Method for preparing high-strength quartz fiber board through roll forming

Abstract

The invention belongs to the technical field of ceramic fiber board preparation, and relates to a method for preparing a high-strength quartz fiber board through roll forming, which is characterized by comprising the following steps: (1) adding fused quartz powder, a mixed solution of water and silica sol, and an aqueous solution of carboxymethyl cellulose and polyvinyl alcohol into a pug mill together to prepare a mud blank; (2) repeatedly rolling the mud blank in a roller press to uniformly mix the components in the mud blank; (3) wrapping part of the chopped quartz fibers with the mud blank, and repeatedly rolling in a roller press to disperse the fibers in the mud blank; (4) wrapping the residual chopped quartz fiber with the mud blank, and repeatedly rolling in a roller press to uniformly disperse the wrapped fiber; and (5) rolling and leveling the mud blank containing the fibers on a plate making machine to prepare a flat plate, cutting, drying and grinding the flat plate, and sintering. The distribution direction of fibers in the fiberboard is carded through rolling forming, the utilization rate of the fibers in the stress direction is increased, and the mechanical property and toughness of the quartz fiberboard are greatly improved.

Description

Technical Field

[0001] This invention relates to the field of ceramic materials, and more specifically to a method for preparing high-strength quartz fiberboard by roll forming. Background Technology

[0002] High-strength, high-toughness ceramic fiberboard is a structural component used in high-temperature environments, primarily in conditions requiring high temperature and pressure and specific thermal insulation properties. A typical application is in the high-temperature hot-pressing process for manufacturing diamond composite cutting tools. To protect the graphite mold in this high-temperature, high-pressure environment, it needs to be secured with metal hoops to increase its pressure resistance and lifespan. In practical applications, the graphite mold must be insulated from the metal hoops to prevent current flow and high temperatures, while simultaneously preventing heat transfer from the mold to the metal hoops to ensure their mechanical properties. Therefore, a gasket with high-temperature, high-pressure resistance and electrical and thermal insulation properties needs to be placed between the graphite mold and the metal hoops to ensure insulation and reduce heat transfer. Currently, calcium silicate boards and surface-hardened fiberboard products are commonly used as insulating gaskets in high-temperature hot-pressing processes. However, these materials are difficult to use for extended periods under the high pressure of hot-pressing, and their high price and short service life significantly increase the production cost of diamond composite cutting tools. Summary of the Invention

[0003] In view of the fact that current calcium silicate insulation boards, traditional fiberboards and porous insulation materials have low compressive strength or poor toughness and cannot be used in high temperature and high pressure environments, the purpose of this invention is to propose a method for preparing high-strength quartz fiberboard by roll forming.

[0004] To achieve the above objectives, the present invention employs the following technical solution: A method for preparing high-strength quartz fiberboard by roll forming is characterized by: sequentially mixing fused quartz powder, a water and silica sol mixture, and an aqueous solution composed of carboxymethyl cellulose and PVA to form a plastic blank; placing the plastic blank in a ply mill to remove air bubbles and uniformly mix the adhesive components in the plastic blank; wrapping 20% ​​to 50% of the total fiber content of chopped fused quartz fibers in the plastic blank and repeatedly rolling it in a mixer, wherein the entire blank is rolled at least 20 times until the wrapped fibers are uniformly dispersed in the blank; then wrapping the remaining chopped fused quartz fibers in the plastic blank and repeatedly rolling it in a roll mill until the fibers are uniformly dispersed in the blank; rolling the blank containing uniformly dispersed fibers into a flat plate of a certain thickness on a plate press, and then sintering it after drying and leveling processes.

[0005] The fused silica powder is fused silica powder with a particle size of 5000 mesh.

[0006] The mass ratio of water to silica sol in the mixed solution of water and silica sol is 7:3; the aqueous solution of carboxymethyl cellulose and PVA has a mass fraction of 3w for carboxymethyl cellulose and 5w for PVA.

[0007] The mass ratio of the fused silica powder, the water and silica sol mixture, and the aqueous solution composed of carboxymethyl cellulose and PVA is 150:100:10.

[0008] The mass ratio of chopped fused silica fiber to fused silica powder is 2 to 10:100; wherein the mass ratio of fused silica fiber to fused silica powder in low-toughness fiberboard is 2:100, and the mass ratio of chopped fused silica fiber to fused silica powder in high-toughness fiberboard is 10:100.

[0009] The fiberboard drying process involves first drying slowly in a cool, windless place for more than 36 hours; then transferring the fiberboard to a 60°C oven for drying for 24 hours. The leveling process involves using a polishing machine to polish both sides of the fiberboard, thereby smoothing the surface of the fiberboard and ensuring that the thickness and flatness of the fiberboard meet the application requirements.

[0010] The sintering temperature is between 700 and 1000℃, with the ultra-high strength quartz fiber board sintering at 1000℃ and the high toughness low strength quartz fiber board sintering at 750℃.

[0011] The sintering temperature is between 700 and 1000℃, wherein the sintering temperature of the ultra-high strength quartz ceramic fiber board is 1000℃, and the sintering temperature of the high toughness low strength quartz ceramic fiber board is 750℃.

[0012] This invention proposes a method for preparing high-strength quartz fiberboard by roll forming. The method involves repeatedly roll-forming a plastic blank containing chopped quartz fibers to uniformly disperse the fibers within the blank. Following board making, drying, leveling, and sintering processes, a high-strength, high-toughness quartz fiberboard with uniformly dispersed fibers is obtained. The fiberboard prepared by this process features uniform internal fiber distribution, controllable fiber direction, and a simple preparation process. The high strength, high toughness, low coefficient of thermal expansion, and low thermal conductivity of the quartz fiberboard fully meet the production requirements of high-temperature hot-pressing processes. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of quartz fibers that are oriented and uniformly dispersed. Detailed Implementation

[0014] The specific embodiments of the present invention will be described in detail below; however, the present invention can be implemented in various different forms and is not limited to the embodiments described herein. The present invention will be further described in conjunction with embodiments: Example 1:

[0015] 1. In batches, 1.5 kg of 5000 mesh fused silica powder, 1 kg of water and sol mixture, and 20 g of carboxymethyl cellulose and PVA aqueous solution are simply mixed and put into a ply maker for stirring. During the ply maker process, air bubbles in the ply are removed. 2. Mix the adhesive and other components in the clay blank evenly to form a plastic clay blank. Remove the kneaded clay blank and shape it into a cake. Add 15 grams of chopped fused silica fiber, then repeatedly roll the clay blank with the added chopped fiber in a mixer to disperse the fibers encased in the clay blank; for example... Figure 1 As shown; 3. Wrap the remaining 15 grams of chopped fiber in the clay blank and roll it repeatedly 20 times in the roller press to make the wrapped fiber evenly dispersed in the clay blank. Roll the ceramic clay blank containing the evenly dispersed fiber into a flat plate of a certain thickness on the plate press. 4. Place the fiberboard in a cool, windless place to dry slowly. After drying for 36 hours, transfer it to a 60℃ oven and dry for another 24 hours. Then, use a polishing machine to finish the surface and reduce the thickness of the dried fiberboard to meet the usage requirements. 5. Heat-treat the fiberboard with the required dimensions and flatness at 750℃ for 3 hours to obtain a fiberboard with relatively low strength and low toughness (compressive strength 35MPa, flexural strength greater than or equal to 20MPa).

[0016] Example 2: 1. In batches, 1.5 kg of 5000 mesh fused silica powder, 1 kg of water and sol mixture, and 20 g of carboxymethyl cellulose and PVA aqueous solution are simply mixed and put into a ply maker for stirring. During the ply maker process, air bubbles in the ply are removed. 2. Mix the components such as adhesives in the clay blank evenly to make a plastic clay blank. Take out the kneaded clay blank and shape it into a cake. Add 50 grams of short-cut fused silica fiber to the cake, and then repeatedly roll the clay blank with the added short-cut fiber in a mixer to disperse the fiber wrapped in the clay blank; 3. Wrap the remaining 150 grams of chopped fibers in the clay blank and roll it repeatedly in the roller press 20 times to make the wrapped fibers evenly dispersed in the clay blank. Roll the ceramic clay blank containing evenly dispersed fibers into a flat plate of a certain thickness on the plate press. 4. Place the fiberboard in a cool, windless place to dry slowly. After drying for 36 hours, transfer it to a 60℃ oven and dry for another 24 hours. Then, use a polishing machine to finish the surface and reduce the thickness of the dried fiberboard to meet the usage requirements. 5. Fiberboards that meet the requirements for appearance, dimensions and flatness are heat-treated at 850℃ for 3 hours to obtain fiberboards with relatively low strength and high toughness (compressive strength 40MPa, flexural strength greater than or equal to 30MPa).

[0017] Example 3: 1. In batches, 1.5 kg of 5000 mesh fused silica powder, 1 kg of water and sol mixture, and 20 g of aqueous solution composed of glycerol, carboxymethyl cellulose and PVA are simply mixed and put into a ply maker for stirring. During the ply maker process, air bubbles in the clay are removed. 2. Mix the components such as adhesives in the clay blank evenly to make a plastic clay blank. Take out the kneaded clay blank and shape it into a cake. Add 50 grams of short-cut fused silica fiber to the cake, and then repeatedly roll the clay blank with the added short-cut fiber in a mixer to disperse the fiber wrapped in the clay blank; 3. Wrap the remaining 150 grams of chopped fibers in the clay blank and roll it repeatedly in the roller press 20 times to make the wrapped fibers evenly dispersed in the clay blank. Roll the ceramic clay blank containing evenly dispersed fibers into a flat plate of a certain thickness on the plate press. 4. Place the fiberboard in a cool, windless place to dry slowly. After drying for 36 hours, transfer it to a 60℃ oven and dry for another 24 hours. Then, use a polishing machine to finish the surface and reduce the thickness of the dried fiberboard to meet the usage requirements. 5. Heat-treat the fiberboard with the required appearance, dimensions and flatness at 1000℃ for 1 hour to obtain a fiberboard with relatively high strength and medium toughness (compressive strength greater than 55MPa, flexural strength greater than or equal to 25MPa).

Claims

1. A method for preparing high-strength quartz fiberboard by roll forming, characterized in that: A plastic clay blank is prepared by sequentially mixing fused silica powder, a water and silica sol mixture, and an aqueous solution of carboxymethyl cellulose and PVA. The plastic clay blank is then placed in a ply mill to remove air bubbles and ensure uniform mixing of the adhesive components. Short-cut fused silica fibers, comprising 20%–50% of the total fiber content, are wrapped in the plastic clay blank and repeatedly rolled in a mixer, with the entire blank being rolled at least 20 times until the wrapped fibers are evenly dispersed within the blank. The remaining short-cut fused silica fibers are then wrapped in the plastic clay blank and repeatedly rolled in a roller press until the fibers are evenly dispersed within the blank. The blank containing the evenly dispersed fibers is then rolled into a flat plate of a certain thickness on a plate press, and after drying and leveling, sintered.

2. The method for preparing high-strength quartz fiberboard by roll forming as described in claim 1, characterized in that: The fused silica powder is fused silica powder with a particle size of 5000 mesh.

3. The method for preparing high-strength quartz fiberboard by roll forming as described in claim 1, characterized in that: The mass ratio of water to silica sol in the mixed solution of water and silica sol is 7:3; the aqueous solution of carboxymethyl cellulose and PVA has a mass fraction of 3w for carboxymethyl cellulose and 5w for PVA.

4. The method for preparing high-strength quartz fiberboard by roll forming as described in claim 1, characterized in that: The mass ratio of the fused silica powder, the water and silica sol mixture, and the aqueous solution composed of carboxymethyl cellulose and PVA is 150:100:

10.

5. The method for preparing high-strength quartz fiberboard by roll forming as described in claim 1, characterized in that: The mass ratio of chopped fused silica fiber to fused silica powder is 2 to 10:100; wherein the mass ratio of fused silica fiber to fused silica powder in low-toughness fiberboard is 2:100, and the mass ratio of chopped fused silica fiber to fused silica powder in high-toughness fiberboard is 10:

100.

6. The method for preparing high-strength quartz fiberboard by roll forming as described in claim 1, characterized in that: The fiberboard drying process involves first drying slowly in a cool, windless place for more than 36 hours; then transferring the fiberboard to a 60°C oven for drying for 24 hours.

7. The method for preparing high-strength quartz fiberboard by roll forming as described in claim 1, characterized in that: The leveling process involves using a polishing machine to polish both sides of the fiberboard, thereby smoothing the surface of the fiberboard and ensuring that the thickness and flatness of the fiberboard meet the application requirements.

8. The method for preparing high-strength quartz fiberboard by roll forming as described in claim 1, characterized in that: The sintering temperature is between 700 and 1000℃, with the ultra-high strength quartz fiber board sintering at 1000℃ and the high toughness low strength quartz fiber board sintering at 750℃.

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