Electrostatic vacuum plate structure and flexible aluminum plastic film production method

Abstract

The invention discloses an electrostatic vacuum plate structure and a flexible aluminum plastic film production method, and relates to the field of vacuum plates, the electrostatic vacuum plate structure comprises an upper vacuum plate and a lower vacuum plate, the space between the two vacuum plates is in a vacuumized state to form a vacuum cavity, and the two ends of the vacuum cavity are subjected to heat edge sealing treatment; the upper vacuum plate, the lower vacuum plate and the sealing edges at the two ends are attached through flexible insulating aluminum plastic films containing PTFE layers; inner-layer aluminum foils are pasted on the upper vacuum plate and the lower vacuum plate in the vacuum cavity respectively, the two inner-layer aluminum foils sense same-polarity negative static electricity, external air pressure is resisted through electrostatic repulsive force, and the thickness of the vacuum cavity is maintained to be in the preset size. Compared with a traditional glass fiber vacuum plate, heat transfer of an inner core material is avoided, the heat conductivity is reduced, the thickness of the vacuum plate can be reduced to be within 0.5 mm, high-performance heat-insulation ultrathin performance is achieved, a hard plate is changed into a flexible film material, and the fitting adaptability of a product on different surfaces is greatly improved.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of vacuum panels, and in particular to an electrostatic vacuum panel structure and a method for producing a flexible aluminum-plastic film. Background Art

[0002] Vacuum insulation panels are a high-performance insulation material with a thermal conductivity 10-20 times lower than that of conventional insulation cotton. The technical principle is to evacuate the core material and heat-seal it with aluminum-plastic film. This design eliminates the heat conduction of air inside the core material, thus greatly improving its insulation performance. The aluminum-plastic film wrapped on the outside protects the internal vacuum and blocks the entry of external gas. At the same time, the aluminum-plastic film can reflect external heat radiation, further improving its insulation performance. Vacuum insulation panels are currently widely used in refrigerators, cold chain and other industries.

[0003] The vacuum panels currently produced on the market generally have the disadvantages of high production cost, difficulty in reducing thickness, high overall hardness and poor adaptability. Summary of the invention

[0004] The embodiments of the present application provide an electrostatic vacuum plate structure and a method for producing a flexible aluminum-plastic film, which are used to solve the problem that the thickness is difficult to reduce, the overall hardness is relatively high, and the lamination adaptability is poor.

[0005] On the one hand, the present application provides an electrostatic vacuum plate structure, comprising an upper vacuum plate and a lower vacuum plate, wherein the space between the two vacuum plates is evacuated to form a vacuum cavity, and both ends of the vacuum cavity are heat-sealed;

[0006] The upper vacuum plate, the lower vacuum plate and the edge seals at both ends are laminated with a flexible insulating aluminum-plastic film containing a polytetrafluoroethylene (PTFE) layer; inner aluminum foils are respectively pasted on the upper vacuum plate and the lower vacuum plate inside the vacuum cavity, and the two inner aluminum foils induce the same negative static electricity, which resists the external air pressure through electrostatic repulsion, thereby maintaining the thickness of the vacuum cavity at a preset size.

[0007] Specifically, the insulating aluminum-plastic film comprises, in layers, an outer nylon protective layer, an upper glue film layer, an aluminum foil layer, a PTFE insulating layer, a lower glue film layer, and an inner polyethylene PE layer;

[0008] The upper adhesive film layer is adhered to the outer nylon protective layer and the aluminum foil layer, and the lower adhesive film layer is adhered to the PTFE insulating layer and the inner PE layer. The PTFE insulating layer isolates the aluminum foil layer and the inner PE layer.

[0009] Specifically, the thickness of the PTFE insulation layer is 2-4 μm, the thickness of the aluminum foil layer is 7-15 μm; the thickness of the inner PE is 10-80 μm; the thickness of the inner aluminum foil is 1-10 μm;

[0010] The upper adhesive film layer and the lower adhesive film layer are polyurethane adhesive or acrylic adhesive.

[0011] Specifically, the size of the inner aluminum foil inside the vacuum cavity is smaller than the size of the upper and lower vacuum plates, and the inner aluminum foil does not contact the edge sealing position.

[0012] Specifically, a getter is arranged inside the vacuum cavity near the edge sealing position, and the thickness of the electrostatic vacuum plate maintained by electrostatic repulsion does not exceed 0.5 mm.

[0013] On the other hand, the present application provides a filled electrostatic vacuum plate, comprising an upper vacuum plate and a lower vacuum plate, wherein the space between the two vacuum plates is evacuated to form a vacuum cavity, and heat-sealed edges are performed at both ends of the vacuum cavity;

[0014] The upper vacuum plate, the lower vacuum plate and the edge seals at both ends are laminated with a flexible insulating aluminum-plastic film containing a polytetrafluoroethylene (PTFE) layer;

[0015] The core material is filled in the vacuum cavity, and negative static electricity of the same polarity is induced on the contact surfaces between the core material and the upper and lower vacuum plates.

[0016] Specifically, the core material comprises at least one of glass fiber, basalt fiber, ceramic fiber, fumed silica, and polyurethane foam;

[0017] The thickness of the electrostatic vacuum plate after filling the core material and maintaining it by electrostatic repulsion does not exceed 0.5 mm.

[0018] In another aspect, the present application provides a method for producing a flexible aluminum-plastic film, the method comprising:

[0019] Prepare an aluminum foil with a thickness of 7-15 μm and a PTFE film with a thickness of 2-4 μm, and after degreasing and cleaning, compound and shape the PTFE film and the aluminum foil coated with an adhesive through a hot press;

[0020] Prepare nylon with a thickness of 12-100 μm and polyethylene plastic film with a thickness of 10-80 μm, use chemical solvent to clean and decontaminate the composite shaped aluminum foil, and perform corona treatment on the surface of the plastic film;

[0021] The adhesive is evenly coated on each layer of plastic film, and after coating, the chemical solvent is removed through a drying device to initially solidify the adhesive;

[0022] The cured plastic film is compounded and shaped with the aluminum foil surface and the PTFE film using a hot press to generate a flexible insulating aluminum-plastic film.

[0023] Specifically, the hot pressing temperature of the aluminum foil and the PTFE film is 300-400°C and the pressure is 0.5-2MPa;

[0024] The hot pressing temperature of the plastic film and the aluminum foil surface, as well as the hot pressing temperature of the plastic film and the PTFE film is 100-150°C and the pressure is 0.5-1.5Mpa.

[0025] Specifically, the curing temperature after compounding is set to 50-80° C., and the curing time is 24-48 hours.

[0026] The beneficial effects brought by the technical solution provided by the embodiment of the present application include at least:

[0027] 1. Compared with traditional glass fiber vacuum panels, electrostatic vacuum panels have no core material inside, and the manufacturing process of vacuum panels (core material manufacturing, cutting, baking, etc.) is greatly simplified, and the overall cost can be reduced by 60%.

[0028] 2. There is no core material inside the electrostatic vacuum panel, which eliminates the heat transfer of the vacuum panel through the internal core material, and the thermal conductivity can be further reduced by more than 2 times.

[0029] 3. Due to the coreless design inside the electrostatic vacuum panel, the thickness of the vacuum panel can be reduced to less than 0.5mm, achieving ultra-thin high-performance thermal insulation. At the same time, the vacuum insulation material is changed from a hard plate material to a flexible film material, which greatly improves the product's adaptability to different surfaces. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic diagram of the structure of the electrostatic vacuum plate provided by the present application;

[0031] Figure 2 It is a schematic diagram of the structure of the flexible insulating aluminum-plastic film provided in an embodiment of the present application;

[0032] Figure 3 is a schematic diagram of a filled electrostatic vacuum panel structure in another embodiment;

[0033] Figure 4 It is a flow chart of the electrostatic vacuum plate structure plating method provided in the present application. DETAILED DESCRIPTION

[0034] In order to make the objectives, technical solutions and advantages of the present application clearer, the implementation methods of the present application will be further described in detail below with reference to the accompanying drawings.

[0035] The present application provides an electrostatic vacuum plate structure, such as Figure 1 As shown, it includes an upper vacuum plate and a lower vacuum plate. After the two vacuum plates are heat-sealed at the edge positions at both ends, vacuum is drawn between the two plates to form a vacuum cavity.

[0036] The upper vacuum plate, the lower vacuum plate and the edge seals at both ends are all laminated with a flexible insulating aluminum-plastic film containing a polytetrafluoroethylene (PTFE) layer. The structure of the flexible insulating aluminum-plastic film laminate determines the flexibility of the structure and effectively reduces the hardness of the vacuum plate.

[0037] Inside the vacuum cavity, inner aluminum foils are respectively pasted on the upper vacuum plate and the lower vacuum plate (i.e., the upper and lower flexible insulating aluminum-plastic films), and negative static electricity of the same sex is induced on the two inner aluminum foils. Under the action of induced static electricity, the two aluminum-plastic films support the vacuum cavity through electrostatic repulsion and resist the external atmospheric pressure, maintaining the thickness of the vacuum cavity at a preset size. In the actual industrial system, the size of the electrostatic charge is determined by the size and thickness of the vacuum plate. Because the PTFE layer material is added to the flexible insulating aluminum-plastic film, it has a good insulation effect, which can isolate the induced static electricity of the inner aluminum foil of the cavity inside, so as not to leak to the outside of the vacuum plate. Under the effect of good edge sealing, the electrostatic support effect can be maintained for more than ten years, which fully meets industrial needs.

[0038] In addition, in addition to inducing static electricity to support the cavity, the inner aluminum foil can also effectively isolate the heat exchange between the inside and the outside, achieving strong thermal insulation.

[0039] Compared with traditional glass fiber vacuum panels, in order to maintain the vacuum degree and size requirements, the aluminum-plastic film is made of a relatively hard film layer material, and glass fiber and other core materials are added inside to maintain the influence of external atmospheric pressure. However, in this application, the filling core material is directly eliminated, and two layers of aluminum foil that induce static electricity are directly implanted into the vacuum cavity. Based on the electrostatic repulsion to maintain and resist the influence of external atmospheric pressure, the manufacturing process of the vacuum panel (manufacturing, cutting, baking, etc. of the core material) is greatly simplified, and the overall cost can be reduced by 60%. It can also reduce the effective thickness of the vacuum panel to a considerable range, and achieve ultra-thin high-performance thermal insulation.

[0040] In addition, because the filling core material has more physical contact surfaces, that is, the high-density contact between the glass fiber and the aluminum-plastic film will accelerate heat conduction. Compared with the cavity structure of the present application, the heat transfer of the vacuum panel through the internal core material is eliminated, and the thermal conductivity can be further reduced by more than 2 times.

[0041] Furthermore, since the present application uses a flexible insulating aluminum-plastic film containing a PTFE film layer to replace the traditional hard aluminum-plastic film, the flexibility of the surface of the vacuum panel is increased, making it more convenient to cut, seal and fold.

[0042] Figure 2 It is a schematic diagram of the structure of the flexible insulating aluminum-plastic film provided in an embodiment of the present application, which comprises, in hierarchical order, an outer nylon protective layer, an upper adhesive film layer, an aluminum foil layer, a PTFE insulating layer, a lower adhesive film layer, and an inner polyethylene PE layer.

[0043] The nylon material is located on the outermost side, providing a certain degree of flexibility and protective structure. The upper and lower film layers are mainly used for film layer bonding. The upper film layer is bonded to the outer nylon protective layer and the aluminum foil layer, and the lower film layer is bonded to the PTFE insulation layer and the inner PE layer. The PTFE insulation layer isolates the aluminum foil layer and the inner PE layer. The aluminum foil layer is mainly used to isolate gas molecules from entering and destroying the internal vacuum, while the PTFE insulation layer is used to prevent internal static electricity and transmission losses to the outside. These two film layers achieve internal and external isolation to ensure the long-term maintenance of the vacuum.

[0044] The inner PE layer is mainly set to cooperate with the inner aluminum foil layer. Because the inner aluminum foil layer is induced by static electricity, it is necessary to isolate the charge transfer between the flexible aluminum-plastic film, so the PE film layer is used. And the inner aluminum foil layer maintains a vacuum cavity under the action of static electricity, without contact with fillers, and the thermal insulation effect is further improved.

[0045] In some embodiments, in order to achieve a better edge sealing effect, when pasting the inner aluminum foil layer, the size is designed to be smaller than the size of the upper and lower vacuum plates, that is, the inner aluminum foil does not extend to and contact the edge sealing position. This ensures that the internal same-sex electrostatic repulsion force does not extend to the edge sealing, and will not destroy the sealing strength of the edge sealing.

[0046] In some other embodiments, a getter or a getter bag may be installed in the vacuum cavity and placed at the edge sealing position of the cavity or other positions to keep the interior dry.

[0047] In some specific implementation schemes, the thickness of the PTFE insulation layer is designed to be 2-4μm, the thickness of the aluminum foil layer is 7-15μm; the thickness of the inner PE is 10-80μm; the thickness of the inner aluminum foil is 1-10μm; the upper adhesive film layer and the lower adhesive film layer are bonded with polyurethane adhesive or acrylic adhesive. In this way, the thickness of the electrostatic vacuum plate maintained by electrostatic repulsion can be maintained within 0.5mm. Compared with the thickness of the traditional filler vacuum plate, it can be ultra-thin with high-performance heat insulation, greatly improving the product's adaptability to different surfaces.

[0048] Based on the design scheme provided in the present application for using electrostatic repulsion to maintain the stability of the cavity, the present application can also design a filled electrostatic vacuum plate to adapt to special scenarios such as special high pressure resistance.

[0049] Figure 3 Schematic diagram of the structure of a filled electrostatic vacuum panel. Compared with the traditional filled vacuum panel, the upper and lower vacuum panels of this structure both use the flexible insulating aluminum-plastic film in the above embodiment. Although there is a vacuum cavity between the upper and lower vacuum panels, the core material filled inside and the contact surface between the core material and the upper and lower vacuum panels induces the same negative static electricity, and the two ends of the vacuum cavity are heat-sealed.

[0050] The upper vacuum plate, the lower vacuum plate and the edge sealing at both ends are laminated with a flexible insulating aluminum-plastic film containing a polytetrafluoroethylene (PTFE) layer. The difference between this structure and the traditional structure is that the core material filling can reduce the filling amount under the action of electrostatic support, that is, the fiber density in the cavity can be greatly reduced, and at the same time, the low-density fiber filling can reduce the actual contact area, thereby reducing heat conduction. The core material in this embodiment can include one or more of glass fiber, basalt fiber, ceramic fiber, fumed silica, and polyurethane foam. Under the action of electrostatic support, the filling amount is reduced, and the thickness of the electrostatic vacuum plate can also be compressed to less than 0.5 mm.

[0051] Figure 4 : is a flow chart of the electrostatic vacuum plate structure plating method provided by the present application, the method comprising the following steps:

[0052] S1, prepare an aluminum foil with a thickness of 7-15 μm and a PTFE film with a thickness of 2-4 μm, and after degreasing and cleaning, compound and shape the PTFE film and the aluminum foil coated with an adhesive through a hot press;

[0053] S2, prepare nylon with a thickness of 12-100 μm and polyethylene plastic film with a thickness of 10-80 μm, use chemical solvent to clean and decontaminate the composite shaped aluminum foil, and perform corona treatment on the surface of the plastic film;

[0054] S3, evenly coating the adhesive on each layer of plastic film, removing the chemical solvent through a drying device after coating, and preliminarily curing the adhesive;

[0055] S4. Compound and shape the cured plastic film, the aluminum foil surface and the PTFE film using a hot press to generate a flexible insulating aluminum-plastic film.

[0056] In the specific production process, the aluminum foil and PTFE film are required to have clean and oil-free surfaces. The hot pressing temperature and pressure of the hot pressing machine are required to be 300-400℃ and 0.5-2MPa respectively, and the time is usually 1-5 minutes. After the hot pressing is completed, the material is cooled and shaped, and the cooling roller is used to shape the material to ensure that the material is flat and has no deformation.

[0057] When selecting the plastic film layer, the outer layer of nylon should take into account wear resistance and puncture resistance, while the inner PE layer only needs to have flexibility. Polyurethane glue or acrylic glue is usually used to compound the various layers of materials.

[0058] Aluminum foil cleaning usually uses chemical solvents or ultrasonic cleaning equipment to remove oil and oxide layers on the surface of the foil to ensure that the surface of the foil is clean and improve the bonding effect. For plastic films, the surface needs to be corona treated to increase surface energy and enhance bonding strength.

[0059] The method of applying adhesive on plastic film is determined according to the specific needs, mainly including the following:

[0060] Roller coating: The adhesive is evenly applied on the material surface by a coating roller;

[0061] Spraying: Use spraying equipment to atomize the adhesive and then spray it on the material surface;

[0062] Scraping: Use a scraper to evenly apply the adhesive on the surface of the material.

[0063] After coating is completed, it is cured and then the composite process is performed. The hot pressing temperature of the plastic film and the aluminum foil surface and the hot pressing temperature of the PTFE film are 100-150°C and the pressure is 0.5-1.5Mpa to ensure that each layer is tightly combined. Each layer needs to be cooled and shaped after compounding to ensure that the material is flat and without deformation. Finally, the composite material is placed in the curing chamber to completely cure the adhesive. In this embodiment, the curing temperature is set to 50-80°C and the curing time is 24-48 hours. After curing, the bonding strength between the layers of material is significantly improved.

[0064] In some embodiments, after the size of the vacuum plate is determined, a slitting machine is required to slit the wide aluminum-plastic film into the width required by the customer, and the slitting accuracy must be controlled within ±0.1mm. Optional quality inspection is also required, including:

[0065] Thickness testing: Use a thickness gauge to ensure uniform thickness of each layer.

[0066] Adhesion strength test: Use a tensile testing machine to test the bonding strength between the layers.

[0067] Barrier performance test: detect water vapor and oxygen transmission rates to ensure that the barrier performance meets the standards.

[0068] Appearance inspection: Ensure there are no defects such as scratches, bubbles, impurities, etc.

[0069] This specific embodiment is merely an explanation of the present invention and is not a limitation of the present invention. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed. However, as long as they are within the scope of the claims of the present invention, they are protected by the patent law.

Claims

1. An electrostatic vacuum plate structure, characterized in that: It includes an upper vacuum plate and a lower vacuum plate, the space between the two vacuum plates is in a vacuum state to form a vacuum cavity, and both ends of the vacuum cavity are heat-sealed; The upper vacuum plate, the lower vacuum plate and the edge seals at both ends are laminated with a flexible insulating aluminum-plastic film containing a polytetrafluoroethylene (PTFE) layer; inner aluminum foils are respectively pasted on the upper vacuum plate and the lower vacuum plate inside the vacuum cavity, and the two inner aluminum foils induce the same negative static electricity, which resists the external air pressure through electrostatic repulsion, thereby maintaining the thickness of the vacuum cavity at a preset size.

2. The electrostatic vacuum panel structure according to claim 1, characterized in that: The insulating aluminum-plastic film comprises, in layers, an outer nylon protective layer, an upper adhesive film layer, an aluminum foil layer, a PTFE insulating layer, a lower adhesive film layer, and an inner polyethylene PE layer; The upper adhesive film layer is adhered to the outer nylon protective layer and the aluminum foil layer, and the lower adhesive film layer is adhered to the PTFE insulating layer and the inner PE layer. The PTFE insulating layer isolates the aluminum foil layer and the inner PE layer.

3. The electrostatic vacuum panel structure according to claim 2, characterized in that: The thickness of the PTFE insulation layer is 2-4 μm, the thickness of the aluminum foil layer is 7-15 μm; the thickness of the inner PE is 10-80 μm; the thickness of the inner aluminum foil is 1-10 μm; The upper adhesive film layer and the lower adhesive film layer are polyurethane adhesive or acrylic adhesive.

4. The electrostatic vacuum panel structure according to claim 1, characterized in that: The size of the inner aluminum foil inside the vacuum cavity is smaller than the size of the upper and lower vacuum plates, and the inner aluminum foil does not contact the edge sealing position.

5. The electrostatic vacuum panel structure according to claim 4, characterized in that: A getter is arranged inside the vacuum cavity near the edge sealing position, and the thickness of the electrostatic vacuum plate maintained by electrostatic repulsion does not exceed 0.5 mm.

6. A filled electrostatic vacuum panel, characterized in that: It includes an upper vacuum plate and a lower vacuum plate, the space between the two vacuum plates is in a vacuum state to form a vacuum cavity, and heat-sealed edges are performed at both ends of the vacuum cavity; The upper vacuum plate, the lower vacuum plate and the edge seals at both ends are laminated with a flexible insulating aluminum-plastic film containing a polytetrafluoroethylene (PTFE) layer; The core material is filled in the vacuum cavity, and negative static electricity of the same polarity is induced on the contact surfaces between the core material and the upper and lower vacuum plates.

7. The filled electrostatic vacuum panel according to claim 6, characterized in that: The core material comprises at least one of glass fiber, basalt fiber, ceramic fiber, fumed silica, and polyurethane foam; The thickness of the electrostatic vacuum plate after filling the core material and maintaining it by electrostatic repulsion does not exceed 0.5 mm.

8. A method for producing a flexible aluminum-plastic film, characterized in that: The method comprises: Prepare an aluminum foil with a thickness of 7-15 μm and a PTFE film with a thickness of 2-4 μm, and after degreasing and cleaning, compound and shape the PTFE film and the aluminum foil coated with an adhesive through a hot press; Prepare nylon with a thickness of 12-100 μm and polyethylene plastic film with a thickness of 10-80 μm, use chemical solvent to clean and decontaminate the composite shaped aluminum foil, and perform corona treatment on the surface of the plastic film; The adhesive is evenly coated on each layer of plastic film, and after coating, the chemical solvent is removed through a drying device to initially solidify the adhesive; The cured plastic film is compounded and shaped with the aluminum foil surface and the PTFE film using a hot press to generate a flexible insulating aluminum-plastic film.

9. The method for producing a flexible aluminum-plastic film according to claim 8, characterized in that: The hot pressing temperature of aluminum foil and PTFE film is 300-400℃ and the pressure is 0.5-2MPa; The hot pressing temperature of the plastic film and the aluminum foil surface, as well as the hot pressing temperature of the plastic film and the PTFE film is 100-150°C and the pressure is 0.5-1.5Mpa.

10. The method for producing a flexible aluminum-plastic film according to claim 8, characterized in that: The curing temperature after compounding is set to 50-80°C and the curing time is 24-48 hours.

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