave plasma torch connecting device (9) is provided in five units for connecting the single-mode electrodeless microwave plasma torch (13); the glass fiber conveyor belt (10) is connected to the drive shaft (11) for transmission.

2. The apparatus according to claim 1, characterized in that, The specific convergence angle of the compressed waveguide (2) is adapted to the centralized transmission requirements of 2.45GHz microwaves below 3000W.

3. The apparatus according to claim 1, characterized in that, The height of the glass fiber conveyor belt (10) of the transmission production workbench (14) is adjusted so that the microwave plasma can directly contact the glass fiber.

4. A method for modifying glass fibers using microwave plasma with the apparatus described in any one of claims 1-3, characterized in that, Includes the following steps: S1: Nitrogen gas is generated through a gas cylinder and transported to the nitrogen inlet (3) through a silicone tube. The nitrogen flow rate is controlled at 10L / min-30L / min. S2: Turn on the 1500W-3000W frequency conversion microwave power supply to power the water-cooled magnetron (5), and at the same time, cool water is introduced through the cooling water inlet (6) and the cooling water flows out from the cooling water outlet (7) to ensure that the water-cooled magnetron (5) works at a suitable temperature. S3: The water-cooled magnetron (5) generates microwaves in the excitation cavity (8). After the microwaves are concentrated and transmitted through the compressed waveguide (2), they react with nitrogen gas through the high-temperature resistant transparent quartz reaction chamber (1) to ionize the nitrogen gas and form microwave plasma. S4: Spread the glass fiber to be treated on the glass fiber conveyor belt (10), start the drive shaft (11) to drive the glass fiber conveyor belt (10) to move, so that the glass fiber passes through the plasma action area of ​​the single-mode electrodeless microwave plasma torch (13) connected by the microwave plasma torch combination device (9) in sequence, and performs 30s-90s modification treatment. S5: The glass fiber processed in step S4 is flipped 180° and transported again through the glass fiber conveyor belt (10) to the plasma interaction area for repeated modification treatment.

5. The method according to claim 4, characterized in that, In step S3, the microwave frequency is 2.45 GHz.

6. The method according to claim 4, characterized in that, In step S4, the five single-mode electrodeless microwave plasma torches (13) operate simultaneously to perform a streamlined modification process on the glass fiber.

Images