Packaging adhesive film and photovoltaic module
By using a composite co-extrusion process with textured patterns in the infrared light transmitting layer and the reflective layer, the problems of film wrinkles and low module performance in the production of black photovoltaic modules have been solved, resulting in increased module power, reduced temperature, and improved appearance.
Patent Information
- Application Number
- CN202520089188.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-15
- Publication Date
- 2026-01-27
- Estimated Expiration
- 2035-01-15
AI Technical Summary
Existing black photovoltaic modules are prone to problems such as encapsulant film wrinkles, whitening and graying on the outside, and blackening and graying on the back during the production process. In addition, the modules have low initial power and high operating temperature.
An infrared light transmitting layer and an infrared light reflecting layer are stacked together. The surface of the infrared light transmitting layer is provided with a first embossed pattern, and the surface of the infrared light reflecting layer is provided with a second embossed pattern. The composite co-extrusion process prevents the film from penetrating the layers and increases light absorption to improve blackness.
It effectively prevents film penetration, increases the initial power of photovoltaic modules and reduces operating temperature, while also improving the aesthetic appearance of the modules.
Smart Images
Figure CN223844156U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of photovoltaic encapsulant technology, and more specifically, to an encapsulating encapsulant and a photovoltaic module. Background Technology
[0002] With the rapid development of photovoltaic (PV) power generation technology and applications, Building Integrated Photovoltaics (BIPV), as the intersection of the building and PV markets, has broad development prospects. The integration of PV with buildings is one of the most important areas of future PV applications, possessing enormous market potential. PV modules installed on industrial and commercial building rooftops often have aesthetic and light pollution prevention requirements, typically using black PV modules. However, black PV modules not only have high operating temperatures but also lower initial power output. To address the issues of low initial power output and high operating temperature, most systems now employ a double-layer composite structure: one layer uses infrared-transmitting pigments, and the other uses infrared-reflecting pigments. This significantly reduces the module's operating temperature, and due to the high reflectivity in the infrared band, the PV module's power output can be increased by approximately 3-5%.
[0003] However, the aforementioned double-layer composite structure has high requirements for the production process. The double-layer co-extrusion structure is prone to film wrinkles at the lamination end due to uneven basis weight, resulting in white and gray overflow on the front and black and gray overflow on the back, which seriously affects the appearance of the module. In addition, the infrared light-transmitting films are all pre-crosslinked films with high hardness. During the lamination process, if the heating temperature of the upper chamber of the laminator is too high, it will cause the top cover to deform. Therefore, the temperature of the upper chamber of the laminator will be lower than that of the lower chamber. During lamination, the infrared light-transmitting film layer will soften first and have good fluidity, while the infrared light-reflecting film layer is still in a stage of poor fluidity. The combination of soft and hard films and uneven thickness may increase the probability of interpenetration. Utility Model Content
[0004] This invention provides an encapsulating film and a photovoltaic module, which can prevent the phenomenon of layer penetration and increase light absorption, thereby increasing the blackness of the encapsulating film.
[0005] The embodiments of this utility model can be implemented as follows:
[0006] An embodiment of this utility model provides an encapsulating film, comprising:
[0007] An infrared light transmitting layer and an infrared light reflecting layer are stacked together, and the surface of the infrared light transmitting layer away from the infrared light reflecting layer is provided with a first embossed pattern; the infrared light transmitting layer and the infrared light reflecting layer are co-extruded together.
[0008] In an optional embodiment, the first embossed pattern includes a plurality of first protrusions and a plurality of first recesses, wherein the plurality of first protrusions are spaced apart and a first recess is formed between two adjacent first protrusions.
[0009] In an optional embodiment, the surface of the infrared light reflecting layer away from the infrared light transmitting layer is provided with a second embossed pattern, the second embossed pattern being provided corresponding to the first embossed pattern; and the recess depth of the second embossed pattern is less than the recess depth of the first embossed pattern.
[0010] In an optional embodiment, the depth of the first embossed pattern is 25 μm to 100 μm deeper than the depth of the second embossed pattern.
[0011] In an optional embodiment, the second embossed pattern includes a plurality of second protrusions and a plurality of second recesses, the plurality of second protrusions being spaced apart, and a second recess being formed between two adjacent second protrusions; the plurality of first protrusions and the plurality of second protrusions are arranged in a one-to-one correspondence.
[0012] In an optional embodiment, the depth of the first recess is 150 μm to 200 μm; the depth of the second recess is 100 μm to 200 μm.
[0013] In an optional embodiment, the first protrusion and the second protrusion have the same width.
[0014] In an optional embodiment, the width of both the first protrusion and the second protrusion is 50μm to 150μm.
[0015] In optional embodiments, the first embossed pattern includes one or more of the following: triangular pyramidal embossed pattern, quadrilateral embossed pattern, spherical embossed pattern, and prism embossed pattern; and / or, the second embossed pattern includes one or more of the following: triangular pyramidal embossed pattern, quadrilateral embossed pattern, spherical embossed pattern, and prism embossed pattern.
[0016] An embodiment of this utility model also provides a photovoltaic module, including the encapsulating film described in any of the above embodiments.
[0017] The beneficial effects of the encapsulating film and photovoltaic module of this utility model embodiment include, for example:
[0018] This photovoltaic module includes a stacked infrared light transmitting layer and an infrared light reflecting layer. The surface of the infrared light transmitting layer away from the infrared light reflecting layer has a first embossed pattern. The infrared light transmitting layer and the infrared light reflecting layer are co-extruded. The infrared light reflecting layer controls the wavelength range, preventing heat loss or excessive heat ingress; the infrared light transmitting layer enhances the system's response to specific infrared bands, helps control heat flow, and protects the internal structure from external high-intensity infrared radiation. Combining the infrared light transmitting layer and the infrared light reflecting layer effectively improves the problems of low initial power and high operating temperature in photovoltaic modules. Because the infrared light transmitting layer has higher fluidity than the infrared light reflecting layer, by creating the first embossed pattern on the surface of the infrared light transmitting layer away from the infrared light reflecting layer, during lamination, the adhesive film at the raised areas of the infrared light transmitting layer flows to the recessed areas, avoiding or reducing the phenomenon of layer penetration caused by the infrared light reflecting layer being squeezed due to the high fluidity of the infrared light transmitting layer. Attached Figure Description
[0019] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this utility model and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.
[0020] Figure 1 This is a schematic diagram of the encapsulating film provided in an embodiment of the present invention;
[0021] Figure 2 This is a schematic diagram of the encapsulating film layer after co-extrusion in an embodiment of this utility model.
[0022] Icons: 1000 - Encapsulation film; 100 - Infrared light transmission layer; 110 - First embossed pattern; 111 - First protrusion; 112 - First depression; 200 - Infrared light reflection layer; 120 - Second embossed pattern; 121 - Second protrusion; 122 - Second depression. Detailed Implementation
[0023] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. The components of the embodiments of this utility model described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.
[0024] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.
[0025] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.
[0026] In the description of this utility model, it should be noted that if terms such as "upper," "lower," "inner," or "outer" are used to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the utility model product is usually placed during use, they are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.
[0027] Furthermore, the terms "first" and "second" are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.
[0028] It should be noted that, where there is no conflict, the features in the embodiments of this utility model can be combined with each other.
[0029] With the rapid development of photovoltaic (PV) power generation technology and applications, Building Integrated Photovoltaics (BIPV), as the intersection of the building and PV markets, has broad development prospects. The integration of PV with buildings is one of the most important areas of future PV applications, possessing enormous market potential. PV modules installed on industrial and commercial building rooftops often have aesthetic and anti-light pollution requirements, therefore black PV modules are typically used. Conventional black encapsulation films use carbon black as pigment, achieving the required blackness. However, carbon black is a full-spectrum absorber, resulting in higher operating temperatures and lower initial power compared to conventional transparent modules of the same size. To address the issues of low initial power and high operating temperature, most systems now employ a black-white dual-layer composite structure. One layer uses infrared-transmitting black pigment, and the other uses infrared-reflective white pigment. This not only achieves a completely black module but also significantly reduces operating temperature. Due to the high infrared reflectivity, module power can be increased by approximately 3-5%.
[0030] However, the actual production process requires high-level technical control. The double-layer co-extrusion structure is prone to film wrinkles at the lamination end due to uneven basis weight, resulting in white and gray overflow on the front and black and gray overflow on the back, which seriously affects the appearance of the module. In addition, the black film is a pre-crosslinked film with high hardness. During the lamination process, if the heating temperature of the upper chamber of the laminator is too high, it will cause the top cover to deform. Therefore, the temperature of the upper chamber of the laminator will be lower than that of the lower chamber. During lamination, the black layer will soften first and have good fluidity, while the white film layer is still in a stage of poor fluidity. The combination of soft and hard film and uneven thickness may increase the probability of interpenetration.
[0031] Based on this, please refer to Figure 1 The encapsulating film 1000 provided in the embodiments of this utility model can effectively improve the aforementioned technical problems. The encapsulating film 1000 can prevent delamination and increase light absorption, thereby increasing the blackness of the encapsulating film 1000. The encapsulating film 1000 is applied to photovoltaic modules, and photovoltaic modules with the encapsulating film 1000 have the same functions as described above, which will not be elaborated further here.
[0032] The photovoltaic module in this embodiment includes stacked photovoltaic glass, encapsulating film 1000, solar cells, encapsulating film 1000, and a photovoltaic backsheet. The encapsulating film 1000, as one of the materials in the photovoltaic module, primarily functions to bond the photovoltaic cells, photovoltaic glass, and backsheet together. While ensuring the module's light transmission performance, it can isolate external moisture, extend the photovoltaic module's lifespan, protect the solar cells, and encapsulate them into a photovoltaic module capable of outputting direct current. Of course, the photovoltaic module may also include other structures, depending on the specific application scenario and function, and is not limited here.
[0033] Figure 1 This is a schematic diagram of the encapsulating film 1000 provided in an embodiment of the present invention, as shown below. Figure 1As shown, the encapsulating film 1000 in this embodiment includes an infrared light transmitting layer 100 and an infrared light reflecting layer 200 stacked together. The surface of the infrared light transmitting layer 100 away from the infrared light reflecting layer 200 is provided with a first embossed pattern 110. The infrared light transmitting layer 100 and the infrared light reflecting layer 200 are co-extruded. The infrared light reflecting layer 200 can control the wavelength range, preventing heat loss or excessive heat ingress; the infrared light transmitting layer 100 can enhance the system's response to specific infrared bands, helping to control heat flow and protecting the internal structure from the effects of high-intensity infrared radiation. Combining the infrared light transmitting layer 100 and the infrared light reflecting layer 200 can effectively improve the problems of low initial power and high operating temperature of photovoltaic modules. Because the infrared light transmitting layer 100 has a higher fluidity than the infrared light reflecting layer 200, by providing a first embossed pattern 110 on the surface of the infrared light transmitting layer 100 away from the infrared light reflecting layer 200, the adhesive film at the protrusions of the infrared light transmitting layer 100 will flow to the depressions during lamination. This can avoid or reduce the phenomenon of the infrared light transmitting layer 100 being squeezed by the infrared light reflecting layer 200 due to its high fluidity.
[0034] Please continue reading. Figure 1 In this embodiment, the first embossed pattern 110 includes a plurality of first protrusions 111 and a plurality of first recesses 112. The plurality of first protrusions 111 are spaced apart, and a first recess 112 is formed between two adjacent first protrusions 111. Because the infrared light transmitting layer 100 has good fluidity, by providing a plurality of first protrusions 111 and a plurality of first recesses 112, the flow of the infrared light transmitting layer 100 film from the plurality of first protrusions 111 to the plurality of first recesses 112 can be increased during high-temperature lamination. This avoids or reduces the phenomenon of layer penetration caused by the good fluidity of the infrared light transmitting layer 100 being squeezed by the hard infrared light reflecting layer 200.
[0035] Specifically, in this embodiment, there are five first protrusions 111 and four corresponding first recesses 112. Of course, the number of first protrusions 111 can also be two, three, four, or more, and the number of first recesses 112 can be one, two, three, or more. Alternatively, only one first protrusion 111 and one first recess 112 may be provided. The number of first protrusions 111 and first recesses 112 is determined by the length of the adhesive film layer and is not limited here.
[0036] Figure 2 This is a schematic diagram of the 1000-layer co-extruded encapsulating film provided in an embodiment of this utility model. To further prevent delamination, please refer to... Figure 1 and combined Figure 2In this embodiment, the infrared light reflecting layer 200 has a second embossed pattern 120 on its surface away from the infrared light transmitting layer 100. The second embossed pattern 120 corresponds to the first embossed pattern 110; and the recess depth of the second embossed pattern 120 is less than the recess depth of the first embossed pattern 110. That is, the convex portion of the first embossed pattern 110 corresponds to the convex portion of the second embossed pattern 120, and the concave portion of the first embossed pattern 110 corresponds to the concave portion of the second embossed pattern 120.
[0037] In detail, the second embossed pattern 120 in this embodiment includes a plurality of second protrusions 121 and a plurality of second recesses 122. The plurality of second protrusions 121 are spaced apart, and a second recess 122 is formed between two adjacent second protrusions 121. A plurality of first protrusions 111 are correspondingly arranged with the plurality of second protrusions 121. During high-temperature lamination, the infrared light transmitting layer 100 has a high temperature, and the adhesive film at the first protrusion 111 will flow towards the first recess 112 first, rather than towards the infrared light reflecting layer 200. This avoids or reduces the possibility of the infrared light transmitting layer 100 being squeezed by the rigid infrared light reflecting layer 200 due to its good fluidity, causing it to perforate. At the same time, the infrared light reflecting layer 200 has poor fluidity due to the low temperature of the heating plate in the upper chamber, but because the adhesive film at the second protrusion 121 will flow towards the second recess 122 first, rather than towards the infrared light transmitting layer 100. Even if the film thickness at the second recess 122 is greater than that at the first recess 112, resulting in micro-penetration, the degree of micro-penetration is shallow. Subsequently, the first recess 112 of the infrared light transmitting layer 100 will be filled by the first protrusion 111, and the second recess 122 will be filled by the second protrusion 121, thus masking the color during micro-penetration and preventing cross-color bleeding on the surface. Through the above design, after high-temperature lamination and co-extrusion, the infrared light transmitting layer 100 and the infrared light reflecting layer 200 will not exhibit micro-penetration or one side showing white or grayish tinge while the other side shows black or grayish tinge.
[0038] Furthermore, by providing the first recess 112 and the second recess 122, gas can be easily discharged from the recess during the curing process of the encapsulating film 1000, thereby preventing the formation of air bubbles, improving the aesthetic appearance of the encapsulating film 1000 and the reliability of its performance.
[0039] Of course, the first raised pattern 110 and the second raised pattern 120 can also be staggered, that is, the first protrusion 111 corresponds to the second recess 122, and the first recess 112 corresponds to the second protrusion 121. Alternatively, a portion of the first protrusion 111 corresponds to the second protrusion 121, and a portion of the first protrusion 111 corresponds to the second recess 122.
[0040] Optionally, in this embodiment, the recess depth of the first embossed pattern 110 is 25μm to 100μm deeper than the recess depth of the second embossed pattern 120. The recess depth of the first embossed pattern 110 can be 25μm, 30μm, 35μm, 40μm, 45μm, 50μm, 55μm, 60μm, 65μm, 70μm, 75μm, 80μm, 85μm, 90μm, 100μm, etc. Of course, the difference in recess depth between the two can also be within other ranges, depending on the actual processing conditions, and is not limited here.
[0041] Optionally, in this embodiment, the depth of the first recess 112 is 150μm to 200μm; the depth of the second recess 122 is 100μm to 200μm. The depth of the first recess 112 can be 150μm, 160μm, 170μm, 180μm, 190μm, 200μm, etc. Of course, the depth of the first recess 112 can also be other values, depending on the thickness of the actual encapsulating film 1000, and is not limited here. The depth of the second recess 122 can be 100μm, 110μm, 120μm, 130μm, 140μm, 150μm, 160μm, 170μm, 180μm, 190μm, 200μm, etc. Of course, the depth of the first recess 112 can also be other values, depending on the thickness of the actual encapsulating film 1000, and is not limited here.
[0042] To prevent the infrared light transmitting layer 100 and the infrared light reflecting layer 200 from penetrating each other, the first protrusion 111 and the second protrusion 121 in this embodiment have the same width. Optionally, the width of both the first protrusion 111 and the second protrusion 121 is 50μm to 150μm. Specifically, the width of the first protrusion 111 and the second protrusion 121 can be 50μm, 60μm, 70μm, 80μm, 90μm, 100μm, etc. Of course, the width of the first protrusion 111 and the second protrusion 121 can also be other values, depending on the actual length of the encapsulating film 1000, and is not limited here. In addition, the widths of the first protrusion 111 and the second protrusion 121 can also be different, with the width of the first protrusion 111 being slightly wider than the width of the second protrusion 121.
[0043] In this embodiment, the first embossed pattern 110 includes one or more of the following: triangular pyramidal embossed patterns, quadrilateral embossed patterns, spherical embossed patterns, and prism embossed patterns; and / or, the second embossed pattern 120 includes one or more of the following: triangular pyramidal embossed patterns, quadrilateral embossed patterns, spherical embossed patterns, and prism embossed patterns. Of course, the first embossed pattern 110 and the second embossed pattern 120 may also include patterns of other shapes such as ellipsoidal embossed patterns, which are not limited here. In this embodiment, both the first embossed pattern 110 and the second embossed pattern 120 are spherical embossed patterns. After light enters the encapsulating film 1000, the spherical embossed pattern on the surface of the encapsulating film 1000 increases the number of refractions and reflections of light inside the encapsulating film 1000, increases the optical path, and improves the blackness of the encapsulating film 1000.
[0044] In this embodiment, the infrared transmitting layer uses an infrared-transmitting black pigment, and the infrared reflecting layer 200 uses an infrared-reflecting white pigment. Of course, the infrared transmitting layer can also use an infrared-transmitting blue pigment, and the infrared reflecting layer 200 can also use an infrared-reflecting transparent pigment; this is not limited here. The encapsulating film 1000 can be composed of two layers of co-extruded composite material in different colors such as black and white, blue and white, or black and transparent. In this embodiment, the thickness of the encapsulating film 1000 is 400μm to 600μm. Specifically, the thickness of the encapsulating film 1000 can be 400μm, 450μm, 500μm, 550μm, 600μm, etc. Of course, the thickness of the encapsulating film 1000 can also be other values within a certain range, depending on the actual application; this is not limited here. To further prevent interpenetration between the infrared light transmitting layer 100 and the infrared light reflecting layer 200 during lamination, the interlayer ratio of the infrared light transmitting layer 100 and the infrared light reflecting layer 200 in this embodiment is 1:1 composite co-extrusion. Of course, the interlayer ratio of the infrared light transmitting layer 100 and the infrared light reflecting layer 200 can also be adjusted to other ratios such as 1:1.2, as long as interpenetration is not easily observed. The setting of the interlayer ratio is not limited here.
[0045] In this embodiment, the encapsulating film 1000 is a black and white composite EVA encapsulating film 1000, with a thickness ratio of 1:1 between the black infrared light transmitting layer 100 and the white infrared light reflecting layer 200. The total thickness of the encapsulating film 1000 is 450 μm, the thickness of the first protrusion of the black infrared light transmitting layer 100 is 200 μm, the thickness of the second protrusion 121 of the white infrared light reflecting layer 200 is 100 μm, and the widths of the first recess 112 and the second recess 122 are 100 μm.
[0046] In summary, the photovoltaic module includes a stacked infrared light transmitting layer 100 and an infrared light reflecting layer 200. The surface of the infrared light transmitting layer 100 away from the infrared light reflecting layer 200 is provided with a first embossed pattern 110. The infrared light transmitting layer 100 and the infrared light reflecting layer 200 are co-extruded. The infrared light reflecting layer 200 can control the wavelength range, preventing heat loss or excessive heat ingress; the infrared light transmitting layer 100 can enhance the system's response to specific infrared bands, helping to control heat flow and protecting the internal structure from the effects of high-intensity infrared radiation. Combining the infrared light transmitting layer 100 and the infrared light reflecting layer 200 can effectively improve the problems of low initial power and high operating temperature of photovoltaic modules. Because the infrared light transmitting layer 100 has a higher fluidity than the infrared light reflecting layer 200, by providing a first embossed pattern 110 on the surface of the infrared light transmitting layer 100 away from the infrared light reflecting layer 200, the adhesive film at the protrusions of the infrared light transmitting layer 100 will flow to the depressions during lamination, thus avoiding or reducing the phenomenon of layer penetration caused by the infrared light reflecting layer 200 being squeezed due to the good fluidity of the infrared light transmitting layer 100.
[0047] The above description is only a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model.
Claims
1. An encapsulating film, characterized in that, include: An infrared light transmitting layer (100) and an infrared light reflecting layer (200) are stacked together. The surface of the infrared light transmitting layer (100) away from the infrared light reflecting layer (200) is provided with a first embossed pattern (110). The infrared light transmitting layer (100) and the infrared light reflecting layer (200) are co-extruded together.
2. The encapsulating film according to claim 1, characterized in that, The first embossed pattern (110) includes a plurality of first protrusions (111) and a plurality of first recesses (112), the plurality of first protrusions (111) are spaced apart, and a first recess (112) is formed between two adjacent first protrusions (111).
3. The encapsulating film according to claim 2, characterized in that, The infrared light reflecting layer (200) has a second embossed pattern (120) on its surface away from the infrared light transmitting layer (100). The second embossed pattern (120) is provided in correspondence with the first embossed pattern (110). The depth of the second embossed pattern (120) is less than the depth of the first embossed pattern (110).
4. The encapsulating film according to claim 3, characterized in that, The depth of the first embossed pattern (110) is 25 μm to 100 μm deeper than the depth of the second embossed pattern (120).
5. The encapsulating film according to claim 3, characterized in that, The second embossed pattern (120) includes a plurality of second protrusions (121) and a plurality of second recesses (122). The plurality of second protrusions (121) are spaced apart, and a second recess (122) is formed between two adjacent second protrusions (121). The plurality of first protrusions (111) are arranged in a one-to-one correspondence with the plurality of second protrusions (121).
6. The encapsulating film according to claim 5, characterized in that, The depth of the first recess (112) is 150μm to 200μm; the depth of the second recess (122) is 100μm to 200μm.
7. The encapsulating film according to claim 5, characterized in that, The first protrusion (111) and the second protrusion (121) have the same width.
8. The encapsulating film according to claim 7, characterized in that, The widths of the first protrusion (111) and the second protrusion (121) are both 50μm to 150μm.
9. The encapsulating film according to claim 3, characterized in that, The first embossed pattern (110) includes one or more of the following: triangular pyramidal embossed pattern, quadrilateral embossed pattern, spherical embossed pattern, and prism embossed pattern; and / or, the second embossed pattern (120) includes one or more of the following: triangular pyramidal embossed pattern, quadrilateral embossed pattern, spherical embossed pattern, and prism embossed pattern.
10. A photovoltaic module, characterized in that, Includes the encapsulating film (1000) as described in any one of claims 1-9.