Microwave hot air glass fiber setting process
By using a four-stage control process in a microwave hot air mixing and setting equipment, problems such as uneven internal and external properties and fiber bursting and embrittlement during glass fiber setting are solved. This achieves uniform heating and cooling of glass fiber products, improves stiffness and production efficiency, and reduces energy consumption.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- YANTAI NORTH MICROWAVE TECH
- Filing Date
- 2026-04-28
- Publication Date
- 2026-05-29
AI Technical Summary
Existing glass fiber setting processes suffer from problems such as insufficient setting at the center of ultra-large yarn bundles, unevenness between the inside and outside, yarn bursting and brittleness, poor stiffness, and long cycle time. In particular, it is difficult to achieve precise segmented control of preheating temperature uniformity, deep penetration, high-temperature curing, and stepped cooling during the setting process of large-sized glass fiber yarn bundles.
The microwave and hot air hybrid shaping equipment adopts four continuous control stages: preheating and equalization stage, deep penetration shaping stage, high temperature curing and stabilization stage, and stepped cooling shaping stage. Combined with the synergistic heating of microwave and hot air, it achieves precise matching and gradient control of temperature, microwave, and dehumidification system.
It solves the problems of uneven internal and external shaping and insufficient central shaping of large-sized glass fiber yarn bundles, avoids yarn bursting, embrittlement and local overheating, the finished product has a moisture content of less than 0.08%, a stiffness compliance rate of up to 99.5%, and a dimensional deformation rate of less than 0.3%, and significantly shortens the shaping cycle.
Smart Images
Figure CN122102536A_ABST
Abstract
Description
Technical Field
[0001] This invention discloses a microwave hot air glass fiber shaping process, which belongs to the field of glass fiber processing technology. Background Technology
[0002] Glass fiber, as a high-performance inorganic non-metallic material, possesses a series of excellent properties such as high strength, high modulus, high temperature resistance, corrosion resistance, electrical insulation, heat insulation, and sound absorption. It is widely used in numerous fields including construction, transportation, wind power, aerospace, electronics, electrical engineering, and chemical corrosion protection, and is an indispensable basic raw material in modern industrial systems. During the drawing and forming process of glass fiber precursors, a special sizing agent is coated on the surface. This sizing agent contains various components such as film-forming agents, lubricants, antistatic agents, and coupling agents. Its function is to protect the glass fiber monofilaments, prevent wear, improve bundle cohesion, and enhance subsequent processing performance. After being coated with the sizing agent, the glass fiber precursors must undergo a rigorous setting process to ensure uniform sizing film formation, complete moisture removal, elimination of internal fiber stress, and achievement of the required mechanical properties and dimensional stability. Therefore, the setting process is a crucial core link in the glass fiber production process that determines the final product quality, performance grade, and processing suitability.
[0003] Currently, the mainstream glass fiber setting processes in the industry are mainly divided into three categories: The first category is the pure hot air setting process. This process relies on hot air circulation to provide heat, and heats, dehydrates, and sets the glass fiber products through convection heat transfer. The advantages of the pure hot air setting process are simple equipment structure, stable operation, and less risk of fiber damage. However, it has obvious technical defects: First, hot air can only conduct heat from the surface of the glass fiber product to the interior. For large diameter, heavy, and extra-large yarn bundles, the heat transfer speed is slow and the temperature difference between the inside and outside is large, resulting in over-setting of the surface and under-setting of the interior, uneven film formation of the sizing agent, and low stiffness. Second, the setting cycle is extremely long, usually requiring more than 12 hours, resulting in low production efficiency and high energy costs. Third, the equipment occupies a large area, and the capacity of a single machine is limited, making it difficult to adapt to large-scale continuous production lines. The second type is the pure microwave setting process. Microwaves can directly act on the water molecules inside the glass fiber, achieving simultaneous internal and external heating. This results in rapid dehydration and a short cycle. However, pure microwave setting also has insurmountable problems: First, microwave heating is highly selective, and uneven moisture distribution can lead to localized overheating, easily causing glass fiber embrittlement, breakage, and bursting. The sizing agent is also destroyed by high temperatures, significantly reducing film-forming properties. Second, the uniformity of the microwave field distribution is difficult to control; the difference in microwave energy density between the center and edge of large yarn clusters is significant, leading to unstable setting quality. Third, the glass fiber after pure microwave setting lacks stiffness and has poor surface smoothness, affecting subsequent weaving, winding, and laminating processes. The third type is the simplified microwave-hot-air hybrid setting process. This process attempts to combine the advantages of hot air and microwaves, improving upon the shortcomings of pure hot air and pure microwave processes to some extent. However, existing simplified hybrid processes generally suffer from problems such as coarse parameter settings, lack of segmented gradient control, poor synergy between microwaves and hot air, and unreasonable matching of the dehumidification system.
[0004] Specifically, existing technologies have not achieved segmented and precise control of preheating temperature uniformity, deep penetration, high-temperature curing, and stepped cooling, and cannot solve problems such as insufficient center shaping of ultra-large yarn clusters, unevenness inside and outside, yarn bursting and brittleness, poor stiffness, and long cycle time. Summary of the Invention
[0005] The purpose of this invention is to solve the problems of insufficient center setting of ultra-large yarn bundles, unevenness inside and outside, yarn bursting and brittleness, poor stiffness, and long cycle in the existing technology, and to provide a microwave hot air glass fiber setting process.
[0006] This invention is achieved through the following technical solution: A microwave hot air glass fiber setting process, characterized by being implemented using a microwave hot air mixing setting device, and comprising the following four continuous control stages in sequence: (a) Preheating and temperature equalization zone: The temperature of the shaping cavity is set at 90~110℃, the heat preservation time is 40~90min, the microwave power density is controlled at 1.5~2.5kW / m³, the air volume of the dehumidification system is set at 800~1200m³ / h, and the hot air circulation speed is maintained at 0.8~1.2m / s; (b) Deep penetration and shaping section: The temperature of the shaping cavity is set at 115~135℃, the heat preservation time is 90~240min, the microwave power density is controlled at 2.0~3.0kW / m³, the dehumidification system air volume is set at 1200~1800m³ / h, and the hot air circulation speed is maintained at 1.0~1.5m / s; (c) High-temperature curing and stabilization section: The temperature of the curing cavity is set at 130~145℃, the heat preservation time is 60~180min, the microwave power density is controlled at 0.8~1.8kW / m³, the air volume of the dehumidification system is set at 600~1000m³ / h, and the hot air circulation speed is maintained at 0.7~1.1m / s; (d) Step-cooling and shaping section: A multi-gradient step-cooling mode is adopted to gradually reduce the temperature of the shaping cavity from the end temperature of the high-temperature curing and stabilizing section to 50~65℃. The total cooling time is 30~60min. The microwave output is turned off throughout the cooling stage. The air volume of the dehumidification system is set to 1000~1500m³ / h, and the hot air circulation speed is maintained at 0.9~1.3m / s.
[0007] Preferably, the optimal process parameters for the preheating and temperature equalization section are: 100℃ for the shaping cavity, 60min for the heat preservation time, 2.0kW / m³ for the microwave power density, 1000m³ / h for the exhaust air volume, and 1.0m / s for the hot air circulation speed.
[0008] Preferably, the optimal process parameters for the deep penetration and shaping section are: shaping chamber temperature 125℃, heat preservation time 180min, microwave power density 2.5kW / m³, dehumidification air volume 1500m³ / h, and hot air circulation speed 1.2m / s.
[0009] Preferably, the optimal process parameters for the high-temperature curing and stabilizing section are: sizing cavity temperature 135℃, heat preservation time 120min, microwave power density 1.2kW / m³, exhaust air volume 800m³ / h, and hot air circulation speed 0.9m / s.
[0010] Preferably, the cooling gradient of the stepped cooling and shaping section is as follows: the first gradient is from 135℃ to 110℃, and the temperature is held for 10~15 minutes; the second gradient is from 110℃ to 80℃, and the temperature is held for 10~15 minutes; the third gradient is from 80℃ to 60℃, and the temperature is held for 10~20 minutes; the total cooling time is controlled to be 45 minutes, and the final discharge temperature is stabilized at 60℃.
[0011] Preferably, the temperature uniformity deviation of the hot air circulation system is controlled within ±3℃, and the temperature difference between any two points inside the shaping cavity does not exceed 4℃.
[0012] Preferably, the dehumidification system adopts a variable frequency air volume control mode, which can automatically adjust the dehumidification air volume according to the real-time humidity value inside the shaping cavity; the preheating and temperature equalization section and the deep penetration shaping section maintain a high air volume for dehumidification, the high temperature curing and stabilization section reduces the air volume to maintain the temperature stability inside the cavity, and the stepped cooling shaping section maintains a medium air volume to quickly remove residual heat and moisture.
[0013] Preferably, the process is applicable to the setting of glass fiber yarn balls and yarn cakes weighing 5kg to 50kg, as well as continuous roll glass fiber cloth and multi-strand glass fiber yarn, and is especially suitable for setting ultra-large glass fiber yarn balls weighing 40kg.
[0014] Preferably, the glass fiber products after this process have a moisture content of ≤0.08%, a stiffness compliance rate of ≥99.5%, and a dimensional deformation rate of ≤0.3%.
[0015] Preferably, the total setting time of the four continuous control stages is controlled within 5 to 10 hours, and there is no yarn bursting, no brittleness, and no local overheating and yellowing during the setting process.
[0016] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention employs a four-stage gradient precise control combined with microwave hot air heating, which solves the problems of uneven shaping inside and outside large-sized glass fiber yarn bundles and insufficient shaping in the center.
[0017] 2. This invention features coordinated matching of temperature, microwave, dehumidification, and wind speed throughout the entire process, effectively avoiding defects such as yarn bursting, brittleness, and localized overheating and yellowing. The finished product has a moisture content of ≤0.08%, a stiffness compliance rate of ≥99.5%, and a dimensional deformation rate of ≤0.3%.
[0018] 3. The process of this invention is segmented and controllable, with strong adaptability, and can cover a variety of products such as 5-50kg yarn balls and glass fiber cloth, which greatly shortens the shaping cycle and reduces energy consumption. Attached Figure Description
[0019] Figure 1 : Overall flow chart of the microwave hot air glass fiber shaping process of this invention; Figure 2 This invention provides a temperature change curve of the surface and interior of a 20kg glass fiber filament bundle. Figure 3 This invention defines the surface and internal temperature change curves of a 40kg ultra-large glass fiber yarn bundle; Figure 4The present invention defines the surface and internal temperature change curves of the continuous roll electronic-grade glass fiber cloth. Detailed Implementation
[0020] To better understand the above-mentioned objectives, features, and advantages of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.
[0021] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein. Therefore, the scope of protection of the invention is not limited to the specific embodiments disclosed below.
[0022] Example 1: The shaping object is a general-purpose 20kg glass fiber filament yarn bundle. Process steps and parameters: Feeding: Place the yarn bundles neatly on the yarn cart, feed them into the shaping cavity along the conveyor track, and close the microwave hot air leakage prevention door.
[0023] Preheating and temperature equalization zone: set temperature 100℃, hold for 60 minutes, microwave power density 2.0kW / m³, exhaust air volume 1000m³ / h, hot air velocity 1.0m / s.
[0024] Deep penetration and shaping section: set temperature 125℃, heat preservation for 180min, microwave power density 2.5kW / m³, exhaust air volume 1500m³ / h, hot air velocity 1.2m / s.
[0025] High-temperature curing and stabilization section: set temperature 135℃, heat preservation for 120min, microwave power density 1.2kW / m³, exhaust air volume 800m³ / h, hot air velocity 0.9m / s.
[0026] Stepped cooling and shaping section: The temperature is reduced in a gradient of 135℃→110℃→80℃→60℃, with a total duration of 45 minutes. The microwave is turned off, the exhaust air volume is 1200m³ / h, and the hot air velocity is 1.1m / s.
[0027] Feeding: After cooling, open the furnace door and take out the shaped yarn ball.
[0028] Test results: Moisture content: 0.07%; Firmness: Meets the standard; Dimensional deformation rate: 0.22%; Appearance: No bursting, no brittleness, no yellowing, and the film is uniform and intact; Total design time: 6.75 hours.
[0029] The process parameters, surface temperature, and internal temperature of the glass fiber yarn bundles in Example 1 are shown in the table below:
[0030] Example 2: The object being shaped was a 40kg ultra-large glass fiber yarn bundle. Process steps and parameters: Feeding: The extra-large yarn ball is positioned in the center and smoothly fed into the shaping cavity by the yarn train.
[0031] Preheating temperature equalization zone: temperature 95℃, duration 80min, microwave power density 2.2kW / m³, exhaust air volume 1100m³ / h, wind speed 1.1m / s.
[0032] Deep penetration and shaping section: temperature 130℃, duration 220min, microwave power density 2.6kW / m³, exhaust air volume 1600m³ / h, wind speed 1.3m / s.
[0033] High-temperature curing and stabilization section: temperature 140℃, duration 150min, microwave power density 1.3kW / m³, exhaust air volume 900m³ / h, wind speed 1.0m / s.
[0034] Stepped cooling and shaping section: 140℃→115℃→85℃→55℃, duration 50min, microwave off, exhaust air volume 1400m³ / h, wind speed 1.2m / s.
[0035] Feeding: Smoothly remove the extra-large yarn ball.
[0036] Test results: Moisture content: 0.06%; Firmness: Meets the standard; Dimensional deformation rate: 0.27%; Uniformity: The center and surface have the same shaping effect, with no dead corners; Total design time: 8.3 hours.
[0037] The process parameters, surface temperature, and internal temperature of the glass fiber yarn bundles in Example 2 are shown in the table below:
[0038] Example 3: The object being shaped is a continuous roll of electronic-grade glass fiber cloth. Process steps and parameters: Feeding: Place the fiberglass cloth roll on a special support and feed it into the shaping cavity.
[0039] Preheating temperature equalization zone: temperature 105℃, duration 50min, microwave power density 1.8kW / m³, exhaust air volume 900m³ / h, wind speed 0.9m / s.
[0040] Deep penetration and shaping section: temperature 120℃, duration 120min, microwave power density 2.2kW / m³, exhaust air volume 1300m³ / h, wind speed 1.1m / s.
[0041] High-temperature curing and stabilization section: temperature 130℃, duration 90min, microwave power density 1.0kW / m³, exhaust air volume 700m³ / h, wind speed 0.8m / s.
[0042] Stepped cooling and shaping section: 130℃→110℃→80℃→65℃, duration 35min, microwave off, exhaust air volume 1100m³ / h, wind speed 1.0m / s.
[0043] Material cutting: Take out the shaped glass fiber cloth roll.
[0044] Test results: Moisture content: 0.07%; Film-forming properties: uniform and continuous, without bubbles or peeling; Feel: Moderately soft, with adequate firmness; Dimensional stability: No warping, no deformation; Total design time: 4.9 hours.
[0045] The process parameters, surface temperature, and internal temperature of the fiberglass cloth in Example 3 are shown in the table below:
[0046] Figures 2-4 The figures show the surface and internal temperatures of the glass fiber products as a function of time during the setting process of 20kg glass fiber yarn balls, 40kg extra-large glass fiber yarn balls, and continuous rolls of glass fiber cloth, respectively. As can be seen from the curves, the surface and internal temperatures of the glass fiber products remain highly consistent throughout the entire setting cycle, with the internal and external temperature difference consistently controlled within 2℃. There is no significant temperature lag or localized overheating, fully demonstrating that the microwave hot air synergistic four-stage control process employed in this invention can achieve synchronous and uniform heating and cooling of glass fiber products from the surface to the interior, effectively solving the technical defects of traditional processes such as large internal and external temperature differences, insufficient central setting, surface overheating and embrittlement, and yarn bursting.
Claims
1. A microwave hot air glass fiber setting process, characterized in that, The implementation based on microwave hot air mixing and shaping equipment includes the following four continuous control stages: (a) Preheating and temperature equalization zone: The temperature of the shaping cavity is set at 90~110℃, the heat preservation time is 40~90min, the microwave power density is controlled at 1.5~2.5kW / m³, the air volume of the dehumidification system is set at 800~1200m³ / h, and the hot air circulation speed is maintained at 0.8~1.2m / s; (b) Deep penetration and shaping section: The temperature of the shaping cavity is set at 115~135℃, the heat preservation time is 90~240min, the microwave power density is controlled at 2.0~3.0kW / m³, the dehumidification system air volume is set at 1200~1800m³ / h, and the hot air circulation speed is maintained at 1.0~1.5m / s; (c) High-temperature curing and stabilization section: The temperature of the curing cavity is set at 130~145℃, the heat preservation time is 60~180min, the microwave power density is controlled at 0.8~1.8kW / m³, the air volume of the dehumidification system is set at 600~1000m³ / h, and the hot air circulation speed is maintained at 0.7~1.1m / s; (d) Step-cooling and shaping section: A multi-gradient step-cooling mode is adopted to gradually reduce the temperature of the shaping cavity from the end temperature of the high-temperature curing and stabilizing section to 50~65℃. The total cooling time is 30~60min. The microwave output is turned off throughout the cooling stage. The air volume of the dehumidification system is set to 1000~1500m³ / h, and the hot air circulation speed is maintained at 0.9~1.3m / s.
2. The microwave hot air glass fiber shaping process according to claim 1, characterized in that, The optimal process parameters for the preheating and temperature equalization section are: 100℃ for the shaping cavity, 60min for the heat preservation time, 2.0kW / m³ for the microwave power density, 1000m³ / h for the exhaust air volume, and 1.0m / s for the hot air circulation speed.
3. The microwave hot air glass fiber shaping process according to claim 1, characterized in that, The optimal process parameters for the deep penetration and shaping section are: shaping chamber temperature 125℃, heat preservation time 180min, microwave power density 2.5kW / m³, exhaust air volume 1500m³ / h, and hot air circulation speed 1.2m / s.
4. The microwave hot air glass fiber shaping process according to claim 1, characterized in that, The optimal process parameters for the high-temperature curing and stabilization section are: sizing cavity temperature 135℃, heat preservation time 120min, microwave power density 1.2kW / m³, exhaust air volume 800m³ / h, and hot air circulation speed 0.9m / s.
5. The microwave hot air glass fiber shaping process according to claim 1, characterized in that, The cooling gradient of the stepped cooling and shaping section is as follows: the first gradient is from 135℃ to 110℃, and the temperature is held for 10~15 minutes; the second gradient is from 110℃ to 80℃, and the temperature is held for 10~15 minutes; the third gradient is from 80℃ to 60℃, and the temperature is held for 10~20 minutes; the total cooling time is controlled to be 45 minutes, and the final discharge temperature is stabilized at 60℃.
6. The microwave hot air glass fiber setting process according to claim 1, characterized in that, The hot air temperature uniformity deviation of the hot air circulation system is controlled within ±3℃, and the temperature difference between any two points inside the shaping cavity does not exceed 4℃.
7. The microwave hot air glass fiber shaping process according to claim 1, characterized in that, The dehumidification system adopts a variable frequency air volume control mode, which can automatically adjust the dehumidification air volume according to the real-time humidity value inside the shaping cavity. The preheating and temperature equalization section and the deep penetration shaping section maintain a high air volume for dehumidification, the high temperature curing and stabilization section reduces the air volume to maintain the temperature stability inside the cavity, and the stepped cooling shaping section maintains a medium air volume to quickly remove residual heat and moisture.
8. The microwave hot air glass fiber shaping process according to claim 1, characterized in that, The process is applicable to the setting of glass fiber yarn balls and yarn cakes weighing 5kg to 50kg, as well as continuous roll glass fiber cloth and multi-strand glass fiber yarn, and is especially suitable for setting ultra-large glass fiber yarn balls weighing 40kg.
9. The microwave hot air glass fiber shaping process according to claim 1, characterized in that, After the glass fiber products are shaped using this process, the moisture content is ≤0.08%, the stiffness compliance rate is ≥99.5%, and the dimensional deformation rate is ≤0.3%.
10. A microwave hot air glass fiber setting process according to any one of claims 1 to 9, characterized in that, The total setting time for the four continuous control stages is controlled within 5 to 10 hours, and there are no yarn bursting, brittleness, or local overheating and yellowing during the setting process.