Flexible bendable vacuum insulation panel and preparation method thereof

Abstract

The invention provides a flexible bendable vacuum insulation panel and a preparation method thereof. The vacuum insulation panel sequentially comprises a core material layer, an adsorbent layer, a barrier film layer and a packaging layer from inside to outside, the core material layer is made of a flexible aerogel composite material; the adsorption layer is made of a flexible molecular sieve adsorbent; the barrier film layer is a multi-layer barrier film material, and the barrier film material comprises a polyester base material, an aluminum foil or silicon dioxide barrier layer and a polyethylene protective layer; the packaging layer is made of a thermoplastic polyurethane film. Through material innovation and structural design, the problems that a traditional vacuum heat insulation plate is difficult to bend and prone to damage are solved, and the vacuum heat insulation plate has high flexibility, can be bent to the radius of 50 mm without being damaged, meanwhile, is excellent in heat insulation performance, has the heat conductivity coefficient smaller than or equal to 0.0025 W / m.K, and is long in service life, light in weight and suitable for popularization and application. The method can be well applied to the fields of household appliances, cold chains and the like.

Description

Technical Field

[0001] The present application relates to the technical field of sheet materials, and particularly to a flexible and bendable vacuum insulation panel and a preparation method thereof. Background Art

[0002] With the continuous development of society, people's attention to environmental protection and energy conservation has been increasing day by day, and thermal insulation materials are increasingly widely used in many fields. As a highly efficient thermal insulation material, the vacuum insulation panel (VIP panel) plays an important role in industries such as construction, household appliances, and cold chain, relying on its extremely low thermal conductivity. For example, in the construction field, it can be used for exterior wall insulation, roof heat insulation, etc., effectively reducing the energy consumption of buildings; in the household appliance industry, it is commonly used in products such as refrigerators and freezers to improve the thermal insulation performance and reduce energy consumption; in cold chain transportation, it can ensure the quality of goods in a low-temperature environment and reduce cold loss.

[0003] Currently, existing VIP panels generally consist of a film material, a core material, and a getter. During production, the core material and the getter are loaded into a film material bag and then vacuum-sealed. Traditional thermal insulation materials, such as foamed polyurethane and ordinary VIP panels, often require a certain thickness requirement to achieve good thermal insulation performance. Moreover, most traditional VIP panels have a rigid structure and have many limitations in the face of application scenarios with complex shapes.

[0004] Especially in the household appliance industry, the structures of household appliances such as refrigerators and freezers are complex and diverse, and the VIP panels used have a wide variety of styles and different sizes. However, the fixed rigid structure of the VIP panel is difficult to adapt to these complex household appliance structures, resulting in great limitations in its use environment. For example, in some areas with special shapes inside the refrigerator, the rigid VIP panel cannot fit tightly, which not only affects the thermal insulation effect but also may cause space waste. At the same time, during the production process, due to the fixed shape of the rigid VIP panel, it is difficult to meet the diverse needs of different models of household appliances, increasing the production difficulty and cost. In addition, the rigid structure of the VIP panel is also easily damaged due to collisions during transportation and installation, further affecting its use performance and lifespan. Summary of the Invention

[0005] The present application provides a flexible and bendable vacuum insulation panel and a preparation method thereof to solve the problem in the related art that the vacuum insulation panel is too rigid to be bent and thus cannot fit tightly to the product.

[0006] The present application provides a flexible and bendable vacuum insulation panel, which sequentially includes a core material layer, an adsorbent layer, a barrier film layer, and a packaging layer from the inside to the outside;

[0007] The core material layer is made of a flexible aerogel composite material;

[0008] The adsorption layer is made of a flexible molecular sieve adsorbent;

[0009] The barrier film layer is a multi-layer barrier film material, and the barrier film material includes a polyester substrate, an aluminum foil or a silica barrier layer, and a polyethylene protective layer;

[0010] The encapsulation layer is made of a thermoplastic polyurethane film.

[0011] In some possible implementation manners, a corrugated structure is provided on the surface of the core material layer.

[0012] In some possible implementation manners, the aerogel composite material includes silica aerogel and polyurethane.

[0013] In some possible implementation manners, the adsorbent includes calcium oxide, zeolite molecular sieve or silicone rubber.

[0014] In some possible implementation manners, carbon nanotubes are added to the flexible aerogel composite material core, with a length of 5-10 microns, a tube diameter selected from 20-50 nanometers, and a specific surface area of 1000-2000 square meters per gram.

[0015] In some possible implementation manners, the thickness of the barrier film is 50-120 μm.

[0016] In some possible implementation manners, the thickness of the encapsulation layer is 0.1-0.2 mm.

[0017] In some possible implementation manners, the thickness of the core material layer is 5-12 mm.

[0018] In some possible implementation manners,

[0019] In some possible implementation manners, the thermal conductivity of the flexible bendable vacuum insulation panel is ≤0.0025 W / m·K.

[0020] In some possible implementation manners, the preparation method of the flexible bendable vacuum insulation panel includes:

[0021] Mix silica aerogel and polyurethane, and then form a flexible aerogel composite material core through a polyurethane foaming process or 3D printing technology, and form a corrugated structure on the core through molding;

[0022] Mix zeolite molecular sieve powder and silicone rubber, press them into a flexible sheet-like adsorbent, and evenly attach it to the surface of the core or embed it in the core;

[0023] Use a three-layer composite barrier film of a polyester substrate, an aluminum foil or a silica barrier layer, and a polyethylene protective layer to wrap the core material and the adsorbent, and seal the edges by a heat sealing process to obtain a packaged board;

[0024] Place the encapsulated sheet into a vacuum chamber;

[0025] Then use a thermoplastic polyurethane film for final encapsulation to obtain a flexible and bendable vacuum insulation panel.

[0026] In some possible implementation manners, the pressure in the vacuum chamber is less than 0.1 Pa.

[0027] As can be seen from the above, the present application provides a flexible and bendable vacuum insulation panel. The vacuum insulation panel sequentially includes a core material layer, an adsorbent layer, a barrier film layer, and an encapsulation layer from the inside to the outside; the core material layer is made of a flexible aerogel composite material; the adsorption layer is made of a flexible molecular sieve adsorbent; the barrier film layer is a multi-layer barrier film material, and the barrier film material includes a polyester substrate, an aluminum foil or a silicon dioxide barrier layer, and a polyethylene protective layer; the encapsulation layer is made of a thermoplastic polyurethane film. Through material innovation and structural design, the present application solves the problems that traditional vacuum insulation panels are difficult to bend and easily damaged. The vacuum insulation panel provided by the present application has high flexibility, can be bent to a radius of 50 mm without damage, and at the same time has excellent heat insulation performance, a thermal conductivity ≤ 0.0025 W / m·K, a long service life, and a light weight, and can well meet the use in fields such as household appliances and cold chain. Detailed implementation manners

[0028] The implementation manners described in the following embodiments do not represent all implementation manners consistent with the present application. They are only examples of systems and methods consistent with some aspects of the present application detailed in the claims.

[0029] With the continuous development of society, people's attention to environmental protection and energy conservation has been increasing day by day, and heat insulation and thermal insulation materials are more and more widely used in many fields. As an efficient heat insulation and thermal insulation material, a vacuum insulation panel (VIP panel) plays an important role in industries such as construction, household appliances, and cold chain by virtue of its extremely low thermal conductivity. For example, in the construction field, it can be used for exterior wall insulation, roof heat insulation, etc., effectively reducing the energy consumption of buildings; in the household appliance industry, it is commonly used in products such as refrigerators and freezers to improve the heat insulation performance and reduce energy consumption; in cold chain transportation, it can ensure the quality of goods in a low-temperature environment and reduce cold loss.

[0030] At present, existing VIP panels generally consist of a film material, a core material, and a getter. During production, the core material and the getter are loaded into a film material bag and vacuum encapsulated. Traditional heat insulation and thermal insulation materials, such as foamed polyurethane, ordinary VIP panels, etc., often require a certain thickness requirement to achieve better heat insulation performance. Moreover, most traditional VIP panels are of a rigid structure and have many limitations in the face of application scenarios with complex shapes.

[0031] Especially in the household appliance industry, the structures of household appliances such as refrigerators and freezers are complex and diverse, and the VIP boards used have a wide variety of styles and different sizes. However, it is difficult for the VIP boards with a fixed rigid structure to adapt to these complex household appliance structures, resulting in great limitations in their usage environment. For example, in some areas with special shapes inside the refrigerator, the rigid VIP boards cannot fit tightly, which not only affects the heat preservation effect but also may cause space waste. At the same time, during the production process, due to the fixed shape of the rigid VIP boards, it is difficult to meet the diverse needs of different models of household appliances, increasing the production difficulty and cost. In addition, the rigid VIP boards are also easily damaged due to collisions during transportation and installation, further affecting their usage performance and lifespan.

[0032] Based on this, the present application provides a flexible and bendable vacuum insulation panel, which includes a core layer of flexible aerogel composite material, an adsorption layer of flexible molecular sieve adsorbent, a multi-layer composite barrier film layer, and a TPU encapsulation layer. Through material innovation and structural design, the present application solves the problems that traditional vacuum insulation panels are difficult to bend and easily damaged, has high flexibility, can be bent to a radius of 50 mm without damage, and at the same time has excellent heat insulation performance, a thermal conductivity of ≤0.0025 W / m·K, a long service life, and a light weight, well meeting the requirements for use in fields such as household appliances and cold chain.

[0033] In some embodiments, for the flexible and bendable vacuum insulation panel provided by the present application, the vacuum insulation panel sequentially includes a core layer, an adsorbent layer, a barrier film layer, and an encapsulation layer from the inside to the outside;

[0034] The core layer is made of flexible aerogel composite material;

[0035] The adsorption layer is made of flexible molecular sieve adsorbent;

[0036] The barrier film layer is a multi-layer barrier film material, and the barrier film material includes a polyester substrate, an aluminum foil or a silicon dioxide barrier layer, and a polyethylene protective layer;

[0037] The encapsulation layer is made of thermoplastic polyurethane film.

[0038] The core layer adopts a flexible aerogel composite material, which is composed of silica aerogel and polyurethane and has good flexibility itself. At the same time, the surface of the core has a corrugated structure, further enhancing the bending performance, enabling the vacuum insulation panel to be bent to a radius of 50 mm without damage. Compared with traditional rigid vacuum insulation panels, it can better adapt to application scenarios with complex shapes, such as fitting in special structural areas inside household appliances, greatly expanding the scope of use.

[0039] Due to the low thermal conductivity of the flexible aerogel composite core material, it lays the foundation for achieving excellent thermal insulation performance of the vacuum insulation panel. Combined with the multi-layer composite barrier film, the polyester (PET) substrate, aluminum foil (Al) or silica (SiO2) barrier layer, and polyethylene (PE) protective layer work together to effectively block the transfer of heat. Eventually, the thermal conductivity of the entire vacuum insulation panel is ≤0.0025 W / m·K, and the heat insulation effect is significantly improved.

[0040] The adsorbent layer uses a flexible molecular sieve adsorbent, which is composed of calcium oxide or zeolite molecular sieve and silicone rubber. It can still maintain good adsorption performance in the bent state, which helps to maintain the vacuum state. The multi-layer composite barrier film has good barrier performance, which can effectively block the entry of external gases and reduce the risk of vacuum failure. The TPU encapsulation layer has good sealing performance to ensure that the vacuum state is maintained for a long time, thus extending the service life of the vacuum insulation panel.

[0041] The use of the flexible aerogel composite core material reduces the overall weight while ensuring the thermal insulation performance compared to some traditional rigid core materials. This has obvious advantages in application scenarios with certain weight requirements, such as home appliances, cold chain transportation, etc. It not only reduces the transportation cost but also facilitates the installation and use of products.

[0042] In order to further improve the performance of the vacuum insulation panel, in some embodiments, the core material layer is specially designed as follows: a corrugated structure is provided on the surface of the core material layer.

[0043] A corrugated structure is set on the surface of the core material to enhance the bending performance, reduce the stress concentration inside the material during bending, avoid cracking, and ensure the structural stability in application scenarios with complex shapes. The adsorbent is evenly distributed on the surface of the core material or embedded in the core material to ensure uniform adsorption effect and stably maintain the vacuum state. Each layer of material is closely bonded to form a stable overall structure to prevent the interlayer separation from affecting the performance.

[0044] The corrugated structure can effectively disperse stress when the core material is bent. When the vacuum insulation panel undergoes bending deformation, the special shape of the corrugations allows each part of the core material to bear the external force more evenly, avoiding stress concentration at a certain point and causing cracking. In practical applications in fields such as home appliances and cold chain, it can better fit the surface of objects with complex shapes, such as the irregular corners inside the refrigerator and the special structural parts of cold chain transportation equipment, greatly expanding the application scenarios of the product.

[0045] The corrugated structure increases the surface area of the core material. At the same volume, more surface area means that the heat transfer path is more tortuous. When heat passes through the core material, it needs to travel a longer distance, thereby increasing the thermal resistance and reducing the thermal conductivity. The thermal conductivity of the vacuum insulation panel in the present invention is ≤0.0025 W / m·K. The excellent insulation performance effectively reduces heat transfer, improves the heat preservation effect, helps reduce energy consumption in the household appliance field, and can enhance the energy-saving effect of buildings in the construction field.

[0046] The corrugated structure is similar to a kind of reinforcing rib, enhancing the overall structural strength of the core material. Even when subjected to external extrusion or impact, the corrugated structure can play a certain buffering and supporting role, preventing the core material from being easily crushed or deformed, thus ensuring that the vacuum insulation panel can work stably in various complex usage environments and extending the service life of the product.

[0047] In some embodiments, the aerogel composite material includes silica aerogel and polyurethane.

[0048] Silica aerogel has a unique nano-porous structure with a very high porosity. A large number of nano-scale pores effectively limit the heat conduction of gas molecules, resulting in a very low thermal conductivity. This property provides a good insulation basis for the vacuum insulation panel and can significantly reduce heat transfer. Polyurethane itself also has a certain insulation ability. After being compounded with silica aerogel, the two cooperate with each other to further reduce the thermal conductivity of the core material, so that the thermal conductivity of the entire vacuum insulation panel can reach the excellent level of ≤0.0025 W / m·K. When applied in fields such as household appliances, construction, and cold chain, it can efficiently prevent heat dissipation or intrusion and achieve an excellent heat insulation effect.

[0049] Polyurethane has a certain elasticity and flexibility, which can endow the core material layer with good bendability. When compounded with silica aerogel, while ensuring the insulation performance, the core material layer can be bent without damage. For example, the vacuum insulation panel can be bent to a radius of 50 millimeters without breaking. This property enables it to adapt to various complex-shaped application scenarios, such as some special-shaped areas inside household appliances, and can fit tightly, avoiding the problems of poor heat preservation effect and space waste caused by the inability of traditional rigid insulation materials to bend.

[0050] Polyurethane has elasticity and flexibility. Increasing its proportion can make the composite material more easily bendable. When the mass ratio of silica aerogel to polyurethane is 3:7, while ensuring a certain insulation performance, the flexibility of the material can be significantly improved, enabling the vacuum insulation panel to better adapt to complex-shaped application scenarios, such as fitting special structures inside household appliances.

[0051] The presence of polyurethane enhances the mechanical strength of the core material layer. It can serve as a support framework for silica aerogel, preventing the silica aerogel from breaking or collapsing when subjected to external forces. In practical applications, when the vacuum insulation panel is subjected to certain external forces such as extrusion and collision, it can maintain a relatively stable structure, ensuring that its thermal insulation performance is not affected and extending the service life of the product.

[0052] Silica aerogel is a lightweight material with a very low density. After being compounded with polyurethane, the overall weight of the core material layer is relatively light. This is of great significance for some application scenarios with weight requirements, such as thermal insulation equipment in cold chain transportation and thermal insulation materials in the aerospace field. The lighter weight can reduce transportation costs, improve energy utilization efficiency, and also facilitate installation and use.

[0053] In some embodiments, the adsorbent includes calcium oxide, zeolite molecular sieve or silicone rubber.

[0054] Calcium oxide has strong water absorption and can react chemically with water vapor to form calcium hydroxide, thus effectively removing the water vapor inside the vacuum insulation panel. Zeolite molecular sieve has a rich microporous structure and a large specific surface area, and has a good physical adsorption effect on water vapor. Silicone rubber also has a certain ability to adsorb water vapor, and its flexibility can adapt to the bending deformation of the core material layer. The combination of the three can efficiently adsorb the water vapor in the insulation panel, preventing the water vapor from accumulating inside the insulation panel and causing a decline in thermal insulation performance. When used in a high-humidity environment, it can maintain a dry environment inside the insulation panel and ensure its long-term stable thermal insulation effect.

[0055] Zeolite molecular sieve has a selective adsorption effect on various gas molecules and can adsorb gas impurities such as oxygen and nitrogen, further reducing the gas content inside the insulation panel and increasing the vacuum degree. This helps to reduce gas heat conduction, lower the thermal conductivity, and improve the thermal insulation performance. In some application scenarios with high requirements for vacuum degree, such as thermal insulation of high-end household appliances and precision instruments, it can better meet the usage requirements.

[0056] The flexibility of silicone rubber enables the adsorbent to maintain good shape and performance during the bending process of the insulation panel, and will not break or fall off due to bending. It can be used as a binder to bond particulate substances such as calcium oxide and zeolite molecular sieve together to form a whole, ensuring the uniform distribution of the adsorbent on the surface or inside of the core material layer. In this way, when the insulation panel is subjected to external forces or undergoes bending deformation, the adsorbent can still stably play its role and maintain the structural stability and performance stability of the insulation panel.

[0057] By continuously adsorbing water vapor and gas impurities, the vacuum environment and dry state inside the insulation board are maintained, reducing the erosion and damage of the internal materials by water vapor and gas. This helps to extend the service life of other materials in the insulation board, such as the barrier film layer, core material layer, etc., thereby improving the service life of the entire flexible bendable vacuum insulation board, reducing the replacement cost, and improving the economic benefits.

[0058] Design the combination according to the content ratio of water vapor and gas impurities in the application scenario. In a high-humidity environment, appropriately increase the proportion of calcium oxide. For example, the mass ratio of calcium oxide to zeolite molecular sieve is 3:2, giving priority to removing a large amount of water vapor to avoid damage to the internal structure of the vacuum insulation board. In scenarios where strict requirements are placed on the types and contents of gas impurities, such as the thermal insulation application of precision instruments, increase the proportion of zeolite molecular sieve to a mass ratio of 2:3 to ensure effective adsorption of various gas impurities and maintain the vacuum degree.

[0059] Due to the good flexibility of silicone rubber itself, the entire adsorbent system can adapt to the bending deformation of the core material layer. During the bending process of the insulation board, the adsorbent will not crack, fall off, etc., ensuring its use effect in complex-shaped application scenarios. For example, in some parts inside household appliances that need to be bent and installed, the adsorbent can still work normally and maintain the performance of the insulation board.

[0060] In some embodiments, the thickness of the barrier film is 50 - 120 μm.

[0061] The high strength and high modulus of PET endow the barrier film with certain tensile strength and tear resistance, making it not easily damaged during production, transportation, and use. Even when the vacuum insulation board is bent, the barrier film can remain intact without cracking or tearing, ensuring the stability of its barrier performance. At the same time, this good mechanical property helps to protect the internal core material and adsorbent from being damaged by external mechanical forces.

[0062] PE has good heat-sealing performance. In the heat-sealing process, through heating and pressing, the PE layer can be tightly fused with itself or other materials to form a reliable sealing edge. This ensures that the vacuum insulation board has good airtightness after encapsulation, preventing gas leakage and maintaining the internal vacuum degree. As in the embodiment, after heat-sealing the PET / Al / PE barrier film, the heat-sealing strength of the vacuum insulation board is relatively high. For example, the heat-sealing strength in Example 1 reaches 64.86 N / 15 mm, effectively guaranteeing the quality and performance of the product.

[0063] After the three materials of PET, Al, and PE are compounded, the barrier film still has a certain flexibility and can adapt to the bending deformation of the vacuum insulation panel. During the process of bending the vacuum insulation panel to a radius of 50 mm, the barrier film will not crack or break due to bending, ensuring the continuous effectiveness of the barrier performance and enabling the vacuum insulation panel to meet the application requirements of complex shapes, such as installation in special structural areas inside household appliances.

[0064] When the thickness of the barrier film is in the range of 50 - 120 μm, this thickness range can ensure that the barrier film effectively blocks external gases and water vapor. The polyester (PET) substrate provides a certain strength and stability, the aluminum foil (Al) or silica (SiO2) barrier layer blocks gas molecules by virtue of its own characteristics, and the polyethylene (PE) protective layer prevents the barrier layer from being damaged. When the thickness is in the range of 50 - 120 μm, each layer works together to efficiently prevent external gases and water vapor from entering the insulation panel, maintain the internal vacuum state, ensure a low thermal conductivity, and improve the insulation performance, such as making the thermal conductivity of the vacuum insulation panel ≤ 0.0025 W / m·K.

[0066] The barrier film has a certain flexibility and will not affect the bending performance of the vacuum insulation panel due to being too hard or too thick. It can cooperate with the core material layer with bending characteristics, enabling the insulation panel to be bent to a radius of 50 mm without breaking, and adapting to the application scenarios of complex shapes, such as installation in special structural areas inside household appliances. At the same time, this thickness also endows the barrier film with a certain mechanical strength, protecting the internal core material and adsorbent when the insulation panel is subjected to external forces, and preventing damage and vacuum failure caused by external forces.

[0067] A suitable thickness is conducive to the implementation of the heat - sealing process. Within the above - mentioned thickness range, the barrier film can form a good sealing effect during heat - sealing, and the heat - sealing strength is appropriate. A stable vacuum environment can ensure the stable performance of the core material and the adsorbent, avoiding problems such as the core material getting damp and the performance of the adsorbent decreasing due to vacuum failure, indirectly maintaining the overall performance of the vacuum insulation panel, and thus the bending property will not be reduced due to internal performance changes. If the barrier film is too thin, it may cause gases and water vapor to penetrate, affecting the performance of the internal materials and then reducing the bending property; if it is too thick, it may make the overall insulation panel harder, which is also not conducive to bending.

[0068] In practical applications, the barrier film, together with the core material layer, the adsorbent layer, and the encapsulation layer, constitutes the vacuum insulation panel. When the thickness of the barrier film is in the range of 50 - 120 μm, it can work better with other layers. During the bending process, the barrier film within this thickness range has a certain flexibility and will not hinder the bending deformation of the insulation panel due to being too hard or too thick. It cooperates with the core material layer with bending performance, etc., which is generally beneficial for the vacuum insulation panel to achieve a better bending effect and has a positive impact on the bending property to a certain extent.

[0069] In some embodiments, the thickness of the encapsulation layer is 0.1 - 0.2 mm.

[0070] If the encapsulation layer is too thin, such as less than 0.1 mm, the sealing effect of the TPU film will be greatly reduced. External air, water vapor, etc. can more easily penetrate the film into the insulation board and destroy the vacuum state. Once the vacuum degree decreases, the gas molecules in the insulation board increase, heat conduction intensifies, resulting in an increase in thermal conductivity and a serious reduction in thermal insulation performance. When the thickness of the encapsulation layer is 0.1-0.2 mm, a good sealing structure can be formed to effectively block the invasion of external gases, ensure the long-term stability of the vacuum state, maintain excellent thermal insulation performance, and the thermal conductivity can be stably maintained at ≤0.0025W / m·K.

[0071] The thickness of the encapsulation layer has a significant impact on the mechanical strength and flexibility of the insulation board. If the encapsulation layer is too thick, exceeding 0.2 mm, the TPU film will make the insulation board hard and brittle as a whole, and its flexibility will be greatly reduced. It will be difficult to bend to a radius of 50 mm without damage, and it will not be able to meet the needs of complex shape application scenarios, and its applicability in home appliances, cold chain and other fields will be reduced. On the contrary, when the thickness is appropriate, it can not only ensure that the insulation board has high flexibility and meets the bending requirements, but also provide a certain mechanical strength to protect the internal core material, adsorbent and barrier film, so that it is not easily damaged during transportation, installation and use.

[0072] The thickness of the encapsulation layer is closely related to the heat seal strength. When the thickness is unreasonable, the seal is likely to be loose during the heat seal process. An overly thin encapsulation layer has a small heat seal area, weak bonding force, and low heat seal strength. In actual use, the edge is prone to cracking, resulting in vacuum failure. In the thickness range of 0.1-0.2 mm, the heat seal strength can reach an ideal level.

[0073] In some embodiments, the core material layer has a thickness of 5 to 12 mm.

[0074] The appropriate thickness of the core material layer is one of the key factors in achieving excellent insulation performance. A thickness of 5-12mm can ensure that the flexible aerogel composite material in the core material can fully exert its low thermal conductivity characteristics. The composite material composed of silica aerogel and polyurethane can effectively block the transfer of heat within this thickness range. When the thickness is 8mm, the thermal conductivity of the vacuum insulation panel can be ≤0.0025W / m·K. When used in construction, home appliances, cold chain and other fields, it can significantly reduce heat loss or intrusion, improve thermal insulation effects, and reduce energy consumption.

[0075] This thickness range has a positive impact on the bending performance of the vacuum insulation panel. When the thickness is relatively thin at 5 mm, the core material is light in weight and good in flexibility, with less resistance during bending, making it easier to achieve bending deformation and better adapt to application scenarios with complex shapes, such as narrow and irregularly shaped areas inside household appliances. When the thickness is 12 mm, although the overall rigidity is enhanced, since the core material uses a flexible aerogel composite material and has a corrugated structure on the surface, it can still effectively disperse the bending stress, enabling the vacuum insulation panel to be bent to a radius of 50 mm without damage.

[0076] The thickness of 5 - 12 mm provides a certain mechanical strength for the core material. During actual use, the vacuum insulation panel will be subjected to various external forces, such as extrusion, collision, etc. An appropriate thickness can prevent the core material from being easily deformed or damaged when subjected to external forces. When under a certain pressure, the 12 - mm - thick core material can better withstand the pressure, protect the internal structure, maintain the performance stability of the vacuum insulation panel, and extend the service life of the product.

[0077] In some embodiments, nano - materials such as carbon nanotubes and nanofibers can also be added to the flexible aerogel composite core material. Carbon nanotubes have extremely high strength and good flexibility. After adding them, the mechanical properties of the core material can be enhanced, making it less likely to break during the bending process. At the same time, the high specific surface area of the nano - material can further improve the thermal insulation performance of the core material, reduce the thermal conductivity through mechanisms such as phonon scattering, and cooperate with the original silica aerogel and polyurethane to create a more excellent performance combination.

[0078] For the flexible aerogel composite core material, if we hope to significantly enhance the mechanical properties, single - wall carbon nanotubes have obvious advantages in improving the flexibility and tensile strength of the core material due to their thin diameter and high strength. When the diameter is 1 - 1.5 nanometers, they can be evenly dispersed in the aerogel matrix, effectively transfer stress, and enhance the anti - cracking ability of the core material during the bending process. If considering cost and preparation difficulty, multi - wall carbon nanotubes are more suitable, and the appropriate diameter is 20 - 50 nanometers, which can not only ensure a certain enhancement effect but also be well - dispersed to avoid agglomeration affecting the performance.

[0079] The length of carbon nanotubes is usually from a few micrometers to dozens of micrometers. In the flexible aerogel core material, a length of 5 - 10 micrometers is more appropriate. Shorter carbon nanotubes have good dispersibility, but the enhancement effect is limited; too long ones are prone to agglomeration, affecting the material uniformity. A length of 5 - 10 micrometers can be effectively dispersed in the aerogel matrix, form a network structure, enhance the overall strength and flexibility of the material, improve the bending performance of the vacuum insulation panel, and have a relatively small impact on the thermal conductivity.

[0080] The specific surface area of ​​carbon nanotubes is generally between several hundred and several thousand square meters per gram. In this application, a specific surface area of ​​1000 to 2000 square meters per gram is ideal. A higher specific surface area can increase the contact area with aerogel and polyurethane, improve the interfacial bonding force, and enhance the interaction. At the same time, a large specific surface area helps to adsorb and scatter phonons, further reduce the thermal conductivity of the core material, and improve the thermal insulation performance of the vacuum insulation panel, so that it meets the requirement of thermal conductivity ≤ 0.0025W / m·K.

[0081] In some embodiments, the pore size of the flexible molecular sieve adsorbent can also be precisely controlled. Through a special synthesis process, the pore size of the zeolite molecular sieve can be more accurately matched to the size of the gas molecules to be adsorbed, thereby improving the adsorption selectivity and adsorption capacity. This can not only more efficiently remove specific impurity gases and maintain vacuum, but also bring unique technical advantages to the product, which is different from the broad pore size distribution of conventional adsorbents.

[0082] In some embodiments, the thermal conductivity of the flexible bendable vacuum insulation panel is ≤0.0025 W / m·K.

[0083] Traditional vacuum insulation panels mostly use rigid core materials (such as silicon powder, glass fiber board) and metal foil packaging, which cannot be bent and are only suitable for flat structures. However, this application uses flexible porous core materials (such as nanofibers, aerogel composite materials) combined with high barrier but bendable composite films, so that vacuum insulation panels can bend within a certain radius of curvature without breaking, which is suitable for curved surfaces or dynamic structures. At the same time, the surface of the core material is provided with a corrugated structure to increase the degree of flexibility.

[0084] The membrane material of traditional vacuum insulation panels uses aluminum foil or metal composite film, which has good barrier properties, but bending easily leads to micro cracks, allowing gas to penetrate and reducing service life. This application uses a multi-layer flexible high barrier film (such as PET / Al / PE or SiO x Coated film), which allows repeated bending while maintaining high gas barrier properties. PET (polyester) has good mechanical properties and dimensional stability, providing basic structural support for the barrier film. Al (aluminum foil) has an extremely low gas permeability, which can effectively block oxygen, nitrogen and other gas molecules from entering the interior of the vacuum insulation panel, prevent the vacuum degree from decreasing, maintain the vacuum environment inside the panel, and effectively reduce heat conduction. PE (polyethylene) as a protective layer has good chemical stability and moisture resistance, which can prevent the aluminum foil from being corroded by the external environment, and further block the penetration of water vapor. The barrier film composed of these three layers of materials greatly improves the barrier performance of the vacuum insulation panel, ensures that the vacuum state inside it can be maintained for a long time, and then maintains excellent insulation performance, so that the thermal conductivity is ≤0.0025W / m·K.

[0085] This application uses a flexible molecular sieve adsorbent to enhance mechanical flexibility while maintaining a low thermal conductivity. Calcium oxide and zeolite molecular sieves in the flexible molecular sieve adsorbent have a strong adsorption capacity for water vapor and gas impurities. Calcium oxide can chemically react with water vapor to rapidly absorb moisture; zeolite molecular sieves have a rich microporous structure and a large specific surface area, and can adsorb water vapor and various gas molecules through physical adsorption. They can effectively reduce the water vapor and gas content inside the vacuum insulation panel, maintain a good vacuum environment, ensure that the thermal conductivity is maintained at a low level (≤0.0025 W / m·K), and improve the insulation performance.

[0086] Compared with traditional adsorbents, the flexible molecular sieve adsorbent has flexibility due to the inclusion of silicone rubber. During the bending process of the vacuum insulation panel, the adsorbent can deform together with the core material without cracking, shedding, etc. This enables the vacuum insulation panel to still maintain stable adsorption performance when bent to a radius of 50 mm, ensuring the use effect in complex-shaped application scenarios (such as special structural areas inside household appliances).

[0087] The flexible molecular sieve adsorbent can be evenly distributed on the surface of the core material or embedded in the core material. This uniform distribution method ensures the uniformity of the adsorption effect and avoids the problem of large differences in local adsorption capacity. No matter which part of the vacuum insulation panel, it can effectively adsorb water vapor and gas impurities, maintain the overall performance stability, and extend the product service life.

[0088] In some embodiments, the preparation method of the flexible bendable vacuum insulation panel includes:

[0089] Mix silica aerogel with polyurethane, and then form a flexible aerogel composite core material through a polyurethane foaming process or 3D printing technology, and form a corrugated structure on the core material by molding;

[0090] Mix zeolite molecular sieve powder with silicone rubber, press it into a flexible sheet-shaped adsorbent, and evenly attach it to the surface of the core material or embed it in the core material;

[0091] Use a three-layer composite barrier film of a polyester substrate, aluminum foil or silica barrier layer, and a polyethylene protective layer to wrap the core material and the adsorbent, and seal the edges by a heat-sealing process to obtain a packaged board;

[0092] Put the packaged board into a vacuum chamber;

[0093] Then use a thermoplastic polyurethane film for final packaging to obtain a flexible bendable vacuum insulation panel.

[0094] In some embodiments, the pressure in the vacuum chamber is less than 0.1 Pa.

[0095] The vacuum insulation panel prepared in this application uses a flexible aerogel composite material as the core material, and a corrugated structure is formed on the surface of the core material through a molding or 3D printing technology. Then, a flexible molecular sieve is used as the adsorbent, which is evenly adhered to the surface of the core material or embedded in the core material. At the same time, a multi-layer composite barrier film is used to wrap the core material and the adsorbent, and then the edges are sealed by a heat-sealing process. Then, the encapsulated VIP panel is placed in a vacuum chamber, and the vacuum is pumped. Finally, a TPU film is used for the final encapsulation to ensure that the vacuum state is maintained for a long time. The flexible and bendable vacuum insulation panel provided by this application includes a flexible aerogel composite core material, a flexible molecular sieve adsorbent, a multi-layer composite barrier film, and a TPU encapsulation layer. Through material innovation and structural design, it solves the problems that traditional VIP panels are difficult to bend and easily damaged, and has the advantages of high flexibility, excellent heat insulation performance, and long life.

[0096] Example 1

[0097] (1) Mix silica aerogel and polyurethane, and prepare a flexible aerogel composite core material with a thickness of 8 mm through a foaming process. A corrugated structure is formed on the surface through molding.

[0098] (2) Mix zeolite molecular sieve powder and silicone rubber, press them into a flexible sheet-like adsorbent, and evenly adhere it to the surface of the core material.

[0099] (3) Use a PET / Al / PE three-layer composite barrier film to wrap the core material and the adsorbent, and seal the edges by a heat-sealing process.

[0100] (4) Place the encapsulated VIP panel in a vacuum chamber, and pump the vacuum to 0.1 Pa.

[0101] (5) Use a TPU film for the final encapsulation to obtain a flexible and bendable vacuum insulation panel.

[0102] Example 2

[0103] (1) Mix silica aerogel and polyurethane, and prepare a flexible aerogel composite core material with a thickness of 5 mm through 3D printing technology. A corrugated structure is formed on the surface.

[0104] (2) Mix zeolite molecular sieve powder and silicone rubber, press them into a flexible sheet-like adsorbent, and embed it in the core material.

[0105] (3) Use a PET / SiO2 / PE three-layer composite barrier film to wrap the core material and the adsorbent, and seal the edges by a heat-sealing process.

[0106] (4) Place the encapsulated VIP panel in a vacuum chamber, and pump the vacuum to 0.1 Pa.

[0107] (5) Use a TPU film for the final encapsulation to obtain a flexible and bendable vacuum insulation panel.

[0108] Comparative Example:

[0109] To ensure the comparability of the experiments, a traditional rigid VIP board commercially available in the market in the examples was used as the comparative example for comparison. The initial thermal conductivity of the VIP board manufacturer was 2.0 ± 0.2 mw / mk.

[0110] Since the traditional rigid VIP board does not have a bending function, a flexible bendable vacuum insulation board was prepared according to the measurement of the bending properties of plastics in GB / T 9341 Chinese national standard to ensure the effectiveness and wide recognition of the test results. At the same time, a flexible VIP board sample with a size of 100 mm × 25 mm × 8 mm was prepared, ensuring that the edges of the sample were flat, without burrs or damage. Then, multiple samples of the same batch were tested, and the data range of multiple tests was taken as the final result range. The results are as follows:

[0111] 1. The minimum bending radius ≤ 50 mm (the sample can be bent without damage or significant performance degradation).

[0112] 2. The bending modulus of the sample: 10 - 50 MPa (the ratio of stress to strain of the sample in the elastic deformation stage).

[0113] 3. The bending durability of the sample (the ability to maintain performance after repeated bending): The sample was subjected to 100 bending cycles (bending radius 50 mm), and there were no cracks or damage on the appearance.

[0114] 4. The bending strength ≥ 1 MPa (the maximum stress borne by the sample during bending).

[0115] Then, the performance tests of the VIP boards corresponding to Examples 1 and 2 and the comparative example were carried out respectively. At the same time, to ensure the effectiveness and wide recognition of the test results, the test method was carried out according to QB / T 2358-1998 "Test Method for Heat Seal Strength of Plastic Packaging" for heat seal strength; the thermal conductivity was measured using a JW-3 type thermal conductivity measuring instrument of Beijing Jianyan Tianrun Technology Co., Ltd. The results are shown in Table 1 below:

[0116] Table 1

[0117]

[0118] It can be seen that the test results of the flexible bendable VIP and the traditional rigid VIP board with the same or similar initial thermal conductivity are basically the same in terms of thermal conductivity. Therefore, it can be used as a substitute under actual special use conditions that cannot be met by the traditional rigid VIP board. At the same time, there is little difference in the heat seal edge process from the traditional VIP board, so the heat seal strength is not much different.

[0119] As can be seen from the above embodiments, the present application provides a flexible and bendable vacuum insulation panel, which sequentially includes a core material layer, an adsorbent layer, a barrier film layer, and a packaging layer from the inside to the outside; the core material layer is made of a flexible aerogel composite material; the adsorption layer is made of a flexible molecular sieve adsorbent; the barrier film layer is a multi-layer barrier film material, and the barrier film material includes a polyester substrate, an aluminum foil or a silica barrier layer, and a polyethylene protective layer; the packaging layer is made of a thermoplastic polyurethane film. Through material innovation and structural design, the present application solves the problems that traditional vacuum insulation panels are difficult to bend and easily damaged. The vacuum insulation panel provided by the present application has high flexibility, can be bent to a radius of 50 mm without damage, and at the same time has excellent heat insulation performance, a thermal conductivity ≤ 0.0025 W / m·K, a long service life, and a light weight, and can well meet the use in fields such as household appliances and cold chain.

[0120] For the similar parts between the embodiments provided in the present application, reference can be made to each other. The specific embodiments provided above are only several examples under the general concept of the present application, and do not constitute a limitation on the protection scope of the present application. For those skilled in the art, any other implementation manner extended based on the solution of the present application without creative work belongs to the protection scope of the present application.

Claims

1. A flexible and bendable vacuum insulation panel, characterized in that, The vacuum insulation panel sequentially includes a core material layer, an adsorbent layer, a barrier film layer, and a packaging layer from inside to outside; The core material layer is made of a flexible aerogel composite material; The adsorption layer is made of a flexible molecular sieve adsorbent; The barrier film layer is a multi-layer barrier film material, and the barrier film material includes a polyester substrate, an aluminum foil or a silica barrier layer, and a polyethylene protective layer; The packaging layer is made of a thermoplastic polyurethane film.

2. The flexible and bendable vacuum insulation panel according to claim 1, wherein, The surface of the core material layer is provided with a corrugated structure.

3. The flexible and bendable vacuum insulation panel according to claim 2, wherein The aerogel composite material includes silica aerogel and polyurethane.

4. The flexible and bendable vacuum insulation panel according to claim 1, characterized in that, The adsorbent includes calcium oxide, zeolite molecular sieve or silicone rubber.

5. The flexible and bendable vacuum insulation panel according to claim 1, characterized in that, The thickness of the barrier film is 50-120 μm.

6. The flexible and bendable vacuum insulation panel according to claim 1, wherein The thickness of the packaging layer is 0.1-0.2 mm.

7. The flexible and bendable vacuum insulation panel according to claim 1, characterized in that, The thickness of the core material layer is 5-12 mm.

8. The flexible and bendable vacuum insulation panel according to claim 1, characterized in that, The thermal conductivity of the flexible and bendable vacuum insulation panel is ≤0.0025 W / m·K.

9. A preparation method of a flexible and bendable vacuum insulation panel, characterized in that, The flexible and bendable vacuum insulation panel is the flexible and bendable vacuum insulation panel described in claim 1, and the method includes: Mix silica aerogel and polyurethane, and then form a flexible aerogel composite material core through a polyurethane foaming process or 3D printing technology, and form a corrugated structure on the core through molding; Mix zeolite molecular sieve powder and silicone rubber, press them into a flexible sheet-shaped adsorbent, and uniformly attach it to the surface of the core or embed it in the core; Wrap the core material and the adsorbent with a three-layer composite barrier film of a polyester substrate, an aluminum foil or a silica barrier layer, and a polyethylene protective layer, and seal the edge by a heat sealing process to obtain a packaged board; Put the packaged board into a vacuum chamber; Then use a thermoplastic polyurethane film for final packaging to obtain a flexible and bendable vacuum insulation panel.

10. The method according to claim 9, wherein The pressure in the vacuum chamber is less than 0.1 Pa.

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