Aluminum silicate fiber composite material and preparation method thereof

Abstract

The invention provides an aluminum silicate fiber composite material and a preparation method thereof. The aluminum silicate fiber composite material is obtained by compounding aluminum silicate fibers and a curing agent, the content of aluminum oxide in the aluminum silicate fiber is greater than or equal to 43 wt%; the solid content of the curing agent is 20-40%; the density of the aluminum silicate fiber composite material is greater than or equal to 180kg / The aluminum silicate fiber with the aluminum oxide content larger than or equal to 43 wt% and the curing agent with the solid content of 20-40% are compounded, the obtained aluminum silicate fiber composite material has a synergistic effect on the composition level, the density is remarkably improved, the performance target that the density is larger than or equal to 180 kg / m < 3 > is achieved, and meanwhile the performance targets of high bending strength, excellent high-temperature resistance and high stability are achieved; therefore, the specific material combination fundamentally overcomes the problems of low density, insufficient mechanical strength, poor high-temperature resistance and the like of a traditional aluminum silicate fiber product, and can be suitable for non-bearing scenes such as low-temperature heat insulation gaskets, light fireproof partition plates and the like.

Description

Technical Field

[0001] This invention belongs to the field of thermal insulation materials technology, specifically relating to an aluminum silicate fiber composite material and its preparation method. Background Technology

[0002] Currently, aluminum silicate fiber products are mainly produced using two processes: one is high-temperature sintering, with a product density >300 kg / m³. 3 Firstly, it has poor flexibility and is not suitable for lightweight applications; secondly, the resin bonding process, although having a low density (<160kg / m³), 3 However, its temperature resistance limit is <200℃, and the curing process releases a large amount of VOCs (emissions of 50-80 kg / ton), polluting the environment.

[0003] The market has an urgent need for composite materials with a density of ≥180kg / m³ (ensuring structural stability), a bending strength of about 5MPa (suitable for non-load-bearing requirements), and a temperature resistance of ≥800℃ (meeting the requirements for medium and low temperature thermal insulation). However, traditional technologies have the following drawbacks: (1) The combination of silica sol and aluminum silicate fiber blankets is mostly achieved through spraying processes. The silica sol is unevenly distributed, resulting in large fluctuations in product strength (3-8MPa) and difficulty in exceeding 160kg / m³ in density. 3 (2) The fiber blanket is easily deformed and delaminated when soaked and cured without the use of a special mold, with a size deviation of > ±2mm and poor performance stability. (3) When the alumina content of the aluminum silicate fiber blanket is <40% and the silica sol solid content is <20%, the product's temperature resistance and density cannot meet the standards.

[0004] Therefore, an aluminum silicate fiber composite material is provided that combines high density, high flexural strength, excellent high temperature resistance, and high stability, so as to achieve precise and controllable performance. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to provide an aluminosilicate fiber composite material and its preparation method. This invention combines aluminosilicate fibers with an alumina content ≥43wt% with a curing agent having a solid content of 20-40%, resulting in a synergistic effect at the compositional level of the aluminosilicate fiber composite material, achieving a significant increase in density to ≥180 kg / m³. 3 While achieving the performance goals of high bending strength, excellent high temperature resistance and high stability, this specific material combination fundamentally overcomes the problems of low density, insufficient mechanical strength and poor high temperature resistance of traditional aluminum silicate fiber products, and can be applied to non-load-bearing scenarios such as low temperature insulation pads and lightweight fireproof partitions.

[0006] To achieve this objective, the present invention employs the following technical solution:

[0007] In a first aspect, the present invention provides an aluminum silicate fiber composite material, wherein the aluminum silicate fiber composite material is obtained by combining aluminum silicate fibers and a curing agent.

[0008] The alumina content in the aluminosilicate fiber is ≥43wt%; the solid content of the curing agent is 20-40%; and the density of the aluminosilicate fiber composite material is ≥180kg / m³. 3 .

[0009] This invention achieves a significant increase in density by combining aluminosilicate fibers with an alumina content of ≥43wt% with a curing agent with a solid content of 20-40%. This allows the resulting aluminosilicate fiber composite material to exhibit synergistic effects at the compositional level, resulting in a density ≥180 kg / m³. 3 While achieving the performance goals of high bending strength, excellent high temperature resistance and high stability, this specific material combination fundamentally overcomes the problems of low density, insufficient mechanical strength and poor high temperature resistance of traditional aluminum silicate fiber products, and can be applied to non-load-bearing scenarios such as low temperature insulation pads and lightweight fireproof partitions.

[0010] In this invention, the alumina content in the aluminosilicate fiber is ≥43wt%, for example, it can be 43wt%, 45wt%, 47wt%, 50wt%, 55wt%, or 58wt%, etc.; the solid content of the curing agent is 20-40%, for example, it can be 20%, 30%, or 40%, etc.; the density of the aluminosilicate fiber composite material is ≥180kg / m³. 3 For example, it could be 180 kg / m 3 190kg / m 3 200kg / m 3 210kg / m 3 220kg / m 3 230kg / m 3 240kg / m 3 250kg / m 3 Or 260kg / m 3 wait.

[0011] It should be noted that the density test method can be the water displacement method (GB / T 5480.3-2004).

[0012] Preferably, the alumina content in the aluminosilicate fiber is 43-50 wt%, for example, it can be 43 wt%, 45 wt%, 47 wt%, or 50 wt%.

[0013] In this invention, the alumina content in the aluminosilicate fiber is limited to 43-50 wt%, which is beneficial for adapting to high-temperature environments and has certain economic advantages.

[0014] Preferably, the areal density of the aluminosilicate fiber is 300-600 g / m³. 2 For example, it could be 300g / m 2 400g / m 2 500g / m 2 Or 600g / m 2 wait.

[0015] Preferably, the thickness of the aluminum silicate fiber is 8-20 mm, for example, it can be 8 mm, 10 mm, 15 mm or 20 mm.

[0016] Preferably, the diameter of the aluminum silicate fiber is 8-20 μm, for example, it can be 8 μm, 10 μm, 15 μm or 20 μm.

[0017] Preferably, the porosity of the aluminum silicate fiber is 80-95%, for example, it can be 80%, 85%, 90% or 95%.

[0018] In this invention, the appropriate porosity of the aluminum silicate fiber is conducive to the rapid intrusion of silica sol.

[0019] Preferably, the curing agent is silica sol. It should be noted that silica sol is a colloidal solution, specifically a dispersion of nano-sized silica particles in water or a solvent.

[0020] Preferably, in the silica sol, the particle size D50 of the silica particles is 8-50nm, for example, it can be 8nm, 10nm, 15nm, 20nm, 30nm, 40nm or 50nm, etc.

[0021] Preferably, the pH of the silica sol is 8-9, for example, it can be 8, 8.2, 8.4, 8.6, 8.8 or 9.

[0022] Preferably, the sodium ion content in the silica sol is ≤0.2wt%, for example, it can be 0.2wt%, 0.15wt%, 0.1wt%, or 0.05wt%.

[0023] Preferably, the viscosity of the silica sol is 5-25 mPa·s, for example, it can be 5 mPa·s, 8 mPa·s, 10 mPa·s, 15 mPa·s, 20 mPa·s, or 25 mPa·s. A suitable viscosity ensures easy penetration and prevents aggregation during immersion.

[0024] Preferably, the density of the aluminosilicate fiber composite material is 180-250 kg / m³. 3 For example, it could be 180 kg / m 3 190kg / m 3 200kg / m 3 210kg / m3 220kg / m 3 230kg / m 3 240kg / m 3 Or 250kg / m 3 wait.

[0025] Preferably, the flexural strength of the aluminum silicate fiber composite material is 4.5-5.5 MPa, for example, it can be 4.5 MPa, 5 MPa, or 5.5 MPa. It should be noted that the flexural strength can be tested using the three-point bending method (span 50 mm, loading speed 2 mm / min, GB / T 9341-2008).

[0026] Preferably, the volume shrinkage rate of the aluminum silicate fiber composite material is ≤2%, for example, it can be 2%, 1.5%, 1% or 0.5%, etc. It should be noted that the volume shrinkage rate is measured by vernier calipers (difference in dimensions before and after curing and drying, GB / T 15585-1995).

[0027] Preferably, the thermal conductivity of the aluminosilicate fiber composite material is ≤0.05 W / (m·K), for example, it can be 0.05 W / (m·K), 0.04 W / (m·K), 0.03 W / (m·K), 0.02 W / (m·K), or 0.01 W / (m·K), etc. It should be noted that the thermal conductivity is tested using the hot-wire method (GB / T 10294-2008).

[0028] Preferably, the moisture content of the aluminum silicate fiber composite material is ≤0.5%, for example, it can be 0.5%, 0.4%, 0.3%, 0.2%, or 0.1%, etc. It should be noted that the moisture content is tested by placing a sample into a moisture content meter for testing.

[0029] Preferably, the water absorption rate of the aluminum silicate fiber composite material after soaking for 24 hours is ≤5%, for example, it can be 5%, 4%, 3%, 2% or 1%, etc. It should be noted that the test method for water absorption rate is the weight change rate after soaking for 24 hours (GB / T 1733-1993).

[0030] The aluminum silicate fiber composite material provided by this invention meets the above functional indicators, can maintain a certain strength while being lightweight, has a high temperature resistance, good insulation, and excellent thermal insulation performance.

[0031] In a second aspect, the present invention provides a method for preparing the aluminum silicate fiber composite material as described in the first aspect, the method comprising the following steps:

[0032] The invention provides aluminum silicate fiber and a curing agent; wherein the aluminum silicate fiber contains ≥43wt% alumina; and the curing agent has a solid content of 20-40%.

[0033] The aluminum silicate fiber is fixed in a porous mold and then transferred to the curing agent for immersion treatment to obtain a preform.

[0034] The preform is cured and dried to obtain the aluminum silicate fiber composite material; the density of the aluminum silicate fiber composite material is ≥180 kg / m³. 3 .

[0035] This invention uses aluminosilicate fibers with an alumina content ≥43wt% as the base material, and a curing agent with a solid content of 20-40% as an aid. It is prepared through a process of "fixing with a porous mold + soaking-curing + drying," thereby achieving synergistic effects at both the material and process levels. This results in thorough wetting, uniform compounding, and structural shaping of the aluminosilicate fibers and curing agent, leading to an aluminosilicate fiber composite material with a density ≥180kg / m³. 3 While achieving the performance targets, this process also realizes high flexural strength, excellent high-temperature resistance, and high stability. Specifically, the fixed porous mold ensures that the aluminosilicate fibers maintain precise dimensions and morphology during immersion and curing, effectively eliminating fiber displacement, deformation, and delamination. The immersion treatment allows the high-solids-content curing agent to fully and uniformly penetrate into the aluminosilicate fibers, achieving deep wetting and uniform loading of the silica sol. Subsequent curing and drying ensure stable transformation and uniform shrinkage of the gel structure. In summary, this process system not only fundamentally overcomes the problems of uneven colloid distribution and large performance fluctuations caused by traditional spraying methods, as well as dimensional instability caused by moldless molding, but also has no VOC emissions throughout the process, possessing both good process repeatability and potential for large-scale production.

[0036] Preferably, the porous mold includes a base, a cavity module, and a cover plate; the base is provided with a groove for accommodating the cavity module, and a sealing ring is embedded in the groove; the cavity module is disposed in the groove, and the inner wall of the cavity module is provided with a protruding positioning element for positioning the aluminum silicate fiber; the cover plate covers the base and is fixedly connected to the base by a locking fastener, thereby sealing the cavity module.

[0037] The cover plate has several through holes for the flow of curing agent during the soaking process.

[0038] For example, the base may be made of polypropylene, and its dimensions may be 300mm × 300mm × 20mm; the cavity module may be made of polytetrafluoroethylene, and its dimensions may be 200mm × 200mm × 8mm (accuracy ±0.5mm); the cover may be made of polypropylene; the sealing ring may be made of nitrile rubber, and its cross-sectional diameter may be 5mm; the protruding positioning element may be made of plastic. "Several" refers to at least one, such as 1, 5, or 10; the diameter of the through hole may be 5mm, and the hole spacing may be 20mm.

[0039] Preferably, the protrusion height of the protrusion positioning member is 2-3mm, for example, it can be 2mm, 2.5mm or 3mm, etc.

[0040] Preferably, the number of the protruding positioning elements includes at least one, such as 1, 5, 10 or 20.

[0041] Preferably, the spacing between adjacent protruding positioning elements is 10-15mm, for example, it can be 10mm, 11mm, 12mm, 13mm, 14mm or 15mm.

[0042] Preferably, the locking device is a snap-fit.

[0043] Preferably, during the soaking process, the liquid level of the curing agent is ≥ the height of the porous mold + 50mm.

[0044] Preferably, during the soaking process, the temperature of the curing agent is 25-30°C, for example, it can be 25%, 26%, 27%, 28%, 29% or 30%, etc.

[0045] Preferably, the soaking time is 20-40 minutes, for example, 20 minutes, 30 minutes or 40 minutes.

[0046] Preferably, based on the weight of the aluminum silicate fiber, the content of the curing agent in the preform is 25-50 wt%, for example, it can be 25 wt%, 30 wt%, 35 wt%, 40 wt%, 45 wt%, or 50 wt%.

[0047] In this invention, after soaking at a specific temperature and time, the content of curing agent in the preform is 25-50 wt%. This content allows a certain amount of silica to be preserved after the silica sol is dried. If the content is too low, the curing strength will be too low, and if the content is too high, the strength will be too high and the flexibility will not be maintained.

[0048] Preferably, the curing temperature is 40-60℃, for example, 40℃, 50℃ or 60℃.

[0049] Preferably, the curing time is 4-8 hours, for example, 4 hours, 5 hours, 6 hours, 7 hours or 8 hours.

[0050] In this invention, by combining specific temperature and time during the curing process, the conversion rate of silica sol adsorbed by aluminosilicate fibers to silica can be ensured to be ≥90%. It should be noted that the conversion rate can be detected using thermogravimetric analysis (TGA).

[0051] Preferably, the drying process includes a first stage of drying and a second stage of drying performed by sequentially increasing the temperature.

[0052] Preferably, the drying temperature of the first drying stage is 80-90℃, for example, 80℃, 85℃ or 90℃, and the drying time is 1.5-2h, for example, 1.5h, 1.6h, 1.7h, 1.8h, 1.9h or 2h.

[0053] In this invention, the first stage of drying is carried out at a relatively low temperature, which can remove free water from the surface of the material.

[0054] Preferably, the drying temperature of the second drying stage is 110-120℃, for example, 110℃, 115℃ or 120℃, and the drying time is 1-1.5h, for example, 1h, 1.1h, 1.2h, 1.3h, 1.4h or 1.5h.

[0055] In this invention, the second stage of drying is carried out at a relatively high temperature, which can remove bound water from the material.

[0056] Preferably, the preparation method includes the following steps:

[0057] (1) Provide aluminum silicate fibers and silica sol;

[0058] The aluminum silicate fiber contains ≥43wt% alumina; the areal density of the aluminum silicate fiber is 300-600 g / m³. 2 The aluminum silicate fiber has a thickness of 8-20 mm; a fiber diameter of 8-20 μm; a porosity of 80-95%; a solid content of 20-40% in the curing agent; a particle size D50 of 8-50 nm in the silica sol; a pH of 8-9 in the silica sol; a sodium ion content ≤0.2 wt% in the silica sol; and a viscosity of 5-25 mPa·s.

[0059] (2) Pre-treatment of the aluminum silicate fiber includes the following steps: cutting the aluminum silicate fiber to the target size and then drying it at a temperature of 60-70℃ (e.g., 60℃, 65℃ or 70℃, etc.) to obtain aluminum silicate fiber with a moisture content of ≤0.8wt% (e.g., 0.8wt%, 0.6wt%, 0.8wt% or 0.2wt%, etc.).

[0060] The silica sol is pretreated by the following steps: allowing the silica solution to stand at room temperature, and then stirring it at a speed of 200-400 rpm (e.g., 200 rpm, 300 rpm, or 400 rpm) to obtain a uniformly dispersed silica sol.

[0061] (3) Provide a porous mold, lay the pretreated aluminum silicate fiber flat and fix it in the cavity module of the porous mold, and cover it with a cover plate to obtain the part to be impregnated.

[0062] The porous mold includes a base, a cavity module, and a cover plate. The base has a groove for accommodating the cavity module, and a sealing ring is embedded in the groove. The cavity module is disposed in the groove, and the inner wall of the cavity module has a protruding positioning element for positioning the aluminum silicate fiber. The cover plate covers the base and is fixedly connected to the base by fasteners, thereby sealing the cavity module. The cover plate has several through holes for the inflow and outflow of solid solution during the immersion treatment.

[0063] (4) Immerse the part to be impregnated into the pretreated silica sol to soak the aluminum silicate fiber in the porous mold to obtain a porous mold containing the preform.

[0064] During the soaking process, the temperature of the silica sol is 25-30℃; the soaking time is 20-40 min; and the silica sol content in the preform is 25-50 wt% based on the weight of the aluminum silicate fiber.

[0065] (5) Take out the porous mold containing the preform and perform draining and curing treatment so that ≥90% (e.g., 90%, 92%, 94%, 96% or 98% etc.) of the silica sol in the preform is converted into silica to obtain a blank; wherein, the draining treatment time is 8-15min (e.g., 8min, 10min, 12min or 15min etc.); the curing treatment temperature is 40-60℃ and the time is 4-8h.

[0066] (6) The blank is dried in the first stage and the second stage, and then taken out from the porous mold and cooled for 10-24h (e.g., 10h, 16h, 18h or 24h) to obtain aluminum silicate fiber composite material.

[0067] The drying temperature of the first stage is 80-90℃ and the drying time is 1.5-2h; the drying temperature of the second stage is 110-120℃ and the drying time is 1-1.5h.

[0068] The numerical range described in this invention includes not only the point values ​​listed above, but also any point values ​​within the numerical ranges not listed above. Due to space limitations and for the sake of brevity, this invention will not exhaustively list all the specific point values ​​included in the range.

[0069] Compared with the prior art, the present invention has the following beneficial effects:

[0070] (1) This invention combines aluminosilicate fibers with an alumina content of ≥43wt% with a curing agent with a solid content of 20-40%, resulting in a synergistic effect at the composition level of the aluminosilicate fiber composite material, achieving a significant increase in density to ≥180kg / m³. 3 While achieving the performance goals of high bending strength, excellent high temperature resistance and high stability, this specific material combination fundamentally overcomes the problems of low density, insufficient mechanical strength and poor high temperature resistance of traditional aluminum silicate fiber products, and can be applied to non-load-bearing scenarios such as low temperature insulation pads and lightweight fireproof partitions.

[0071] (2) This invention uses aluminosilicate fibers with an alumina content ≥43wt% as the base material, and a curing agent with a solid content of 20-40% as an aid. It is prepared by a process of "fixing with a porous mold + soaking-curing + drying". This achieves synergistic effect at the material and process levels, realizing full wetting, uniform compounding and structural shaping of aluminosilicate fibers and curing agents, so that the resulting aluminosilicate fiber composite material achieves a density ≥180kg / m³. 3 While achieving the performance targets, this process also realizes high flexural strength, excellent high-temperature resistance, and high stability. Specifically, the fixed porous mold ensures that the aluminosilicate fibers maintain precise dimensions and morphology during immersion and curing, effectively eliminating fiber displacement, deformation, and delamination. The immersion treatment allows the high-solids-content curing agent to fully and uniformly penetrate into the aluminosilicate fibers, achieving deep wetting and uniform loading of the silica sol. Subsequent curing and drying ensure stable transformation and uniform shrinkage of the gel structure. In summary, this process system not only fundamentally overcomes the problems of uneven colloid distribution and large performance fluctuations caused by traditional spraying methods, as well as dimensional instability caused by moldless molding, but also has no VOC emissions throughout the process, possessing both good process repeatability and potential for large-scale production. Detailed Implementation

[0072] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0073] Example 1

[0074] This embodiment provides an aluminum silicate fiber composite material, which is obtained by combining aluminum silicate fibers and silica sol.

[0075] The aluminum silicate fiber contains 43 wt% alumina and has a surface density of 300 g / m³. 2 The aluminum silicate fiber has a thickness of 8 mm; a fiber diameter of 8 μm; a porosity of 95%; a solid content of 20%; a particle size D50 of 20 nm for silica particles; a pH of 8; a sodium ion content of 0.15 wt%; and a viscosity of 8 mPa·s.

[0076] The preparation method of the aluminum silicate fiber composite material includes the following steps:

[0077] (1) The aluminum silicate fiber is used as the substrate and the silica sol is used as the curing agent.

[0078] (2) The aluminum silicate fiber is pretreated by cutting the aluminum silicate fiber to the target size (200mm×200mm) and then drying it at 65°C for 2 hours to obtain aluminum silicate fiber with a water content of 0.6wt%.

[0079] The silica sol is pretreated by: letting the silica solution stand at 28°C for 20 minutes, and then stirring at 300 rpm for 15 minutes to obtain a uniformly dispersed silica sol.

[0080] (3) Provide a porous mold, lay the pretreated aluminum silicate fiber flat and fix it in the cavity module of the porous mold, attach the protruding positioning piece, and cover the cover plate so that the positioning piece is embedded in the surface of the aluminum silicate fiber to obtain the part to be impregnated.

[0081] The porous mold includes a polypropylene base (300mm×300mm×20mm), a polytetrafluoroethylene cavity module (200mm×200mm×8mm), and a polypropylene cover plate. The base has a groove for accommodating the cavity module, and a nitrile rubber sealing ring is embedded within the groove. The cavity module is positioned within the groove, and its inner wall has several plastic protrusions for positioning the aluminum silicate fibers. The cover plate is fitted onto the base and fixedly connected to it via snap-fit ​​mechanisms, thereby sealing the cavity module. The cover plate has several through holes for the inflow and outflow of the solid solution during the immersion process. The protrusion height of each protrusion is 2mm, and the distance between adjacent protrusions is 10mm. The diameter of each through hole is 5mm, and the spacing between the holes is 20mm.

[0082] (4) Immerse the part to be impregnated into the pretreated silica sol, ensuring that the height of the silica sol is greater than or equal to the height of the porous mold + 50 mm, and soak the aluminum silicate fiber in the porous mold to obtain a porous mold containing the preform.

[0083] During the soaking process, the temperature of the silica sol is 28°C; the soaking time is 40 minutes; and the content of silica sol in the preform is 35 wt% based on the weight of the aluminum silicate fiber.

[0084] (5) Take out the porous mold containing the preform and drain it upside down for 12 minutes until there is no dripping. Then, perform a curing treatment in a constant temperature oven at 60°C for 6 hours to convert the silica sol in the preform into silica with a conversion rate of 92% to obtain the blank.

[0085] (6) The blank is dried in the first stage and the second stage to reduce the moisture content to 0.4%. Then it is taken out from the porous mold and cooled naturally for 18 hours to obtain aluminum silicate fiber composite material.

[0086] The first stage of drying is performed at a temperature of 85°C for 2 hours; the second stage of drying is performed at a temperature of 115°C for 1.2 hours.

[0087] Example 2

[0088] This embodiment provides an aluminum silicate fiber composite material, which is obtained by combining aluminum silicate fibers and silica sol.

[0089] The aluminum silicate fiber contains 43 wt% alumina and has a surface density of 300 g / m³. 2The aluminum silicate fiber has a thickness of 8 mm; a fiber diameter of 8 μm; a porosity of 95%; a solid content of 25%; a particle size D50 of 20 nm for silica particles; a pH of 8.2; a sodium ion content of 0.15 wt%; and a viscosity of 12 mPa·s.

[0090] The preparation method of the aluminum silicate fiber composite material includes the following steps:

[0091] (1) The aluminum silicate fiber is used as the substrate and the silica sol is used as the curing agent.

[0092] (2) The aluminum silicate fiber is pretreated by cutting the aluminum silicate fiber to the target size (200mm×200mm) and then drying it at 65°C for 1.8h to obtain aluminum silicate fiber with a water content of 0.7wt%.

[0093] The silica sol is pretreated by the following steps: the silica solution is allowed to stand at 27°C for 20 minutes, and then stirred at 350 rpm for 15 minutes to obtain a uniformly dispersed silica sol.

[0094] (3) Same as Example 1.

[0095] (4) Immerse the part to be impregnated into the pretreated silica sol, ensuring that the height of the silica sol is greater than or equal to the height of the porous mold + 50 mm, and soak the aluminum silicate fiber in the porous mold to obtain a porous mold containing the preform.

[0096] During the soaking process, the temperature of the silica sol is 27°C; the soaking time is 35 minutes; and the content of silica sol in the preform is 40 wt% based on the weight of the aluminum silicate fiber.

[0097] (5) Take out the porous mold containing the preform and drain it upside down for 10 minutes until there is no dripping. Then, perform a curing treatment in a constant temperature oven at 55°C for 5 hours to convert the silica sol in the preform into silica with a conversion rate of 93% to obtain the blank.

[0098] (6) The blank is dried in the first stage and the second stage to reduce the moisture content to 0.4%. Then it is taken out from the porous mold and naturally cooled for 15 hours to obtain aluminum silicate fiber composite material.

[0099] The first stage of drying is performed at a temperature of 85°C for 1.8 hours; the second stage of drying is performed at a temperature of 115°C for 1 hour.

[0100] Example 3

[0101] This embodiment provides an aluminum silicate fiber composite material, which is obtained by combining aluminum silicate fibers and silica sol.

[0102] The aluminum silicate fiber contains 43 wt% alumina and has a surface density of 350 g / m³. 2 The aluminum silicate fiber has a thickness of 10 mm; a fiber diameter of 8 μm; a porosity of 92%; a solid content of 25%; a particle size D50 of 25 nm for silica particles; a pH of 8; a sodium ion content of 0.15 wt%; and a viscosity of 14 mPa·s.

[0103] The preparation method of the aluminum silicate fiber composite material includes the following steps:

[0104] (1) The aluminum silicate fiber is used as the substrate and the silica sol is used as the curing agent.

[0105] (2) The aluminum silicate fiber is pretreated by cutting the aluminum silicate fiber to the target size (200mm×200mm) and then drying it at 68°C for 1.6h to obtain aluminum silicate fiber with a water content of 0.5wt%.

[0106] The silica sol is pretreated by the following steps: the silica solution is allowed to stand at 29°C for 20 minutes, and then stirred at 320 rpm for 15 minutes to obtain a uniformly dispersed silica sol.

[0107] (3) The only difference from step (3) in Example 1 is that the size of the cavity module is 200mm×200mm×12mm, the protrusion height of the protrusion positioning member is 2.5mm, and the distance between adjacent protrusion positioning members is 12mm.

[0108] (4) Immerse the part to be impregnated into the pretreated silica sol, ensuring that the height of the silica sol is greater than or equal to the height of the porous mold + 50 mm, and soak the aluminum silicate fiber in the porous mold to obtain a porous mold containing the preform.

[0109] During the soaking process, the temperature of the silica sol is 29°C; the soaking time is 32 minutes; and the content of silica sol in the preform is 38 wt% based on the weight of the aluminum silicate fiber.

[0110] (5) Take out the porous mold containing the preform and drain it upside down for 12 minutes until there is no dripping. Then, perform a curing treatment in a constant temperature oven at 58°C for 5.5 hours to convert the silica sol in the preform into silica with a conversion rate of 91% to obtain the blank.

[0111] (6) The blank is dried in the first stage and the second stage to reduce the moisture content to 0.4%. Then it is taken out from the porous mold and naturally cooled for 15 hours to obtain aluminum silicate fiber composite material.

[0112] The drying temperature of the first stage is 88℃ and the drying time is 1.7h; the drying temperature of the second stage is 112℃ and the drying time is 1.1h.

[0113] Example 4

[0114] This embodiment provides an aluminum silicate fiber composite material, which is obtained by combining aluminum silicate fibers and silica sol.

[0115] The aluminum silicate fiber contains 45 wt% alumina and has a surface density of 400 g / m³. 2 The aluminum silicate fiber has a thickness of 12 mm; a fiber diameter of 8 μm; a porosity of 90%; a solid content of 25%; a particle size D50 of 30 nm for silica particles; a pH of 8; a sodium ion content of 0.15 wt%; and a viscosity of 10 mPa·s.

[0116] The preparation method of the aluminum silicate fiber composite material includes the following steps:

[0117] (1) The aluminum silicate fiber is used as the substrate and the silica sol is used as the curing agent.

[0118] (2) The aluminum silicate fiber is pretreated by cutting the aluminum silicate fiber to the target size (200mm×200mm) and then drying it at 66°C for 2 hours to obtain aluminum silicate fiber with a water content of 0.6wt%.

[0119] The silica sol is pretreated by the following steps: the silica solution is allowed to stand at 26°C for 20 minutes, and then stirred at 300 rpm for 15 minutes to obtain a uniformly dispersed silica sol.

[0120] (3) The only difference from step (3) in Example 1 is that the size of the cavity module is 200mm×200mm×12mm, the protrusion height of the protrusion positioning member is 3mm, and the distance between adjacent protrusion positioning members is 15mm.

[0121] (4) Immerse the part to be impregnated into the pretreated silica sol, ensuring that the height of the silica sol is greater than or equal to the height of the porous mold + 50 mm, and soak the aluminum silicate fiber in the porous mold to obtain a porous mold containing the preform.

[0122] During the soaking process, the temperature of the silica sol is 26°C; the soaking time is 30 minutes; and the content of silica sol in the preform is 35 wt% based on the weight of the aluminum silicate fiber.

[0123] (5) Take out the porous mold containing the preform and drain it upside down for 12 minutes until there is no dripping. Then, perform a curing treatment in a constant temperature oven at 56°C for 5 hours to convert the silica sol in the preform into silica with a conversion rate of 92% to obtain the blank.

[0124] (6) The blank is dried in the first stage and the second stage to reduce the moisture content to 0.4%. Then it is taken out from the porous mold and cooled naturally for 20 hours to obtain aluminum silicate fiber composite material.

[0125] The first stage of drying is performed at a temperature of 86°C for 1.8 hours; the second stage of drying is performed at a temperature of 110°C for 1.2 hours.

[0126] Example 5

[0127] This embodiment provides an aluminum silicate fiber composite material, which is obtained by combining aluminum silicate fibers and silica sol.

[0128] The aluminum silicate fiber contains 45 wt% alumina and has a surface density of 400 g / m³. 2 The aluminum silicate fiber has a thickness of 12 mm; a fiber diameter of 8 μm; a porosity of 90%; a solid content of 30%; a particle size D50 of 30 nm for silica particles; a pH of 8; a sodium ion content of 0.15 wt%; and a viscosity of 15 mPa·s.

[0129] The preparation method of the aluminum silicate fiber composite material includes the following steps:

[0130] (1) The aluminum silicate fiber is used as the substrate and the silica sol is used as the curing agent.

[0131] (2) The aluminum silicate fiber is pretreated by cutting the aluminum silicate fiber to the target size (200mm×200mm) and then drying it at 67°C for 1.7h to obtain aluminum silicate fiber with a water content of 0.5wt%.

[0132] The silica sol is pretreated by the following steps: the silica solution is allowed to stand at 28°C for 20 minutes, and then stirred at 380 rpm for 15 minutes to obtain a uniformly dispersed silica sol.

[0133] (3) Same as Example 4.

[0134] (4) Immerse the part to be impregnated into the pretreated silica sol, ensuring that the height of the silica sol is greater than or equal to the height of the porous mold + 50 mm, and soak the aluminum silicate fiber in the porous mold to obtain a porous mold containing the preform.

[0135] During the soaking process, the temperature of the silica sol is 28°C; the soaking time is 28 minutes; and the content of silica sol in the preform is 42 wt% based on the weight of the aluminum silicate fiber.

[0136] (5) Take out the porous mold containing the preform and drain it upside down for 12 minutes until there is no dripping. Then, perform a curing treatment in a constant temperature oven at 52°C for 4.5 hours to convert the silica sol in the preform into silica with a conversion rate of 94% to obtain the blank.

[0137] (6) The blank is dried in the first stage and the second stage to reduce the moisture content to 0.4%. Then it is taken out from the porous mold and naturally cooled for 15 hours to obtain aluminum silicate fiber composite material.

[0138] The first stage of drying is performed at a temperature of 87°C for 1.6 hours; the second stage of drying is performed at a temperature of 113°C for 1 hour.

[0139] Example 6

[0140] This embodiment provides an aluminum silicate fiber composite material, which is obtained by combining aluminum silicate fibers and silica sol.

[0141] The aluminum silicate fiber contains 45 wt% alumina and has a surface density of 450 g / m³. 2The aluminum silicate fiber has a thickness of 15 mm; a fiber diameter of 8 μm; a porosity of 88%; a solid content of 30%; a particle size D50 of 35 nm for silica particles; a pH of 8; a sodium ion content of 0.15 wt%; and a viscosity of 18 mPa·s.

[0142] The preparation method of the aluminum silicate fiber composite material includes the following steps:

[0143] (1) The aluminum silicate fiber is used as the substrate and the silica sol is used as the curing agent.

[0144] (2) The aluminum silicate fiber is pretreated by cutting the aluminum silicate fiber to the target size (200mm×200mm) and then drying it at 65°C for 2.2h to obtain aluminum silicate fiber with a water content of 0.7wt%.

[0145] The silica sol is pretreated by the following steps: the silica solution is allowed to stand at 27°C for 20 minutes, and then stirred at 350 rpm for 15 minutes to obtain a uniformly dispersed silica sol.

[0146] (3) The only difference from step (3) in Example 1 is that the size of the cavity module is 200mm×200mm×15mm, the protrusion height of the protrusion positioning member is 2.8, and the distance between adjacent protrusion positioning members is 14mm.

[0147] (4) Immerse the part to be impregnated into the pretreated silica sol, ensuring that the height of the silica sol is greater than or equal to the height of the porous mold + 50 mm, and soak the aluminum silicate fiber in the porous mold to obtain a porous mold containing the preform.

[0148] During the soaking process, the temperature of the silica sol is 27°C; the soaking time is 25 minutes; and the content of silica sol in the preform is 40 wt% based on the weight of the aluminum silicate fiber.

[0149] (5) Take out the porous mold containing the preform and drain it upside down for 12 minutes until there is no dripping. Then, perform a curing treatment in a constant temperature oven at 50°C for 4 hours to convert the silica sol in the preform into silica with a conversion rate of 93% to obtain the blank.

[0150] (6) The blank is dried in the first stage and the second stage to reduce the moisture content to 0.4%. Then it is taken out from the porous mold and cooled naturally for 20 hours to obtain aluminum silicate fiber composite material.

[0151] The first stage of drying is performed at a temperature of 85°C for 1.5 hours; the second stage of drying is performed at a temperature of 114°C for 1.1 hours.

[0152] Example 7

[0153] This embodiment provides an aluminum silicate fiber composite material, which is obtained by combining aluminum silicate fibers and silica sol.

[0154] The aluminum silicate fiber contains 47 wt% alumina and has a surface density of 500 g / m³. 2 The aluminum silicate fiber has a thickness of 15 mm; a fiber diameter of 8 μm; a porosity of 85%; a solid content of 30%; a particle size D50 of 40 nm for silica particles; a pH of 8; a sodium ion content of 0.15 wt%; and a viscosity of 20 mPa·s.

[0155] The preparation method of the aluminum silicate fiber composite material includes the following steps:

[0156] (1) The aluminum silicate fiber is used as the substrate and the silica sol is used as the curing agent.

[0157] (2) The aluminum silicate fiber is pretreated by cutting the aluminum silicate fiber to the target size (200mm×200mm) and then drying it at 69°C for 1.9h to obtain aluminum silicate fiber with a water content of 0.6wt%.

[0158] The silica sol is pretreated by the following steps: the silica solution is allowed to stand at 29°C for 20 minutes, and then stirred at 320 rpm for 15 minutes to obtain a uniformly dispersed silica sol.

[0159] (3) Same as Example 6.

[0160] (4) Immerse the part to be impregnated into the pretreated silica sol, ensuring that the height of the silica sol is greater than or equal to the height of the porous mold + 50 mm, and soak the aluminum silicate fiber in the porous mold to obtain a porous mold containing the preform.

[0161] During the soaking process, the temperature of the silica sol is 29°C; the soaking time is 25 minutes; and the content of silica sol in the preform is 38 wt% based on the weight of the aluminum silicate fiber.

[0162] (5) Take out the porous mold containing the preform and drain it upside down for 12 minutes until there is no dripping. Then, perform a curing treatment in a constant temperature oven at 48°C for 4.2 hours to convert the silica sol in the preform into silica with a conversion rate of 92% to obtain the blank.

[0163] (6) The blank is dried in the first stage and the second stage to reduce the moisture content to 0.4%. Then it is taken out from the porous mold and cooled naturally for 18 hours to obtain aluminum silicate fiber composite material.

[0164] The first stage of drying is performed at a temperature of 89°C for 1.7 hours; the second stage of drying is performed at a temperature of 111°C for 1.3 hours.

[0165] Example 8

[0166] This embodiment provides an aluminum silicate fiber composite material, which is obtained by combining aluminum silicate fibers and silica sol.

[0167] The aluminum silicate fiber contains 47 wt% alumina and has a surface density of 500 g / m³. 2 The aluminum silicate fiber has a thickness of 15 mm; a fiber diameter of 8 μm; a porosity of 85%; a solid content of 35%; a particle size D50 of 40 nm for silica particles; a pH of 8; a sodium ion content of 0.15 wt%; and a viscosity of 22 mPa·s.

[0168] The preparation method of the aluminum silicate fiber composite material includes the following steps:

[0169] (1) The aluminum silicate fiber is used as the substrate and the silica sol is used as the curing agent.

[0170] (2) The aluminum silicate fiber is pretreated by cutting the aluminum silicate fiber to the target size (200mm×200mm) and then drying it at 68°C for 2 hours to obtain aluminum silicate fiber with a water content of 0.5wt%.

[0171] The silica sol is pretreated by the following steps: the silica solution is allowed to stand at 28°C for 20 minutes, and then stirred at 400 rpm for 15 minutes to obtain a uniformly dispersed silica sol.

[0172] (3) Same as Example 6.

[0173] (4) Immerse the part to be impregnated into the pretreated silica sol, ensuring that the height of the silica sol is greater than or equal to the height of the porous mold + 50 mm, and soak the aluminum silicate fiber in the porous mold to obtain a porous mold containing the preform.

[0174] During the soaking process, the temperature of the silica sol is 28°C; the soaking time is 22 minutes; and the content of silica sol in the preform is 45 wt% based on the weight of the aluminum silicate fiber.

[0175] (5) Take out the porous mold containing the preform and drain it upside down for 12 minutes until there is no dripping. Then, perform a curing treatment in a constant temperature oven at 45°C for 4 hours to convert the silica sol in the preform into silica with a conversion rate of 95% to obtain the blank.

[0176] (6) The blank is dried in the first stage and the second stage to reduce the moisture content to 0.4%. Then it is taken out from the porous mold and cooled naturally for 20 hours to obtain aluminum silicate fiber composite material.

[0177] The first stage of drying is performed at a temperature of 88°C for 1.6 hours; the second stage of drying is performed at a temperature of 112°C for 1.2 hours.

[0178] Example 9

[0179] This embodiment provides an aluminum silicate fiber composite material, which is obtained by combining aluminum silicate fibers and silica sol.

[0180] The aluminum silicate fiber contains 50 wt% alumina; the areal density of the aluminum silicate fiber is 600 g / m³. 2 The aluminum silicate fiber has a thickness of 20 mm; a fiber diameter of 8 μm; a porosity of 80%; a solid content of 35%; a particle size D50 of 50 nm for silica particles; a pH of 8; a sodium ion content of 0.15 wt%; and a viscosity of 25 mPa·s.

[0181] The preparation method of the aluminum silicate fiber composite material includes the following steps:

[0182] (1) The aluminum silicate fiber is used as the substrate and the silica sol is used as the curing agent.

[0183] (2) The aluminum silicate fiber is pretreated by cutting the aluminum silicate fiber to the target size (200mm×200mm) and then drying it at 70°C for 2.5h to obtain aluminum silicate fiber with a water content of 0.4wt%.

[0184] The silica sol is pretreated by the following steps: the silica solution is allowed to stand at 30°C for 20 minutes, and then stirred at 380 rpm for 15 minutes to obtain a uniformly dispersed silica sol.

[0185] (3) The only difference from step (3) in Example 1 is that the size of the cavity module is 200mm×200mm×20mm, the protrusion height of the protrusion positioning member is 3mm, and the distance between adjacent protrusion positioning members is 15mm.

[0186] (4) Immerse the part to be impregnated into the pretreated silica sol, ensuring that the height of the silica sol is greater than or equal to the height of the porous mold + 50 mm, and soak the aluminum silicate fiber in the porous mold to obtain a porous mold containing the preform.

[0187] During the soaking process, the temperature of the silica sol is 30°C; the soaking time is 20 minutes; and the content of silica sol in the preform is 42 wt% based on the weight of the aluminum silicate fiber.

[0188] (5) Take out the porous mold containing the preform and drain it upside down for 12 minutes until there is no dripping. Then, perform a curing treatment in a constant temperature oven at 40°C for 8 hours to convert the silica sol in the preform into silica with a conversion rate of 94% to obtain the blank.

[0189] (6) The blank is dried in the first stage and the second stage to reduce the moisture content to 0.4%, and then it is taken out from the porous mold and cooled naturally for 12 hours to obtain aluminum silicate fiber composite material.

[0190] The first stage of drying is performed at a temperature of 90°C for 2 hours; the second stage of drying is performed at a temperature of 120°C for 1.5 hours.

[0191] Example 10

[0192] This embodiment provides an aluminum silicate fiber composite material, which is obtained by combining aluminum silicate fibers and silica sol.

[0193] The aluminum silicate fiber contains 48 wt% alumina and has a surface density of 450 g / m³. 2The aluminum silicate fiber has a thickness of 18 mm; a fiber diameter of 8 μm; a porosity of 86%; a solid content of 32%; a particle size D50 of 38 nm for silica particles; a pH of 8; a sodium ion content of 0.15 wt%; and a viscosity of 16 mPa·s.

[0194] The preparation method of the aluminum silicate fiber composite material includes the following steps:

[0195] (1) The aluminum silicate fiber is used as the substrate and the silica sol is used as the curing agent.

[0196] (2) The aluminum silicate fiber is pretreated by cutting the aluminum silicate fiber to the target size (200mm×200mm) and then drying it at 67°C for 2.1h to obtain aluminum silicate fiber with a water content of 0.6wt%.

[0197] The silica sol is pretreated by the following steps: the silica solution is allowed to stand at 27°C for 20 minutes, and then stirred at 350 rpm for 15 minutes to obtain a uniformly dispersed silica sol.

[0198] (3) The only difference from step (3) in Example 1 is that the size of the cavity module is 200mm×200mm×18mm, the protrusion height of the protrusion positioning member is 2.5mm, and the distance between adjacent protrusion positioning members is 13mm.

[0199] (4) Immerse the part to be impregnated into the pretreated silica sol, ensuring that the height of the silica sol is greater than or equal to the height of the porous mold + 50 mm, and soak the aluminum silicate fiber in the porous mold to obtain a porous mold containing the preform.

[0200] During the soaking process, the temperature of the silica sol is 27°C; the soaking time is 26 minutes; and the content of silica sol in the preform is 41 wt% based on the weight of the aluminum silicate fiber.

[0201] (5) Take out the porous mold containing the preform and drain it upside down for 12 minutes until there is no dripping. Then, perform a curing treatment in a constant temperature oven at 49°C for 4.8 hours to convert the silica sol in the preform into silica with a conversion rate of 93% to obtain the blank.

[0202] (6) The blank is dried in the first stage and the second stage to reduce the moisture content to 0.4%. Then it is taken out from the porous mold and cooled naturally for 18 hours to obtain aluminum silicate fiber composite material.

[0203] The first stage of drying is performed at a temperature of 86°C for 1.8 hours; the second stage of drying is performed at a temperature of 113°C for 1.2 hours.

[0204] Example 11

[0205] The difference between this embodiment and embodiment 3 is that in step (4), the soaking time is 15 min, so that the content of silica sol in the preform is 18 wt%.

[0206] The remaining preparation methods and parameters are consistent with those in Example 3.

[0207] Example 12

[0208] The difference between this embodiment and Embodiment 1 is that the porosity of the aluminum silicate fiber is 75%.

[0209] The remaining preparation methods and parameters are consistent with those in Example 1.

[0210] Example 13

[0211] The difference between this embodiment and embodiment 3 is that in step (4), the soaking time is 50 minutes.

[0212] The remaining preparation methods and parameters are consistent with those in Example 3.

[0213] Example 14

[0214] The difference between this embodiment and Embodiment 1 is that the porosity of the aluminum silicate fiber is 55%.

[0215] The remaining preparation methods and parameters are consistent with those in Example 1.

[0216] Example 15

[0217] The difference between this embodiment and Embodiment 1 is that the viscosity of the silica sol is 5 mPa·s.

[0218] The remaining preparation methods and parameters are consistent with those in Example 1.

[0219] Example 16

[0220] The difference between this embodiment and Embodiment 1 is that the viscosity of the silica sol is 30 mPa·s.

[0221] The remaining preparation methods and parameters are consistent with those in Example 1.

[0222] Comparative Example 1

[0223] This comparative example provides a conventional resin-bonded aluminosilicate fiber product, which is obtained by combining aluminosilicate fiber and resin.

[0224] The aluminum silicate fiber contains 40 wt% alumina; the areal density of the aluminum silicate fiber is 300 g / m³. 2 The thickness of the aluminum silicate fiber is 10 mm.

[0225] The resin comprises epoxy resin with a solid content of 50% and a curing agent in a mass ratio of 1:1.

[0226] The preparation method of the conventional resin-bonded aluminosilicate fiber product includes the following steps:

[0227] (1) The aluminum silicate fiber is used as the substrate and the resin is used as the curing agent.

[0228] (2) Cut the aluminum silicate fiber to the target size (200mm×200mm) and then dry it at 60℃ for 1h to obtain aluminum silicate fiber with a water content of 1wt%.

[0229] (3) The resin is sprayed at a distance of 20cm from the cut aluminum silicate fiber using a spray gun (1.5mm diameter, 0.3MPa pressure) and the spray thickness is 0.5mm. Then it is cured at room temperature (25℃) for 24h to obtain the conventional resin bonded aluminum silicate fiber product.

[0230] Comparative Example 2

[0231] The difference between this comparative example and Example 5 is that, in step (3), a porous mold is not used for soaking. Instead, the pretreated aluminum silicate fiber is directly immersed in the pretreated silica sol and soaked at 28°C for 28 minutes to obtain the preform.

[0232] The remaining preparation methods and parameters are consistent with those in Example 5.

[0233] Comparative Example 3

[0234] The difference between this comparative example and Example 1 is that the aluminum oxide content in the aluminum silicate fiber is 40 wt%.

[0235] The remaining preparation methods and parameters are consistent with those in Example 1.

[0236] Comparative Example 4

[0237] The difference between this comparative example and Example 1 is that the solid content of the silica sol is 15%.

[0238] The remaining preparation methods and parameters are consistent with those in Example 1.

[0239] Comparative Example 5

[0240] The difference between this comparative example and Example 1 is that the solid content of the silica sol is 45%.

[0241] The remaining preparation methods and parameters are consistent with those in Example 1.

[0242] Performance testing

[0243] The performance of the aluminum silicate fiber composite materials provided in the above embodiments and comparative examples was tested, including density (drainage method (GB / T 5480.3-2004)), flexural strength (three-point bending method (span 50 mm, loading speed 2 mm / min, GB / T9341-2008)), temperature resistance (muffle furnace insulation (flexural strength retention rate measured after insulation at 600℃ / 800℃ for 2 h), volume shrinkage rate (vernier caliper measurement (difference in dimensions before and after curing and drying, GB / T 15585-1995)), thermal conductivity (hot wire method (GB / T10294-2008)), water absorption rate (weight change rate after soaking for 24 h (GB / T 1733-1993)) and moisture content (halogen moisture meter detection).

[0244] The test results are shown in Table 1.

[0245] Table 1

[0246]

[0247] analyze:

[0248] As shown in Table 1, this invention uses aluminosilicate fibers with an alumina content ≥43wt% as the substrate, and a curing agent with a solid content of 20-40% as an aid. The process involves "fixing with a porous mold + soaking - curing + drying," achieving synergistic effects at both the material and process levels. This results in the full wetting, uniform compounding, and structural shaping of the aluminosilicate fibers and curing agent, leading to an aluminosilicate fiber composite material with a density ≥180kg / m³. 3 The process not only achieves the performance targets of high flexural strength (4.5-5.5MPa), excellent high-temperature resistance (retention rate ≥85% at 600℃ / 2h, retention rate ≥80% at 800℃ / 2h), and high stability (dimensional deviation accuracy within ±0.5mm), but also exhibits a volume shrinkage rate ≤2%, thermal conductivity ≤0.05W / (m·K), moisture content ≤0.5%, and water absorption rate ≤5% after immersion for 24h. This process system not only fundamentally overcomes the problems of uneven colloid distribution and large performance fluctuations caused by traditional spraying methods, as well as dimensional instability caused by moldless molding, but also has no VOC emissions throughout the entire process, possessing both good process repeatability and potential for large-scale production.

[0249] As can be seen from the comparison between Example 1 and Example 11, if the soaking time in step (4) is too short, the content of silica sol in the preform will be 18wt%, resulting in insufficient silica sol adsorption, which ultimately leads to the density, strength, temperature resistance, shrinkage rate and water absorption rate of the aluminum silicate fiber composite material not meeting the standards.

[0250] A comparison between Example 1 and Example 12 shows that if the porosity of the aluminum silicate fiber is small, i.e., 75%, its density, strength, temperature resistance, shrinkage rate and water absorption rate all fail to meet the standards.

[0251] As can be seen from the comparison between Example 1 and Example 13, if the soaking time in step (4) is too long, the material density will be too high, the strength retention rate at high temperature will be low, and the thermal conductivity will be high.

[0252] As can be seen from the comparison between Example 1 and Example 14, if the porosity of the aluminum silicate fiber is too small, i.e., 55%, the silica sol cannot be fully penetrated, the material density and strength are low, and it cannot play a supporting role.

[0253] As can be seen from the comparison between Example 1 and Examples 15-16, if the viscosity of the silica sol is too low, the amount of silica sol impregnation is large, the material strength is improved but the temperature resistance is reduced; if the viscosity of the silica sol is too high, the silica sol cannot be fully impregnated, and the material strength is low.

[0254] As can be seen from the comparison between Example 1 and Comparative Example 1, the density, temperature resistance, shrinkage rate, thermal conductivity and water absorption rate of the traditional resin-bonded aluminum silicate fiber products are all substandard, and they release VOCs.

[0255] As can be seen from the comparison between Example 1 and Comparative Example 2, if the pretreated aluminum silicate fiber is directly immersed in the pretreated silica sol, the density, temperature resistance, shrinkage rate, thermal conductivity and water absorption rate of the aluminum silicate fiber composite material will not meet the standards, and the dimensional deviation will be large.

[0256] As can be seen from the comparison between Example 1 and Comparative Example 3, if the alumina content in the aluminum silicate fiber is too low, the strength at high temperature cannot be guaranteed.

[0257] As can be seen from the comparison between Example 1 and Comparative Examples 4-5, if the solid content of the silica sol is too low, the residual silica content will be low and the material strength will be low; if the solid content of the silica sol is too high, the residual silica content will be too high and the residual strength at high temperature will be low.

[0258] It should be noted that the present invention is illustrated through the above embodiments, but the present invention is not limited to the above process steps, that is, it does not mean that the present invention must rely on the above process steps to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent substitutions of the raw materials used in the present invention, additions of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. An aluminum silicate fiber composite material, characterized in that, The aluminum silicate fiber composite material is obtained by combining aluminum silicate fibers and a curing agent; The aluminum silicate fiber contains ≥43wt% alumina; the curing agent has a solid content of 20-40%; and the aluminum silicate fiber composite material has a density ≥180kg / m³. 3 .

2. The aluminosilicate fiber composite material according to claim 1, characterized in that, The aluminum oxide content in the aluminum silicate fiber is 43-50 wt%. And / or, the areal density of the aluminosilicate fibers is 300-600 g / m³. 2 ; And / or, the thickness of the aluminum silicate fiber is 8-20 mm; And / or, the diameter of the aluminum silicate fiber is 8-20 μm; And / or, the porosity of the aluminum silicate fiber is 80-95%.

3. The aluminosilicate fiber composite material according to claim 1 or 2, characterized in that, The curing agent is silica sol; And / or, in the silica sol, the particle size D50 of the silica particles is 8-50 nm; And / or, the pH of the silica sol is 8-9; And / or, the sodium ion content in the silica sol is ≤0.2wt%; And / or, the viscosity of the silica sol is 5-25 mPa·s.

4. The aluminosilicate fiber composite material according to any one of claims 1-3, characterized in that, The density of the aluminum silicate fiber composite material is 180-250 kg / m³. 3 ; And / or, the flexural strength of the aluminum silicate fiber composite material is 4.5-5.5 MPa; And / or, the volume shrinkage rate of the aluminum silicate fiber composite material is ≤2%; And / or, the thermal conductivity of the aluminum silicate fiber composite material is ≤0.05W / (m·K); And / or, the moisture content of the aluminum silicate fiber composite material is ≤0.5%; And / or, the water absorption rate of the aluminum silicate fiber composite material after soaking for 24 hours is ≤5%.

5. A method for preparing the aluminosilicate fiber composite material as described in any one of claims 1-4, characterized in that, The preparation method includes the following steps: The invention provides aluminum silicate fiber and a curing agent; wherein the aluminum silicate fiber contains ≥43wt% alumina; and the curing agent has a solid content of 20-40%. The aluminum silicate fiber is fixed in a porous mold and then transferred to the curing agent for immersion treatment to obtain a preform; The preform is cured and dried to obtain the aluminum silicate fiber composite material; the density of the aluminum silicate fiber composite material is ≥180 kg / m³. 3 .

6. The preparation method according to claim 5, characterized in that, The porous mold includes a base, a cavity module, and a cover plate; the base has a groove for accommodating the cavity module, and a sealing ring is embedded in the groove; the cavity module is disposed in the groove, and the inner wall of the cavity module has a protruding positioning element for positioning the aluminum silicate fiber; the cover plate covers the base and is fixedly connected to the base by a locking fastener, thereby sealing the cavity module; The cover plate has several through holes for the flow of curing agent during the soaking process.

7. The preparation method according to claim 5 or 6, characterized in that, During the soaking process, the temperature of the curing agent is 25-30℃; And / or, the soaking treatment time is 20-40 min; And / or, based on the weight of the aluminum silicate fiber, the content of the curing agent in the preform is 25-50 wt%.

8. The preparation method according to any one of claims 5-7, characterized in that, The curing temperature is 40-60℃; And / or, the curing time is 4-8 hours.

9. The preparation method according to any one of claims 5-8, characterized in that, The drying process includes a first stage of drying and a second stage of drying performed by sequentially increasing the temperature. The drying temperature of the first stage is 80-90℃, and the drying time is 1.5-2 hours; The drying temperature for the second stage is 110-120℃, and the drying time is 1-1.5h.

10. The preparation method according to any one of claims 5-9, characterized in that, The preparation method includes the following steps: (1) Provide aluminum silicate fibers and silica sol; The aluminum silicate fiber contains ≥43wt% alumina; the areal density of the aluminum silicate fiber is 300-600 g / m³. 2 The aluminum silicate fiber has a thickness of 8-20 mm; a fiber diameter of 8-20 μm; a porosity of 80-95%; a solid content of 20-40% in the curing agent; a particle size D50 of 8-50 nm in the silica sol; a pH of 8-9 in the silica sol; a sodium ion content ≤0.2 wt% in the silica sol; and a viscosity of 5-25 mPa·s. (2) The aluminum silicate fiber is pretreated by cutting the aluminum silicate fiber to the target size and then drying it at a temperature of 60-70°C to obtain aluminum silicate fiber with a water content of ≤0.8wt%. The silica sol is pretreated by the following steps: allowing the silica solution to stand at room temperature, and then stirring at a speed of 200-400 rpm for 2 minutes to obtain a uniformly dispersed silica sol. (3) Provide a porous mold, lay the pretreated aluminum silicate fiber flat and fix it in the cavity module of the porous mold, and close the cover plate to obtain the part to be impregnated; The porous mold includes a base, a cavity module, and a cover plate. The base has a groove for accommodating the cavity module, and a sealing ring is embedded within the groove. The cavity module is disposed within the groove, and its inner wall has protruding positioning elements for positioning the aluminum silicate fibers. The cover plate covers the base and is fixedly connected to it via fasteners, thereby sealing the cavity module. The cover plate has several through holes for the inflow and outflow of the solid solution during the immersion process. (4) Immerse the part to be impregnated into the pretreated silica sol to soak the aluminum silicate fiber in the porous mold to obtain a porous mold containing a preform. During the immersion treatment, the temperature of the silica sol is 25-30℃; the immersion time is 20-40 minutes; and the silica sol content in the preform is 25-50 wt% based on the weight of the aluminum silicate fiber. (5) Take out the porous mold containing the preform and perform draining and curing treatment to convert the silica sol in the preform into silica to obtain a blank; wherein, the draining treatment time is 8-15 min; the curing treatment temperature is 40-60℃ and the time is 4-8 h; (6) The blank is dried in the first stage and the second stage, and then taken out from the porous mold and cooled for 10-24 hours to obtain aluminum silicate fiber composite material; The drying temperature of the first stage is 80-90℃ and the drying time is 1.5-2h; the drying temperature of the second stage is 110-120℃ and the drying time is 1-1.5h.

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