High temperature resistant thermal blanket and preparation method thereof

Abstract

The present application relates to a kind of high temperature-resistant heat-insulating blanket and preparation method thereof, belong to high temperature insulation material technical field.The heat-insulating blanket disclosed in the present application includes in turn ultra-high temperature reflection layer, high temperature insulation transition layer, medium temperature bearing layer, low temperature high-efficiency insulation layer and surface protection sealing layer, and is integrally combined by needle punching fiber interlocking to form continuous transition interface between each layer, the highest use temperature of the heat-insulating blanket of the present application is greater than or equal to 1600 DEG C, the thermal conductivity is less than or equal to 0.048 W / (m·K) at 1000 DEG C, the minimum thermal conductivity change rate is 2.1% after 10 times thermal shock cycle, with ultra-high temperature resistance, high-efficiency insulation and excellent structural stability, suitable for mobile house fireplace, high temperature pipeline and building fireproof isolation.

Description

Technical Field

[0001] This invention belongs to the field of high-temperature insulation materials technology, and relates to a high-temperature resistant insulation blanket and its preparation method. Background Technology

[0002] Thermal insulation blankets are a widely used type of thermal insulation product. They are typically made of materials such as asbestos and fiberglass, but these materials are usually limited to a working temperature of 500-600℃, which is insufficient to meet the insulation requirements under higher temperature conditions.

[0003] Chinese patent CN205522750U discloses a high-temperature resistant insulation blanket with a four-layer structure: a supersaturated silicone coating layer, a high-silica cotton core layer, a high-silica cloth layer, and a zirconia fiber layer. This design utilizes the zirconia fiber layer to enable use in environments exceeding 1600℃. However, the interlayer bonding method in this patent carries a risk of high-temperature failure. CN205522750U discloses bonding the layers with heat-resistant silicone, but the silicone adhesive ages and decomposes during long-term high-temperature service, leading to decreased interlayer bonding strength or even complete peeling, severely impacting the service life and reliability of the insulation blanket. Meanwhile, the core layer has insufficient high-temperature strength. It uses a high-silica cotton core layer with steel wire reinforcement mesh for structural reinforcement. However, the strength of the steel wire will decrease significantly at around 500℃. Although the solution intends to control the core layer temperature through the zirconium oxide fiber layer, heat conduction and heat radiation in actual working conditions may still cause the core layer temperature to exceed the safe operating temperature of the steel wire. The multi-layer composite structure is a simple stacking, with each layer having a single function. The structure is bulky and lacks flexibility, making it difficult to meet the engineering application scenarios that require flexibility.

[0004] Therefore, developing a high-temperature resistant insulation blanket that combines ultra-high temperature resistance, gradient thermal insulation design, integrated molding structure, and good flexibility has significant application value. Summary of the Invention

[0005] This invention relates to a high-temperature resistant insulation blanket and its preparation method, belonging to the technical field of high-temperature insulation materials. The insulation blanket disclosed in this invention comprises, sequentially, an ultra-high temperature reflective layer, a high-temperature insulation transition layer, a medium-temperature load-bearing layer, a low-temperature high-efficiency insulation layer, and a surface protective sealing layer. The layers are integrally bonded by needle-punched fibers to form a continuous transition interface. The insulation blanket of this invention has a maximum operating temperature ≥1600℃, a thermal conductivity ≤0.048W / (m·K) at 1000℃, and a minimum thermal conductivity change rate of 2.1% after 10 thermal shock cycles. It possesses ultra-high temperature resistance, high-efficiency insulation, and excellent structural stability, making it suitable for mobile home fireplaces, high-temperature pipelines, and building fireproofing.

[0006] The objective of this invention can be achieved through the following technical solutions: A high-temperature resistant insulation blanket has the following structural layers in sequence: an ultra-high temperature reflective layer, a high temperature insulation transition layer, a medium temperature load-bearing layer, a low temperature high-efficiency insulation layer, and a surface protective sealing layer. The layers are integrated by fiber needle-punching interlocking, and the fibers of each layer are intertwined and linked together in the thickness direction to form a continuous transition interface.

[0007] Furthermore, the ultra-high temperature reflective layer comprises zirconium oxide fiber and platinum-rhodium alloy wire, wherein the zirconium oxide fiber has a ZrO2 content ≥99% and a fiber diameter of 5-8μm, and the platinum-rhodium alloy wire has a diameter of 0.05-0.2mm.

[0008] Furthermore, the high-temperature thermal insulation transition layer comprises an aerogel doped with alumina fibers and an infrared shading agent, wherein the alumina fibers have an Al2O3 content ≥95%, and the infrared shading agent is titanium dioxide nanoparticles with a particle size of 20-50 nm and a doping amount of 5-15 wt%.

[0009] Furthermore, the intermediate temperature bearing layer comprises zirconium aluminosilicate fibers and mullite whiskers, wherein the zirconium aluminosilicate fibers contain 15-18% ZrO2, and the mullite whiskers have an aspect ratio of 20:1 and are added in an amount of 5-10 wt%.

[0010] Furthermore, the low-temperature high-efficiency insulation layer comprises ceramic fibers and silica aerogel, wherein the silica aerogel has a particle size of 5-50 nm, and the surface protective sealing layer is a fluorosilane hydrophobic coating with a contact angle ≥140°.

[0011] A method for preparing a high-temperature resistant insulation blanket specifically includes the following steps: S1. Preparation of fiber gradient preform: After opening and carding, the fibers of all structural layers are laid up in the order of functional gradient and reinforced by double-sided needle punching to obtain fiber gradient preform; S2. Gradient sol preparation: Prepare aluminum sol, silicon-aluminum composite sol and silica sol with different concentrations; S3. High-pressure vacuum gradient impregnation: The fiber gradient preform is placed in an impregnation tank, and sol is injected sequentially under vacuum negative pressure. The sol forms a gradient distribution along the thickness direction and is allowed to gel after standing. S4. Grading and sintering: The gelled blanket is subjected to supercritical drying and graded high-temperature sintering. S5. Surface protection treatment: Finally, apply a hydrophobic coating to the low-temperature surface, dry and cure to obtain a high-temperature resistant insulation blanket.

[0012] Furthermore, the needle density of the double-sided needle punching process in step S1 is 200-300 needles / cm², and the solid content of the aluminum sol in step S2 is 25-35%, the solid content of the silicon-aluminum composite sol is 15-25%, and the solid content of the silica sol is 8-15%.

[0013] Furthermore, the vacuum negative pressure in step S3 is -0.08 to -0.1 MPa, and the gradient impregnation sequentially injects aluminum sol, silicon-aluminum composite sol, and silica sol.

[0014] Further, step S4, supercritical drying, uses CO2 as the medium, and is carried out at a temperature of 40-50℃ and a pressure of 10-15MPa for 4-8 hours. The high-temperature sintering involves heating to 600℃ at a rate of 2-5℃ / min and holding for 2 hours, followed by heating to 1200℃ at a rate of 3-5℃ / min and holding for 4 hours. Step S5, hydrophobic coating, is a fluorosilane modified solution with a concentration of 1-5wt% and a spraying amount of 50-100 g / m². The drying temperature is 80-120℃, and the curing time is 30-60 minutes.

[0015] Compared with existing technologies, its beneficial effects include: 1. The thermal insulation blanket disclosed in this invention comprises, sequentially, an ultra-high temperature reflective layer, a high temperature thermal insulation transition layer, a medium temperature load-bearing layer, a low temperature high-efficiency thermal insulation layer, and a surface protective sealing layer. These layers are interconnected by needle-punched fibers to form a continuous transition interface. The ultra-high temperature reflective layer contains zirconium oxide fibers and platinum-rhodium alloy reinforcing wires; the high temperature thermal insulation transition layer contains alumina fibers and titanium oxide nanoparticle-doped aerogel; the medium temperature load-bearing layer contains zirconium-containing aluminosilicate fibers and mullite whiskers; and the low temperature high-efficiency thermal insulation layer contains ceramic fibers and silica aerogel. The preparation method employs a layered web-laying combined with double-sided needle-punching to form a preform. High-pressure vacuum gradient impregnation distributes different concentrations of sol along the thickness direction. Subsequent supercritical drying and high-temperature sintering are performed, followed by a hydrophobic coating. The thermal insulation blanket of this invention has a maximum operating temperature ≥1600℃, a thermal conductivity ≤0.048W / (m·K) at 1000℃, and a minimum thermal conductivity change rate of 2.1% after 10 thermal shock cycles, exhibiting ultra-high temperature tolerance, high-efficiency thermal insulation, and excellent structural stability. Detailed Implementation

[0016] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features and effects of the present invention, in conjunction with embodiments, is provided below.

[0017] Example 1 A high-temperature resistant insulation blanket has the following structural layers in sequence: an ultra-high temperature reflective layer, a high temperature insulation transition layer, a medium temperature load-bearing layer, a low temperature high-efficiency insulation layer, and a surface protective sealing layer. The layers are integrated by fiber needle-punching interlocking, and the fibers of each layer are intertwined and linked together in the thickness direction to form a continuous transition interface.

[0018] The ultra-high temperature reflective layer comprises zirconium oxide fiber and platinum-rhodium alloy wire, wherein the zirconium oxide fiber has a ZrO2 content of 99% and a fiber diameter of 5μm, and the platinum-rhodium alloy wire has a diameter of 0.05mm.

[0019] The high-temperature thermal insulation transition layer comprises an aerogel doped with alumina fibers and an infrared shading agent. The alumina fibers have an Al2O3 content of 95%, and the infrared shading agent is titanium oxide nanoparticles with a particle size of 20 nm and a doping amount of 5 wt%.

[0020] The intermediate temperature support layer comprises zirconium aluminum silicate fiber and mullite whiskers, wherein the zirconium aluminum silicate fiber contains 15% ZrO2, and the mullite whiskers have an aspect ratio of 20:1 and are added in an amount of 5wt%.

[0021] The low-temperature high-efficiency thermal insulation layer comprises ceramic fibers and silica aerogel, wherein the silica aerogel has a particle size of 5 nm, and the surface protective sealing layer is a fluorosilane hydrophobic coating with a contact angle of 140°.

[0022] A method for preparing a high-temperature resistant insulation blanket specifically includes the following steps: S1. Preparation of fiber gradient preform: After opening and carding, the fibers of all structural layers are laid up in the order of functional gradient and reinforced by double-sided needle punching process, wherein the needle punching density is 200 needles / cm², to obtain the fiber gradient preform. S2. Gradient sol preparation: The solid content of the aluminum sol is 25%, the solid content of the silicon-aluminum composite sol is 15%, and the solid content of the silica sol is 8%. S3. High-pressure vacuum gradient impregnation: The fiber gradient preform is placed in an impregnation tank, and sol is injected sequentially under a vacuum of -0.08MPa. The sol forms a gradient distribution along the thickness direction and is allowed to gel by standing. S4. Graded drying and sintering: The gelled blanket is subjected to supercritical drying and graded high-temperature sintering. The supercritical drying is carried out with CO2 as the medium, at a temperature of 40℃ and a pressure of 10MPa for 4 hours. The high-temperature sintering is carried out by heating to 600℃ at 2℃ / min and holding for 2 hours, and then heating to 1200℃ at 3℃ / min and holding for 4 hours. S5. Surface protection treatment: Finally, apply a hydrophobic coating of fluorosilane modified solution to the low-temperature surface, and dry and cure at 80°C for 30 minutes to obtain a high-temperature resistant insulation blanket.

[0023] Example 2 A high-temperature resistant insulation blanket has the following structural layers in sequence: an ultra-high temperature reflective layer, a high temperature insulation transition layer, a medium temperature load-bearing layer, a low temperature high-efficiency insulation layer, and a surface protective sealing layer. The layers are integrated by fiber needle-punching interlocking, and the fibers of each layer are intertwined and linked together in the thickness direction to form a continuous transition interface.

[0024] The ultra-high temperature reflective layer comprises zirconium oxide fiber and platinum-rhodium alloy wire, wherein the zirconium oxide fiber has a ZrO2 content of 99% and a fiber diameter of 6μm, and the platinum-rhodium alloy wire has a diameter of 0.1mm.

[0025] The high-temperature thermal insulation transition layer comprises an aerogel doped with alumina fibers and an infrared shading agent. The alumina fibers have an Al2O3 content of 95%, and the infrared shading agent is titanium oxide nanoparticles with a particle size of 35 nm and a doping amount of 10 wt%.

[0026] The intermediate temperature support layer comprises zirconium aluminum silicate fiber and mullite whiskers, wherein the zirconium aluminum silicate fiber contains 16.5% ZrO2, and the mullite whiskers have an aspect ratio of 20:1 and are added in an amount of 8wt%.

[0027] The low-temperature high-efficiency insulation layer comprises ceramic fibers and silica aerogel, wherein the silica aerogel has a particle size of 35nm, and the surface protective sealing layer is a fluorosilane hydrophobic coating with a contact angle of 140°.

[0028] A method for preparing a high-temperature resistant insulation blanket specifically includes the following steps: S1. Preparation of fiber gradient preform: After opening and carding, the fibers of all structural layers are laid up in the order of functional gradient and reinforced by double-sided needle punching process, wherein the needle punching density is 250 needles / cm², to obtain the fiber gradient preform. S2. Gradient sol preparation: The solid content of the aluminum sol is 30%, the solid content of the silicon-aluminum composite sol is 20%, and the solid content of the silica sol is 12%. S3. High-pressure vacuum gradient impregnation: The fiber gradient preform is placed in an impregnation tank, and sol is injected sequentially under a vacuum of -0.09MPa. The sol forms a gradient distribution along the thickness direction and is allowed to gel by standing. S4. Graded drying and sintering: The gelled blanket is subjected to supercritical drying and graded high-temperature sintering. The supercritical drying is carried out with CO2 as the medium, at a temperature of 45°C and a pressure of 12MPa for 6 hours. The high-temperature sintering is carried out by heating to 600°C at 3°C / min and holding for 2 hours, and then heating to 1200°C at 4°C / min and holding for 4 hours. S5. Surface protection treatment: Finally, apply a hydrophobic coating of fluorosilane modified solution to the low-temperature surface, and dry and cure at 100°C for 45 minutes to obtain a high-temperature resistant insulation blanket.

[0029] Example 3 A high-temperature resistant insulation blanket has the following structural layers in sequence: an ultra-high temperature reflective layer, a high temperature insulation transition layer, a medium temperature load-bearing layer, a low temperature high-efficiency insulation layer, and a surface protective sealing layer. The layers are integrated by fiber needle-punching interlocking, and the fibers of each layer are intertwined and linked together in the thickness direction to form a continuous transition interface.

[0030] The ultra-high temperature reflective layer comprises zirconium oxide fiber and platinum-rhodium alloy wire, wherein the zirconium oxide fiber has a ZrO2 content of 99% and a fiber diameter of 8μm, and the platinum-rhodium alloy wire has a diameter of 0.2mm.

[0031] The high-temperature thermal insulation transition layer comprises an aerogel doped with alumina fibers and an infrared shading agent. The alumina fibers have an Al2O3 content of 95%, and the infrared shading agent is titanium oxide nanoparticles with a particle size of 50 nm and a doping amount of 15 wt%.

[0032] The intermediate temperature support layer comprises zirconium aluminum silicate fiber and mullite whiskers, wherein the zirconium aluminum silicate fiber contains 18% ZrO2, and the mullite whiskers have an aspect ratio of 20:1 and are added in an amount of 10wt%.

[0033] The low-temperature high-efficiency insulation layer comprises ceramic fibers and silica aerogel, wherein the silica aerogel has a particle size of 50 nm, and the surface protective sealing layer is a fluorosilane hydrophobic coating with a contact angle of 140°.

[0034] A method for preparing a high-temperature resistant insulation blanket specifically includes the following steps: S1. Preparation of fiber gradient preform: After opening and carding, the fibers of all structural layers are laid up in the order of functional gradient and reinforced by double-sided needle punching process, wherein the needle punching density is 300 needles / cm², to obtain the fiber gradient preform. S2. Gradient sol preparation: The solid content of the aluminum sol is 35%, the solid content of the silicon-aluminum composite sol is 25%, and the solid content of the silica sol is 15%. S3. High-pressure vacuum gradient impregnation: The fiber gradient preform is placed in an impregnation tank, and sol is injected sequentially under a vacuum of -0.1MPa. The sol forms a gradient distribution along the thickness direction and is allowed to gel by standing. S4. Graded drying and sintering: The gelled blanket is subjected to supercritical drying and graded high-temperature sintering. The supercritical drying is carried out with CO2 as the medium, at a temperature of 50°C and a pressure of 15MPa for 8 hours. The high-temperature sintering is carried out by heating to 600°C at 5°C / min and holding for 2 hours, and then heating to 1200°C at 5°C / min and holding for 4 hours. S5. Surface protection treatment: Finally, apply a hydrophobic coating of fluorosilane modified solution to the low-temperature surface, and dry and cure at 120°C for 60 minutes to obtain a high-temperature resistant insulation blanket.

[0035] Comparative Example 1 Based on Example 2, the composite method of CN205522750U is adopted: the layers are bonded together with heat-resistant silicone adhesive, without needle-punching interlocking process or gradient sol-gel impregnation treatment. The high-temperature surface layer is zirconia fiber cloth, the core layer is high-silica cotton (with built-in steel wire mesh), and the low-temperature surface is high-silica cloth. Other conditions are the same as in Example 2.

[0036] Comparative Example 2 Based on Example 2, following the steps in CN105114761A, aluminum silicate needled blanket was used as the substrate, and after being impregnated with sol, an aluminum film reflective layer was formed on the outer surface. Other conditions were the same as in Example 2.

[0037] Performance testing The high-temperature resistant insulation blankets prepared in Examples 1-3 and Comparative Examples 1-2 were used as samples. Their thermal conductivity was tested according to GB / T 10294-2008 "Determination of Steady-State Thermal Resistance and Related Properties of Insulation Materials - Protective Hot Plate Method" at temperatures of 200℃, 700℃, and 1400℃. After holding the samples at 1000℃ for 30 minutes, they were quickly removed and cooled in room temperature air for 5 minutes, then placed in a high-temperature furnace for heating. This cycle was repeated 10 times. The rate of change in thermal conductivity before and after the cycle was measured. Each sample was placed in a high-temperature furnace and heated to the target temperature at a rate of 5℃ / min, holding for 4 hours. The changes in the sample's state were observed. The bending performance of the samples was tested according to GB / T 5480.6-2004 "Test Method for Bending Properties of Mineral Wool Products" to evaluate their flexibility and construction adaptability.

[0038] The test results are shown in Tables 1, 2, and 3.

[0039] Table 1 Thermal conductivity test results

[0040] A comprehensive analysis of the data in Table 1 shows that the thermal conductivity of Example 1-3 is lower than that of Comparative Example 1-2, especially in high-temperature regions where the advantage is more obvious. Comparative Example 2 failed at 1400℃ due to the melting of the aluminum film.

[0041] Table 2 Thermal conductivity test results

[0042] Table 2 shows that Examples 1-3 maintained structural integrity after 10 severe thermal shock cycles, with thermal conductivity increasing by only 2.1-4.5%; Comparative Example 1 showed significant interlayer separation due to adhesive aging and thermal expansion mismatch; Comparative Example 2 suffered from severe deterioration of aerogel structure collapse performance, resulting in incomplete structure after cycling.

[0043] Table 3 Test Results

[0044] As can be seen from Table 3, Examples 1-3 have higher temperature resistance and do not exhibit delamination during flexibility testing, thus enabling the material to achieve ultra-high temperature resistance, high-efficiency thermal insulation, and excellent structural stability.

[0045] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A high-temperature resistant insulation blanket, characterized in that, The high-temperature resistant insulation blanket has the following structural layers in sequence: ultra-high temperature reflective layer, high temperature insulation transition layer, medium temperature load-bearing layer, low temperature high-efficiency insulation layer and surface protective sealing layer. The layers are integrated by fiber needle-punching interlocking, and the fibers of each layer are intertwined and linked together in the thickness direction to form a continuous transition interface.

2. The high-temperature resistant insulation blanket according to claim 1, characterized in that, The ultra-high temperature reflective layer comprises zirconium oxide fiber and platinum-rhodium alloy wire, wherein the zirconium oxide fiber has a ZrO2 content ≥99% and a fiber diameter of 5-8μm, and the platinum-rhodium alloy wire has a diameter of 0.05-0.2mm.

3. The high-temperature resistant insulation blanket according to claim 1, characterized in that, The high-temperature thermal insulation transition layer comprises an aerogel doped with alumina fibers and an infrared shading agent. The alumina fibers have an Al2O3 content of ≥95%, and the infrared shading agent is titanium dioxide nanoparticles with a particle size of 20-50 nm and a doping amount of 5-15 wt%.

4. The high-temperature resistant insulation blanket according to claim 1, characterized in that, The intermediate temperature support layer comprises zirconium aluminum silicate fiber and mullite whiskers, wherein the zirconium aluminum silicate fiber contains 15-18% ZrO2, and the mullite whiskers have an aspect ratio of 20:1 and are added in an amount of 5-10 wt%.

5. The high-temperature resistant insulation blanket according to claim 1, characterized in that, The low-temperature high-efficiency thermal insulation layer comprises ceramic fibers and silica aerogel, wherein the silica aerogel has a particle size of 5-50nm, and the surface protective sealing layer is a fluorosilane hydrophobic coating with a contact angle ≥140°.

6. A method for preparing a high-temperature resistant insulation blanket as described in claim 1, characterized in that, Specifically, the following steps are included: S1. Preparation of fiber gradient preform: After opening and carding, the fibers of all structural layers are laid up in the order of functional gradient and reinforced by double-sided needle punching to obtain fiber gradient preform; S2. Gradient sol preparation: Prepare aluminum sol, silicon-aluminum composite sol and silica sol with different concentrations; S3. High-pressure vacuum gradient impregnation: The fiber gradient preform is placed in an impregnation tank, and sol is injected sequentially under vacuum negative pressure. The sol forms a gradient distribution along the thickness direction and is allowed to gel after standing. S4. Grading and sintering: The gelled blanket is subjected to supercritical drying and graded high-temperature sintering. S5. Surface protection treatment: Finally, apply a hydrophobic coating to the low-temperature surface, dry and cure to obtain a high-temperature resistant insulation blanket.

7. The method for preparing a high-temperature resistant insulation blanket according to claim 6, characterized in that, The needle density of the double-sided needle punching process in step S1 is 200-300 needles / cm², and the solid content of the aluminum sol in step S2 is 25-35%, the solid content of the silicon-aluminum composite sol is 15-25%, and the solid content of the silica sol is 8-15%.

8. The method for preparing a high-temperature resistant insulation blanket according to claim 6, characterized in that, The vacuum negative pressure in step S3 is -0.08 to -0.1 MPa, and the gradient impregnation sequentially injects aluminum sol, silicon-aluminum composite sol and silica sol.

9. The method for preparing a high-temperature resistant insulation blanket according to claim 6, characterized in that, The supercritical drying step S4 uses CO2 as the medium and is carried out at a temperature of 40-50℃ and a pressure of 10-15MPa for 4-8 hours. The high-temperature sintering involves heating to 600℃ at a rate of 2-5℃ / min and holding for 2 hours, then heating to 1200℃ at a rate of 3-5℃ / min and holding for 4 hours.

10. The method for preparing a high-temperature resistant insulation blanket according to claim 6, characterized in that, The hydrophobic coating in step S5 is a fluorosilane modified solution with a concentration of 1-5 wt% and a spraying amount of 50-100 g / m². The drying temperature is 80-120℃ and the curing time is 30-60 minutes.

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