A heat retaining cover for a cooking appliance and a manufacturing process thereof

Abstract

The application discloses a heat preservation cover of a cooking utensil and a manufacturing process thereof. The heat preservation cover surrounds a containing cavity for placing an inner container. The heat preservation cover comprises a body and a heat preservation layer arranged on the inner wall and / or the outer wall of the body. The heat preservation layer comprises aerogel particles arranged on the surface of the body. The aerogel particles have relatively arranged wide ends and narrow ends. The narrow ends are towards the body, and the wide ends are away from the body. The structure of the aerogel particles in the application is that one end is wider and the other end is narrower. After the heat preservation layer is formed on the surface of the body, the narrow ends are towards the body and closer to the surface of the body, and the wide ends are away from the body. In this way, the aerogel particles are regularly arranged on the surface of the body to form an aerogel layer, the covering rate of the aerogel on the surface of the body is improved, the porosity of adjacent aerogel particles in the aerogel layer is greatly reduced, and therefore, the energy loss from the gaps between the aerogel particles can be effectively prevented, and the heat preservation effect of the heat preservation layer on the body is improved.

Description

Technical Field

[0001] This application belongs to the field of kitchen appliance technology, specifically relating to a heat preservation cover for a cooking utensil and its manufacturing process. Background Technology

[0002] The energy efficiency requirements for electrical appliances are also increasing. As a result, many products are constantly being optimized. Rice cookers, pressure cookers, and other cooking appliances are essential small kitchen appliances for people's daily meals, and the need for improved energy efficiency is becoming increasingly urgent.

[0003] In existing technologies, to improve the energy efficiency of cooking appliances, a common method is to add insulation cotton or film to the outside of the insulation cover on the outer side of the inner pot. This enhances the insulation effect of the cover, concentrating the heat from the heating element and the heat emitted by the inner pot inside the cover and preventing excessive heat loss to the outside. While this approach can improve energy efficiency to some extent, it is costly, and manually applying the insulation film is difficult. Furthermore, it requires a high degree of uniformity in the insulation film and cotton; inconsistent uniformity can lead to significant differences in energy efficiency across different areas.

[0004] In addition, some manufacturers improve the insulation effect of insulation covers by spraying an insulation layer onto the surface. While this method allows the insulation layer to adhere evenly to the surface, it cannot control the uniform distribution of the insulation material within the layer. This results in varying energy efficiency in different areas after the insulation layer is applied. Therefore, the only solution is usually to increase the thickness of the insulation layer to cover the insulation cover as much as possible. This undoubtedly increases processing costs significantly and makes the insulation cover heavier overall, hindering the development of thinner and lighter designs. Summary of the Invention

[0005] This application provides a heat preservation cover for cooking appliances and its manufacturing process to solve the problems of poor heat preservation effect of heat preservation covers, which makes it difficult to effectively improve the energy efficiency of cooking appliances, and the difficulty in processing heat preservation covers, and the uneven distribution of heat preservation layers and heat preservation materials on the surface of heat preservation covers, which leads to differences in energy efficiency in different areas.

[0006] The technical solution adopted in this application is as follows:

[0007] A heat preservation cover for a cooking appliance, the heat preservation cover forming a cavity for placing an inner pot, the heat preservation cover including a body and a heat preservation layer disposed on the inner wall and / or outer wall of the body, the heat preservation layer including aerogel particles arranged along the surface of the body, the aerogel particles having a wide end and a narrow end disposed opposite to each other, the narrow end facing the body and the wide end away from the body.

[0008] In this application, the insulation layer includes aerogel particles. Due to its unique nanoporous structure and extremely low density, aerogel exhibits excellent thermal insulation performance. Specifically, the solid framework of the aerogel is composed of nanoscale particles, forming a three-dimensional network structure. There are very few contact points between the solid particles, and the nanoscale framework significantly extends the heat conduction path through the solid. Heat is transferred in the solid via phonons (lattice vibrations), but the nanoscale pores and framework defects strongly scatter phonons, significantly reducing the solid-state thermal conductivity. Furthermore, the pore size of the aerogel is much smaller than the mean free path of air molecules. Gas molecules frequently collide with the pore walls rather than other molecules within the pores, resulting in a significant reduction in the gas's thermal conductivity. While the aerogel has high porosity, the pores are closed or semi-closed, hindering gas flow and further reducing gas heat transfer. Based on this, by arranging aerogel particles on the surface of the body, the thermal insulation effect of the insulation cover can be significantly improved, concentrating heat within the cavity enclosed by the insulation cover and making it more difficult for heat to escape to the outside of the cavity, thus improving energy efficiency.

[0009] However, the arrangement of aerogel particles in the coating substrate of the insulation layer is usually disordered, resulting in random shading and coverage of the aerogel particles on the substrate. This leads to energy loss through the irregular gaps between the aerogel particles. This application addresses this issue by designing the aerogel particle structure in which the width of the wider end is greater than the width of the narrower end, creating a structure that is wider at one end and narrower at the other. After the insulation layer is formed on the substrate surface, the narrower end faces the substrate, getting closer to the surface, while the wider end is further away. This orderly arrangement of aerogel particles on the substrate surface forms an aerogel layer. This orderly arrangement significantly improves the coverage of the aerogel on the substrate surface, reduces the gaps between adjacent aerogel particles, and greatly reduces the porosity of adjacent aerogel particles in the aerogel layer. Therefore, it effectively prevents energy loss through the gaps between the aerogel particles, improving the insulation effect of the insulation layer on the substrate.

[0010] The insulation layer also includes a coating substrate, in which aerogel particles are mixed, wherein the proportion of aerogel particles in the mixture formed by the aerogel particles and the coating substrate is 0.5%-20%.

[0011] In this design, if the proportion of aerogel particles in the mixture is small, the number of aerogel particles in an equal amount of mixture will be insufficient. After combining the insulation layer with the main body, the aerogel particles may not be able to completely cover the surface of the main body, or the gaps between adjacent aerogel particles may be too large, allowing heat to easily escape through the gaps, resulting in poor thermal insulation performance. Conversely, if the number of aerogel particles is too large, aerogel particles will stack in the thickness direction of the main body, leading to at least some areas having double or even multiple aerogel layers. While this improves the thermal insulation effect, it cannot guarantee uniform thickness of the aerogel layer in each area, resulting in differences in insulation performance across different regions and affecting the uniformity of energy efficiency. Furthermore, multiple aerogel layers significantly increase the processing difficulty and production cost of the aerogel. Designing the proportion of aerogel particles in the mixture to 0.5%-20% allows for the reduction of the aerogel layer thickness while ensuring at least a single layer of full coverage of the main body surface, thereby saving costs and reducing processing difficulty.

[0012] The density of the coating substrate is 0.6 g / cm³. 3 -1.5g / cm 3 .

[0013] In this design, a higher density coating substrate generally results in a denser molecular structure, potentially increasing thermal conductivity and weakening the overall insulation performance of the insulation layer, as heat is more easily conducted through the high-density coating substrate. Simultaneously, the insulation performance of aerogel particles depends on their porous structure (low density, high porosity). If a high-density coating substrate fills the gaps between aerogel particles, it may hinder the formation of an effective insulation network, limiting the aerogel's function and reducing the overall insulation efficiency of the composite material. Furthermore, high-density coating substrates have higher viscosity, making it difficult to disperse aerogel particles when mixed with them. Optimized mixing processes are needed to avoid localized agglomeration, affecting the consistency of insulation performance. However, high-density coating substrates typically have higher strength and rigidity, improving the insulation layer's resistance to compression and deformation. Density also affects the interfacial bonding strength between the coating substrate and aerogel particles. Too low a density may lead to weak bonding and easy detachment of aerogel particles, while too high a density may cause microcracks to propagate due to the brittleness of the coating substrate. This application designs the density of the coating substrate to be 0.6 g / cm³. 3 -1.5g / cm 3 This approach ensures the mechanical strength of the insulation layer while minimizing its negative impact on the thermal insulation performance of the aerogel. Furthermore, it reduces the difficulty of mixing aerogel particles with the coating substrate during processing, allowing the aerogel particles to be more uniformly and dispersed within the coating substrate, thus facilitating uniform adhesion of the aerogel particles to the substrate surface.

[0014] The coating substrate can melt at high temperatures to coat the surface of the aerogel particles and can combine the aerogel particles with the body to coat the surface of the body with the insulation layer.

[0015] In this solution, the initial state of the coating substrate is powder. If it is directly mixed with aerogel particles in powder form, uneven mixing and localized accumulation of aerogel particles on the coating substrate will occur. By heating the coating substrate at high temperature to melt it into a liquid state, it can then coat the surface of the aerogel particles, allowing the coating substrate to uniformly coat each aerogel particle, thus greatly improving the mixing uniformity of the coating substrate and aerogel particles. After mixing, the coating substrate cools back to a powder state, making it easy to store and apply to the surface of the substrate by spraying. Furthermore, the molten structure of the coating substrate allows it to be melted again during subsequent processing with the substrate surface at high temperatures, ensuring complete bonding with the substrate surface and improving the bonding stability between the insulation layer and the substrate.

[0016] Aerogel particles form an aerogel layer on the surface of the bulk material, and the thickness of the aerogel layer is the same as the equivalent circle diameter of the aerogel particles from the narrow end to the wide end.

[0017] In this design, aerogel particles are arranged on the surface of the substrate to form an aerogel layer. The uniform arrangement of the aerogel particles ensures that the aerogel layer and the aerogel particles have the same equivalent circular diameter, and the thickness is the length from the narrow end to the wide end (equivalent circular diameter). This results in a single layer of aerogel particles covering the substrate surface. While ensuring uniform and complete coverage of the substrate surface, the overall thickness of the insulation layer is reduced, thus saving costs.

[0018] The aerogel particles are multiple and arranged along the surface of the body, with the wide ends of adjacent aerogel particles in contact.

[0019] In this design, the gaps between adjacent aerogel particles would form channels for heat loss. However, the wide ends of adjacent aerogel particles contact each other, which to some extent minimizes or even eliminates these gaps, thus sealing the channels and reducing heat loss to the outside of the insulation layer. Simultaneously, the close arrangement of the aerogel particles improves the structural strength and stability of the formed aerogel layer, enabling it to withstand certain external forces and preventing changes in the orientation and position of localized aerogel particles due to collisions or scratches with the insulation cover, which could lead to a decrease in localized insulation performance.

[0020] The body includes side walls, a bottom wall, and flanges that fold outward from the top of the side walls. An insulation layer is provided on the surfaces of the side walls and the bottom wall to form an exposed area at the flanges.

[0021] In this design, the insulation layer is located on the bottom and side walls, while the flanged surface is uncovered. During use, the inner pot is typically placed within the space enclosed by the side and bottom walls. Therefore, placing the insulation layer on the side and bottom walls ensures that it surrounds the inner pot as much as possible, guaranteeing effective heat retention. The flanged portion, however, is exposed to the outside of the pot. When the user grips the inner pot, their hand is likely to come into contact with the flanged edge. Since the flanged edge is not covered by the insulation layer, it loses the insulating effect of the insulation layer, allowing the main body to directly contact the outside air. Heat transferred to the flanged edge can also be quickly dissipated, resulting in better heat dissipation and helping to maintain a lower temperature. Shortly after cooking, the flanged edge cools down quickly, preventing burns from contact with the user.

[0022] This application also discloses a manufacturing process for a heat-insulating cover, used to manufacture the heat-insulating cover for the aforementioned cooking utensil, comprising the following steps: Aerogel preparation stage: constructing a gel structure with one narrow end and one wide end as a granular structure by mixing colloid and liquid; drying the gel particles to evaporate the liquid solvent and water inside the gel, forming porous aerogel particles; mixing stage: mixing the aerogel particles with a coating substrate; molding stage: using electrostatic coating to electrostatically adsorb the mixture of aerogel particles and coating substrate onto the surface of the body, during which, under the action of electrostatics, the narrow end of the aerogel particles is close to the surface of the body, and the wide end is far away from the surface of the body; melting the powdered coating substrate by high-temperature sintering, bonding it together with the body, and cooling to form a heat-insulating layer.

[0023] In this application, the aerogel particles are constructed into a structure that is wide at one end and narrow at the other while still in a liquid and colloid mixture stage, and then dried to evaporate the internal moisture. This allows the aerogel particles to be formed in a liquid state, simplifying the shaping process and reducing the risk of breakage, thus ensuring the structural and shape stability of the aerogel particles. Furthermore, due to the shaping characteristics of the aerogel particles, electrostatic spraying is used to adsorb them onto the surface of the substrate. During processing, the narrow end accumulates charge more easily than the wide end, and under electrostatic adsorption, the narrow end naturally moves closer to the substrate than the wide end, ensuring that each aerogel particle is arranged in an ideal posture. Finally, heating melts the coating substrate, allowing it to fully bond with the substrate surface, firmly fixing the aerogel particles to the substrate. Compared to simple spraying or pasting methods, this method provides a more secure fixation of the aerogel particles to the substrate, and the melted coating substrate flows liquid on the substrate surface, resulting in a more uniform distribution and ensuring consistent insulation performance across all areas.

[0024] In the aerogel preparation stage, the gel, which is a mixture of colloid and liquid, is placed in an extrusion tube. The extrusion nozzle of the extrusion tube is located at the top of a closed chamber. The granular gel is extruded into the closed chamber through the extrusion nozzle, so that the granular gel forms a structure with one narrow end and the other wide end under the action of gravity.

[0025] In this method, when the gel is in a liquid state, it is extruded from top to bottom into a closed chamber using an extrusion tube. Under the influence of gravity, the gel drips into the closed chamber in a droplet shape, naturally forming a structure with a wide bottom and a narrow top. Using this method, the gel can be easily and conveniently constructed into ideal shapes without the need for additional shaping tools and complex shaping steps, greatly simplifying the process and reducing processing difficulty.

[0026] During the mixing stage, the powdered coating substrate is melted by high temperature, and then aerogel particles are stirred and mixed into it. After cooling, the coating substrate is coated on the surface of the aerogel particles.

[0027] In this solution, the coating substrate is heated to a high temperature to melt it into a liquid state, which then coats the surface of the aerogel particles. This allows the coating substrate to uniformly coat each aerogel particle, thereby greatly improving the mixing uniformity of the coating substrate and the aerogel particles. Attached Figure Description

[0028] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0029] Figure 1 This is a schematic diagram of the structure of the body according to one embodiment of this application;

[0030] Figure 2 This is a cross-sectional view of a heat insulation cover according to one embodiment of this application;

[0031] Figure 3 for Figure 2 A magnified view of area A in the middle;

[0032] Figure 4 This is a partial enlarged cross-sectional view of the heat insulation cover according to another embodiment of this application;

[0033] Figure 5 This is a cross-sectional view of an apparatus for processing aerogel particles according to one embodiment of this application;

[0034] Figure 6 This is a partial cross-sectional view of aerogel particles according to one embodiment of this application;

[0035] Figure 7This is a cross-sectional view of a cooking appliance according to one embodiment of this application.

[0036] in:

[0037] 1. Insulation cover; 11. Body; 111. Side wall; 112. Bottom wall; 113. Flanged edge;

[0038] 2. Insulation layer; 21. Aerogel particles; 211. Narrow end; 212. Wide end; 22. Coating substrate;

[0039] 3. Enclosed chamber; 31. Extrusion barrel; 32. Extrusion port;

[0040] 4. Inner liner. Detailed Implementation

[0041] To more clearly illustrate the overall concept of this application, a detailed explanation is provided below with reference to the accompanying drawings.

[0042] Many specific details are set forth in the following description in order to provide a full understanding of this application. However, this application may also be implemented in other ways different from those described herein. Therefore, the scope of protection of this application is not limited to the specific embodiments disclosed below.

[0043] Furthermore, it should be understood in the description of this application that the terms "top", "bottom", "inner", "outer", "axial", "radial", "circumferential", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0044] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a communication connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0045] In this application, unless otherwise expressly specified and limited, the "above" or "below" of the second feature can mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. In the description of this specification, references to terms such as "implementation," "example," "a particular embodiment," "example," or "specific example," etc., indicate that the specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described can be combined in any suitable manner in one or more embodiments or examples.

[0046] like Figure 2 , Figure 3 , Figure 7 As shown, a heat preservation cover 1 for a cooking appliance is provided. The heat preservation cover 1 forms a cavity for placing an inner pot 4. The heat preservation cover 1 includes a body 11 and a heat preservation layer 2 disposed on the inner wall and / or outer wall of the body 11. The heat preservation layer 2 includes aerogel particles 21 arranged along the surface of the body 11. The aerogel particles 21 have a wide end 212 and a narrow end 211 disposed opposite to each other. The narrow end 211 faces the body 11 and the wide end 212 is away from the body 11.

[0047] It is understandable that the width of the wide end 212 is greater than the width of the narrow end 211. Preferably, as shown... Figure 2 , Figure 5 , Figure 6 As shown, the aerogel particles 21 have a teardrop-shaped structure, with one end being a pointed tip or a narrow arc, and the other end being a wider arc. Of course, the aerogel particles 21 can also have other structural shapes, such as trapezoids, etc., which are not limited here.

[0048] Preferably, the aerogel material can be silicon-based, carbon-based, metal oxide-based, sulfur-based, or other similar materials.

[0049] In this application, the insulation layer 2 includes aerogel particles 21, such as... Figure 6As shown, aerogels possess excellent thermal insulation properties due to their unique nanoporous structure and extremely low density. Specifically, the solid framework of aerogels is composed of nanoscale particles, forming a three-dimensional network structure. There are very few contact points between the solid particles, and the nanoscale framework significantly extends the heat conduction path through the solid. Heat is transferred in the solid via phonons (lattice vibrations), but the nanoscale pores and framework defects strongly scatter phonons, significantly reducing the solid-state thermal conductivity. Furthermore, the pore size of aerogels is much smaller than the mean free path of air molecules. Gas molecules frequently collide with the pore walls rather than other molecules within the pores, resulting in a significant reduction in the gas's thermal conductivity. While aerogels have high porosity, the pores are closed or semi-closed, hindering gas flow and further reducing heat transfer. Based on this, by arranging aerogel particles 21 on the surface of the body 11, the thermal insulation effect of the insulation cover 1 can be significantly improved, concentrating heat within the cavity enclosed by the insulation cover 1 and making it more difficult for heat to escape to the outside of the cavity, thus improving energy efficiency.

[0050] However, under normal circumstances, the arrangement of aerogel particles 21 in the coating substrate 22 of the insulation layer 2 is often disordered, resulting in random shading rate and coverage of the aerogel particles 21 on the body 11. This causes energy to be lost from the irregular gaps between the aerogel particles 21.

[0051] This application designs the structure of aerogel particles 21 such that the width of the wide end 212 is greater than the width of the narrow end 211, resulting in a structure that is wider at one end and narrower at the other. After the insulation layer 2 is formed on the surface of the body 11, the narrow end 211 faces the body 11, getting closer to its surface, while the wide end 212 is further away. This allows the aerogel particles 21 to be arranged regularly on the surface of the body 11, forming an aerogel layer. This orderly arrangement significantly increases the coverage of the aerogel on the surface of the body 11, reduces the gap between adjacent aerogel particles 21, and greatly reduces the porosity of adjacent aerogel particles 21 in the aerogel layer. Therefore, it effectively prevents energy loss from the gaps between the aerogel particles 21, improving the insulation effect of the insulation layer 2 on the body 11.

[0052] It should be noted that the insulation layer 2 can be disposed on the outer surface or the inner surface of the main body 11. Of course, if... Figure 2 As shown, insulation layers 2 can also be provided on both the inner and outer surfaces of the body 11.

[0053] Furthermore, such as Figure 1 , Figure 2 As shown, the body 11 includes a side wall 111, a bottom wall 112, and a flange 113 that folds outward from the top of the side wall 111. The insulation layer 2 is disposed on the surface of the side wall 111 and the bottom wall 112 to form an exposed area on the flange 113.

[0054] The insulation layer 2 is located on the bottom wall 112 and side wall 111, while the flange 113 is not covered by the insulation layer 2. During use, the inner pot 4 is usually placed within the space enclosed by the side wall 111 and bottom wall 112. The insulation layer 2 is thus positioned on the side wall 111 and bottom wall 112 to ensure it surrounds the inner pot 4 as much as possible, guaranteeing insulation performance. The flange 113 is partially exposed to the outside of the pot body. When the user grips the inner pot 4, their hand is likely to come into contact with the flange 113. Since the flange 113 is not covered by the insulation layer 2, it loses its heat insulation function, allowing the main body 11 to directly contact the outside air. Heat transferred to the flange 113 can also be quickly dissipated, resulting in better heat dissipation of the flange 113 and helping to maintain a lower temperature. Shortly after cooking, the flange 113 can cool down quickly, preventing burns when touched.

[0055] As a preferred embodiment of this application, such as Figure 3 , Figure 4 As shown, the insulation layer 2 also includes a coating substrate 22, in which aerogel particles 21 are mixed, wherein the proportion of aerogel particles 21 in the mixture formed by aerogel particles 21 and coating substrate 22 is 0.5%-20%.

[0056] It should be noted that if the proportion of aerogel particles 21 in the mixture is small, the number of aerogel particles 21 in an equal amount of mixture will be small. After the insulation layer 2 is combined with the body 11, the aerogel particles 21 may not be able to completely cover the surface of the body 11, or the gap between two adjacent aerogel particles 21 may be too large, allowing heat to easily escape through the gaps, resulting in poor thermal insulation performance. On the other hand, if the number of aerogel particles 21 is too large, the aerogel particles 21 will stack in the thickness direction of the body 11, resulting in at least some areas having double or even multiple aerogel layers. Although this improves the thermal insulation performance, it cannot guarantee the uniformity of the aerogel layer thickness in each area, thus leading to differences in the thermal insulation effect in different areas and affecting the uniformity of energy efficiency in each area. At the same time, multiple aerogel layers will also greatly increase the processing difficulty and production cost of aerogel.

[0057] In this embodiment, the proportion of aerogel particles 21 in the mixture is designed to be 0.5%-20%. This can reduce the thickness of the aerogel layer while ensuring that the aerogel particles 21 form a single layer of full coverage on the surface of the body 11, thereby saving costs and reducing processing difficulty.

[0058] Preferably, the density of the coating substrate 22 is 0.6 g / cm³. 3 -1.5g / cm 3 .

[0059] The higher the density of the coating substrate 22, the denser its molecular structure, which may lead to an increase in thermal conductivity. This weakens the overall thermal insulation performance of the insulation layer 2 because heat is more easily conducted through the high-density coating substrate 22. Simultaneously, the thermal insulation performance of the aerogel particles 21 depends on their porous structure (low density, high porosity). If the high-density coating substrate 22 fills the gaps between the aerogel particles 21, it may hinder the formation of an effective thermal insulation network, limiting the aerogel's function and reducing the overall thermal insulation efficiency of the composite material. Furthermore, the higher viscosity of the high-density coating substrate 22 makes it difficult to disperse the aerogel particles 21 when mixed with it, requiring optimized mixing processes to avoid localized agglomeration and affecting the consistency of the insulation effect. However, the high-density coating substrate 22 typically has higher strength and rigidity, which can improve the compressive and deformation resistance of the insulation layer 2. Meanwhile, density affects the interfacial bonding strength between the coating substrate 22 and the aerogel particles 21. If the density is too low, the two may not bond well and the aerogel particles 21 may easily fall off. If the density is too high, the microcracks may propagate due to the brittleness of the coating substrate 22.

[0060] This application designs the density of the coating substrate 22 to be 0.6 g / cm3-1.5 g / cm3, which ensures the mechanical strength of the insulation layer 2 while minimizing its negative impact on the thermal insulation performance of the aerogel. Furthermore, it reduces the difficulty of mixing the aerogel particles 21 with the coating substrate 22 during processing, allowing the aerogel particles 21 to be more uniformly and dispersedly mixed within the coating substrate 22, thus facilitating the uniform adhesion of the aerogel particles 21 to the surface of the body 11.

[0061] This application does not limit the mixing method of the coating substrate 22 and the aerogel particles 21. Preferably, the coating substrate 22 can be melted at high temperature to coat the surface of the aerogel particles 21, and can combine the aerogel particles 21 with the body 11 so that the heat insulation layer 2 coats the surface of the body 11.

[0062] Specifically, the initial state of the coating substrate 22 is powder. If it is directly mixed with the aerogel particles 21 in powder form, uneven mixing and localized accumulation of aerogel particles 21 on the coating substrate 22 will occur. By heating the coating substrate 22 at a high temperature to melt it into a liquid state, and then coating it onto the surface of the aerogel particles 21, the coating substrate 22 can uniformly coat each aerogel particle 21, thereby greatly improving the mixing uniformity of the coating substrate 22 and aerogel particles 21. After mixing, the coating substrate 22 cools back to a powder state, which is convenient for storage and easy to apply to the surface of the body 11 by spraying. Furthermore, the molten structure of the coating substrate 22 allows it to be melted again by high-temperature processing during subsequent processing with the surface of the body 11, so as to completely bond with the surface of the body 11 and improve the bonding stability between the insulation layer 2 and the body 11.

[0063] In a preferred embodiment, aerogel particles 21 form an aerogel layer on the surface of the body 11, and the thickness of the aerogel layer is the same as the equivalent circle diameter of the aerogel particles 21 from the narrow end 211 to the wide end 212.

[0064] Aerogel particles 21 are arranged on the surface of the body 11 to form an aerogel layer. The aerogel particles 21 are arranged in a uniform manner, so that the aerogel layer and the aerogel particles 21 have the same equivalent circular diameter, and the thickness is the length (equivalent circular diameter) from the narrow end 211 to the wide end 212. This allows the aerogel particles 21 to be arranged in a single layer on the surface of the body 11. While ensuring that the aerogel layer uniformly and completely covers the surface of the body 11, the overall thickness of the insulation layer 2 is reduced to save costs.

[0065] Specifically, the length from the narrow end 211 to the wide end 212 of the aerogel particle 21 is the equivalent circle diameter mentioned above.

[0066] Preferably, the thickness of the aerogel layer (equivalent circle diameter of aerogel particles 21) is 5-50 μm.

[0067] It is understandable that, such as Figure 3 , Figure 4 As shown, the insulation layer 2 also includes a coating substrate 22, in which aerogel particles 21 are mixed and fixed to the surface of the body 11 by the coating substrate 22. This application does not limit the thickness of the coating substrate 22 adhering to the surface of the body 11. Figure 3 As shown, it can be smaller than the thickness of the aerogel layer, so the thickness of the aerogel layer (the equivalent circle diameter of the aerogel particles 21) is the overall thickness of the insulation layer 2. Figure 4 As shown, the thickness of the coating substrate can also be equal to or greater than the thickness of the aerogel layer, so that the coating substrate 22 is still wrapped around the outer surface of the aerogel layer. In this case, the thickness of the insulation layer 2 is the thickness of the coating substrate 22, which is greater than or equal to the thickness of the aerogel layer.

[0068] It should be noted that this application does not limit the distribution of aerogel particles 21 on the surface of the body 11. In a preferred embodiment, such as... Figure 3 , Figure 4 As shown, there are multiple aerogel particles 21 arranged along the surface of the body 11, and the wide ends 212 of adjacent aerogel particles 21 are in contact.

[0069] The gaps between adjacent aerogel particles 21 can form channels for heat loss. However, the wide ends 212 of adjacent aerogel particles 21 are in contact, which can minimize or even eliminate the gaps between them, thus sealing the channels and reducing heat loss to the outside of the insulation layer 2. At the same time, the close arrangement of the aerogel particles 21 can also improve the structural strength and stability of the aerogel layer, enabling it to withstand certain external forces and preventing changes in the orientation and position of the aerogel particles 21 due to collisions or scratches with the insulation cover 1, which would reduce the local insulation effect.

[0070] It is understandable that, since the width of the narrow end 211 is smaller than that of the wide end 212, and each aerogel particle 21 is arranged side by side in the same posture, even if the wide ends 212 of adjacent aerogel particles 21 are in contact, there is still a gap between the narrow ends 211 of adjacent aerogel particles 21.

[0071] Of course, gaps can also be made between the wide ends 212 of adjacent aerogel particles 21. However, in this embodiment, it is necessary to ensure that the gaps between the wide ends 212 of each aerogel particle 21 are consistent, so as to form a uniform heat insulation layer 2 on the surface of the body 11 and make the heat insulation effect of each area as uniform as possible.

[0072] This application also discloses a manufacturing process for a heat insulation cover 1, used to manufacture the heat insulation cover 1 of the cooking utensil described above, which includes the following steps: Aerogel preparation stage: the gel structure of the mixture of colloid and liquid is formed into a granular structure with one narrow end 211 and one wide end 212; the gel particles are dried to evaporate the liquid solvent and water inside the gel, forming porous aerogel particles 21; mixing stage: the aerogel particles 21 are mixed with the coating substrate 22; molding stage: the mixture of aerogel particles 21 and coating substrate 22 is electrostatically adsorbed onto the surface of the body 11 by electrostatic coating. During this process, under the action of electrostatics, the narrow end 211 of the aerogel particles 21 is close to the surface of the body 11, and the wide end 212 is away from the surface of the body 11; the powdered coating substrate 22 is melted by high-temperature sintering and combined with the body 11, and cooled to form a heat insulation layer 2.

[0073] The gel is mainly formed into nanoclusters through the condensation reaction of sol. The clusters are bonded together by gels, and at this stage, the gel is a mixture of colloid and liquid. While the gel is still in the liquid-colloid mixture stage, it is shaped into a structure that is wide at one end and narrow at the other, and then dried to evaporate the internal moisture. This allows the aerogel particles 21 to be shaped in a liquid state, making the shaping simpler and less prone to breakage during the shaping process, thus ensuring the structural and shape stability of the aerogel particles 21.

[0074] Furthermore, due to the shape characteristics of the aerogel particles 21, electrostatic spraying is used to adsorb them onto the surface of the body 11. During the processing, the narrow end 211 is more likely to accumulate charge, while the wide end 212 is less likely to accumulate charge. Therefore, under the effect of electrostatic adsorption, the narrow end 211 will naturally be closer to the body 11 than the wide end 212, so that each aerogel particle 21 is arranged in an ideal posture. Finally, the coating substrate 22 is melted by heating, and then completely bonded to the surface of the body 11, firmly fixing the aerogel particles 21 to the surface of the body 11. Compared with simple spraying or pasting methods, the fixation of aerogel particles 21 to the body 11 is more firm, and the coating substrate 22 flows in a liquid state on the surface of the body 11 after melting, making the distribution on the surface of the body 11 more uniform and consistent, thereby ensuring that the heat preservation effect in each area tends to be consistent.

[0075] Preferably, in this application, the coating substrate 22 is a polymer, preferably an epoxy resin.

[0076] In a preferred embodiment, such as Figure 5 As shown, in the aerogel preparation stage, the gel, which is a mixture of colloid and liquid, is placed in an extrusion cylinder 31. The extrusion port 32 of the extrusion cylinder 31 is located at the top of a closed chamber 3. The granular gel is extruded into the closed chamber 3 through the extrusion port 32, so that the granular gel forms a structure with one end narrow 211 and the other end wide 212 under the action of gravity.

[0077] When the gel is in a liquid state, it is extruded from top to bottom into the closed chamber 3 using the extrusion tube 31. Under the action of gravity, the gel drips into the closed chamber 3 in the form of water droplets, thus naturally forming a structure with a wide bottom end 212 and a narrow top end 211. Using this method, the gel can be easily and conveniently constructed into ideal shapes without the need for additional shaping tools and complex shaping steps, greatly simplifying the process and reducing the processing difficulty.

[0078] Preferably, the diameter of the extrusion port 32 is 5-50 μm.

[0079] In a preferred embodiment, during the mixing stage, the powdered coating substrate 22 is melted by high temperature, and then the aerogel particles 21 are stirred and mixed into it. After cooling, the coating substrate 22 is coated on the surface of the aerogel particles 21.

[0080] The initial state of the coating substrate 22 is powder. After mixing the powdered coating substrate 22 with aerogel particles 21, the coating substrate 22 is melted into a liquid state by high-temperature heating, thereby coating the surface of the aerogel particles 21. This allows the coating substrate 22 to uniformly coat each aerogel particle 21, greatly improving the mixing uniformity of the coating substrate 22 and aerogel particles 21. After mixing, the coating substrate 22 is cooled and returns to a powder state.

[0081] For any parts not mentioned in this application, existing technologies may be used or referenced.

[0082] The various embodiments in this specification are described in a progressive manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

[0083] The above description is merely an embodiment of this application and is not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A heat-insulating cover for a cooking appliance, the heat-insulating cover forming a receiving cavity for housing an inner pot, characterized in that, The heat insulation cover includes a body and a heat insulation layer disposed on the inner wall and / or outer wall of the body. The heat insulation layer includes aerogel particles arranged along the surface of the body. The aerogel particles have wide ends and narrow ends disposed opposite to each other, with the narrow ends facing the body and the wide ends away from the body.

2. The heat-insulating cover for a cooking appliance according to claim 1, characterized in that, The insulation layer also includes a coating substrate, in which the aerogel particles are mixed, wherein the aerogel particles account for 0.5%-20% of the mixture formed by the aerogel particles and the coating substrate.

3. The heat-insulating cover for a cooking appliance according to claim 2, characterized in that, The density of the coating substrate is 0.6 g / cm³. 3 -1.5g / cm 3 .

4. The heat-insulating cover for a cooking appliance according to claim 2, characterized in that, The coating substrate can melt at high temperature to coat the surface of the aerogel particles and can combine the aerogel particles with the body so that the insulation layer coats the surface of the body.

5. The heat-insulating cover for a cooking appliance according to claim 1, characterized in that, The aerogel particles form an aerogel layer on the surface of the body, and the thickness of the aerogel layer is the same as the equivalent circle diameter of the aerogel particles from the narrow end to the wide end.

6. The heat-insulating cover for a cooking appliance according to claim 1, characterized in that, The aerogel particles are multiple and arranged along the surface of the body, with the wide ends of adjacent aerogel particles in contact.

7. The heat-insulating cover for a cooking appliance according to claim 1, characterized in that, The body includes a side wall, a bottom wall, and a flange that folds outward from the top of the side wall. The insulation layer is disposed on the surface of the side wall and the bottom wall to form an exposed area on the flange.

8. A manufacturing process for a heat insulation cover, characterized in that, A heat-insulating cover for manufacturing a cooking appliance according to any one of claims 1-7, comprising the following steps: Aerogel preparation stage: The gel, which is a mixture of colloid and liquid, is constructed into a granular structure with one end being the narrow end and the other end being the wide end; the gel particles are dried to evaporate the liquid solvent and water inside the gel, forming porous aerogel particles. Mixing stage: The aerogel particles are mixed with the coating substrate; Molding stage: Electrostatic coating is used to electrostatically adsorb the mixture of aerogel particles and coating substrate onto the surface of the body. During this process, under the action of static electricity, the narrow end of the aerogel particles is close to the surface of the body, while the wide end is away from the surface of the body. The powdered coating substrate is melted by high-temperature sintering and combined with the body. After cooling, the insulation layer is formed.

9. The manufacturing process of the heat insulation cover according to claim 8, characterized in that, In the aerogel preparation stage, a gel consisting of a colloid and a liquid is placed in an extrusion cylinder. The extrusion nozzle of the extrusion cylinder is located at the top of a closed chamber. Granular gel is extruded into the closed chamber through the extrusion nozzle, so that the granular gel forms a structure with one end being the narrow end and the other end being the wide end under the action of gravity.

10. The manufacturing process of the heat insulation cover according to claim 8, characterized in that, During the mixing stage, the powdered coating substrate is melted by high temperature, and then the aerogel particles are stirred and mixed into it. After cooling, the coating substrate coats the surface of the aerogel particles.

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