Multilayer composite high-reflection photovoltaic white film
By applying a multi-layer composite high-reflection photovoltaic white film on photovoltaic modules, the problem of difficulty in reducing the thickness of the back of the photovoltaic module and insufficient reflectivity of ordinary white films is solved, and the effect of high reflectivity and reduced production costs is achieved.
Patent Information
- Application Number
- CN202421340493.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-13
- Publication Date
- 2025-03-25
- Estimated Expiration
- 2034-06-13
AI Technical Summary
The thickness of the back glass on existing photovoltaic modules is difficult to further reduce, and the reflectivity and reliability of ordinary white films are insufficient, making it impossible to effectively increase the power of photovoltaic modules.
A multi-layer composite high-reflection photovoltaic white film, including a white reflective layer, a carrier layer, an ultra-high reflective layer and an adhesive layer, was prepared by vacuum aluminum plating and wet coating technology, and applied to the gaps, surrounding edges and back glass of the photovoltaic module cell.
The reflectivity of photovoltaic modules is improved to more than 85%, replacing the glaze plating process, reducing the glass thickness and production costs, and reducing the cost of white film.
Smart Images
Figure CN222674869U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of photovoltaics, in particular to a multi-layer composite high-reflection white film for photovoltaics. Background Art
[0002] Solar energy is a green and environmentally friendly renewable energy. With the increase of global population and the dependence and large-scale consumption of today's mainstream non-renewable fossil fuels, the world is not only worried about energy depletion, but also about environmental pollution. At the same time, there is an urgent need to develop new green and environmentally friendly renewable energy. Today, based on the principle of photovoltaics, single-crystal silicon and polycrystalline silicon photovoltaic cell components that use sunlight to generate power have become very mature.
[0003] In recent years, the photovoltaic industry has developed rapidly, industry requirements have continued to increase, and cost reduction and efficiency improvement have become the key tasks of major component manufacturers.
[0004] At present, the mainstream glass on the back of photovoltaic modules is white glazed glass. The white glaze reflects the sunlight between the cells to increase the module power; the white grid style also further beautifies the appearance of the module; however, with the demand of module manufacturers to reduce costs, the thickness of glass is getting thinner and thinner; but the self-explosion rate of glazed glass itself is higher than that of conventional glass, which limits the thinning of glass; the other is ordinary white film, which is mainly a glue layer and a carrier layer, with a relatively simple structure, poor reliability, and low power gain.
[0005] Therefore, it is necessary to provide a multi-layer composite high-reflection photovoltaic white film. Utility Model Content
[0006] The utility model provides a multi-layer composite high-reflection photovoltaic white film to solve the above technical problems.
[0007] In order to achieve the above-mentioned purpose, an embodiment of the utility model provides a multi-layer composite high-reflection white film for photovoltaics, which comprises in sequence: a white reflective layer 1, a carrier layer, an ultra-high reflective layer, a white reflective layer 2 and an adhesive layer, wherein the carrier layer has a first surface and a second surface, the white reflective layer 1 is bonded to the first surface, the ultra-high reflective layer is bonded to the second surface, the white reflective layer 2 is arranged on the other side of the ultra-high reflective layer, and the white film is applied between the gaps between the cell sheets of the photovoltaic module, on the edges around the photovoltaic module and on the back glass of the photovoltaic module.
[0008] Furthermore, the thickness of the adhesive layer is 60 μm to 120 μm.
[0009] Furthermore, the material of the adhesive layer is EVA and / or POE.
[0010] Furthermore, the thickness of the ultra-high reflective layer is 30nm to 100nm.
[0011] Furthermore, the material of the ultra-high reflective layer is aluminum.
[0012] Furthermore, the carrier layer has a thickness of 20 μm to 60 μm.
[0013] Furthermore, the material of the carrier layer is PET.
[0014] Furthermore, the PET is transparent or white.
[0015] Furthermore, the thickness of the first white reflective layer and the second white reflective layer is 4 μm to 12 μm.
[0016] Furthermore, the fillers of the first white reflective layer and the second white reflective layer are titanium dioxide.
[0017] Compared with the prior art, the beneficial effects of the utility model are:
[0018] 1. Compared with the white glazed glass and white film in the related art, the white film in this embodiment has a higher reflectivity, and the reflectivity reaches more than 85%;
[0019] 2. In addition, the reflectivity of the white film in the utility model can replace the glazing process, and the glass does not need to be glazed, so the thickness of the glass can be further reduced, thereby reducing the production cost;
[0020] 3. The cost of white film is lower than that of white glaze, which further reduces the cost of producing photovoltaic modules. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] The utility model is further described below in conjunction with the accompanying drawings and embodiments.
[0022] Figure 1 This is a structural diagram of an optimal embodiment of a multi-layer composite high-reflection photovoltaic white film of the utility model.
[0023] Among them, 1. White reflective layer 1; 2. Carrier layer; 3. Ultra-high reflective layer; 4. White reflective layer 2; 5. Adhesive layer. DETAILED DESCRIPTION
[0024] Now the utility model is further described in detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, which only illustrate the basic structure of the utility model in a schematic manner, and therefore only show the components related to the utility model.
[0025] See also Figure 1 , Figure 1This is a structural diagram of the optimal embodiment of a multi-layer composite high-reflection photovoltaic white film of the utility model. Figure 1 As shown, at least one embodiment provides a multi-layer composite high-reflection photovoltaic white film, which includes: a white reflective layer 1, a carrier layer 2, an ultra-high reflective layer 3, a white reflective layer 2 4 and an adhesive layer 5. The carrier layer 2 has a first surface and a second surface, the white reflective layer 1 is bonded to the first surface, the ultra-high reflective layer 3 is bonded to the second surface, and the white reflective layer 2 4 is arranged on the other side of the ultra-high reflective layer 3. The white film is applied between the gaps between the cells of the photovoltaic module, the edges around the photovoltaic module, and the back glass of the photovoltaic module.
[0026] The adhesive layer 5 is any one or a combination of EVA and POE, and a certain amount of crosslinking agent, coupling agent, auxiliary crosslinking agent, ultraviolet absorber, and antioxidant can also be added on this basis. The content of EVA or POE is 80% to 90%, the crosslinking agent is 0.1% to 2%, the coupling agent is 0.1% to 2%, the auxiliary crosslinking agent is 0.1% to 2%, the ultraviolet absorber is 0.1% to 1%, and the antioxidant is 0.1% to 1%. The material of the adhesive layer 5 is EVA and / or POE.
[0027] As shown in Table 1, Table 1 is a table showing the relationship between the thickness of the adhesive layer 5 and the peeling strength. As the thickness of the adhesive layer 5 increases, the peeling strength between the adhesive layer 5 and the glass increases. (The design requires that after lamination, the peeling strength between the adhesive layer 5 and the glass is greater than 12N / cm).
[0028]
[0029] Table 1
[0030] As shown in Table 1, the results show that when the thickness of the adhesive layer 5 is greater than 60 μm, the design requirements are met, and when it is greater than 100 μm, the peel strength does not increase significantly. Therefore, the design thickness is 60 μm to 120 μm.
[0031] The material of the ultra-high reflective layer 3 is aluminum. For details, please refer to Table 2, which is a relationship diagram between the reflective coating material and the reflectivity.
[0032]
[0033] Table 2
[0034] As can be seen from Table 2, several common high-reflective materials are coated on the PET surface for reflectivity testing. After testing, the reflectivity of metal aluminum is significantly higher than that of traditional reflective fillers. Therefore, the material of the ultra-high reflective layer 3 is aluminum.
[0035] Please refer to Table 3, which is a graph showing the relationship between the thickness of the aluminum layer and the reflectivity.
[0036]
[0037] Table 3
[0038] It can be seen from Table 3 that when the thickness of the ultra-high reflective layer, i.e. the aluminum layer, is greater than 30nm, the design required reflectivity is greater than 90%. When the aluminum plating layer is greater than 100nm, the emissivity does not increase significantly. Therefore, the ultra-high reflective layer thickness is designed to be 30nm to 100nm.
[0039] The material of the carrier layer 2 is PET. The PET is transparent or white. Please refer to Table 4, which is a graph showing the relationship between PET thickness and breaking force. (When the breaking force meets the requirements, it needs to be >5N)
[0040]
[0041] Table 4
[0042] It can be seen from Table 4 that when the carrier layer thickness is ≥25μm, it meets the customer's requirement of >5N. Considering the cost, the design thickness is 30μm to 60μm.
[0043] The white reflective layer includes a white reflective layer 1 and a white reflective layer 2 4, and the fillers of the white reflective layer 1 and the white reflective layer 2 4 are titanium dioxide. Specifically, the fillers of the white reflective layer 1 and the white reflective layer 2 4 are as follows: 70% to 90% of fluororesin, 0.1% to 5% of silicon dioxide, 0.1% to 5% of a curing agent and 0.1% to 5% of an anti-ultraviolet agent, 0.1% to 5% of a light stabilizer, and 0.8% to 1.2% of a white filler.
[0044] Please refer to Table 5, which is a graph showing the relationship between the thickness of the white reflective layer and the reflectivity of a single-layer white coating.
[0045]
[0046] Table 5
[0047] It can be seen from Table 5 that when the thickness is 4 μm, the single-layer reflectivity of the white reflective layer reaches the design requirement. Considering the operability and cost of the coating equipment, the thickness of the white reflective layer 1 and the white reflective layer 2 4 is 4 μm to 12 μm.
[0048] The above Figure 1 The method for preparing a multi-layer composite high-reflection photovoltaic white film shown comprises the following steps:
[0049] Step 1 Preparation of ultra-high reflective layer 3:
[0050] Through vacuum aluminum plating equipment, metal aluminum is vacuum plated onto the carrier layer 2 (PET) to obtain PET with an aluminum layer.
[0051] Step 2 Preparation of white reflective layer:
[0052] Component A: 90% of fluororesin, 0.2% of silicon dioxide, 1% of curing agent, 0.5% of anti-ultraviolet agent, 0.1% of light stabilizer, and 0.8% of titanium dioxide are mixed and stirred in a stirring kettle. The mixture is wet-coated on the first surface of the carrier layer 2 and the surface of the ultra-high reflective layer 3, and then heat-cured at 100-220°C to obtain the white reflective layer 1 and the white reflective layer 2.
[0053] Step 3 Preparation of bonding layer 5:
[0054] Adhesive layer 5 components: by weight, EVA resin 82.2%, crosslinking agent 0.7%, coupling agent 0.4%, auxiliary crosslinking agent 0.6%, UV absorber 0.5%, antioxidant 0.5% are weighed. The above components are mixed evenly in a stirring kettle, and the formula is melt-coated on the white reflective layer 2 by a single-screw coater.
[0055] After the above three steps, a multi-layer composite high-reflection photovoltaic white film can be produced.
[0056] Example 1
[0057] Aluminum is plated onto 40μm thick white PET through vacuum aluminum plating equipment, and the thickness of aluminum plating is 30nm. After aluminum plating, the substrate is subjected to a hundred-grid test to check the adhesion between the aluminum plating layer and PET. If it passes the test, it is placed for use.
[0058] 97.2% of fluororesin, 0.2% of silicon dioxide, 1% of curing agent, 0.5% of anti-ultraviolet agent, 0.2% of light stabilizer and 0.9% of titanium dioxide are mixed and stirred in a stirring kettle. The coating is applied on the aluminum-plated surface and the non-aluminum-plated surface of the carrier layer by wet method and then heat-cured at 100-220°C to obtain a coating thickness of 6 μm.
[0059] According to weight, 97.5% EVA resin, 0.7% crosslinking agent, 0.4% coupling agent, 0.6% crosslinking agent, 0.4% UV absorber, and 0.4% antioxidant are weighed. The above components are mixed evenly in a stirring kettle, and the formula is melt-coated on 2 by a single-screw coater, and coated on the white reflective layer close to the aluminum layer, with a thickness of 70 μm.
[0060] A multi-layer composite high-reflection photovoltaic white film was prepared, and the reflectivity (400nm-1100nm) was tested to be 88%, which met the design requirements.
[0061] Example 2
[0062] Aluminum is plated onto 25μm thick white PET through vacuum aluminum plating equipment, and the thickness of aluminum plating is 40nm. After aluminum plating, the substrate is subjected to a hundred-grid test to check the adhesion between the aluminum plating layer and PET. If it passes the test, it is placed for use.
[0063] 97.4% fluororesin, 0.2% silicon dioxide, 0.8% curing agent, 0.4% anti-ultraviolet agent, 0.2% light stabilizer and 1% titanium dioxide are mixed and stirred in a stirring kettle. The coating is applied on the aluminum-plated surface and the non-aluminum-plated surface of the carrier layer by wet method and then heat-cured at 100-220℃ to obtain a coating thickness of 8μm.
[0064] According to weight, 97.9% EVA resin, 0.5% crosslinking agent, 0.4% coupling agent, 0.4% crosslinking agent, 0.4% UV absorber, and 0.4% antioxidant are weighed. The above components are mixed evenly in a stirring kettle, and the formula is melt-coated on the white reflective layer close to the aluminum-plated surface of the carrier layer by a single-screw coater, and the coating thickness is 76 μm.
[0065] A multi-layer composite high-reflection photovoltaic white film was prepared, and the reflectivity (400nm-1100nm) was tested to be 89%, which met the design requirements.
[0066] Example 3
[0067] Aluminum is plated onto 50μm thick white PET through vacuum aluminum plating equipment, and the thickness of aluminum plating is 50nm. After aluminum plating, the substrate is subjected to a hundred-grid test to check the adhesion between the aluminum plating layer and PET. If it passes the test, it is placed for use.
[0068] 97.5% fluororesin, 0.2% silicon dioxide, 0.6% curing agent, 0.4% anti-ultraviolet agent, 0.2% light stabilizer, and 1.1% titanium dioxide are mixed and stirred in a stirring kettle. The coating is applied on the aluminum-plated surface and the non-aluminum-plated surface of the carrier layer by wet method, and then thermally cured at 100-220°C to obtain a coating thickness of 10 μm.
[0069] By weight, 97.9% EVA resin, 0.5% crosslinking agent, 0.4% coupling agent, 0.3% crosslinking agent, 0.5% UV absorber, and 0.4% antioxidant are weighed. The above components are mixed evenly in a stirring kettle, and the formula is melt-coated on the white weather-resistant layer 2 by a single-screw coater, with a coating thickness of 69μm. The multi-layer composite high-reflection photovoltaic white film is obtained, and the reflectivity (400nm-1100nm) is 91% after testing, which meets the design requirements.
[0070] To sum up, compared with the white glazed glass and white film in the related art, the white film in this embodiment has a higher reflectivity, and the reflectivity is above 85%; (the reflectivity of white glaze and conventional white film is less than 80%); in addition, the reflectivity in this embodiment can replace the glazing process, so that the glass does not need to be glazed, and the thickness of the glass can be further reduced, thereby reducing the production cost; and the cost of the white film is lower than that of the white glaze, which further reduces the cost of producing photovoltaic modules.
[0071] Based on the above ideal embodiments of the utility model, the relevant staff can make various changes and modifications without deviating from the technical concept of the utility model through the above description. The technical scope of the utility model is not limited to the content of the specification, and its technical scope must be determined according to the scope of the claims.
Claims
1. A multi-layer composite high-reflection photovoltaic white film, characterized in that: Including in order: A white reflective layer 1 (1), a carrier layer (2), an ultra-high reflective layer (3), a white reflective layer 2 (4) and an adhesive layer (5), wherein the carrier layer (2) has a first surface and a second surface, the white reflective layer 1 (1) is bonded to the first surface, the ultra-high reflective layer (3) is bonded to the second surface, the white reflective layer 2 (4) is arranged on the other side of the ultra-high reflective layer (3), and the white film is applied between the gaps between the cell sheets of a photovoltaic module, the edges around the photovoltaic module and the back glass of the photovoltaic module.
2. A multi-layer composite high-reflection photovoltaic white film as claimed in claim 1, characterized in that: The thickness of the adhesive layer (5) is 60 μm to 120 μm.
3. The multi-layer composite high-reflection photovoltaic white film according to claim 1, characterized in that: The material of the adhesive layer (5) is EVA and / or POE.
4. The multi-layer composite high-reflection photovoltaic white film according to claim 1, characterized in that: The thickness of the ultra-high reflective layer (3) is 30nm-100nm.
5. The multi-layer composite high-reflection photovoltaic white film according to claim 1, characterized in that: The material of the ultra-high reflective layer (3) is aluminum.
6. The multi-layer composite high-reflection photovoltaic white film according to claim 1, characterized in that: The thickness of the carrier layer (2) is 20 μm to 60 μm.
7. The multi-layer composite high-reflection photovoltaic white film according to claim 1, characterized in that: The material of the carrier layer (2) is PET.
8. The multi-layer composite high-reflection photovoltaic white film according to claim 7, characterized in that: The PET is transparent or white.
9. The multi-layer composite high-reflection photovoltaic white film according to claim 1, characterized in that: The thickness of the white reflective layer 1 (1) and the white reflective layer 2 (4) is 4 μm to 12 μm.
10. The multi-layer composite high-reflection photovoltaic white film according to claim 1, characterized in that: The fillers of the first white reflective layer (1) and the second white reflective layer (4) are titanium dioxide.