Packaging adhesive film and preparation method and application thereof
By introducing a water-blocking zone and an oxygen-blocking zone into the encapsulant film, dual barriers to water vapor and oxygen are achieved, solving the problems of encapsulant film aging and adhesive overflow, and improving the lifespan and production efficiency of photovoltaic modules.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-10
- Publication Date
- 2026-04-07
AI Technical Summary
Existing double-glass photovoltaic module encapsulant films have poor water vapor barrier performance, are prone to aging, and are prone to adhesive overflow during lamination, leading to module warping and increased production costs.
Design an encapsulation film comprising a central filling region, a water-blocking region, an oxygen-blocking region, and an edge filling region along the TD direction. Through the synergistic effect of the water-blocking region and the oxygen-blocking region, a dual barrier of water vapor and oxygen is achieved. The high-melting-point material of the oxygen-blocking region provides stable support during the lamination process, reducing adhesive overflow.
It significantly improves the outdoor operating life and structural stability of photovoltaic modules, reduces production costs, simplifies the production process, and enhances the impact resistance and long-term operational stability of the modules.
Smart Images
Figure CN121801484A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of encapsulation film technology, and relates to an encapsulation film, and more particularly to an encapsulation film, its preparation method and application. Background Technology
[0002] Currently, double-glass photovoltaic modules have become the preferred encapsulation method for ground-mounted power plants and distributed photovoltaic applications due to their excellent weather resistance, resistance to potential-induced degradation (PID), and longer design life. The core encapsulation logic utilizes the high strength and high light transmittance of the front and back glass to encapsulate the solar cells, and then uses an encapsulating film to fill the gaps between the cells and the glass, achieving a tight bond between the three and ultimately forming a structurally stable module capable of withstanding complex outdoor environments.
[0003] Currently, the commonly used encapsulant film combinations for double-glass modules in the industry are double EVA, EPE+EVA, or POE+EVA. The core consideration of these solutions is that EVA encapsulant film has good adhesion performance, processing fluidity, and cost advantages, which can meet the needs of large-scale mass production. However, EVA material itself has poor water vapor barrier performance and is prone to hydrolysis and aging in long-term outdoor environments, resulting in a decrease in adhesion.
[0004] Furthermore, the existing solutions have relatively simple structural designs and a single barrier function, failing to consider the lamination process requirements during module production. Conventional encapsulants are prone to melting and flowing during lamination, leading to excessive overflow of the encapsulant at the edges, making it difficult to ensure uniform edge thickness. This necessitates the use of additional metal lamination frames for restraint, which not only increases production costs but also easily causes module warping later due to the difference in thermal expansion coefficients between the lamination frames and the encapsulant. Summary of the Invention
[0005] In view of the shortcomings of the existing technology, the purpose of this invention is to provide an encapsulating film, its preparation method and application, which achieves dual barrier of water vapor and oxygen, while reducing edge overflow and simplifying the production process.
[0006] To achieve this objective, the present invention adopts the following technical solution:
[0007] In a first aspect, the present invention provides an encapsulating film, wherein along the TD direction of the encapsulating film, the encapsulating film includes a central filling area and a water-blocking area, an oxygen-blocking area, and an edge filling area disposed sequentially on both sides of the central filling area from the inside to the outside.
[0008] The material melting point of the oxygen barrier zone is higher than that of the material melting point of the central filling zone, the water barrier zone, and the edge filling zone.
[0009] In the field of film manufacturing, MD (Machine Direction) specifically refers to the direction in which the film travels along the production line, that is, the direction in which the film moves forward during the extrusion, stretching, and winding processes. In this invention, TD (Transverse Direction) specifically refers to the direction perpendicular to the MD direction, that is, the width direction of the film.
[0010] The encapsulating film provided by this invention achieves dual barrier of water vapor and oxygen through the synergistic effect of the water-blocking zone and the oxygen-blocking zone, cutting off the synergistic aging path of water, oxygen and ultraviolet rays, significantly reducing the aging rate of the material in the central filling zone, and improving the outdoor operating life of photovoltaic modules.
[0011] Furthermore, the high-melting-point material in the oxygen barrier zone provides stable support during lamination, effectively reducing edge adhesive overflow and ensuring uniform thickness at the module edges. This eliminates the need for an additional lamination frame, simplifying the production process. The composite barrier structure in each region effectively ensures the structural integrity of the encapsulated module. The synergistic bonding between the edge barrier zone and the central filling zone significantly improves the module's impact resistance and long-term operational stability, balancing economic efficiency and practicality.
[0012] Preferably, the central filling area accounts for ≥50% of the total area of the encapsulating film.
[0013] Preferably, the water-blocking area accounts for 1%-10% of the total area of the encapsulating film.
[0014] Preferably, the oxygen barrier region accounts for 1%-10% of the total area of the encapsulating film.
[0015] Preferably, the edge filling area accounts for 2%-10% of the total area of the encapsulating film.
[0016] Preferably, the material of the central filling region includes at least one of ethylene-vinyl acetate copolymer or polyolefin elastomer, and more preferably ethylene-vinyl acetate copolymer.
[0017] Preferably, the material of the water-blocking zone includes at least one of polyolefin elastomer, butyl rubber, or high-density polyethylene, and more preferably polyolefin elastomer, specifically including ethylene-butene copolymer elastomer or ethylene-octene copolymer elastomer.
[0018] Preferably, the material of the edge filling area includes ethylene-vinyl acetate copolymer or polyolefin elastomer.
[0019] Preferably, the material of the oxygen barrier region has a melting point ≥150℃.
[0020] Preferably, the material of the oxygen barrier region includes at least one of ethylene-vinyl alcohol copolymer, butyl rubber, modified polypropylene, thermoplastic polyolefin, polyethylene terephthalate, polyvinylidene chloride, or polyamide, and more preferably ethylene-vinyl alcohol copolymer.
[0021] Preferably, the shape of the oxygen barrier region includes a strip shape, a polyhedron shape, or a square shape.
[0022] In a second aspect, the present invention provides a method for preparing an encapsulating film as described in the first aspect, comprising the following steps:
[0023] (1) Prepare the central filling zone mixture and the edge barrier zone mixture separately;
[0024] (2) The mixture obtained in step (1) is extruded through three sets of co-extrusion dies to obtain a soft film, and the soft film includes a central filling area and edge barrier areas disposed on both sides of the central filling area.
[0025] (3) An oxygen barrier support structure is prepared by a twin-screw extruder. Then, the obtained oxygen barrier support structure is pressed and embedded into the edge barrier area during the extrusion and casting stage of the soft film in step (2). After cooling and curing, it is cut to obtain the encapsulation film.
[0026] The edge barrier area, after being pressurized and embedded in the oxygen barrier support structure, consists of a water barrier area, an oxygen barrier area, and an edge filling area arranged sequentially from the inside to the outside.
[0027] Preferably, the central filling zone mixture in step (1) includes ethylene-vinyl acetate copolymer and additives.
[0028] Preferably, the edge barrier mixture in step (1) includes a polyolefin elastomer and additives.
[0029] Preferably, the extrusion temperature of the co-extrusion die in step (2) is 70-95℃.
[0030] Preferably, the area ratio of the central filling area and the edge barrier area in step (2) is adjusted by the feeding rate of the corresponding mixture.
[0031] Preferably, the extrusion temperature of the oxygen barrier support structure in step (3) is 150-240℃.
[0032] Preferably, the shape of the oxygen barrier support structure in step (3) includes a strip shape, a polyhedron shape, or a square shape.
[0033] Thirdly, the present invention provides an application of the encapsulating film as described in the first aspect, the encapsulating film being used to encapsulate a double-glass photovoltaic module.
[0034] Compared with the prior art, the present invention has the following beneficial effects:
[0035] (1) The encapsulating film provided by the present invention achieves dual barrier of water vapor and oxygen through the synergistic effect of the water-blocking area and the oxygen-blocking area, cuts off the synergistic aging path of water, oxygen and ultraviolet rays, significantly reduces the aging rate of the material in the central filling area, and improves the outdoor operating life of photovoltaic modules.
[0036] (2) The high-melting-point material in the oxygen barrier zone provides stable support during the lamination process, effectively reducing the amount of adhesive overflow at the edges and ensuring the uniformity of the module edge thickness. No additional lamination frame is required, simplifying the production process. The composite barrier structure in each area effectively ensures the structural integrity of the module after encapsulation. The synergistic bonding effect between the edge barrier zone and the central filling zone significantly improves the module's impact resistance and long-term operational stability, taking into account both economy and practicality. Attached Figure Description
[0037] Figure 1 This is a schematic diagram of the encapsulation film provided in Example 1.
[0038] Figure 2 This is a cross-sectional structural diagram of the encapsulating film provided in Example 1.
[0039] Figure 3 This is a flowchart of the encapsulation film preparation process provided in Example 1.
[0040] Figure 4 This is a schematic diagram of the encapsulation film provided in Example 2.
[0041] Figure 5 This is a schematic diagram of the encapsulation film provided in Example 3.
[0042] Wherein: 1-Central filling zone; 2-Water blocking zone; 3-Oxygen blocking zone; 4-Edge filling zone; 5-Edge barrier zone. Detailed Implementation
[0043] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.
[0044] One embodiment of the present invention provides an encapsulating film. Along the TD direction of the encapsulating film, the encapsulating film includes a central filling area and a water-blocking area, an oxygen-blocking area, and an edge filling area disposed sequentially on both sides of the central filling area from the inside to the outside.
[0045] The material melting point of the oxygen barrier zone is higher than that of the material melting point of the central filling zone, the water barrier zone, and the edge filling zone.
[0046] In the field of film manufacturing, MD (Machine Direction) specifically refers to the direction in which the film travels along the production line, that is, the direction in which the film moves forward during the extrusion, stretching, and winding processes. In this invention, TD (Transverse Direction) specifically refers to the direction perpendicular to the MD direction, that is, the width direction of the film.
[0047] The encapsulating film provided by this invention achieves dual barrier of water vapor and oxygen through the synergistic effect of the water-blocking zone and the oxygen-blocking zone, cutting off the synergistic aging path of water, oxygen and ultraviolet rays, significantly reducing the aging rate of the material in the central filling zone, and improving the outdoor operating life of photovoltaic modules.
[0048] Furthermore, the high-melting-point material in the oxygen barrier zone provides stable support during lamination, effectively reducing edge adhesive overflow and ensuring uniform thickness at the module edges. This eliminates the need for an additional lamination frame, simplifying the production process. The composite barrier structure in each region effectively ensures the structural integrity of the encapsulated module. The synergistic bonding between the edge barrier zone and the central filling zone significantly improves the module's impact resistance and long-term operational stability, balancing economic efficiency and practicality.
[0049] In some embodiments, the central filling area accounts for ≥50% of the total area of the encapsulating film, for example, it can be 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90% or 95%, but is not limited to the listed values, and other unlisted values within this range are also applicable.
[0050] In some embodiments, the water-blocking area accounts for 1%-10% of the total area of the encapsulating film, for example, it can be 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9% or 10%, but is not limited to the listed values. Other unlisted values within this range are also applicable.
[0051] In some embodiments, the oxygen barrier region accounts for 1%-10% of the total area of the encapsulating film, for example, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9% or 10%, but is not limited to the listed values. Other unlisted values within this range are also applicable.
[0052] In some embodiments, the edge filling area accounts for 2%-10% of the total area of the encapsulating film, for example, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9% or 10%, but is not limited to the listed values. Other unlisted values within this range are also applicable.
[0053] This invention maintains a high area ratio in the central filling area, which serves as the main material, and precisely controls the area ratio of the barrier area. While ensuring barrier performance, it avoids over-reliance on expensive materials, thus achieving a good balance between economy and practicality.
[0054] In some embodiments, the material of the central filling area includes at least one of ethylene-vinyl acetate copolymer or polyolefin elastomer, more preferably ethylene-vinyl acetate copolymer. The above materials have the characteristics of easy processing, low cost and good adhesion performance, and mainly play the role of bonding the battery cell to the glass and filling the excess space between the battery cell and the glass.
[0055] In some embodiments, the material of the water-blocking zone includes at least one of polyolefin elastomer, butyl rubber, or high-density polyethylene, and is more preferably a polyolefin elastomer, specifically including ethylene-butene copolymer elastomer or ethylene-octene copolymer elastomer, which mainly serves to block water vapor.
[0056] As a preferred technical solution of the present invention, the material of the central filling area is ethylene-vinyl acetate copolymer, and the material of the water-blocking area is polyolefin elastomer, that is, a composite barrier structure of POE+EVA+POE (PEP) is formed. By means of the water vapor barrier capability of POE material, the edge water-blocking of the encapsulation film is achieved.
[0057] Furthermore, in the traditional EVA+POE+EVA (EPE) composite barrier structure, the POE region has limited space for thinning, and the performance of POE is significantly affected by its thickness, requiring a certain thickness to be maintained. In contrast, the POE region in the PEP composite barrier structure defined in this invention does not have the problem of thinning; only the width needs to be adjusted, which can greatly reduce the amount of POE used while still achieving a good water-blocking effect.
[0058] In some embodiments, the material of the edge filling area includes ethylene-vinyl acetate copolymer or polyolefin elastomer, which mainly serves to fill and bond, effectively ensuring the integrity of the component structure.
[0059] In some embodiments, the material of the oxygen barrier region has a melting point ≥150°C, such as 150°C, 160°C, 170°C, 180°C, 190°C, 200°C, 210°C, 220°C, 230°C or 240°C, but is not limited to the listed values. Other unlisted values within this range are also applicable.
[0060] In some embodiments, the material of the oxygen barrier region includes at least one of ethylene-vinyl alcohol copolymer, butyl rubber, modified polypropylene, thermoplastic polyolefin, polyethylene terephthalate, polyvinylidene chloride, or polyamide, and is more preferably ethylene-vinyl alcohol copolymer. Its main functions are oxygen barrier, structural support, and reducing edge film overflow during the lamination stage, thereby ensuring edge thickness.
[0061] In some embodiments, the shape of the oxygen barrier region includes an elongated strip, a polyhedral shape, or a U-shaped shape.
[0062] One embodiment of the present invention also provides a method for preparing the encapsulating film described in any of the above embodiments, comprising the following steps:
[0063] (1) Prepare the central filling zone mixture and the edge barrier zone mixture separately;
[0064] (2) The mixture obtained in step (1) is extruded through three sets of co-extrusion dies to obtain a soft film, and the soft film includes a central filling area and edge barrier areas disposed on both sides of the central filling area.
[0065] (3) An oxygen barrier support structure is prepared by a twin-screw extruder. Then, the obtained oxygen barrier support structure is pressed and embedded into the edge barrier area during the extrusion and casting stage of the soft film in step (2). After cooling and curing, it is cut to obtain the encapsulation film.
[0066] The edge barrier area, after being pressurized and embedded in the oxygen barrier support structure, consists of a water barrier area, an oxygen barrier area, and an edge filling area arranged sequentially from the inside to the outside.
[0067] In some embodiments, the central filling zone mix in step (1) includes an ethylene-vinyl acetate copolymer and additives.
[0068] In some embodiments, the edge barrier compound in step (1) includes a polyolefin elastomer and additives.
[0069] In some embodiments, the extrusion temperature of the co-extrusion die in step (2) is 70-95°C, for example, it can be 70°C, 75°C, 80°C, 85°C, 90°C or 95°C, but is not limited to the listed values. Other unlisted values within this range are also applicable.
[0070] In some embodiments, the area ratio of the central filling area and the edge blocking area in step (2) is adjusted by the feeding rate of the corresponding mixture.
[0071] In some embodiments, the extrusion temperature of the oxygen barrier support structure in step (3) is 150-240°C, for example, it can be 150°C, 160°C, 170°C, 180°C, 190°C, 200°C, 210°C, 220°C, 230°C or 240°C, but is not limited to the listed values. Other unlisted values within this range are also applicable.
[0072] In some embodiments, the shape of the oxygen barrier support structure in step (3) includes a strip shape, a polyhedron shape, or a square shape.
[0073] One embodiment of the present invention also provides an application of the encapsulating film described in any of the above embodiments, wherein the encapsulating film is used to encapsulate a double-glass photovoltaic module.
[0074] The numerical range described in this invention includes not only the point values listed above, but also any point values within the numerical ranges not listed above. Due to space limitations and for the sake of brevity, this invention will not exhaustively list all the specific point values included in the range.
[0075] Example 1
[0076] This embodiment provides an encapsulating film and its preparation method, such as Figure 1 As shown, along the TD direction of the encapsulation film, the encapsulation film includes a central filling area and water-blocking area, oxygen-blocking area and edge filling area arranged sequentially on both sides of the central filling area from the inside to the outside.
[0077] In this embodiment, the central filling area is made of ethylene-vinyl acetate copolymer, accounting for 75% of the area; the water-blocking area and the edge filling area are both made of ethylene-butene copolymer elastomer, each accounting for 10% of the area; and the oxygen-blocking area is made of ethylene-vinyl alcohol copolymer, accounting for 5% of the area. The melting point of the ethylene-vinyl alcohol copolymer is 170±10℃, significantly higher than the melting point of the materials in the other areas.
[0078] Figure 2 This is a cross-sectional view of the encapsulating film, showing that each region is elongated.
[0079] The method for preparing the encapsulating film provided in this embodiment includes the following steps:
[0080] (1) Ethylene-vinyl acetate copolymer particles and additives are put into a reactor for mixing, and then put into a twin-screw extruder for kneading to obtain a central filling zone mixture; similarly, ethylene-butene copolymer elastomer particles and additives are put into a reactor for mixing, and then put into a twin-screw extruder for kneading to obtain an edge barrier zone mixture.
[0081] (2) The mixture obtained in step (1) is extruded through three sets of co-extrusion dies, and the extrusion temperature is controlled at 85°C. At the same time, the feeding rate of each mixture is adjusted to control the area ratio of different regions, so as to obtain a soft film. The soft film includes a central filling area and edge barrier areas set on both sides of the central filling area (see Figure 3 );
[0082] (3) Ethylene-vinyl alcohol copolymer is extruded through a twin-screw extruder at 170°C to obtain the following: Figure 3 The two oxygen barrier support structures shown are then pressed and embedded into the edge barrier area during the extrusion and casting stage of the soft adhesive film in step (2), forming a water barrier area, an oxygen barrier area and an edge filling area arranged sequentially from the inside to the outside. After cooling and curing, the film is cut to obtain the encapsulation film.
[0083] In this embodiment, the components of the additive in step (1) include a crosslinking agent, an antioxidant, a light stabilizer, and a coupling agent. The total mass of the corresponding mixture is used as the calculation basis. The crosslinking agent is 0.5 wt% triallyl isocyanurate, the antioxidant is 0.05 wt% methyl octadecyl alcohol-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, the light stabilizer is 0.1 wt% bis(1,2,2,6,6-pentamethylpiperidinol) sebacate, and the coupling agent is 0.25 wt% vinyltriethoxysilane. The above materials are dispersed and granulated in sequence to form a masterbatch, which is then put into a reaction vessel and mixed with the corresponding resin to obtain the corresponding mixture.
[0084] Example 2
[0085] This embodiment provides an encapsulating film and its preparation method, such as Figure 4 As shown, along the TD direction of the encapsulation film, the encapsulation film includes a central filling area and water-blocking area, oxygen-blocking area and edge filling area arranged sequentially on both sides of the central filling area from the inside to the outside.
[0086] The only difference between this embodiment and Embodiment 1 is that the water-blocking zone, oxygen-blocking zone, and edge-filling zone are all polyhedral in shape. All other conditions are the same as in Embodiment 1 and will not be repeated here.
[0087] Example 3
[0088] This embodiment provides an encapsulating film and its preparation method, such as Figure 4 As shown, along the TD direction of the encapsulation film, the encapsulation film includes a central filling area and a water-blocking area, an oxygen-blocking area, and an edge filling area arranged sequentially from the inside to the outside around the central filling area.
[0089] The difference between this embodiment and Embodiment 1 is only that: the shapes of the water blocking area, oxygen blocking area and edge filling area are all in the shape of a double-square character, and the other conditions are the same as those in Embodiment 1, which will not be elaborated here.
[0090] Performance Test
[0091] The encapsulation adhesive films obtained in Embodiments 1 to 3 were used to encapsulate TOPCon double-glass photovoltaic modules. The lamination temperature during the encapsulation process was 148 °C. Subsequently, through the damp heat accelerated aging test (long-term aging test under the conditions of 85 °C / 85% RH), no corrosion phenomenon of the solar cells in the edge and back glass opening areas of the modules occurred, and no edge glue overflow phenomenon occurred during the lamination process.
[0092] Thus, it can be seen that the encapsulation adhesive film provided by the present invention realizes the dual barrier of water vapor and oxygen through the synergistic effect of the water blocking area and the oxygen blocking area, cuts off the synergistic aging path of water, oxygen and ultraviolet rays, significantly reduces the aging rate of the materials in the central filling area, and improves the outdoor operation life of the photovoltaic module.
[0093] In addition, the high melting point material in the oxygen blocking area provides stable support during the lamination process, effectively reducing the amount of edge glue overflow, ensuring the thickness uniformity of the module edge, and eliminating the need for an additional lamination frame, thus simplifying the production process. The composite barrier structure in each area effectively guarantees the structural integrity of the encapsulated module. The synergistic bonding effect between the edge barrier area and the central filling area significantly improves the impact resistance and long-term operation stability of the module, taking into account both economy and practicality.
[0094] The above description is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention fall within the protection scope and public scope of the present invention.
Claims
1. An encapsulating film, characterized in that, Along the TD direction of the encapsulation film, the encapsulation film includes a central filling area and a water-blocking area, an oxygen-blocking area, and an edge filling area arranged sequentially from the inside to the outside on both sides of the central filling area; The material melting point of the oxygen barrier zone is higher than that of the material melting point of the central filling zone, the water barrier zone, and the edge filling zone.
2. The encapsulating film according to claim 1, characterized in that, The central filling area accounts for ≥50% of the total area of the encapsulating film; And / or, the water-blocking area accounts for 1%-10% of the total area of the encapsulating film; And / or, the oxygen barrier region accounts for 1%-10% of the total area of the encapsulating film; And / or, the edge filling area accounts for 2%-10% of the total area of the encapsulating film.
3. The encapsulating film according to claim 1 or 2, characterized in that, The material of the central filling region includes at least one of ethylene-vinyl acetate copolymer or polyolefin elastomer; And / or, the material of the water-blocking region includes at least one of polyolefin elastomer, butyl rubber or high-density polyethylene; And / or, the material of the edge filling area includes ethylene-vinyl acetate copolymer or polyolefin elastomer.
4. The encapsulating film according to claim 3, characterized in that, The material of the oxygen barrier region has a melting point ≥150℃; And / or, the material of the oxygen barrier region includes at least one of ethylene-vinyl alcohol copolymer, butyl rubber, modified polypropylene, thermoplastic polyolefin, polyethylene terephthalate, polyvinylidene chloride, or polyamide.
5. The encapsulating film according to claim 1 or 2, characterized in that, The shape of the oxygen barrier zone includes a strip shape, a polyhedron shape, or a square shape.
6. A method for preparing an encapsulating film as described in any one of claims 1-5, characterized in that, The preparation method includes the following steps: (1) Prepare the central filling zone mixture and the edge barrier zone mixture separately; (2) The mixture obtained in step (1) is extruded through three sets of co-extrusion dies to obtain a soft film, and the soft film includes a central filling area and edge barrier areas disposed on both sides of the central filling area. (3) An oxygen barrier support structure is prepared by a twin-screw extruder. Then, the obtained oxygen barrier support structure is pressed and embedded into the edge barrier area during the extrusion and casting stage of the soft film in step (2). After cooling and curing, it is cut to obtain the encapsulation film. The edge barrier area, after being pressurized and embedded in the oxygen barrier support structure, consists of a water barrier area, an oxygen barrier area, and an edge filling area arranged sequentially from the inside to the outside.
7. The method for preparing the encapsulating film according to claim 6, characterized in that, The central filling zone mixture in step (1) includes ethylene-vinyl acetate copolymer and additives; And / or, the edge barrier compound in step (1) includes a polyolefin elastomer and additives.
8. The method for preparing the encapsulating film according to claim 6, characterized in that, The extrusion temperature of the co-extrusion die in step (2) is 70-95℃; And / or, the area ratio of the central filling area and the edge blocking area in step (2) is adjusted by the feeding rate of the corresponding mixture.
9. The method for preparing the encapsulating film according to claim 6, characterized in that, The extrusion temperature of the oxygen barrier support structure in step (3) is 150-240℃; And / or, the shape of the oxygen barrier support structure in step (3) includes a strip shape, a polyhedron shape, or a square shape.
10. An application of the encapsulating film as described in any one of claims 1-5, characterized in that, The encapsulating film is used to encapsulate double-glass photovoltaic modules.