A surface-porous organic fiber core material VIP board and a preparation method and application thereof

Abstract

The present application belongs to the field of vacuum insulation materials, and specifically discloses a surface-porous organic fiber core material VIP plate, a preparation method and application thereof. The preparation raw material of the heat insulation core material comprises organic fibers and porous materials; the porous materials comprise irregular spherical or spherical-like particles with a porous structure; the diameter of the porous materials is 0.05-3 microns, and the pore diameter of the porous materials is 1-100 nm. The heat insulation core material has a low density and a very low thermal conductivity, and has a good application prospect in vacuum insulation plates and heat preservation and insulation equipment. The present application also provides a preparation method of the heat insulation core material and a vacuum insulation plate.

Description

Technical Field

[0001] This invention relates to the field of vacuum insulation materials technology, and in particular to a porous organic fiber core VIP board, its preparation method, and its application. Background Technology

[0002] Thermal insulation materials are typically used in appliances with refrigeration or freezing functions (such as refrigerators). Traditional thermal insulation materials, such as rigid polyurethane foam, have a thermal conductivity of 19–23 mW / (m·K). On the one hand, current thermal insulation materials are increasingly unable to meet higher design and energy consumption requirements; on the other hand, there is a desire to maintain lightweight materials while increasing storage capacity to a certain extent.

[0003] Vacuum insulation panels (VIP panels) possess excellent thermal insulation properties, making them increasingly advantageous in applications such as refrigeration and freezing insulation equipment. The structure of a VIP panel generally includes: a core material, a getter / desiccant, and an outer packaging film. The core material is the core component of the vacuum insulation panel, and its material, structure, and composition have a crucial impact on the thermal conductivity. Currently, the most mature and widely used VIP core materials are granular fumed silica and glass fiber. Under low vacuum conditions, fumed silica powder particles have low porosity and high contact thermal conductivity. However, fumed silica as a core material faces challenges such as high cost and difficulty in further reducing its thermal conductivity. Glass fiber, as a core material for VIP (vacuum insulation panels), also has some obvious drawbacks. First, the production process of glass fiber core material requires cutting, which results in a large amount of glass fiber dust. This dust easily adheres to human 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. In addition, at present, the desire for a low thermal conductivity makes the use of glass fiber as a core material for vacuum insulation panels face the technical dilemma of not being able to further reduce the thermal conductivity.

[0004] Therefore, it is necessary to improve the materials used for VIP core materials to prepare high-performance organic core VIP boards with ultra-low thermal conductivity. Summary of the Invention

[0005] This invention aims to address at least one of the technical problems existing in the prior art. To this end, this invention provides an insulating core material and a vacuum insulation panel (VIP panel), aiming to solve the problem that conventional thermal insulation materials are increasingly unable to meet higher design and energy consumption requirements. Through optimization of material selection, structural design, and manufacturing processes, this invention overcomes the difficulties of cost, environmental impact, and the inability to achieve ultra-low thermal conductivity, resulting in an insulating core material with lower density and a vacuum insulation panel with extremely low thermal conductivity.

[0006] An embodiment of the first aspect of the present invention provides a thermal insulation core material, wherein the raw materials for preparing the thermal insulation core material include organic fibers and porous materials;

[0007] The porous material includes spherical or near-spherical irregular particles with a porous structure; the diameter of the porous material is 0.05 to 3 μm, and the pore size of the porous material is 1 to 100 nm.

[0008] The thermal insulation core material of the first aspect of the present invention has at least the following beneficial effects:

[0009] The thermal insulation core material of the present invention is used as a vacuum thermal insulation core material. The high rigidity of the organic fibers therein provides support for the three-dimensional network structure of the VIP core material. Heat transfer takes place in the three-dimensional network architecture of the fibers, which can make full use of the low intrinsic thermal conductivity of the organic fibers. The porous material introduces cavities on the surface of the low-conductivity organic fibers, increases the overall porosity and reduces contact heat transfer, further reducing the thermal conductivity of the VIP plate. The VIP plate prepared using this VIP core material has an ultra-low thermal conductivity of less than 1.4 mW / m·K.

[0010] The VIP core material of this invention has a low density, below 200 kg / m³. 3 This allows the VIP panels to maintain excellent thermal insulation performance while being lighter, significantly reducing the overall weight of the product, facilitating transportation and installation, and further enhancing the product's application flexibility and market competitiveness.

[0011] Furthermore, the raw materials used in the preparation of the VIP core material of this invention are all environmentally friendly and meet strict environmental standards. These materials do not cause pollution to the environment during production, use, or disposal, and pose no harm to human health. More importantly, the use of these environmentally friendly materials does not increase production costs; on the contrary, it effectively controls the production costs of the VIP core material and VIP board of this invention, resulting in a high cost-performance ratio and providing strong support for the widespread application of the product.

[0012] In some embodiments of the present invention, the organic fiber includes at least one of polypropylene fiber, polyethylene fiber, polyester fiber, polyamide fiber, polyacrylonitrile fiber, or polyvinyl alcohol fiber.

[0013] The VIP core material of this invention uses widely available organic fibers as raw materials. These organic fibers are all mature products produced using existing mature processes. Compared with the glass fibers commonly used in traditional VIP panels, the organic fibers used in this invention can avoid the potential health hazards of glass fiber dust during production, processing, and use, thus improving the safety of the product during production and use. In addition, the use of organic fibers provides a more environmentally friendly and sustainable raw material option for the preparation of VIP core materials, further expanding the application scope and market prospects of VIP panels.

[0014] In some embodiments of the present invention, the organic fiber has a length of 0.5 to 250 mm and a diameter of 0.5 to 50 μm.

[0015] This invention discovers that significant performance advantages can be achieved when the organic fibers used in the VIP core material are within the aforementioned length and diameter range. Specifically, organic fibers within this size range not only enable the VIP core material to maintain a low density but also achieve better compatibility with porous materials. This allows the three-dimensional network architecture formed by the organic fibers and the void structure introduced by the porous materials to work synergistically, further reducing the overall thermal conductivity of the VIP core material and thus significantly improving the thermal insulation performance of the VIP panel.

[0016] In some embodiments of the present invention, the porous material includes at least one of fumed silica powder, hollow glass microspheres, or porous polylactic acid.

[0017] In some embodiments of the present invention, the diameter of the porous material is 0.05 to 1 μm, and the pore size of the porous material is 1 to 20 nm.

[0018] In some embodiments of the present invention, the diameter of the porous material is less than 1 / 3 of the diameter of the organic fiber.

[0019] This invention further explores and discovers that the performance of porous materials used in VIP core materials can be significantly improved by optimizing their particle size and pore size. When the particle size and pore size of the porous material are within the aforementioned range, it can form a good synergistic effect with the aforementioned organic fibers. Specifically, the porous material can be uniformly dispersed in the three-dimensional network architecture constructed by organic fibers, forming a more uniform and stable void structure. This structure not only significantly improves the porosity of the VIP core material but also further reduces the overall thermal conductivity of the VIP core material, thereby effectively improving the thermal insulation performance of the VIP board.

[0020] In some embodiments of the present invention, the mass ratio of the organic fiber to the porous material in the raw materials is (3-10):1.

[0021] The present invention also optimizes the proportions of raw materials used in the preparation of VIP core materials. By precisely adjusting the proportions of each raw material component, not only is the internal structure of the material optimized, further reducing its thermal conductivity, but the production efficiency of VIP core materials is also improved, raw material waste is reduced, and production costs are effectively lowered. This optimized proportioning scheme makes the preparation process of VIP core materials more efficient and economical, while ensuring the high performance and stability of the product.

[0022] A second aspect of the present invention provides a method for preparing the above-mentioned VIP core material, comprising the following steps:

[0023] The porous material is uniformly dispersed on the surface of the organic fiber to obtain a surface porous organic fiber mixture;

[0024] The surface porous organic fiber mixture is filtered to remove the porous material agglomerates, resulting in surface porous organic fibers;

[0025] The porous organic fibers on the surface are dispersed into a liquid to obtain a fiber suspension, which is then wet-laid and dried to obtain a fiber cloth.

[0026] The fiber cloth is stacked and heat-treated to obtain the thermal insulation core material.

[0027] The VIP core material preparation method provided by this invention can produce the VIP core material described in the first aspect of this invention, and therefore this preparation method also includes the aforementioned advantages of the VIP core material of this invention. Furthermore, this preparation method of this invention features simple process, mild reaction conditions, ease of operation, and high production efficiency, making it suitable for large-scale production applications.

[0028] The preparation method of this invention enables good dispersion of organic fibers and porous materials, significantly improving the uniformity of the mixed material. By employing a wet web-forming process, the porous organic fibers can achieve efficient suspension during dispersion, thereby ensuring uniform dispersion of the fibers in the mixed system. This efficient dispersion method provides favorable conditions for reducing the basis weight of the fiber cloth in the wet web-forming process, resulting in a VIP core material with low density and extremely low thermal conductivity, significantly improving the thermal insulation performance of the VIP core material.

[0029] In some embodiments of the present invention, the method of uniformly dispersing the porous material on the surface of the organic fiber includes at least one of external force stirring and extrusion, liquid dispersion, or blower dispersion.

[0030] This invention utilizes mechanical means to uniformly disperse porous materials on the surface of organic fibers. All of the above methods are simple and efficient.

[0031] In some embodiments of the present invention, the concentration (slurry concentration) of the surface porous organic fibers in the fiber suspension is 0.005 wt% to 1 wt%.

[0032] In some embodiments of the present invention, the areal density of the fiber cloth is 2 to 150 g / m². 2 .

[0033] In some embodiments of the present invention, the drying temperature is 100–240°C.

[0034] The present invention also optimizes the process parameters in the preparation method. Research has shown that when the concentration of porous organic fibers on the surface of the fiber suspension, the areal density of the fiber cloth, and the drying temperature are all within the aforementioned ranges, high-performance VIP core materials can be prepared. Simultaneously, the optimized process parameters significantly improve the success rate and production efficiency of the product preparation, reduce raw material waste, and further enhance economic efficiency.

[0035] A third aspect of the present invention provides a vacuum insulation panel comprising the aforementioned insulation core material.

[0036] The VIP panel of the present invention has all the advantages of the aforementioned VIP core material, and has better heat insulation and lighter weight compared to traditional VIP panels.

[0037] A fourth aspect of the present invention provides a method for preparing a vacuum insulation panel, comprising the following steps:

[0038] The insulating core material is bagged, vacuum-sealed, and then the bag is sealed to obtain the vacuum insulation board.

[0039] In some embodiments of the present invention, a getter and / or a desiccant are also added to the vacuum insulation panel.

[0040] The preparation method of the present invention is characterized by simple process, easy operation and high production efficiency, and is suitable for large-scale production application.

[0041] According to a fifth aspect of the present invention, a heat preservation and / or heat insulation device is provided, including the above-described vacuum insulation panel.

[0042] In some embodiments of the present invention, the heat preservation and / or heat insulation equipment includes refrigerators, freezers, refrigerated containers, refrigerated transport vehicles, cold storage facilities, or insulated boxes.

[0043] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the description and claims. Attached Figure Description

[0044] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0045] Figure 1 This is a schematic diagram of the porous organic fibers with a porous surface obtained in Example 1 of the present invention;

[0046] Figure 2 This is a schematic diagram of the filtration process in Embodiment 1 of the present invention;

[0047] Figure 3 This is a schematic diagram of the core material made from stacked fiber cloth according to Embodiment 1 of the present invention;

[0048] Figure reference numerals: 1-Organic fiber, 2-Porous material, 3-Porous structure, 4-Porous material aggregate, 5-Surface porous organic fiber, 6-Filter device, 7-Fiber cloth, 8-VIP core material. Detailed Implementation

[0049] The following will describe the concept and technical effects of the present invention clearly and completely with reference to embodiments, so as to fully understand the purpose, features and effects of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are all within the scope of protection of the present invention.

[0050] In the description of this invention, the terms "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the invention. 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 may be combined in any suitable manner in one or more embodiments or examples.

[0051] In the description of this invention, unless otherwise stated, the numerical range "a to b" represents a shortened representation of any combination of real numbers between a and b, where a and b are both real numbers. Unless otherwise stated, the various reaction or operation steps may be performed sequentially or not sequentially. In some embodiments, the reaction methods in this invention are performed sequentially.

[0052] Unless otherwise specified in the following examples, the techniques or conditions described in the literature in this field or in accordance with the product instructions shall apply. All reagents or instruments without a specified manufacturer are commercially available conventional products.

[0053] A first aspect of the present invention provides a thermal insulation core material, wherein the raw materials for preparing the thermal insulation core material include organic fibers and porous materials;

[0054] The porous material includes spherical or near-spherical irregular particles with a porous structure; the diameter of the porous material is 0.05 to 3 μm, and the pore size of the porous material is 1 to 100 nm.

[0055] The thermal insulation core material of the first aspect of the present invention has at least the following beneficial effects:

[0056] The thermal insulation core material of this invention is used as a vacuum thermal insulation core material. The high rigidity of the organic fibers provides support for the three-dimensional network structure of the VIP core material. Heat transfer takes place in the three-dimensional network structure of the fibers, which can make full use of the low intrinsic thermal conductivity of the organic fibers. The porous material introduces cavities on the surface of the low-conductivity organic fibers, increases the overall porosity and reduces contact heat transfer, further reducing the thermal conductivity of the VIP plate. The VIP plate prepared using this VIP core material has an ultra-low thermal conductivity of less than 1.4 mW / m·K.

[0057] The VIP core material of this invention has a low density, below 200 kg / m³. 3 This allows the VIP panels to maintain excellent thermal insulation performance while being lighter, significantly reducing the overall weight of the product, facilitating transportation and installation, and further enhancing the product's application flexibility and market competitiveness.

[0058] Furthermore, the raw materials used in the preparation of the VIP core material in this invention are all environmentally friendly and meet strict environmental standards. These materials do not pollute the environment during production, use, or disposal, and pose no harm to human health. More importantly, the use of these environmentally friendly materials does not increase production costs; on the contrary, it effectively controls the production costs of the VIP core material and VIP board of this invention, resulting in a high cost-performance ratio and providing strong support for the widespread application of the product.

[0059] In some embodiments of the present invention, the organic fiber includes at least one of polypropylene fiber, polyethylene fiber, polyester fiber, polyamide fiber, polyacrylonitrile fiber, or polyvinyl alcohol fiber.

[0060] In some embodiments of the present invention, the organic fiber includes polyester fiber and / or polyacrylonitrile fiber.

[0061] The VIP core material of this invention uses widely available organic fibers as raw materials. These organic fibers are all mature products produced using existing mature processes. Compared with the glass fibers commonly used in traditional VIP panels, the organic fibers used in this invention can avoid the potential health hazards of glass fiber dust during production, processing, and use, thus improving the safety of the product during production and use. Furthermore, the use of organic fibers provides a more environmentally friendly and sustainable raw material option for the preparation of VIP core materials, further expanding the application scope and market prospects of VIP panels.

[0062] In some embodiments of the present invention, the organic fiber has a length of 0.5 to 250 mm and a diameter of 0.5 to 50 μm.

[0063] In some embodiments of the present invention, the organic fiber has a length of 1 to 50 mm and a diameter of 2 to 20 μm.

[0064] In some embodiments of the present invention, the organic fiber has a length of 2 to 10 mm and a diameter of 5 to 15 μm.

[0065] This invention discovers that significant performance advantages can be achieved when the organic fibers used in the VIP core material are within the aforementioned length and diameter range. Specifically, organic fibers within this size range not only enable the VIP core material to maintain a low density but also achieve better compatibility with porous materials. This allows the three-dimensional network architecture formed by the organic fibers and the void structure introduced by the porous materials to work synergistically, further reducing the overall thermal conductivity of the VIP core material and thus significantly improving the thermal insulation performance of the VIP panel.

[0066] In some embodiments of the present invention, the porous material has open or closed pores on its surface or inside.

[0067] In some embodiments of the present invention, the porous material includes at least one of fumed silica powder, hollow glass microspheres, or porous polylactic acid.

[0068] In some embodiments of the present invention, the porous material comprises fumed silica powder and / or hollow glass microspheres.

[0069] In some embodiments of the present invention, the diameter of the porous material is 0.05 to 1 μm, and the pore size of the porous material is 1 to 20 nm.

[0070] In some embodiments of the present invention, the diameter of the porous material is 0.1 to 1 μm, and the pore size of the porous material is 1 to 10 nm.

[0071] In some embodiments of the present invention, the diameter of the porous material is less than 1 / 3 of the diameter of the organic fiber.

[0072] This invention also reveals that the performance of porous materials used in VIP core materials can be significantly improved by optimizing their particle size and pore size. When the particle size and pore size of the porous material are within the aforementioned range, it can form a good synergistic effect with the aforementioned organic fibers. Specifically, the porous material can be uniformly dispersed in the three-dimensional network architecture constructed by organic fibers, forming a more uniform and stable void structure. This structure not only significantly improves the porosity of the VIP core material but also further reduces the overall thermal conductivity of the VIP core material, thereby effectively improving the thermal insulation performance of the VIP board.

[0073] In some embodiments of the present invention, the mass ratio of the organic fiber to the porous material in the raw materials is (3-10):1.

[0074] In some embodiments of the present invention, the mass ratio of the organic fiber to the porous material in the preparation raw materials is (4-8):1. This includes any value therein, all ranges, and any subranges. For example, it includes 5:1, 6:1, and 7:1.

[0075] This invention optimizes the proportions of raw materials used in the preparation of VIP core materials. By precisely adjusting the ratios of each raw material component, not only is the internal structure of the material optimized, further reducing its thermal conductivity, but the production efficiency of VIP core materials is also improved, reducing raw material waste and thus effectively lowering production costs. This optimized proportioning scheme makes the preparation process of VIP core materials more efficient and economical, while ensuring the high performance and stability of the product.

[0076] A second aspect of the present invention provides a method for preparing the above-mentioned VIP core material, comprising the following steps:

[0077] S1. The porous material is uniformly dispersed on the surface of the organic fiber to obtain a surface porous organic fiber mixture;

[0078] S2. Filter the surface porous organic fiber mixture to remove the porous material agglomerates therein, and obtain surface porous organic fibers;

[0079] S3. Disperse the porous organic fibers in a liquid to obtain a fiber suspension, wet-form it into a web, and dry it to obtain a fiber cloth;

[0080] S4. Stack the fiber cloth and heat treat it to obtain the heat insulation core material.

[0081] The VIP core material preparation method provided in this embodiment of the invention can prepare the VIP core material described in the first aspect of the invention, and therefore this preparation method also includes the aforementioned advantages of the VIP core material of the invention. Furthermore, this preparation method of the invention features simple process, mild reaction conditions, ease of operation, and high production efficiency, making it suitable for large-scale production applications.

[0082] The preparation method of this invention can achieve good dispersion of organic fibers and porous materials, significantly improving the uniformity of the mixed material. By employing a wet web-forming process, the porous organic fibers can achieve efficient suspension during dispersion, thereby ensuring uniform dispersion of the fibers in the mixed system. This efficient dispersion method provides favorable conditions for reducing the basis weight of the fiber cloth in the wet web-forming process, thus enabling the prepared VIP core material to have a low density and extremely low thermal conductivity, significantly improving the thermal insulation performance of the VIP core material.

[0083] In some embodiments of the present invention, the method of uniformly dispersing the porous material on the surface of the organic fiber in step S1 includes at least one of external force stirring and extrusion, liquid dispersion, or blower dispersion.

[0084] The embodiments of the present invention utilize mechanical means to uniformly disperse porous materials on the surface of organic fibers. The above methods are all simple and efficient.

[0085] In some embodiments of the present invention, the concentration (slurry concentration) of the surface porous organic fibers in the fiber suspension of step S3 is 0.005 wt% to 1 wt%. This includes any value therein and all ranges and any subranges. For example, it includes 0.02 wt%, 0.05 wt%, and 0.08 wt%.

[0086] In some embodiments of the present invention, the concentration (slurry concentration) of the surface porous organic fiber in the fiber suspension in step S3 is 0.01wt% to 0.1wt%.

[0087] In some embodiments of the present invention, the areal density of the fiber cloth in step S3 is 2 to 150 g / m². 2 .

[0088] In some embodiments of the present invention, the areal density of the fiber cloth in step S3 is 5 to 100 g / m². 2 .

[0089] In some embodiments of the present invention, the areal density of the fiber cloth in step S3 is 10-20 g / m². 2 .

[0090] In some embodiments of the present invention, the drying temperature in step S3 is 100–240°C.

[0091] In some embodiments of the present invention, the drying temperature in step S3 is 140–200°C. This includes any value therein, all ranges, and any subranges. For example, it includes 150°C, 160°C, and 180°C.

[0092] This invention also optimizes the aforementioned process parameters in the preparation method. Research has shown that when the concentration of porous organic fibers on the surface of the fiber suspension, the areal density of the fiber cloth, and the drying temperature are all within the aforementioned ranges, high-performance VIP core materials can be prepared. Simultaneously, the optimized process parameters significantly improve the success rate and production efficiency of the product preparation, reduce raw material waste, and further enhance economic efficiency.

[0093] In some embodiments of the present invention, the liquid in step S3 includes water.

[0094] In some embodiments of the present invention, in order to achieve a better monofilament suspension dispersion effect, mechanical stirring or microwave heating is used to disperse and prepare the fiber suspension in step S3.

[0095] In some embodiments of the present invention, the thickness of the fiber cloth after stacking in step S4 is 0.5 to 5 cm.

[0096] In some embodiments of the present invention, the thickness of the fiber cloth after stacking in step S4 is 0.6 to 3 cm.

[0097] In some embodiments of the present invention, the heat treatment temperature in step S4 is 150-200°C and the time is 0.5-3 hours.

[0098] A third aspect of the present invention provides a vacuum insulation panel, comprising the above-mentioned insulation core material.

[0099] The VIP panel of this invention has all the advantages of the VIP core material described above, and has better heat insulation and lighter weight compared to traditional VIP panels.

[0100] A fourth aspect of the present invention provides a method for preparing a vacuum insulation panel, comprising the following steps:

[0101] The insulating core material is bagged, vacuum-sealed, and then the bag is sealed to obtain the vacuum insulation board.

[0102] The preparation method of this invention has the characteristics of simple process, easy operation and high production efficiency, and is suitable for large-scale production application.

[0103] In some embodiments of the present invention, a getter and / or a desiccant are also added to the vacuum insulation panel.

[0104] A fifth aspect of the present invention provides a heat preservation and / or heat insulation device, including the above-mentioned vacuum insulation panel.

[0105] In some embodiments of the present invention, the heat preservation and / or heat insulation equipment includes refrigerators, freezers, refrigerated containers, refrigerated transport vehicles, cold storage facilities, or insulated boxes.

[0106] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the description and claims.

[0107] Example 1

[0108] This embodiment provides a porous organic fiber VIP core material.

[0109] The raw materials for preparing the porous organic fiber VIP core material in this embodiment are organic fibers and porous materials in a mass ratio of 5:1.

[0110] Among them, the porous material is a hollow glass microsphere with open or closed pores on the surface and inside, the diameter of the hollow glass microsphere is 500nm and the size of the pores is 5nm; the organic fiber is a polyacrylonitrile fiber with a fiber diameter of 10μm and a length of 5mm.

[0111] The preparation steps of the porous organic fiber VIP core material in this embodiment are as follows:

[0112] (1) Take 2000g and 400g of the above-mentioned organic fiber and porous material respectively, mix them, and mechanically stir to evenly distribute the porous material on the surface of the organic fiber. The treatment diagram is shown below. Figure 1 As shown; a mixture of surface porous organic fibers and remaining porous material agglomerates was obtained. The mixture was then filtered using a filter screen to remove the porous material agglomerates. A schematic diagram of the process is shown below. Figure 2 As shown, a material with a surface porous organic fiber mass fraction of over 90% was obtained;

[0113] (2) The porous organic fiber material obtained in step (1) is dispersed in water and mechanically stirred to disperse it evenly, so as to prepare a fiber suspension with a porous organic fiber mass content (slurry concentration) of 0.05%.

[0114] (3) The fiber suspension obtained in step (2) is wet-laid and water-controlled for 5 minutes, then placed in an oven at 180℃ for 2 hours and baked. After demolding, a surface density of 13 g / m³ is obtained. 2 Fiber cloth;

[0115] (4) Stack the fiber cloth obtained in step (3) to form a core material, as shown in the schematic diagram. Figure 3 As shown, the material is placed in an oven at 200℃ and baked again for 2 hours to obtain the VIP core material.

[0116] The fiber cloth is cut to a size of 1000mm×650mm, and the number of fiber cloth layers is controlled to a final board thickness of 1cm when stacked.

[0117] This embodiment also provides a method for preparing a VIP board using the VIP core material prepared above, with the specific steps as follows:

[0118] (1) The VIP core material prepared above is bagged (a multi-layer composite film containing aluminum film and polyethylene), one getter (self-made, 3.5g / bag) and one desiccant (calcium oxide, self-made, 15g / packet) are added, and then placed in a vacuum sealing machine for vacuuming. When the vacuum degree reaches 3.5×10 -3 When Pa is reached, a heat sealing process is performed, with the heat sealing time set to 15s and the heat sealing voltage set to 13V, to obtain a sealed VIP board;

[0119] (2) Press the VIP board to puncture the getter shell and further reduce the internal pressure of the VIP board. After placing it at room temperature for 12 hours, test the thermal conductivity.

[0120] Example 2

[0121] This embodiment provides a porous organic fiber VIP core material.

[0122] The raw materials for preparing the porous organic fiber VIP core material in this embodiment are organic fibers and porous materials in a mass ratio of 5:1.

[0123] The porous material is fumed silica with open or closed pores on its surface and inside. The diameter of the fumed silica is 100 nm and the size of the pores is 3 nm. The organic fiber is polyethylene terephthalate (PET) fiber with a diameter of 10 μm and a length of 5 mm.

[0124] The preparation steps of the porous organic fiber VIP core material in this embodiment are as follows:

[0125] (1) Take 2000g and 400g of the above organic fiber and porous material respectively, mix them, and mechanically stir to evenly distribute the porous material on the surface of the organic fiber to obtain a mixture of surface porous organic fiber and remaining porous material agglomerates. Use a filter screen to filter the mixture to remove the porous material agglomerates and obtain a material with a surface porous organic fiber mass fraction of more than 90%.

[0126] (2) The porous organic fiber material obtained in step (1) is dispersed in water and mechanically stirred to disperse it evenly, so as to prepare a fiber suspension with a porous organic fiber mass content (slurry concentration) of 0.05%.

[0127] (3) The fiber suspension obtained in step (2) is wet-laid and water-controlled for 5 minutes, then placed in an oven at 180℃ for 2 hours and baked. After demolding, a surface density of 15 g / m³ is obtained. 2 Fiber cloth;

[0128] (4) Stack the fiber cloth obtained in step (3) into a core material and bake it again in a drying tunnel at a temperature of 200℃ for 2 hours to obtain VIP core material;

[0129] The fiber cloth is cut to a size of 1000mm×650mm, and the number of fiber cloth layers is controlled to a final board thickness of 1cm when stacked.

[0130] This embodiment also provides a method for preparing a VIP board using the VIP core material prepared above, with the specific steps as follows:

[0131] (1) The VIP core material prepared above is bagged (a multi-layer composite film containing aluminum film and polyethylene), one getter (self-made, 3.5g / bag) and one desiccant (calcium oxide, self-made, 15g / packet) are added, and then placed in a vacuum sealing machine for vacuuming. When the vacuum degree reaches 3.5×10 -3 When Pa is reached, a heat sealing process is performed, with the heat sealing time set to 15s and the heat sealing voltage set to 13V, to obtain a sealed VIP board;

[0132] (2) Press the VIP board to puncture the getter shell and further reduce the internal pressure of the VIP board. After placing it at room temperature for 12 hours, test the thermal conductivity.

[0133] Comparative Example 1

[0134] This comparative example provides a VIP core material.

[0135] The raw material for preparing the VIP core material in this comparative example is round glass fiber;

[0136] The glass fiber has a diameter of 10μm and a length of 5mm.

[0137] The preparation steps of the VIP core material in this comparative example are as follows:

[0138] (1) Take 2000g of round glass fibers and disperse them in water. After mechanical stirring, the fibers are dispersed evenly to prepare a glass fiber suspension with a fiber mass content of 0.05%.

[0139] (2) The glass fiber suspension obtained in step (1) is wet-laid and water-controlled for 5 minutes, then placed in an oven at 180℃ for 2 hours and baked. After demolding, a surface density of 25 g / m³ is obtained. 2 Fiber cloth;

[0140] (3) Stack the fiber cloth obtained in step (2) into a core material and bake it again in a drying tunnel at a temperature of 200℃ for 2 hours to obtain VIP core material;

[0141] The fiber cloth is cut to a size of 1000mm×650mm, and the number of fiber cloth layers is controlled to a final board thickness of 1cm when stacked.

[0142] This comparative example also provides the preparation of a VIP board using the VIP core material prepared above, with the specific steps as follows:

[0143] (1) The VIP core material prepared above is bagged (a multi-layer composite film containing aluminum film and polyethylene), one getter (self-made, 3.5g / bag) and one desiccant (calcium oxide, self-made, 15g / packet) are added, and then placed in a vacuum sealing machine for vacuuming. When the vacuum degree reaches 3.5×10 -3 When Pa is reached, a heat sealing process is performed, with the heat sealing time set to 15s and the heat sealing voltage set to 13V, to obtain a sealed VIP board;

[0144] (2) Press the VIP board to puncture the getter shell and further reduce the internal pressure of the VIP board. After placing it at room temperature for 12 hours, test the thermal conductivity.

[0145] Comparative Example 2

[0146] This comparative example provides a VIP core material.

[0147] The raw material for preparing the VIP core material in this comparative example is round polyacrylonitrile fiber;

[0148] The polyacrylonitrile fiber has a diameter of 10μm and a length of 5mm.

[0149] The preparation steps of the VIP core material in this comparative example are as follows:

[0150] (1) Take 2000g of round polyacrylonitrile fibers and disperse them in water. After mechanical stirring, the fibers are dispersed evenly to prepare a glass fiber suspension with a fiber mass content of 0.05%.

[0151] (2) The glass fiber suspension obtained in step (1) is wet-processed into a web and water is controlled for 5 minutes. It is then placed in an oven at 180℃ and baked for 2 hours. After demolding, a surface density of 15 g / m³ is obtained. 2 Fiber cloth;

[0152] (3) Stack the fiber cloth obtained in step (2) into a core material and bake it again in a drying tunnel at a temperature of 200℃ for 2 hours to obtain VIP core material;

[0153] The fiber cloth is cut to a size of 1000mm×650mm, and the number of fiber cloth layers is controlled to a final board thickness of 1cm when stacked.

[0154] This comparative example also provides the preparation of a VIP board using the VIP core material prepared above, with the specific steps as follows:

[0155] (1) The VIP core material prepared above is bagged (a multi-layer composite film containing aluminum film and polyethylene), one getter (self-made, 3.5g / bag) and one desiccant (calcium oxide, self-made, 15g / packet) are added, and then placed in a vacuum sealing machine for vacuuming. When the vacuum degree reaches 3.5×10 -3 When Pa is reached, a heat sealing process is performed, with the heat sealing time set to 15s and the heat sealing voltage set to 13V, to obtain a sealed VIP board;

[0156] (2) Press the VIP board to puncture the getter shell and further reduce the internal pressure of the VIP board. After placing it at room temperature for 12 hours, test the thermal conductivity.

[0157] Comparative Example 3

[0158] This comparative example provides a porous organic fiber VIP core material.

[0159] The raw materials for preparing the surface-porous organic fiber VIP core material of this comparative example are organic fibers and porous materials in a mass ratio of 5:1.

[0160] Among them, the porous material is a hollow glass microsphere with open or closed pores on the surface and inside, the diameter of the hollow glass microsphere is 5μm and the size of the pores is 50nm; the organic fiber is a polyacrylonitrile fiber with a fiber diameter of 10μm and a length of 5mm.

[0161] The preparation steps of the surface-porous organic fiber VIP core material in this comparative example are as follows:

[0162] (1) Take 2000g and 400g of the above organic fiber and porous material respectively, mix them, and mechanically stir to evenly distribute the porous material on the surface of the organic fiber to obtain a mixture of surface porous organic fiber and remaining porous material agglomerates. Use a filter screen to filter the mixture to remove the porous material agglomerates and obtain a material with a surface porous organic fiber mass fraction of more than 90%.

[0163] (2) The porous organic fiber material obtained in step (1) is dispersed in water and mechanically stirred to disperse it evenly, so as to prepare a fiber suspension with a porous organic fiber mass content (slurry concentration) of 0.05%.

[0164] (3) The fiber suspension obtained in step (2) is wet-laid and water-controlled for 5 minutes, then placed in an oven at 180℃ for 2 hours and baked. After demolding, a surface density of 12 g / m³ is obtained. 2 Fiber cloth;

[0165] (4) Stack the fiber cloth obtained in step (3) into a core material and bake it again in a drying tunnel at a temperature of 200℃ for 2 hours to obtain VIP core material;

[0166] The fiber cloth is cut to a size of 1000mm×650mm, and the number of fiber cloth layers is controlled to a final board thickness of 1cm when stacked.

[0167] This comparative example also provides the preparation of a VIP board using the VIP core material prepared above, with the specific steps as follows:

[0168] (1) The VIP core material prepared above is bagged (a multi-layer composite film containing aluminum film and polyethylene), one getter (self-made, 3.5g / bag) and one desiccant (calcium oxide, self-made, 15g / packet) are added, and then placed in a vacuum sealing machine for vacuuming. When the vacuum degree reaches 3.5×10 -3 When Pa is reached, a heat sealing process is performed, with the heat sealing time set to 15s and the heat sealing voltage set to 13V, to obtain a sealed VIP board;

[0169] (2) Press the VIP board to puncture the getter shell and further reduce the internal pressure of the VIP board. After placing it at room temperature for 12 hours, test the thermal conductivity.

[0170] Performance testing:

[0171] The density of the VIP core material prepared in each embodiment and comparative example was tested, and the thermal conductivity of the prepared VIP board was tested (refer to GB / T 39704-2020). The test results and some parameters in the preparation steps of each embodiment and comparative example are summarized and compared in Table 1.

[0172] Table 1

[0173]

[0174] The test results above show that the VIP core material prepared using Examples 1 and 2 of the present invention has a low density and also results in an extremely low thermal conductivity for the prepared VIP sheet material. The density of the VIP core material can reach as low as 180 kg / m³. 3The thermal conductivity of the VIP panel is as low as 1.26 mW / m·K.

[0175] Therefore, the vacuum insulation panel (VIP panel) of this invention exhibits significant advantages in terms of thermal insulation performance and lightweight properties. Specifically, through optimization of raw material selection, structural design, and manufacturing process, the VIP panel achieves extremely low thermal conductivity, thereby possessing excellent thermal insulation effects. Simultaneously, its unique structure allows it to maintain high performance while having low density, achieving good lightweight properties. With these characteristics, the VIP panel of this invention has broad application prospects in equipment requiring efficient thermal insulation or heat preservation. For example, in the field of household appliances, the VIP panel can be used in refrigeration or freezing equipment, effectively reducing energy consumption and improving the equipment's thermal insulation performance; in industrial equipment, it can be used in insulation systems requiring strict temperature control, such as cold storage and cold chain transportation equipment, significantly improving the equipment's thermal insulation efficiency and reducing its weight. Therefore, the VIP panel of this invention not only meets existing market demands but also provides a more efficient and energy-saving solution for related fields, demonstrating significant economic and social benefits.

[0176] Comparative Example 1 uses a preparation method similar to that of the embodiments of the present invention, but its raw material is only the traditional material glass fiber. The use of glass fiber has known drawbacks, such as generating a large amount of glass fiber dust, which can easily harm human health. The VIP core material prepared using the process of the present invention has a density as high as 270 kg / m³. 3 Furthermore, the thermal conductivity of the prepared VIP board is also high, reaching 1.913 mW / m·K. Therefore, the performance of VIP core material and VIP board prepared using traditional materials is not good.

[0177] Comparative Example 2, compared to Example 1 of the present invention, used only polyacrylonitrile without using porous materials, and the density of the VIP core material prepared thereby was 203 kg / m³. 3 The thermal conductivity of the prepared VIP board was 1.85 mW / m·K, which is higher than that of the product prepared in Example 2. This indicates that the process of preparing VIP core material using a combination of organic fibers and porous materials in this invention can achieve better thermal insulation and lighter weight.

[0178] Although Comparative Example 3 also used a combination of polyacrylonitrile fibers and hollow glass microspheres, the diameter of its hollow glass microspheres was 5 μm and the pore size was 50 nm. Compared with the hollow glass microspheres used in Example 1, its diameter and pore size were larger. Although the VIP core material prepared using the combination of hollow glass microspheres and polyacrylonitrile fibers in Comparative Example 3 had a lower core material density, the thermal conductivity of the VIP board prepared by it was significantly higher, reaching 3.1 mW / m·K. This cannot well meet the increasingly high requirements for thermal insulation and energy consumption of current thermal insulation materials.

[0179] In summary, this invention utilizes the efficient suspension and dispersion of organic fibers to create conditions for low basis weight of the fiber cloth after wet web forming. Simultaneously, it leverages the high rigidity of organic fiber materials to provide support for the three-dimensional network structure of the VIP core material. Heat transfer in the VIP plate of this invention takes place within the three-dimensional fiber network architecture, fully utilizing the low intrinsic thermal conductivity of organic fibers. The porous material introduces cavities on the surface of the low-conductivity organic fibers, increasing the overall porosity and reducing contact heat transfer, further lowering the thermal conductivity of the VIP plate.

[0180] The embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention. Furthermore, the embodiments of the present invention and the features thereof can be combined with each other unless otherwise specified.

Claims

1. A thermal insulation core material, characterized in that, The raw materials for preparing the thermal insulation core material include organic fibers and porous materials; The porous material includes spherical or near-spherical irregular particles with a porous structure; the diameter of the porous material is 0.05 to 3 μm, and the pore size of the porous material is 1 to 100 nm.

2. The thermal insulation core material according to claim 1, characterized in that, The organic fiber includes at least one of polypropylene fiber, polyethylene fiber, polyester fiber, polyamide fiber, polyacrylonitrile fiber, or polyvinyl alcohol fiber.

3. The thermal insulation core material according to claim 1, characterized in that, The organic fibers have a length of 0.5–250 mm and a diameter of 0.5–50 μm.

4. The thermal insulation core material according to claim 1, characterized in that, The porous material includes at least one of fumed silica powder, hollow glass microspheres, or porous polylactic acid.

5. The thermal insulation core material according to claim 1, characterized in that, The diameter of the porous material is 0.1 to 1 μm, and the pore size of the porous material is 1 to 20 nm.

6. The thermal insulation core material according to any one of claims 1 to 5, characterized in that, The diameter of the porous material is less than 1 / 3 of the diameter of the organic fiber.

7. The thermal insulation core material according to any one of claims 1 to 5, characterized in that, In the preparation raw materials, the mass ratio of the organic fiber to the porous material is (3-10):

1.

8. A method for preparing an insulating core material as described in any one of claims 1 to 7, characterized in that, Includes the following steps: The porous material is uniformly dispersed on the surface of the organic fiber to obtain a surface porous organic fiber mixture; The surface porous organic fiber mixture is filtered to remove porous material agglomerates, resulting in surface porous organic fibers; The porous organic fibers on the surface are dispersed into a liquid to obtain a fiber suspension, which is then wet-laid and dried to obtain a fiber cloth. The fiber cloth is stacked and heat-treated to obtain the heat-insulating core material.

9. The preparation method according to claim 8, characterized in that, Methods for uniformly dispersing the porous material on the surface of the organic fiber include at least one of external force stirring and extrusion, liquid dispersion, or blower dispersion.

10. The preparation method according to claim 8, characterized in that, The concentration of the porous organic fibers in the fiber suspension is 0.005 wt% to 1 wt%.

11. The preparation method according to claim 8, characterized in that, The areal density of the fiber cloth is 2-150 g / m². 2 .

12. The preparation method according to claim 8, characterized in that, The drying temperature is 100–240°C.

13. A vacuum insulation panel, characterized in that, Includes the thermal insulation core material as described in any one of claims 1 to 7.

14. A method for preparing a vacuum insulation panel as described in claim 13, characterized in that, Includes the following steps: The insulating core material is bagged, vacuum-sealed, and then the bag is sealed to obtain the vacuum insulation board.

15. The method for preparing a vacuum insulation panel according to claim 14, characterized in that, The vacuum insulation panel also contains a getter and / or a desiccant.

16. A heat preservation and / or heat insulation device, characterized in that, Including the vacuum insulation panel as described in claim 13.

17. The heat preservation and / or heat insulation device according to claim 16, characterized in that, The insulation and / or heat insulation equipment includes refrigerators, freezers, refrigerated containers, refrigerated transport vehicles, cold storage facilities, or insulated boxes.

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