Heat insulation liner and preparation method thereof

Abstract

The heat insulation liner comprises a liner body and aerogel functional layers arranged on the liner body, and the aerogel functional layers include the first aerogel functional layer and the second aerogel functional layer; wherein the first aerogel functional layer is prepared from tetraethoxysilane, absolute ethyl alcohol and deionized water; the second aerogel functional layer is prepared from the following materials: polyether sulfone, N, N-dimethylformamide, graphene oxide and a carbon nano tube. The invention further provides a preparation method of the heat insulation liner, the liner body is wrapped by the aerogel functional layers to form the novel heat insulation liner, and the first aerogel functional layer and the second aerogel functional layer are prepared to form the heat insulation liner. The isomorphic graphene oxide and the carbon nanotubes are used for balancing the heat-conducting property and the tensile property of the aerogel material, so that the aerogel material can meet the use requirements of a three-way catalyst.

Description

Technical Field

[0001] The invention relates to the field of engine exhaust treatment, and in particular to a thermal insulation pad and a preparation method thereof. Background Art

[0002] The catalytic converter heat insulation sealing gasket is a part that wraps the carrier. Its main functions include fixing and encapsulating the carrier, providing buffer protection, heat insulation, sound insulation, etc. The quality of the gasket directly affects the effect of engine exhaust treatment and emission. If the gasket's supporting force is too large, it is easy to crush the carrier, causing exhaust leakage, substandard emissions, environmental pollution, and affecting the social influence and reputation of automobile manufacturers.

[0003] The existing technical solution mainly uses ordinary ceramic fiber cotton to add a certain proportion of vermiculite and adhesive, and processes it into a liner through a wet process. The aging durability of ordinary ceramic fibers is difficult to meet the technical requirements of the stringent National VI exhaust gas standards. Summary of the invention

[0004] The object of the present invention is to provide a thermal insulation pad and a preparation method thereof to solve the above technical problems.

[0005] To achieve the above object, the present invention provides the following technical solutions: A thermal insulation pad, characterized in that it includes a pad body and an aerogel functional layer arranged on the pad body, the aerogel functional layer is a first aerogel functional layer and a second aerogel functional layer; wherein the first aerogel functional layer is prepared from materials including tetraethyl orthosilicate, anhydrous ethanol, and deionized water; and the second aerogel functional layer is prepared from materials including polyethersulfone, N,N-dimethylformamide, graphene oxide, and carbon nanotubes.

[0006] The present invention further provides that the aerogel functional layer is provided by wrapping the cushion body with the first aerogel functional layer or by wrapping the cushion body with the second aerogel functional layer.

[0007] The present invention further provides that the second aerogel layer wraps the first aerogel functional layer and the cushion body, wherein the first aerogel functional layer wraps the cushion body.

[0008] The present invention further arranges that the liner body is placed in the solution formed by the first aerogel functional layer, and the amount of glue suction is controlled by a vacuum suction filtration device; after the gelation and aging steps, it is placed in a drying medium with carbon dioxide, and a product of the thermal insulation liner and the first aerogel functional layer is obtained through supercritical drying; after the thermal insulation liner and the first aerogel functional layer are combined, they are also placed in the solution formed by the second aerogel functional layer and solidified to form the final product.

[0009] The present invention provides a method for preparing a thermal insulation pad, which is characterized by comprising the preparation of a pad body, the preparation of a first aerogel functional layer and the preparation of a second aerogel functional layer, wherein the preparation method of the pad body is as follows: S-Process 1: Preparation of ceramic fiber raw materials, wherein the fiber raw materials include alumina fiber, silica fiber, and iron oxide fiber, and the ratio thereof is 4-5:4-5:1; S-Process 2: Preparation of adhesive, wherein the adhesive is acrylic emulsion; S-Process 3: Put the ceramic fiber raw material in S-Process 1 into the pulper, add water to stir and pulp until the ceramic fiber raw material is completely crushed, open the pulp pump valve, and transport the pulp to the pulp barrel; S-Process 4: Turn on the propeller of the pulp barrel to stir so that the fibers are evenly dispersed, and take samples to measure the concentration; if the concentration does not meet the technical parameters, add water or adjust the fibers and re-measure the concentration until it meets the production requirements; S-Process 5: According to the production plan and process parameters, set the corresponding conveyor net speed parameters and the corresponding pressure roller height parameters; open the conveyor net, open the flushing valve, open the feed pump, open the glue machine, and place the adhesive in the glue machine, and finally open the headbox to evenly disperse the fibers on the mesh belt; S-Process 6: Open the vacuum pump water suction valve to absorb water from the formed fiber pad on the mesh belt to reduce the water content of the pad; S-Process 7: After the pressing roller flattens the fiber mat, it moves smoothly and automatically to the drying tunnel; according to different models of products, the temperature of the corresponding five temperature zones of the drying tunnel is set; S-Process 8: After drying and forming, the liner is cut to the corresponding length according to the production plan requirements, weighed, and the appearance is checked and sampled again. The sampled semi-finished products are tested to ensure that they meet the design requirements.

[0010] The present invention further provides that the preparation method of the first aerogel functional layer is as follows: graphene oxide, carbon nanotubes and deionized water are dispersed by ultrasonic dispersion to form a solution, then tetraethyl orthosilicate is mixed with anhydrous ethanol, deionized water and the solution in a certain amount ratio and stirred, and then 0.1 mol / L oxalic acid solution is added to adjust the pH to 3.5, and after sufficient hydrolysis, 1 mol / L ammonia solution is added to adjust the pH to 5.5 to obtain a SiO2 sol containing graphene oxide and carbon nanotubes, wherein the molar ratio of tetraethyl orthosilicate to anhydrous ethanol and deionized water is 1:6:4, the mass of graphene oxide is 4-5% of the mass of tetraethyl orthosilicate, and the mass of carbon nanotubes is 4-10% of the mass of tetraethyl orthosilicate.

[0011] The present invention further provides that the preparation process of the second aerogel functional layer is as follows: using N,N-dimethylformamide as a solvent, a fixed amount of graphene oxide and carbon nanotubes are uniformly dispersed by ultrasonic dispersion to obtain a graphene oxide / carbon nanotube / solution, polyether sulfone is added to the solution, and after heating to fully dissolve, a polyether sulfone / graphene oxide / carbon nanotube solution is obtained.

[0012] The present invention further provides that the prepared gasket body is placed in a SiO2 sol containing graphene oxide and carbon nanotubes, so that the gasket body is fully infiltrated into the prepared SiO2 sol, and the vacuum degree is adjusted by a vacuum suction filtration device to control the amount of glue suction; after gelation and aging steps, it is modified using hexamethyldisilazane, wherein the molar ratio of tetraethyl orthosilicate to hexamethyldisilazane is 1:0.6, and then it is placed in an environment with carbon dioxide as a drying medium, and an intermediate product of a thermal gasket and a first aerogel functional layer is obtained through supercritical drying.

[0013] The present invention further arranges that the intermediate product is placed in a corresponding mold, and the polyethersulfone / graphene oxide / carbon nanotube solution is introduced into the mold so that the intermediate product and the polyethersulfone / graphene oxide / carbon nanotube solution are fully in contact, and then the mold is placed on a copper cold finger with liquid nitrogen as a cold source to perform vertical directional freezing, and after the solution is completely converted into a solid, it is quickly transferred to a freeze dryer to perform sublimation of N,N-dimethylformamide solid in a vacuum environment of -50 to -45°C, and the polyethersulfone / graphene oxide / carbon nanotube after the solvent N,N-dimethylformamide is removed is combined with the intermediate product to form a solid to form a final product.

[0014] The present invention further arranges that the temperatures of the five temperature zones of the drying tunnel are: 85°C to 95°C in the first temperature zone, 120°C to 165°C in the second temperature zone, 130°C to 170°C in the third temperature zone, 125°C to 165°C in the fourth temperature zone, and 80°C to 130°C in the fifth temperature zone.

[0015] Beneficial effects of the present invention: The present invention wraps the gasket body with an aerogel functional layer to form a new thermal insulation gasket, wherein in the preparation of the first aerogel functional layer and the second aerogel functional layer, isostructural graphene oxide and carbon nanotubes are used to balance the thermal conductivity and tensile strength of the aerogel material, so that it can meet the use requirements of the three-way catalytic converter. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings: Figure 1 This is a structural schematic diagram of one embodiment of the present invention.

[0017] Figure 2 This is a structural schematic diagram of one embodiment of the present invention.

[0018] Figure 3 This is a structural schematic diagram of one embodiment of the present invention.

[0019] Figure 4 This is a schematic diagram of the structure of the mold in Example 2 of the present invention.

[0020] Reference numerals: 10. Pad body; 20. First aerogel functional layer; 30. Second aerogel functional layer; DETAILED DESCRIPTION

[0021] The following will describe the implementation methods of the present application in detail with the help of accompanying drawings and examples, so that the implementation process of how the present application uses technical means to solve technical problems and achieve technical effects can be fully understood and implemented accordingly.

[0022] Example 1

[0023] like Figure 1-Figure 3 As shown, this embodiment provides a thermal insulation pad, including a pad body 10 and an aerogel functional layer arranged on the pad body 10, the aerogel functional layer is a first aerogel functional layer 20 and a second aerogel functional layer 30; wherein the first aerogel functional layer 20 is prepared from materials including tetraethyl orthosilicate, anhydrous ethanol, and deionized water; the second aerogel functional layer 30 is prepared from materials including polyethersulfone, N,N-dimethylformamide, graphene oxide, and carbon nanotubes.

[0024] The aerogel functional layer can be provided as a single layer on the cushion body 10, and one of the methods is as follows: Figure 1 As shown, the aerogel functional layer is provided by wrapping the cushion body 10 with the first aerogel functional layer 20; Another method is to wrap the cushion body 10 with the second aerogel functional layer 30 .

[0025] In addition, a double-layer aerogel structure may be used to wrap the cushion body 10 , that is, the second aerogel layer wraps the first aerogel functional layer 20 and the cushion body 10 , wherein the first aerogel functional layer 20 wraps the cushion body 10 .

[0026] In this embodiment, a double-layer structure is preferably adopted, and when the liner body 10 is combined with the first aerogel functional layer 20, the following method is adopted: the first liner body 10 is placed in the solution formed by the first aerogel functional layer 20, and the amount of glue suction is controlled by a vacuum suction filtration device; after the gel and aging steps, it is placed in a drying medium with carbon dioxide, and an intermediate product of the thermal insulation liner and the first aerogel functional layer 20 is obtained through supercritical drying; after the thermal insulation liner and the first aerogel functional layer 20 are combined, it is also placed in the solution formed by the second aerogel functional layer 30 and solidified to form the final product.

[0027] Example 2

[0028] This embodiment provides a method for preparing a thermal insulation gasket, which includes preparing a gasket body, preparing a first aerogel functional layer, and preparing a second aerogel functional layer, wherein the method for preparing the gasket body is as follows: S-Process 1: Preparation of ceramic fiber raw materials, wherein the fiber raw materials include alumina fiber, silica fiber, and iron oxide fiber, and the ratio thereof is 4-5:4-5:1; S-Process 2: Preparation of adhesive, wherein the adhesive is acrylic emulsion; S-Process 3: Put the ceramic fiber raw material in S-Process 1 into the pulper, add water to stir and pulp until the ceramic fiber raw material is completely crushed, open the pulp pump valve, and transport the pulp to the pulp barrel; S-Process 4: Turn on the propeller of the pulp barrel to stir so that the fibers are evenly dispersed, and take samples to measure the concentration; if the concentration does not meet the technical parameters, add water or adjust the fibers and re-measure the concentration until it meets the production requirements; S-Process 5: According to the production plan and process parameters, set the corresponding conveyor net speed parameters and the corresponding pressure roller height parameters; open the conveyor net, open the flushing valve, open the feed pump, open the glue machine, and place the adhesive in the glue machine, and finally open the headbox to evenly disperse the fibers on the mesh belt; S-Process 6: Open the vacuum pump water suction valve to absorb water from the formed fiber pad on the mesh belt to reduce the water content of the pad; S-Process 7: After the pressing roller flattens the fiber mat, it moves to the drying tunnel smoothly and automatically; according to different models of products, the temperatures of the five temperature zones of the drying tunnel are set, where the temperatures of the five temperature zones of the drying tunnel are: the first temperature zone is 85℃~95℃, the second temperature zone is 120℃~165℃, the third temperature zone is 130℃~170℃, the fourth temperature zone is 125℃~165℃, and the fifth temperature zone is 80℃~130℃; S-Process 8: After drying and forming, the liner is cut to the corresponding length according to the production plan requirements, weighed, and the appearance is checked and sampled again. The sampled semi-finished products are tested to ensure that they meet the design requirements.

[0029] After the liner is made, the first aerogel functional layer is prepared, and the preparation method is as follows: graphene oxide, carbon nanotubes and deionized water are dispersed by ultrasonic dispersion to form a solution, then tetraethyl orthosilicate is mixed with anhydrous ethanol, deionized water and the solution in a certain amount ratio and stirred, and then 0.1 mol / L oxalic acid solution is added, and the pH is adjusted to 3.5. After sufficient hydrolysis, 1 mol / L ammonia solution is added, and the pH is adjusted to 5.5 to obtain SiO2 sol containing graphene oxide and carbon nanotubes, wherein the molar ratio of tetraethyl orthosilicate to anhydrous ethanol and deionized water is 1:6:4, the mass of graphene oxide is 4-5% of the mass of tetraethyl orthosilicate, and the mass of carbon nanotubes is 4-10% of the mass of tetraethyl orthosilicate.

[0030] The preparation process of the second aerogel functional layer is as follows: using N,N-dimethylformamide as a solvent, a fixed amount of graphene oxide and carbon nanotubes are uniformly dispersed by ultrasonic dispersion to obtain graphene oxide / carbon nanotube / solution, polyethersulfone is added to the solution, and after heating to fully dissolve, a polyethersulfone / graphene oxide / carbon nanotube solution is obtained; the prepared gasket body is placed in a SiO2 sol containing graphene oxide and carbon nanotubes, so that the gasket body is fully infiltrated into the prepared SiO2 sol, and the vacuum degree is adjusted by a vacuum suction filtration device to control the amount of glue suction; after gelation and aging steps, it is modified using hexamethyldisilazane, wherein the molar ratio of ethyl orthosilicate to hexamethyldisilazane is 1:0.6, and then it is placed in an environment with carbon dioxide as a drying medium, and an intermediate product of a thermal gasket and a first aerogel functional layer is obtained by supercritical drying.

[0031] After the intermediate products are made, the final products are made: The intermediate product is placed in a corresponding mold, and the polyethersulfone / graphene oxide / carbon nanotube solution is introduced into the mold, wherein the mold is made of Figure 4 The structure shown in the figure allows the intermediate product and the polyethersulfone / graphene oxide / carbon nanotube solution to fully contact each other, and then the mold is placed on a copper cold finger with liquid nitrogen as a cold source for vertical directional freezing. After the solution is completely converted into a solid, it is quickly transferred to a freeze dryer for sublimation of N,N-dimethylformamide solid in a vacuum environment of -50 to -45°C. After the solvent N,N-dimethylformamide is removed, the polyethersulfone / graphene oxide / carbon nanotube is combined with the intermediate product to form a solid final product.

[0032] The product with the first aerogel functional layer and the second aerogel functional layer was subjected to performance testing: The mass ratio of the first aerogel functional layer to the second aerogel functional layer is 1:1; Sample (mass of aerogel functional layer) The first aerogel functional layer quality Second aerogel functional layer quality Thermal conductivity at 600 degrees Celsius (to four decimal places) 10% 5% 5% 0.0511W / m·K) 15% 7.5% 7.5% 0.0496 W / (m·K) 20% 10% 10% 0.0483 W / (m·K) 25% 12.5% 12.5% 0.0475 W / (m·K) 30% 15% 15% 0.0462W / (m·K) 35% 17.5% 17.5% 0.0468 W / (m·K) 40% 20% 20% 0.0484 W / (m·K) According to the above table, it can be seen that with the increase of the mass of the aerogel functional layer, the thermal conductivity of the product shows a trend of first decreasing and then increasing in the range of 10-40% of the mass of the aerogel functional layer; when the mass of the aerogel functional layer is 30%, its thermal conductivity is the lowest, and the thermal conductivity in the above range meets the requirements of the thermal insulation pad.

[0033] The tensile strength test of the aerogel functional layer with a mass of 30% was carried out, and the measured data was 0.45MPa, which also meets the use standard; The present invention wraps the gasket body with an aerogel functional layer to form a new thermal insulation gasket, wherein in the preparation of the first aerogel functional layer and the second aerogel functional layer, isostructural graphene oxide and carbon nanotubes are used to balance the thermal conductivity and tensile strength of the aerogel material so that it can meet the use requirements of the three-way catalytic converter.

[0034] For example, certain words are used in the specification and claims to refer to specific components. Those skilled in the art should understand that hardware manufacturers may use different terms to refer to the same component. This specification and claims do not use differences in names as a way to distinguish components, but use differences in the functions of components as the criteria for distinction. For example, "including" mentioned throughout the specification and claims is an open term, so it should be interpreted as "including but not limited to". "Approximately" means that within an acceptable error range, those skilled in the art can solve technical problems within a certain error range and basically achieve technical effects.

[0035] It should be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a product or system including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such product or system. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the product or system including the elements.

[0036] The above description shows and describes several preferred embodiments of the present invention, but as before, it should be understood that the present invention is not limited to the form disclosed herein, and should not be regarded as excluding other embodiments, but can be used in various other combinations, modifications and environments, and can be modified within the scope of the invention concept of this article through the above teachings or the technology or knowledge of the relevant field. And the changes and modifications made by those skilled in the art do not depart from the spirit and scope of the present invention, and should be within the scope of protection of the claims attached to the present invention.

Claims

1. A thermal insulation pad, characterized in that: It includes a pad body and an aerogel functional layer arranged on the pad body, the aerogel functional layer is a first aerogel functional layer and a second aerogel functional layer; the first aerogel functional layer is prepared by materials including tetraethyl orthosilicate, anhydrous ethanol, and deionized water; the second aerogel functional layer is prepared by materials including polyethersulfone, N,N-dimethylformamide, graphene oxide, and carbon nanotubes.

2. A thermal insulation pad according to claim 1, characterized in that: The aerogel functional layer is provided by wrapping the cushion body with a first aerogel functional layer or by wrapping the cushion body with a second aerogel functional layer.

3. A thermal insulation pad according to claim 1, characterized in that: The second aerogel layer wraps the first aerogel functional layer and the cushion body, wherein the first aerogel functional layer wraps the cushion body.

4. A thermal insulation pad according to claim 1, characterized in that: The pad body is placed in the solution formed by the first aerogel functional layer, and the amount of glue suction is controlled by a vacuum suction filtration device; after the gelation and aging steps, it is placed in a drying medium with carbon dioxide, and a product of a thermal insulation pad and a first aerogel functional layer is obtained through supercritical drying; after the thermal insulation pad and the first aerogel functional layer are combined, they are also placed in the solution formed by the second aerogel functional layer and solidified to form the final product.

5. A method for preparing a thermal insulation pad, characterized in that: The method comprises the preparation of a gasket body, the preparation of a first aerogel functional layer and the preparation of a second aerogel functional layer, wherein the preparation method of the gasket body is as follows: S-Process 1: Preparation of ceramic fiber raw materials, wherein the fiber raw materials include alumina fiber, silica fiber, and iron oxide fiber, and the ratio thereof is 4-5:4-5:1; S-Process 2: Preparation of adhesive, wherein the adhesive is acrylic emulsion; S-Process 3: Put the ceramic fiber raw material in S-Process 1 into the pulper, add water to stir and pulp until the ceramic fiber raw material is completely crushed, open the pulp pump valve, and transport the pulp to the pulp barrel; S-Process 4: Turn on the propeller of the pulp barrel to stir so that the fibers are evenly dispersed, and take samples to measure the concentration; if the concentration does not meet the technical parameters, add water or adjust the fibers and re-measure the concentration until it meets the production requirements; S-Process 5: According to the production plan and process parameters, set the corresponding conveyor network speed parameters and the corresponding roller height parameters; Open the conveying net, open the flushing valve, turn on the feed pump, turn on the glue machine, and place the adhesive in the glue machine, and finally open the headbox to evenly disperse the fibers on the mesh belt; S-Process 6: Open the vacuum pump water suction valve to absorb water from the formed fiber pad on the mesh belt to reduce the water content of the pad; S-Process 7: After the pressing roller flattens the fiber mat, it moves to the drying tunnel smoothly and automatically; according to different models of products, the temperature of the corresponding five temperature zones of the drying tunnel is set; S-Process 8: After drying and forming, the liner is cut to the corresponding length according to the production plan requirements, weighed, and the appearance is checked and sampled again. The sampled semi-finished products are tested to ensure that they meet the design requirements.

6. The method for preparing a thermal insulation pad according to claim 3, characterized in that: The preparation method of the first aerogel functional layer is as follows: graphene oxide, carbon nanotubes and deionized water are dispersed by ultrasonic dispersion to form a solution, then tetraethyl orthosilicate is mixed with anhydrous ethanol, deionized water and the solution in a certain amount ratio and stirred, and then 0.1 mol / L oxalic acid solution is added to adjust the pH to 3.5, and after sufficient hydrolysis, 1 mol / L ammonia solution is added to adjust the pH to 5.5 to obtain SiO2 sol containing graphene oxide and carbon nanotubes, wherein the molar ratio of tetraethyl orthosilicate to anhydrous ethanol and deionized water is 1:6:4, the mass of graphene oxide is 4-5% of the mass of tetraethyl orthosilicate, and the mass of carbon nanotubes is 4-10% of the mass of tetraethyl orthosilicate.

7. The method for preparing a thermal insulation pad according to claim 3, characterized in that: The preparation process of the second aerogel functional layer is as follows: using N,N-dimethylformamide as a solvent, a fixed amount of graphene oxide and carbon nanotubes are uniformly dispersed by ultrasonic dispersion to obtain a graphene oxide / carbon nanotube / solution, polyethersulfone is added to the solution, and after heating to fully dissolve, a polyethersulfone / graphene oxide / carbon nanotube solution is obtained.

8. A method for preparing a thermal insulation pad according to claim 4 or 5, characterized in that: The prepared gasket body is placed in a SiO2 sol containing graphene oxide and carbon nanotubes, so that the gasket body is fully infiltrated into the prepared SiO2 sol, and the vacuum degree is adjusted by a vacuum suction filtration device to control the amount of glue suction; after gelation and aging steps, it is modified with hexamethyldisilazane, wherein the molar ratio of tetraethyl orthosilicate to hexamethyldisilazane is 1:0.6, and then it is placed in an environment with carbon dioxide as the drying medium, and the intermediate product of the thermal gasket and the first aerogel functional layer is obtained through supercritical drying.

9. The method for preparing a thermal insulation pad according to claim 6, characterized in that: The intermediate product is placed in a corresponding mold, and the polyethersulfone / graphene oxide / carbon nanotube solution is introduced into the mold so that the intermediate product and the polyethersulfone / graphene oxide / carbon nanotube solution are fully in contact. The mold is then placed on a copper cold finger with liquid nitrogen as a cold source for vertical directional freezing. After the solution is completely converted into a solid, it is quickly transferred to a freeze dryer for sublimation of N,N-dimethylformamide solid in a vacuum environment of -50 to -45°C. After the solvent N,N-dimethylformamide is removed, the polyethersulfone / graphene oxide / carbon nanotube is combined with the intermediate product to form a solid to form a final product.

10. The method for preparing a thermal insulation pad according to claim 3, characterized in that: The temperatures of the five temperature zones of the drying tunnel are: 85℃~95℃ in the first temperature zone, 120℃~165℃ in the second temperature zone, 130℃~170℃ in the third temperature zone, 125℃~165℃ in the fourth temperature zone, and 80℃~130℃ in the fifth temperature zone.

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