Thermal insulation material, preparation method thereof and household appliance

Abstract

The invention provides a thermal insulation material, a preparation method thereof and a household electrical appliance, and relates to the technical field of thermal insulation materials, the thermal insulation material comprises a main body and an organic core material, the main body is provided with an inner cavity, and the organic core material is filled in the inner cavity of the main body; the organic core material comprises fumed silica composite organic fibers. According to the technical scheme, the fumed silica is compounded with the organic fibers to serve as the organic core material to prepare the heat insulation material, glass fibers are prevented from being used, meanwhile, the organic core material prepared by compounding the fumed silica and the organic fibers is internally provided with a porous structure, the heat insulation effect of the organic core material can be further improved, and the service life of the heat insulation material is prolonged. The heat conductivity coefficient of the heat insulation material is reduced and the heat insulation performance of the heat insulation material is enhanced.

Description

Technical Field

[0001] This invention relates to the field of thermal insulation materials technology, and particularly to thermal insulation materials, their preparation methods, and household appliances. Background Technology

[0002] In household appliances requiring refrigeration or freezing functions (such as refrigerators), thermal insulation materials are typically used. Traditional thermal insulation materials, such as rigid polyurethane foam, have a thermal conductivity ranging from 19 mW / (m·K) to 23 mW / (m·K). On the one hand, facing increasingly stringent energy consumption requirements, current thermal insulation materials are finding it increasingly difficult to meet higher design and energy consumption standards. On the other hand, there is also a desire to maintain lightweight construction while maximizing usable volume.

[0003] Vacuum insulation panels (VIPs) have good thermal insulation performance and are increasingly showing significant advantages in insulation applications such as refrigeration or freezing. Their structure generally includes: main core material, getter / desiccant, and outer packaging film. Among them, the core material is the core material of the vacuum insulation panel, and its material, structure and composition have a great influence on the thermal conductivity of the vacuum insulation panel.

[0004] Currently, the main commercially available VIP core materials are granular fumed silica and glass fiber. Under low vacuum conditions, fumed silica powder particles have more contact points and higher contact thermal conductivity. However, fumed silica as a core material faces challenges such as high cost and difficulty in further reducing its thermal conductivity.

[0005] Organic core materials for vacuum insulation panels made from glass fibers (such as synthetic glass fibers) have high porosity and low thermal conductivity. Glass fibers also offer advantages such as high temperature resistance, fire resistance, and low cost. Glass fibers effectively meet the requirements of low energy consumption and high volumetric properties in thermal insulation equipment, and have become a mainstream material in the market. However, glass fibers still have some significant drawbacks. First, the production process of glass fibers requires cutting, resulting in a large amount of glass fiber dust that adheres to the skin and mucous membranes, causing strong irritation and harming health. Second, the glass fiber industry is a high-energy-consuming and high-polluting industry, and the location of its production plants is strictly restricted. Furthermore, at present, the use of glass fibers as a core material for vacuum insulation panels faces the technical challenge of not being able to further reduce the thermal conductivity in order to achieve the desired low thermal conductivity. Summary of the Invention

[0006] The main objective of this invention is to provide a thermal insulation material, its preparation method, and a household appliance, with the aim of providing a thermal insulation material with a low thermal conductivity.

[0007] To achieve the above objectives, the present invention proposes a thermal insulation material, comprising a main body and an organic core material, wherein the main body has an inner cavity, and the organic core material fills the inner cavity of the main body;

[0008] The organic core material includes fumed silica composite organic fibers.

[0009] In one embodiment, the fumed silica composite organic fiber comprises fumed silica and organic fibers:

[0010] In the fumed silica composite organic fiber, the mass percentage of fumed silica is 6% to 10%; and / or,

[0011] The porosity of the fumed silica is not less than 85%; and / or,

[0012] The organic fiber includes at least one of polypropylene, polyethylene, polyester, polyamide, polyacrylonitrile, and polyvinyl alcohol.

[0013] In one embodiment, the pore size of the fumed silica is 100–1000 nm; and / or,

[0014] The length of the fumed silica composite organic fiber is L, where 1 mm ≤ L ≤ 250 mm; and / or,

[0015] The diameter of the fumed silica composite organic fiber is D, where 0.5μm≤D≤50μm.

[0016] In one embodiment, the length of the fumed silica composite organic fiber is L, where 25mm ≤ L ≤ 250mm.

[0017] In one embodiment, the pore size of the fumed silica is 200–300 nm; and / or,

[0018] The length of the fumed silica composite organic fiber is L, where 1 mm ≤ L ≤ 12 mm; and / or,

[0019] The diameter of the fumed silica composite organic fiber is D, where 3μm≤D≤15μm.

[0020] In one embodiment, the thermal insulation material further includes a desiccant and a getter disposed within the inner cavity of the main body.

[0021] In one embodiment, the thermal conductivity of the insulation material is less than 1.3 mW·(m K). -1 .

[0022] In one embodiment, the inner cavity is sealed and vacuum-provided; and / or,

[0023] The main body is plate-shaped; and / or,

[0024] The material of the main body includes plastic or metallized materials.

[0025] In one embodiment, the inner cavity is sealed and vacuum-equipped, with a vacuum level of 1×10⁻⁶. -3 ~8×10 -3 Pa.

[0026] This invention also proposes a method for preparing a thermal insulation material, comprising the following steps:

[0027] S10. Mix the fumed silica composite organic fiber with the dispersion to obtain an organic fiber suspension;

[0028] S20. The organic fiber suspension is made into a fiber web and dried to obtain a fiber cloth;

[0029] S30. After stacking the fiber cloth, heat treat it to obtain an organic core material;

[0030] S40. The organic core material is placed inside the inner cavity of the main body to obtain a heat insulation material.

[0031] In one embodiment, in step S10, the mass concentration of the fumed silica composite organic fiber in the organic fiber suspension is 0.005% to 1.0%.

[0032] In one embodiment, in step S10, the mass concentration of the fumed silica composite organic fiber in the organic fiber suspension is 0.01% to 0.1%.

[0033] In one embodiment, in step S20, a wet web-forming process is used to form the organic fiber suspension into a fiber web.

[0034] In one embodiment, in step S20, the baking temperature of the wet web forming process is 100–240°C; and / or,

[0035] The baking time for the wet web forming process is 30–120 minutes.

[0036] In one embodiment, in step S20, the baking temperature of the wet web forming process is 140-200°C.

[0037] In one embodiment, in step S20, the density of the fiber cloth is 2-150 g / m³. 2 .

[0038] In one embodiment, in step S20, the density of the fiber cloth is 5-100 g / m³. 2 .

[0039] In one embodiment, in step S30, the heat treatment temperature is 140–220°C; and / or,

[0040] The heat treatment time is 30 to 120 minutes.

[0041] In one embodiment, step S40 includes: placing an organic core material inside the inner cavity of the main body, evacuating the inner cavity, and then sealing the main body to obtain a heat insulation material.

[0042] In one embodiment, in step S40, the getter and / or the desiccant are wrapped with an outer shell, and a puncture portion is provided in the inner cavity of the main body corresponding to the outer shell;

[0043] After step S40, the following is also included:

[0044] S50, by applying pressure to the puncture portion outside the main body to puncture the outer shell, the getter and / or the desiccant are released.

[0045] The present invention also proposes a household appliance comprising the heat insulation material as described above.

[0046] In one embodiment, the household appliance includes a refrigerator.

[0047] In the technical solution of the present invention, fumed silica composite organic fiber is used as organic core material to prepare thermal insulation material, avoiding the use of glass fiber. At the same time, the organic core material obtained by fumed silica and organic fiber composite has a porous structure, which can further improve the thermal insulation effect of the organic core material, thereby reducing the thermal conductivity of the thermal insulation material and enhancing the thermal insulation performance of the thermal insulation material. Attached Figure Description

[0048] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0049] Figure 1 A schematic diagram of the structure of an embodiment of the thermal insulation material provided by the present invention;

[0050] Figure 2 An axial cross-sectional view of an embodiment of the fumed silica composite organic fiber provided by the present invention;

[0051] Figure 3 This is a cross-sectional view of an embodiment of fumed silica in fumed silica composite organic fiber provided by the present invention.

[0052] Figure 4 This is a schematic flowchart of an embodiment of the method for preparing the thermal insulation material provided by the present invention.

[0053] Explanation of icon numbers:

[0054] 100. Thermal insulation material; 10. Main body; 20. Organic core material; 21. Fumed silica composite organic fiber; 211. Organic fiber; 212. Fumed silica; 212a. Pores.

[0055] The objectives, features, and advantages of this invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0056] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them.

[0057] It should be noted that, unless specific conditions are specified in the embodiments, conventional conditions or conditions recommended by the manufacturer should be followed. Reagents or instruments whose manufacturers are not specified are all commercially available products. Furthermore, the meaning of "and / or" throughout the text includes three parallel solutions; for example, "A and / or B" includes solution A, solution B, or a solution that simultaneously satisfies A and B. In addition, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, such a combination should be considered non-existent and not within the scope of protection claimed by this invention. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of this invention.

[0058] In household appliances requiring refrigeration or freezing functions (such as refrigerators), thermal insulation materials are typically used. Traditional thermal insulation materials, such as rigid polyurethane foam, have a thermal conductivity ranging from 19 mW / (m·K) to 23 mW / (m·K). On the one hand, facing increasingly stringent energy consumption requirements, current thermal insulation materials are finding it increasingly difficult to meet higher design and energy consumption standards. On the other hand, there is also a desire to maintain lightweight construction while maximizing usable volume.

[0059] Vacuum insulation panels (VIPs) have good thermal insulation performance and are increasingly showing significant advantages in insulation applications such as refrigeration or freezing. Their structure generally includes: main core material, getter / desiccant, and outer packaging film. Among them, the core material is the core material of the vacuum insulation panel, and its material, structure and composition have a great influence on the thermal conductivity of the vacuum insulation panel.

[0060] Currently, the main commercially available VIP core materials are granular fumed silica and glass fiber. Under low vacuum conditions, fumed silica powder particles have more contact points and higher contact thermal conductivity. However, fumed silica as a core material faces challenges such as high cost and difficulty in further reducing its thermal conductivity.

[0061] Organic core materials for vacuum insulation panels made from glass fibers (such as synthetic glass fibers) have high porosity and low thermal conductivity. Glass fibers also offer advantages such as high temperature resistance, fire resistance, and low cost. Glass fibers effectively meet the requirements of low energy consumption and high volumetric properties in thermal insulation equipment, and have become a mainstream material in the market. However, glass fibers still have some significant drawbacks. First, the production process of glass fibers requires cutting, resulting in a large amount of glass fiber dust that adheres to the skin and mucous membranes, causing strong irritation and harming health. Second, the glass fiber industry is a high-energy-consuming and high-polluting industry, and the location of its production plants is strictly restricted. Furthermore, at present, the use of glass fibers as a core material for vacuum insulation panels faces the technical challenge of not being able to further reduce the thermal conductivity in order to achieve the desired low thermal conductivity.

[0062] In view of this, see Figures 1 to 3 The present invention proposes a heat insulation material 100, comprising a main body 20 and an organic core material 10. The main body 20 has an inner cavity, and the organic core material 10 fills the inner cavity of the main body 20. The organic core material 10 comprises fumed silica composite organic fiber 21.

[0063] In the technical solution of the present invention, fumed silica composite organic fiber 21 is used as organic core material 10 to prepare thermal insulation material 100, avoiding the use of glass fiber. At the same time, the organic core material 10 obtained by fumed silica 212 and organic fiber 211 has a porous structure inside, which can further improve the thermal insulation effect of organic core material 10, thereby reducing the thermal conductivity of thermal insulation material 100 and enhancing the thermal insulation performance of thermal insulation material 100.

[0064] In one embodiment, the fumed silica composite organic fiber 21 includes fumed silica 212 and organic fiber 211. Specifically, see [reference needed]. Figure 2The aerogel 212 is embedded between the organic fibers 211, so that the heat transfer process inside the organic fibers 211 will be interfered with by the aerogel 212 multiple times, thereby reducing the thermal conductivity of the insulation material and improving its thermal insulation performance.

[0065] In the fumed silica composite organic fiber 21, the mass percentage of fumed silica 212 is 6% to 10%. In the technical solution of this invention, the mass percentage of fumed silica 212 in the composite material is controlled at 6% to 10%. This ratio ensures excellent thermal insulation performance without making it difficult to form the organic core material 10 due to excessive fumed silica 212 content. The organic fiber 211 improves the processability of the fumed silica composite organic fiber 21, facilitating the formation of the organic core material 10 and further forming the thermal insulation material 100. Further, in some embodiments of this invention, the mass percentage of fumed silica 212 is 8%.

[0066] In one embodiment, the porosity 212a of the fumed silica 212 is not less than 85%. In the technical solution of the present invention, by selecting fumed silica 212 with a porosity 212a of not less than 85%, the thermal conductivity and heat convection of the fumed silica composite organic fiber 21 can be reduced, thereby improving the thermal insulation performance of the fumed silica composite organic fiber 21.

[0067] In one embodiment, the organic fiber 211 includes at least one selected from polypropylene, polyethylene, polyester, polyamide, polyacrylonitrile, and polyvinyl alcohol. In the technical solution of the present invention, by using at least one selected from polypropylene, polyethylene, polyester, polyamide, polyacrylonitrile, and polyvinyl alcohol as the organic fiber 211, the selected materials and proportions can be adjusted according to specific application requirements to regulate the thermal conductivity, ductility, and other properties of the organic fiber 211, so as to achieve better performance. By selecting an organic fiber 211 composed of one or more of the above materials and combining it with fumed silica 212, the mechanical properties, heat resistance, corrosion resistance, and thermal insulation performance of the fumed silica composite organic fiber 21 material can be improved, further improving the thermal insulation performance of the thermal insulation material 100. Specifically, in some embodiments of the present invention, the organic fiber 211 is polyethylene terephthalate fiber (PET fiber).

[0068] In one embodiment, the pore size 212a of the fumed silica 212 is 1–100 nm. In the technical solution of the present invention, by employing fumed silica 212 with pore size 212a of 1–100 nm, the movement of gas molecules within the silica pores 212a is restricted at the molecular level, which is equivalent to adding air with a very small flow range to the fumed silica 212. Since air that does not flow has extremely low heat transfer efficiency, the thermal conductivity within the fumed silica 212 can be reduced, thereby reducing the heat transfer efficiency of the organic core material 10 and the thermal insulation material 100.

[0069] In one embodiment, the length of the fumed silica composite organic fiber 21 is L, where 1 mm ≤ L ≤ 250 mm. In the technical solution of this invention, by setting the length of the fumed silica composite organic fiber 21 between 1 mm and 250 mm, this length range ensures a more uniform distribution of the fiber in the composite material. If the fiber is too long, the processing requirements are higher, and processing becomes difficult; if the fiber is too short, the organic core material 10 formed is prone to insufficient mechanical strength. Furthermore, within this range of 1 mm to 250 mm, the fumed silica composite organic fiber 21 can effectively enhance the tensile and flexural strength of the composite material while maintaining good flexibility, thereby maintaining stable thermal insulation performance.

[0070] In one embodiment, the diameter of the fumed silica composite organic fiber 21 is D, where 0.5 μm ≤ D ≤ 50 μm. In the technical solution of this invention, by controlling the diameter of the fumed silica composite organic fiber 21 between 0.5 μm and 50 μm, heat transfer via thermal conduction can be better limited, especially at the nanoscale, where the gaps between fibers can further reduce heat conduction. Furthermore, controlling the fiber diameter helps ensure uniform fiber distribution within the matrix, avoiding localized aggregation or poor dispersion, thereby improving the consistency and reliability of the final product.

[0071] Further, in one embodiment, the length of the fumed silica composite organic fiber 21 is L, where 25 mm ≤ L ≤ 250 mm. Even further, in one embodiment, the length of the fumed silica composite organic fiber 21 is L, where 1 mm ≤ L ≤ 12 mm.

[0072] Further, in one embodiment, the pore size 212a of the fumed silica 212 is 5–40 nm. In the technical solution of the present invention, the pore size 212a is in the range of 5–40 nm, which can further optimize the thermal insulation effect of the material. Within this size range, the pores 212a of the fumed silica 212 can effectively reduce heat conduction because the pore size 212a is much smaller than the mean free path of air molecules, making it difficult for gas molecules to move freely between the pores 212a, thereby greatly reducing the heat conduction efficiency. Simultaneously, the pore size 212a within this range also helps reduce thermal radiation because the pore size 212a is smaller than the wavelength of infrared light, reducing the penetration ability of thermal radiation, further reducing the heat conduction efficiency, and thus improving the thermal insulation performance of the thermal insulation material 100.

[0073] Furthermore, the diameter of the fumed silica composite organic fiber 21 is D, where 3μm ≤ D ≤ 15μm. In the technical solution of the present invention, fibers with a diameter between 3μm and 15μm have a larger specific surface area, which can more effectively block the heat conduction path, thereby enhancing the thermal insulation performance of the composite material. Fibers of this size can significantly reduce heat conduction through the solid skeleton; and fibers with a diameter within this range can be more uniformly distributed in the composite material, reducing local stress concentration, thereby improving the consistency and reliability of the finished product.

[0074] In one embodiment, the thermal insulation material 100 further includes a desiccant and a getter disposed within the inner cavity of the main body 20. In the technical solution of the present invention, by disposing of a desiccant and a getter within the inner cavity of the main body 20, the moisture and gas content within the inner cavity can be further reduced, thereby reducing the impact of heat conduction and heat convection. The desiccant absorbs residual moisture, preventing moisture condensation from affecting the thermal insulation performance; the getter adsorbs residual gas, maintaining the inner cavity in a vacuum state, ensuring the long-term high-efficiency thermal insulation performance of the thermal insulation material 100. Furthermore, the presence of the desiccant and getter extends the effective service life of the thermal insulation material 100. They can continuously adsorb any moisture and gas that may penetrate, preventing performance degradation due to prolonged use or environmental changes, ensuring that the thermal insulation material 100 maintains a stable thermal insulation effect throughout its entire service life. Specifically, in one embodiment, the desiccant includes calcium chloride, and the getter includes calcium oxide.

[0075] In one embodiment, the thermal conductivity of the insulation material 100 is less than 1.3 mW·(m K). -1 In the technical solution of this invention, the thermal conductivity of the insulation material is less than 1.3 mW·(m K). -1 It is significantly lower than the thermal conductivity of polyurethane insulation materials in the existing technology, which is 19–23 mW·(m K). -1This indicates that the insulation material prepared by this method has better insulation performance.

[0076] In one embodiment, the inner cavity is sealed and evacuated. In the technical solution of the present invention, by sealing the inner cavity, gas exchange between the inner cavity and the outside can be reduced, thereby reducing heat exchange caused by air flow; by evacuating the inner cavity, the amount of air in the inner cavity can be reduced, thereby reducing the heat conduction of the air, and thus improving the heat insulation effect of the heat insulation material 100.

[0077] In one embodiment, the main body 20 is plate-shaped. In the technical solution of the present invention, by setting the main body 20 to a plate shape, the heat insulation area of ​​the heat insulation material 100 can be increased, thereby improving the heat insulation effect.

[0078] In one embodiment, the material of the main body 20 includes plastic or metallized material. In the technical solution of the present invention, using plastic or metallized material as the material of the main body 20 can improve the shapeability of the main body 20, so as to better fit the organic core material 10, reduce the space between the main body 20 and the organic core material 10, and further improve the heat insulation effect of the heat insulation material 100.

[0079] In one embodiment, the inner cavity is sealed and vacuum-equipped, with a vacuum level of 1×10⁻³ to 8×10⁻³ Pa. In the technical solution of the present invention, the vacuum level of the inner cavity is adjusted to 1×10⁻³ Pa. -3 Pa~8×10 -3 The vacuum level of Pa can significantly reduce the air in the inner cavity, allowing the main body to fit tightly against the organic core material. Simultaneously, it reduces the gas inside the organic core material, further decreasing the heat transfer efficiency within the organic core material. Specifically, in one embodiment, the vacuum level of the inner cavity is 3.5 × 10⁻⁶. -3 Pa.

[0080] This invention also proposes a method for preparing thermal insulation material 100, see reference. Figure 4 This includes the following steps:

[0081] S10. Mix the fumed silica composite organic fiber 21 with the dispersion to obtain an organic fiber suspension;

[0082] S20. The organic fiber suspension is made into a fiber web and dried to obtain a fiber cloth;

[0083] S30. After stacking the fiber cloth, heat treat it to obtain organic core material 10;

[0084] S40. The organic core material 10 is placed inside the cavity of the main body 20 to obtain the heat insulation material 100.

[0085] In the technical solution of this invention, by forming an organic fiber suspension into a fiber web and then drying it, a fiber cloth with a certain structure and strength can be formed. This process not only removes excess water from the suspension but also ensures the uniformity and stability of the fiber cloth. By stacking the fiber cloths and heat-treating them, the connection between the fiber cloths can be made stronger, improving the overall integrity and mechanical strength of the material. Placing the organic core material 10 inside the main body 20 with an inner cavity and then performing vacuum sealing can further improve the heat insulation performance of the heat insulation material 100, reduce heat conduction and heat convection, and thus achieve a highly efficient heat insulation effect.

[0086] In one embodiment, in step S10, the mass concentration of the fumed silica composite organic fiber 21 in the organic fiber suspension is 0.005% to 1.0%. In the technical solution of the present invention, by controlling the mass concentration of the fumed silica composite organic fiber 21 within this range, it is possible to ensure that the material has a good thermal insulation effect. An appropriate amount of fiber can effectively prevent heat transfer through conduction and convection, while maintaining the lightweight properties of the material.

[0087] Further, in one embodiment, in step S10, the mass concentration of the fumed silica composite organic fiber 21 in the organic fiber suspension is 0.01% to 0.1%. In the technical solution of the present invention, controlling the mass concentration of the fumed silica composite organic fiber 21 between 0.01% and 0.1% allows for further optimization of the pore structure 212a within the material, blocking heat conduction paths, reducing heat loss, and thus further improving thermal insulation performance.

[0088] In one embodiment, in step S20, a wet web-forming process is used to form a fiber web from the organic fiber suspension. In this invention, the wet web-forming process enables the fumed silica composite organic fibers 21 to be uniformly dispersed in a liquid medium, forming a uniform fiber web. This reduces fiber agglomeration and ensures that the final fiber fabric has good uniformity and consistency. Furthermore, the fiber web formed by the wet web-forming process is easier to process subsequently, simplifying the production process.

[0089] In one embodiment, in step S20, the baking temperature of the wet web forming process is 100-240°C.

[0090] In the technical solution of the present invention, within a temperature range of 100 to 240°C, moisture in the fiber web can be removed quickly, drying time can be shortened, the drying process can be accelerated, and production efficiency can be improved. Furthermore, it can ensure that the moisture in the fiber web evaporates evenly, reduce fiber deformation or damage caused by local overheating, and ensure the uniformity and consistency of the fiber web.

[0091] In one embodiment, the baking time for the wet web forming process is 30–120 minutes. In the technical solution of this invention, a baking time of 30–120 minutes ensures that the moisture in the fiber web evaporates sufficiently, reaching a completely dry state, reducing the possibility of decreased thermal insulation performance due to residual moisture. If the baking time is too short, complete evaporation of moisture cannot be guaranteed; if the baking time is too long, the fiber web may experience localized carbonization due to excessive water loss at high temperatures, causing internal damage to the material and affecting the performance of the fiber web.

[0092] Furthermore, in one embodiment, in step S20, the baking temperature of the wet web forming process is 140–200°C. In the technical solution of this invention, by controlling the baking temperature between 140 and 200°C, the stability of the internal pore structure 212a of the fiber web can be ensured, reducing heat conduction paths and thus improving the thermal insulation performance of the material. Compared to higher temperatures, the temperature range of 140–200°C can reduce the possibility of the fiber web becoming too brittle due to over-baking, maintaining the flexibility and stability of the material.

[0093] In one embodiment, in step S20, the density of the fiber cloth is 2-150 g / m³. 2 In the technical solution of the present invention, by controlling the density of the fiber cloth, the mechanical properties of the material can be adjusted, making the fiber cloth easier to handle in subsequent stacking and heat treatment processes, and less prone to slippage or misalignment during stacking, which helps to form a uniform organic core material 10.

[0094] Furthermore, in one embodiment, in step S20, the density of the fiber cloth is 5-100 g / m³. 2 In the technical solution of this invention, the uniformity of the fiber cloth is better within this density range, which can avoid performance differences caused by local density unevenness, thereby improving the quality consistency of the final product.

[0095] In one embodiment, in step S30, the heat treatment temperature is 140–220°C. In the technical solution of the present invention, heat treatment within a temperature range of 140–220°C can enhance the material stability of the organic core material 10 formed after the fiber fabric is stacked. Appropriate high temperatures can promote the interaction between fibers, making the bond between fibers tighter, thereby improving the overall integrity and mechanical strength of the material.

[0096] In one embodiment, the heat treatment duration in step S30 is 30–120 minutes. In the technical solution of this invention, by performing heat treatment within this time range, the microstructure of the material can be optimized, making the pore structure 212a of the material more uniform and improving the thermal insulation performance of the material. A suitable heat treatment duration ensures that the material maintains its lightweight properties while possessing excellent thermal insulation effects.

[0097] In one embodiment, step S40 includes: placing the organic core material 10 inside the inner cavity of the main body 20, evacuating the inner cavity, and then sealing the main body 20 to obtain the heat insulation material 100. In the technical solution of the present invention, by evacuating the inner cavity, the amount of air in the inner cavity can be reduced, thereby reducing the heat conduction of the air and improving the heat insulation effect of the heat insulation material 100; by sealing the main body 20, the gas exchange between the inner cavity of the main body 20 and the outside of the main body 20 can be reduced, thereby reducing the heat exchange caused by airflow.

[0098] In one embodiment, in step S40, the getter and / or the desiccant are encased in an outer shell, and a puncture portion is provided in the inner cavity of the main body 20 corresponding to the outer shell. It should be noted that the outer shell may encapsulate either the getter or the desiccant, or both simultaneously, or two separate outer shells may encapsulate the getter and the desiccant respectively; no limitation is made here. In the technical solution of this invention, by providing the outer shell, it is ensured that the desiccant and / or the getter will not excessively absorb moisture or gas from the air before use, so that it can absorb moisture or air from the inner cavity after puncture, thereby further improving the thermal insulation performance of the thermal insulation material 100. Specifically, the puncture portion may be provided on the inner wall of the main body, or it may be provided on the getter and / or desiccant encapsulating the outer shell.

[0099] In one embodiment, after step S40, the method further includes:

[0100] S50, by applying pressure to the puncture portion outside the body 20 to puncture the outer shell, the getter and / or the desiccant are released.

[0101] In the technical solution of the present invention, by providing the puncture portion, the getter and / or the desiccant can be released to further absorb the gas inside the organic core material, thereby reducing the gas content inside the organic core material and improving the thermal insulation performance of the organic core material 100.

[0102] The present invention also proposes a household appliance comprising the heat insulation material 100 as described above.

[0103] Since this household appliance adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be repeated here.

[0104] In one embodiment, the household appliance includes a refrigerator. In the technical solution of the present invention, by applying the heat insulation material 100 to the refrigerator, the heat insulation performance of the household appliance can be improved, thereby reducing the energy consumption of the household appliance and thus improving the working efficiency of the household appliance.

[0105] The technical solution of the present invention will be further described in detail below with reference to specific embodiments. It should be understood that the following embodiments are only used to explain the present invention and are not intended to limit the present invention.

[0106] Example 1

[0107] This embodiment provides a thermal insulation material, the preparation method of which includes the following steps:

[0108] (1) Disperse 10 μm diameter and 5 mm length fumed silica composite PET fibers in water and disperse them evenly by mechanical stirring to prepare a fiber suspension with a fiber mass content of 0.05%; in the fumed silica composite PET fibers, the size of the fumed silica particles is 30 nm, the porosity is 92%, and the volume concentration in the fiber is 10%.

[0109] (2) After wet spinning and water control for 5 minutes, the product is placed in a 180℃ oven for 2 hours and then demolded to obtain a surface density of 13 g / m³. 2 Fiber cloth;

[0110] (3) Stack the fiber cloth into a core material and bake it again at 200℃ for 2 hours in the drying tunnel;

[0111] (4) After bagging the core material, adding one getter (homemade, 3.5g / bag) and one desiccant packet (homemade, 15g / packet), place it in a vacuum sealing machine and evacuate to a vacuum degree of 3.5×10⁻⁶. -3 After Pa, heat sealing is performed, with a heat sealing time of 15 seconds and a heat sealing voltage of 13V.

[0112] (5) After removing the sealed VIP board, press and puncture the getter shell to further reduce the internal pressure of the VIP board. After placing it at room temperature for 12 hours, perform a thermal conductivity test.

[0113] Comparative Example 1

[0114] This comparative example provides a glass fiber vacuum insulation panel, the preparation method of which includes the following steps:

[0115] (1) Circular glass fibers with a diameter of 10 μm and a length of 5 mm were dispersed in water and mechanically stirred to disperse them evenly, thus preparing a glass fiber suspension with a fiber mass content of 0.05%.

[0116] (2) After wet forming and water control for 5 minutes, the product is placed in an oven at 180℃ for 2 hours and then demolded to obtain a surface density of 25 g / m³. 2 Fiberglass mat;

[0117] (3) The glass fiber mats are stacked into core material and placed in the drying tunnel to bake again at 200℃ for 2 hours;

[0118] (4) After bagging the core material, adding one getter (homemade, 3.5g / bag) and one desiccant packet (homemade, 15g / packet), place it in a vacuum sealing machine and evacuate to a vacuum degree of 3.5×10⁻⁶. -3 After Pa, heat sealing is performed, with a heat sealing time of 15 seconds and a heat sealing voltage of 13V.

[0119] (5) After removing the sealed VIP board, press and puncture the getter shell to further reduce the internal pressure of the VIP board. After placing it at room temperature for 12 hours, perform a thermal conductivity test.

[0120] Comparative Example 2

[0121] This comparative example provides a PET fiber vacuum insulation board, the preparation method of which includes the following steps:

[0122] (1) Circular PET fibers with a diameter of 10 μm and a length of 5 mm were dispersed in water and mechanically stirred to disperse them evenly, thus preparing a fiber suspension with a fiber mass content of 0.05%.

[0123] (2) After wet forming and water control for 5 minutes, the product is placed in an oven at 180℃ for 2 hours and then demolded to obtain a surface density of 15 g / m³. 2 Fiber cloth;

[0124] (3) Stack the fiber cloth into a core material and bake it again at 200℃ for 2 hours in the drying tunnel;

[0125] (4) After bagging the core material, adding one getter (homemade, 3.5g / bag) and one desiccant packet (homemade, 15g / packet), place it in a vacuum sealing machine and evacuate to a vacuum degree of 3.5×10⁻⁶. -3 After Pa, heat sealing is performed, with a heat sealing time of 15 seconds and a heat sealing voltage of 13V.

[0126] (5) After removing the sealed VIP board, press and puncture the getter shell to further reduce the internal pressure of the VIP board. After placing it at room temperature for 12 hours, perform a thermal conductivity test.

[0127] The performance test results of the vacuum insulation panels provided in Example 1, Comparative Example 1, and Comparative Example 2 are shown in Table 1.

[0128] Table 1. Performance test results of the vacuum insulation panels provided in Example 1, Comparative Example 1, and Comparative Example 2.

[0129]

[0130] As can be seen from the comparative examples and embodiments above, fumed silica PET composite fibers have a lower thermal conductivity and lower areal density compared to pure PET fibers and glass fiber vacuum insulation panels. The resulting VIP exhibits superior thermal insulation performance and a lighter weight.

[0131] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A heat insulation material, characterized in that, It includes a main body and an organic core material, the main body having an inner cavity, and the organic core material filling the inner cavity of the main body; The organic core material includes fumed silica composite organic fibers.

2. The thermal insulation material as described in claim 1, characterized in that, The fumed silica composite organic fiber comprises fumed silica and organic fibers: In the fumed silica composite organic fiber, the mass percentage of fumed silica is 6% to 10%; and / or, The porosity of the fumed silica is not less than 85%; and / or, The organic fiber includes at least one of polypropylene, polyethylene, polyester, polyamide, polyacrylonitrile, and polyvinyl alcohol.

3. The thermal insulation material as described in claim 2, characterized in that, The pore size of the fumed silica is 100–1000 nm; and / or, The length of the fumed silica composite organic fiber is L, where 1 mm ≤ L ≤ 250 mm; and / or, The diameter of the fumed silica composite organic fiber is D, where 0.5μm≤D≤50μm.

4. The thermal insulation material as described in claim 3, characterized in that, The length of the fumed silica composite organic fiber is L, where 25mm ≤ L ≤ 250mm.

5. The thermal insulation material as described in claim 3, characterized in that, The pore size of the fumed silica is 200–300 nm; and / or, The length of the fumed silica composite organic fiber is L, where 1 mm ≤ L ≤ 12 mm; and / or, The diameter of the fumed silica composite organic fiber is D, where 3μm≤D≤15μm.

6. The thermal insulation material as described in claim 1, characterized in that, The thermal insulation material also includes a desiccant and a getter disposed within the inner cavity of the main body.

7. The thermal insulation material as described in claim 1, characterized in that, The thermal conductivity of the insulation material is less than 1.3 mW·(m K). -1 .

8. The thermal insulation material as described in claim 1, characterized in that, The inner cavity is sealed and vacuum-produced; and / or, The main body is plate-shaped; and / or, The material of the main body includes plastic or metallized materials.

9. The thermal insulation material as described in claim 1, characterized in that, The inner cavity is sealed and evacuated, with a vacuum level of 1×10⁻⁶. -3 ~8×10 -3 Pa.

10. A method for preparing a thermal insulation material, characterized in that, Includes the following steps: S10. Mix the fumed silica composite organic fiber with the dispersion to obtain an organic fiber suspension; S20. The organic fiber suspension is made into a fiber web and dried to obtain a fiber cloth; S30. After stacking the fiber cloth, heat treat it to obtain an organic core material; S40. The organic core material is placed inside the inner cavity of the main body to obtain a heat insulation material.

11. The method for preparing the thermal insulation material as described in claim 10, characterized in that, In step S10, the mass concentration of the fumed silica composite organic fiber in the organic fiber suspension is 0.005% to 1.0%.

12. The method for preparing the thermal insulation material as described in claim 11, characterized in that, In step S10, the mass concentration of the fumed silica composite organic fiber in the organic fiber suspension is 0.01% to 0.1%.

13. The method for preparing the thermal insulation material as described in claim 10, characterized in that, In step S20, a wet web-forming process is used to form the organic fiber suspension into a fiber web.

14. The method for preparing the thermal insulation material as described in claim 13, characterized in that, In step S20, the baking temperature for the wet web forming process is 100–240°C; and / or, The baking time for the wet web forming process is 30–120 minutes.

15. The method for preparing the thermal insulation material as described in claim 14, characterized in that, In step S20, the baking temperature of the wet web forming process is 140-200℃.

16. The method for preparing the thermal insulation material as described in claim 10, characterized in that, In step S20, the density of the fiber cloth is 2-150 g / m³. 2 .

17. The method for preparing the thermal insulation material as described in claim 16, characterized in that, In step S20, the density of the fiber cloth is 5-100 g / m³. 2 .

18. The method for preparing the thermal insulation material as described in claim 10, characterized in that, In step S30, the heat treatment temperature is 140–220°C; and / or, The heat treatment time is 30 to 120 minutes.

19. The method for preparing the thermal insulation material as described in claim 10, characterized in that, Step S40 includes: placing the organic core material inside the inner cavity of the main body, evacuating the inner cavity, and sealing the main body to obtain a heat insulation material.

20. The method for preparing the thermal insulation material according to claim 10, characterized in that, Step S40 includes: placing an organic core material, a getter, and a desiccant inside the inner cavity of the main body, evacuating the inner cavity, and then sealing the main body to obtain a heat insulation material.

21. The method for preparing the thermal insulation material as described in claim 20, characterized in that, In step S40, the getter and / or the desiccant are wrapped in an outer shell, and a puncture part is provided in the inner cavity of the main body corresponding to the outer shell; After step S40, the following is also included: S50, by applying pressure to the puncture portion outside the main body to puncture the outer shell, the getter and / or the desiccant are released.

22. A household appliance, characterized in that, The household appliance includes the heat insulation material as described in any one of claims 1 to 9, or the heat insulation material prepared by the method for preparing the heat insulation material as described in any one of claims 10 to 21.

23. The household appliance as described in claim 22, characterized in that, The household appliances include refrigerators.

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