Heterogeneous adhesive film and die head equipment for preparing heterogeneous adhesive film

Abstract

The utility model discloses a heterogeneous adhesive film and a die head device for preparing the heterogeneous adhesive film, the heterogeneous adhesive film is used for a photovoltaic module, the heterogeneous adhesive film is formed by co-extrusion of EVA adhesive material and POE adhesive material, the heterogeneous adhesive film comprises an EVA adhesive film area, POE adhesive film areas arranged on two opposite sides of the EVA adhesive film area, and a mixed adhesive film area formed by EVA adhesive and POE adhesive; eVA glue in the mixed glue film area and EVA glue in the EVA glue film area are of an integrated structure which is communicated with each other, and POE glue in the mixed glue film area and POE glue in the POE glue film area are of an integrated structure which is communicated with each other. The plane where the interface of the EVA glue and the POE glue in the mixed glue film area is located is not perpendicular to the plane where the heterogeneous glue film is located. The heterogeneous adhesive film has a good water vapor isolation function on the photovoltaic module, the cost of the heterogeneous adhesive film is reduced, and the stability of the overall structure of the heterogeneous adhesive film is ensured.

Description

Technical Field

[0001] The utility model relates to the field of photovoltaic products, in particular to a heterogeneous adhesive film and a die head device for preparing the heterogeneous adhesive film. Background Art

[0002] Reference Figure 1 In photovoltaic module encapsulation technology, a front glass panel 101, a front adhesive film layer 102, a photovoltaic cell layer 103, a back adhesive film layer 104, and a backsheet 105 (or a back glass panel) are stacked in order from top to bottom to form a single laminate. This laminate is then encapsulated with a frame to create the photovoltaic module. The front and back adhesive film layers 102 and 104 in the photovoltaic module not only prevent the photovoltaic cell layer 103 from cracking during the lamination process but also provide a water- and vapor-proof seal. Polyethylene glycol (Polyethylene Ethylene Oxide) films are commonly used for these films. However, POE films are relatively expensive and cannot meet the low-cost manufacturing needs of the photovoltaic industry. Utility Model Content

[0003] The purpose of the utility model is to provide a heterogeneous adhesive film and a die head device for preparing the heterogeneous adhesive film, which can reduce the cost of the heterogeneous adhesive film and ensure the stability of the overall structure of the heterogeneous adhesive film while ensuring that the heterogeneous adhesive film has a good function of isolating photovoltaic components from water vapor.

[0004] In order to solve the above technical problems, the utility model provides a heterogeneous adhesive film for photovoltaic modules, and the heterogeneous adhesive film is formed by co-extrusion of EVA adhesive and POE adhesive, comprising:

[0005] An EVA film area, a POE film area provided on at least two opposite sides of the EVA film area, and a mixed film area formed by EVA adhesive and POE adhesive at the junction of the EVA film area and the POE film area;

[0006] Among them, the EVA glue in the mixed film area and the EVA glue in the EVA film area are interconnected as an integrated structure, and the POE glue in the mixed film area and the POE glue in the POE film area are interconnected as an integrated structure; the surface where the interface between the EVA glue and the POE glue in the mixed film area is located is not perpendicular to the plane where the heterogeneous film is located.

[0007] In an optional embodiment of the present application, the thickness of the EVA adhesive in the mixed adhesive film area gradually decreases from one side of the EVA adhesive film area to the side of the POE adhesive film area;

[0008] The thickness of the POE adhesive in the mixed adhesive film area gradually decreases in a direction from one side of the POE adhesive film area to the side of the EVA adhesive film area.

[0009] In an optional embodiment of the present application, the interface between the EVA adhesive and the POE adhesive in the mixed adhesive film area is a serrated concave-convex surface or a wavy curved surface.

[0010] In an optional embodiment of the present application, the width of the EVA film area is greater than the width of the POE film area;

[0011] The angle between the plane where the interface of the EVA adhesive and the POE adhesive in the mixed adhesive film area is located and the plane where the heterogeneous adhesive film is located is not greater than 45°.

[0012] A die head device for preparing a heterogeneous adhesive film, used for preparing the heterogeneous adhesive film as described in any one of the above items, comprising:

[0013] a first feed channel and a second feed channel;

[0014] a first forming channel connected to the first feeding channel, wherein the first forming channel is a connecting channel formed by a first flat half-channel and two first mixing half-channels located on both sides of the first flat half-channel;

[0015] Two second forming channels connected to the second feeding channel, each of the second forming channels being a connecting channel formed by a second flat half-channel and a second mixing half-channel;

[0016] A flat pressed channel, wherein the middle area of the inlet of the flat pressed channel is connected to the first forming channel, and the areas on both sides of the inlet of the flat pressed channel are connected to the second forming channel; wherein, one of the first mixing half-channel and one of the second mixing half-channel are commonly connected to the boundary inlet area between the middle area of the inlet and the areas on both sides of the inlet on the flat pressed channel; the surface shapes of the two adjacent channel inner walls of the first mixing half-channel and the second mixing half-channel match each other, and the plane where the two channel inner walls are located and the plane where the flat pressed channel is located are not perpendicular to each other.

[0017] In an optional embodiment of the present application, the thickness of the first mixing half-channel gradually decreases from a side close to the first flat half-channel to a side away from the first flat half-channel;

[0018] The thickness of the second mixing half-channel gradually decreases from a side close to the second flat half-channel to a side away from the second flat half-channel.

[0019] In an optional embodiment of the present application, the inner walls of the two adjacent channels of the first mixing half-channel and the second mixing half-channel are mutually engaged serrated inner walls or wavy curved inner walls.

[0020] In an optional embodiment of the present application, the width of the first flat half channel is greater than the width of the second flat half channel;

[0021] An angle between a plane where inner walls of two adjacent channels of the first mixing half-channel and the second mixing half-channel are located and a plane where the flat pressing channel is located is not greater than 45°.

[0022] In an optional embodiment of the present application, the first feeding channel and the second feeding channel, the first forming channel and the second forming channel, and the flat pressing channel are sequentially distributed in three layers of upper, middle and lower parts within the same inverted cone;

[0023] The first feed channel includes a first inlet pipe and a first fluid pipe that are perpendicular to each other and are both cylindrical; and a first fluid outlet having the same cross-sectional shape as the first forming channel is formed on the wall of the first fluid pipe;

[0024] The second feed channel includes a first inlet pipe and a second fluid pipe that are perpendicular to each other and are both cylindrical; and two second fluid outlets with the same cross-sectional shape as the second forming channel are respectively formed on the pipe walls at both ends of the second fluid pipe;

[0025] The first shaping channel extends obliquely downward from the first fluid outlet to an inlet middle area of the top end of the flat pressing channel;

[0026] The two second forming channels extend obliquely downward from the two second fluid outlets to the areas on both sides of the inlet at the top of the flat pressing channel; and the first forming channel and the second forming channel extend in opposite oblique directions;

[0027] The flat pressing channel is a plate-shaped channel extending in a vertical direction, and the discharge port of the flat pressing channel is located at the bottom end.

[0028] In an optional embodiment of the present application, a heating resistor is provided at a position where the first mixing half-channel and the second mixing half-channel communicate with the flat pressed channel, and the heating resistor is located between two adjacent channel inner walls of the first flat half-channel and the second mixing half-channel;

[0029] The discharge port of the flat pressing channel is provided with a cooling structure.

[0030] The utility model provides a heterogeneous adhesive film and a die head device for preparing the heterogeneous adhesive film. The heterogeneous adhesive film is used for photovoltaic modules, and the heterogeneous adhesive film is co-extruded by EVA adhesive and POE adhesive, comprising: an EVA adhesive film area, a POE adhesive film area arranged on opposite sides of the EVA adhesive film area, and a mixed adhesive film area formed by EVA adhesive and POE adhesive at the intersection of the EVA adhesive film area and the POE adhesive film area; wherein the EVA adhesive in the mixed adhesive film area and the EVA adhesive in the EVA adhesive film area are an integrated structure interconnected, and the POE adhesive in the mixed adhesive film area and the POE adhesive in the POE adhesive film area are an integrated structure interconnected; and the plane where the interface between the EVA adhesive and the POE adhesive in the mixed adhesive film area is located is not perpendicular to the plane where the heterogeneous adhesive film is located.

[0031] The present application takes into account that in a photovoltaic module, the middle area of the heterogeneous adhesive film is the middle area facing the front glass plate or the back plate, and the middle area itself has good sealing performance and is basically unlikely to have water seepage problems. The side areas of the heterogeneous adhesive film correspond to the side positions of the photovoltaic module and are positions where water seepage is more likely to occur in the photovoltaic module. POE adhesive has a better sealing effect than EVA adhesive, but the cost of EVA adhesive is lower. For this reason, EVA adhesive is used to form the middle area of the heterogeneous adhesive film and POE adhesive is used to form the side areas of the heterogeneous adhesive film in the present application. This can reduce the cost of the entire heterogeneous adhesive film while ensuring the anti-water seepage sealing effect of the heterogeneous adhesive film on the photovoltaic module. On this basis, In this application, two different adhesive materials, EVA adhesive and POE adhesive, are extruded into one body in a flexible state to form a heterogeneous adhesive film, so that the EVA adhesive and POE adhesive in the mixed adhesive film area of the heterogeneous adhesive film can be more tightly adhered and connected, thereby ensuring the structural stability of the entire adhesive film; and in the mixed adhesive film area between the EVA adhesive film area and the POE adhesive film area, the interface between the EVA adhesive and the POE adhesive and the plane where the heterogeneous adhesive film is located are not perpendicular to each other, thereby ensuring that the EVA adhesive and the POE adhesive in the mixed adhesive film area of the entire heterogeneous adhesive film have a larger contact and bonding surface, thereby further improving the tightness of the adhesive connection between the EVA adhesive and the POE adhesive in the mixed adhesive film area, thereby improving the structural stability and sealing effect of the entire heterogeneous adhesive film. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the embodiments of the present invention or the technical solutions of the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0033] Figure 1 This is a schematic diagram of the exploded structure of a part of the photovoltaic module;

[0034] Figure 2 A schematic diagram of the cross-sectional structure of a heterogeneous adhesive film provided in an embodiment of the present application;

[0035] Figure 3 A top view of the heterogeneous adhesive film provided in an embodiment of the present application;

[0036] Figure 4 A first cross-sectional schematic diagram of a mixed film region in a heterogeneous film provided in an embodiment of the present application;

[0037] Figure 5 A second cross-sectional schematic diagram of a mixed film region in a heterogeneous film provided in an embodiment of the present application;

[0038] Figure 6 A second cross-sectional schematic diagram of a mixed film region in a heterogeneous film provided in an embodiment of the present application;

[0039] Figure 7 A third cross-sectional schematic diagram of the mixed film region in the heterogeneous film provided in an embodiment of the present application;

[0040] Figure 8 A fourth cross-sectional schematic diagram of a mixed film region in a heterogeneous film provided in an embodiment of the present application;

[0041] Figure 9 A fifth cross-sectional schematic diagram of a mixed film region in a heterogeneous film provided in an embodiment of the present application;

[0042] Figure 10 A perspective structural diagram of a die head device for preparing heterogeneous adhesive films provided in an embodiment of the present application;

[0043] Figure 11 A schematic structural diagram of a die head device for preparing heterogeneous adhesive films provided in an embodiment of the present application;

[0044] Figure 12 A schematic structural diagram of the first molding channel and the second molding channel in the die head device provided in an embodiment of the present application;

[0045] Figure 13 A schematic cross-sectional view of a die head device provided in an embodiment of the present application;

[0046] Figure 14 A side perspective view of a die head device provided in an embodiment of the present application;

[0047] In the accompanying drawings: 101 is the front glass plate, 102 is the front film layer, 103 is the photovoltaic cell layer, 104 is the rear film layer, 105 is the back plate, 11 is the EVA film area, 12 is the POE film area, 13 is the mixed film area, 130 is the interface, 20 is the inverted cone, 21 is the first feeding channel, 211 is the first inlet channel, 212 is the first fluid channel, 2121 is the first fluid outlet, 22 is the second feeding channel, 221 is the second inlet channel, 222 is the second fluid channel, 2221 is the second fluid outlet, 23 is the first molding channel, 231 is the first flat half channel, 232 is the first mixed half channel, 24 is the second molding channel, 241 is the second flat half channel, 242 is the second mixed half channel, 25 is the flat pressing channel, 26 is the heating resistor, 27 is the cooling structure, 28 is the third molding channel, and 29 is the fourth molding channel. DETAILED DESCRIPTION

[0048] Currently, the encapsulant films used in photovoltaic modules, particularly double-glass modules, primarily include ethylene-vinyl acetate copolymer (EVA) and ethylene-octene copolymer (POE). As a non-polar material, POE film does not form hydrogen bonds with water molecules and offers a water vapor barrier rating seven times higher than that of EVA film. However, POE film is also significantly more expensive than EVA film. While encapsulant film only accounts for a relatively small portion of the entire photovoltaic module, the large-scale production of PV modules still contributes to the relatively high cost of these modules.

[0049] To this end, the present application provides a heterogeneous adhesive film for photovoltaic modules and a die head device for preparing the heterogeneous adhesive film, which can greatly reduce the use cost of the encapsulation film in the photovoltaic module while ensuring that the encapsulation film has a good water vapor isolation function for the photovoltaic module.

[0050] To help those skilled in the art better understand the present invention, the present invention is further described below in conjunction with the accompanying drawings and specific embodiments. Obviously, the embodiments described are only a portion of the present invention, not all of the embodiments. All other embodiments derived by those skilled in the art based on the embodiments of the present invention without inventive effort are also within the scope of protection of the present invention.

[0051] like Figures 2 to 9 As shown, Figure 2 A schematic diagram of a cross section of a heterogeneous adhesive film provided in an embodiment of the present application; Figure 3 A top view of the heterogeneous adhesive film provided in an embodiment of the present application; Figures 4 to 9 Schematic diagrams of five different cross sections of the mixed film region in the heterogeneous film provided in the embodiments of the present application.

[0052] It is understood that the heterogeneous adhesive film in this application refers to a structure used as an encapsulation film in a photovoltaic module.

[0053] In a specific embodiment of the present application, the heterogeneous adhesive film is formed by co-extrusion of an EVA adhesive and a POE adhesive, and the heterogeneous adhesive film may include:

[0054] An EVA film area 11, POE film areas 12 provided on at least two opposite sides of the EVA film area 11, and a mixed film area 13 formed by EVA adhesive and POE adhesive at the junction of the EVA film area 11 and the POE film area 12;

[0055] Among them, the EVA glue in the mixed film area 13 and the EVA glue in the EVA film area 11 are interconnected integral structures, and the POE glue in the mixed film area 13 and the POE glue in the POE film area 12 are interconnected integral structures; the surface where the interface 130 of the EVA glue and POE glue in the mixed film area 13 is located and the plane where the heterogeneous film is located are not perpendicular to each other.

[0056] like Figure 2 As shown, the heterogeneous film in this embodiment is a flat plate structure as a whole, and can be roughly divided into an EVA film area 11 located in the middle and POE film areas 12 located on both sides of the EVA film area. As the name suggests, the EVA film is also the film area formed by extrusion of EVA glue, and the POE film area 12 is also the film area formed by extrusion of POE glue. It can be understood that the photovoltaic module is roughly a rectangular structure, and accordingly, the shape of the heterogeneous film is also roughly a rectangular structure. Therefore, in the heterogeneous film, the two opposite side areas can be the POE film area 12, or they can be as shown in FIG. Figure 3As shown, the two pairs of four side regions surrounding the EVA film region 11 are all POE film regions 12. Therefore, in an encapsulated photovoltaic module, the EVA film region should be located in the center region facing the front glass panel (and back or back glass panel) of the photovoltaic module, while the POE film region should be located in the side edge regions facing the front glass panel (and back or back glass panel). Obviously, the center region of the front glass panel in a photovoltaic module already has a good barrier to moisture. Therefore, even if the heterogeneous film uses the EVA film region 11 in the center region, it can still ensure that the center region of the photovoltaic module is well shielded from moisture. However, the side edge regions of the photovoltaic module, because they are connected to the frame and the side edges of the front glass panel, have a weaker barrier to moisture. Therefore, the heterogeneous film of this embodiment includes POE film on the sides of the EVA film region 11, which ensures that the heterogeneous film has better barrier properties against moisture at the side edges of the photovoltaic module. Moreover, compared with the entire encapsulation film made entirely of EVA film, the heterogeneous film in this application has a better water vapor barrier effect, and compared with the entire encapsulation film made entirely of POE film, the heterogeneous film in this application has a lower cost. It can be seen that the heterogeneous film in this application can further reduce the film cost while ensuring a good water vapor barrier effect on photovoltaic modules.

[0057] On this basis, because the heterogeneous film is formed by co-extrusion of two different adhesive materials in a flexible state that has not yet been solidified, but the adhesion between the two different adhesive materials is relatively weaker than the adhesion of the same adhesive material, therefore, in order to ensure the mutual adhesion between the POE film area 12 and the EVA film area 11 in the heterogeneous film as much as possible, on the basis of extruding the POE adhesive and the EVA adhesive into an integrated structure while they are still in a flexible state, a mixed film area 13 is formed between the EVA film area 11 and the POE film area 12, where the two films transition to each other; thereby, the EVA adhesive in the EVA film area 11 gradually extends into the mixed film area 13, i.e., forming the EVA adhesive in the mixed film area 13; similarly, the POE adhesive in the POE film area 12 gradually extends into the mixed film area 13, i.e., forming the POE adhesive in the mixed film area 13; the POE adhesive and the EVA adhesive in the mixed film area 13 are extruded into each other, i.e., forming the mixed film area 13. Moreover, the plane where the interface 130 between the EVA glue and the POE glue in the mixed film area 13 is located and the plane where the heterogeneous film is located are not perpendicular to each other, thereby allowing the EVA glue and the POE glue in the mixed film area 13 to have a larger mutual contact surface, which can also make the EVA glue and the POE glue more fully bonded to each other, reducing the possibility of the EVA glue and the POE glue cracking each other, thereby ensuring the stability of the overall structure of the heterogeneous film structure; and even if the interface 130 where the EVA glue and the POE glue contact each other may have water seepage problems, the larger contact interface 130 between the EVA film and the POE film will also increase the difficulty of water vapor penetrating into the interior of the photovoltaic module to a certain extent. It can be seen that in this application, by forming a larger interface contact surface between the EVA glue and the POE glue in the mixed film area 13, the water vapor blocking performance of the entire heterogeneous film is further improved.

[0058] In addition, if Figure 3 As shown, the width of the EVA film area 11 should be greater than the width of the POE film area 12 to minimize the amount of POE glue used in the heterogeneous film.

[0059] It is understandable that the EVA adhesive and the POE adhesive in the mixed adhesive film area 13 can be mixed in various ways, and accordingly the interface 130 between the EVA adhesive and the POE adhesive can also have various surface structures.

[0060] First, in the mixed film area 13, the interface 130 between the EVA glue and the POE glue is not necessarily a plane. Second, even if the interface 130 between the EVA glue and the POE glue is a plane, the interface 130 is not perpendicular to the plane of the heterogeneous film.

[0061] In an optional embodiment of the present application, the thickness of the EVA glue in the mixed film area 13 can gradually decrease in the direction from the EVA film area 11 side to the POE film area 12 side; and the thickness of the POE glue can gradually decrease in the direction from the POE film area 12 side to the EVA film area 11 side.

[0062] For example, Figure 2 In the embodiment shown, the EVA glue and POE glue in the mixed film area 13 can be wedge-shaped glue film structures that cooperate with each other; at this time, the angle between the interface 130 between the EVA glue and POE glue in the mixed film area 13 and the plane where the heterogeneous film is located should be no more than 45°, for example, it can be 30°.

[0063] For example Figure 4 In the embodiment shown, the EVA glue and the POE glue in the mixed glue film area 13 form a roughly V-shaped surface, wherein the EVA glue extends to the interior of the POE glue, and the POE glue wraps the upper and lower surfaces of the EVA glue, thereby increasing the wrapping area of the POE glue on the entire outer surface of the heterogeneous glue film to a certain extent, and also increasing the water vapor blocking performance of the heterogeneous glue film; at this time, the angle between the two inclined surfaces of the V-shaped interface 130 and the plane where the heterogeneous glue film is located should also be no more than 45°.

[0064] For example Figure 5 and Figure 6 As shown, in another optional embodiment of the present application, the EVA glue and POE glue in the mixed film area 13 can generally be wedge-shaped glue film structures that cooperate with each other. At the same time, the inclined surface where the EVA glue and POE glue contact each other can be a non-planar surface, for example, a serrated structure or a wavy surface; at this time, the mutual contact area between the EVA glue and POE glue in the mixed film area 13 can also be further increased.

[0065] Of course, the EVA glue and POE glue in the mixed glue film area 13 of the present application are not limited to the above-mentioned thickness increasing or decreasing changes. Figures 7 to 9 As shown, there can also be a step surface, a serrated concave-convex surface or a wavy surface between the EVA glue and the POE glue, and the plane where the step surface is located, the plane where the serrated concave-convex surface is located, and the plane where the wavy surface is located are all roughly parallel to the plane where the heterogeneous adhesive film is located.

[0066] It is understandable that, in the actual process of extruding EVA glue and POE glue to form the mixed glue film area 13, the EVA glue and POE glue are extruded when they are in a flexible state, and their contour shapes cannot be guaranteed to be absolutely accurately controlled. Therefore, the interface 130 between the EVA glue and the POE glue is approximately Figure 2 as well as Figures 4 to 9Any one of the interfaces 130 between the EVA glue and the POE glue in the mixed film area 13 shown can be used. In other words, the interface 130 between the EVA glue and the POE glue in this application does not require to be absolutely accurate. Figure 2 as well as Figures 4 to 9 Interface 130 is shown.

[0067] To sum up, in this application, EVA glue is used to form the middle area of the heterogeneous film and POE glue is used to form the side edge area of the heterogeneous film, thereby reducing the cost of the entire heterogeneous film on the basis of ensuring the anti-water seepage sealing effect of the heterogeneous film on the photovoltaic module; and the heterogeneous film is made of two different glue materials, EVA glue and POE glue, which are extruded into one piece in a flexible state, ensuring that the EVA glue and POE glue in the mixed film area of the heterogeneous film can be more tightly adhered and connected, thereby ensuring the structural stability of the entire film; and in the mixed film area between the EVA film area and the POE film area, the interface between the EVA glue and the POE glue and the plane where the heterogeneous film is located are not perpendicular to each other, ensuring that the EVA glue and the POE glue in the mixed film area of the entire heterogeneous film have a larger contact bonding surface, thereby further improving the tightness of the adhesive connection between the EVA glue and the POE glue in the mixed film area, thereby improving the structural stability and sealing effect of the entire heterogeneous film.

[0068] Based on the above discussion, if Figures 10 to 14 As shown, Figure 10 A perspective structural diagram of a die head device for preparing heterogeneous adhesive films provided in an embodiment of the present application; Figure 11 A schematic structural diagram of a die head device for preparing heterogeneous adhesive films provided in an embodiment of the present application; Figure 12 A schematic structural diagram of the first molding channel and the second molding channel in the die head device provided in an embodiment of the present application; Figure 13 A schematic cross-sectional view of a die head device provided in an embodiment of the present application; Figure 14 A side perspective view of a die head apparatus provided for an embodiment of the present application.

[0069] The present application further provides a die head device for preparing a heterogeneous adhesive film, which can be used to prepare any of the heterogeneous adhesive films described above. In a specific embodiment of the present application, the die head device can include:

[0070] A first feeding channel 21 and a second feeding channel 22;

[0071] A first forming channel 23 connected to the first feeding channel 21, wherein the first forming channel 23 is a connecting channel formed by a first flat half-channel 231 and two first mixing half-channels 232 located on both sides of the first flat half-channel 231;

[0072] Two second forming channels 24 connected to the second feeding channel 22, each second forming channel 24 being a communicating channel formed by a second flat half channel 241 and a second mixing half channel 242;

[0073] The flat pressed channel 25, the middle area of the entrance of the flat pressed channel 25 is connected to the first forming channel 23, and the areas on both sides of the entrance of the flat pressed channel 25 are connected to the second forming channel 24; wherein, a first mixing half-channel 232 and a second mixing half-channel 242 are commonly connected to the entrance area at the junction between the middle area of the entrance and the areas on both sides of the entrance on the flat pressed channel 25; the surface shapes of the inner walls of the two adjacent channels of the first mixing half-channel 232 and the second mixing half-channel 242 cooperate with each other, and the planes where the two channel inner walls are located and the plane where the flat pressed channel 25 is located are not perpendicular to each other.

[0074] Reference Figure 10 and Figure 11 ,exist Figure 10 The inverted cone 20 shown is processed internally to form Figure 11 The channel structure shown; in the actual extrusion process of forming the heterogeneous film, the EVA glue in a flexible state can be introduced into the first feeding channel 21, and the EVA glue is extruded into the first molding channel 23 through the first feeding channel 21 to form an EVA glue integrated structure, and the EVA glue integrated structure is also the structure formed by the EVA glue in the EVA film area 11 and the mixed film area 13 in the heterogeneous film; similarly, the POE glue in a flexible state can be introduced into the second feeding channel 22, and the POE glue passes through the second feeding channel 22 Two POE glue integrated structures can be formed by entering the two second molding channels 24 respectively, wherein each POE glue integrated structure is a structure jointly formed by the POE glue in the POE film area 12 and the mixed film area 13; on this basis, the EVA glue integrated structure enters the middle area of the flat pressing channel 25, and the two POE glue integrated structures enter the two side areas of the flat pressing channel 25 respectively, so that the two sides of the EVA glue integrated structure are respectively combined with the two POE glue integrated structures and squeezed into one, that is, a heterogeneous film structure is formed.

[0075] On this basis, refer to Figure 12The first molding channel 23 includes a first flat half-channel 231 and two first mixing half-channels 232 located on both sides of the first flat half-channel 231. The inner walls of the first flat half-channel 231 and the first mixing half-channel 232 are both cylindrical surfaces. The inner walls of the three cylindrical surfaces are spliced together to form a complete cylindrical channel; and the cross-section of the first flat channel should be the same as the cross-section of the EVA film area 11 in the heterogeneous film, while the cross-section of the two first mixing half-channels 232 should be the same as the cross-section of the structure formed by the EVA glue in the mixed film area 13 in the heterogeneous film. The cross-section is the same, that is, the structure formed by the EVA glue in the mixed film area 13; similarly, for each second molding channel 24, it is also a cylindrical channel formed by splicing a second flat half-channel 241 with a cylindrical inner wall and a second mixed half-channel 242 with a cylindrical inner wall; and the cross-section of the second flat half-channel 241 is the same as the cross-section of the POE film area 12 in the heterogeneous film, and the cross-section of the second mixed half-channel 242 is the same as the cross-section of the structure formed by the POE glue in the mixed film area 13.

[0076] Reference Figures 10 to 12 It can be seen that the surface shape of the two adjacent channel inner walls of the first mixing half-channel 232 and the second mixing half-channel 242 is the surface shape of the interface contact surface between the EVA glue and the POE glue in the mixed glue film area 13. Therefore, the surface shape of the two adjacent channel inner walls of the first mixing half-channel 232 and the second mixing half-channel 242 should be a surface shape that can fit together; the two adjacent channel inner walls of the first mixing half-channel 232 and the second mixing half-channel 242 are two colloid surfaces formed on the EVA glue integrated structure and the POE glue integrated structure respectively, which can cooperate and fit with each other in the flat pressing channel 25, so that the EVA glue integrated structure and the POE glue integrated structure are extruded and bonded to form an integrated structure. The two adjacent channel inner walls of the first mixing half-channel 232 and the second mixing half-channel 242 and the plane where the flat pressing channel 25 is located are not perpendicular to each other. Obviously, the angle between the two adjacent channel inner walls of the first mixing half-channel 232 and the second mixing half-channel 242 and the plane where the flat pressing channel 25 is located determines the angle between the interface contact surface between the EVA glue and the POE glue in the mixed film area 13 and the plane where the heterogeneous film is located. As a result, the EVA glue and the POE glue in the mixed film area 13 of the heterogeneous film can have a larger contact and adhesion surface.

[0077] Furthermore, it is understandable that Figure 11 and Figure 12 This embodiment takes the inner walls of the two adjacent channels of the first mixing half-channel 232 and the second mixing half-channel 242 as plane inner walls as an example. Obviously, at this time, the angle between the plane where the two channel inner walls are located and the plane where the flat pressing channel 25 is located should not be greater than 45°.

[0078] Of course, in this embodiment, the inner walls of the two adjacent channels of the first mixing half-channel 232 and the second mixing half-channel 242 can also be non-planar inner walls. For example, the inner walls of the two adjacent channels of the first mixing half-channel 232 and the second mixing half-channel 242 are mutually interlocking V-shaped inner walls, serrated inner walls, wavy curved inner walls, stepped inner walls, etc., which can accordingly form the above-mentioned interface 130 between the EVA glue and the POE glue. Figures 4 to 9 The V-shaped surface, serrated concave and convex surface or wavy surface shown.

[0079] In addition, the width of the first flat half channel 231 should also be greater than the width of the second flat half channel 241 , thereby ensuring that the width of the EVA film area 11 in the final heterogeneous film is greater than the width of the POE film area 12 .

[0080] Corresponding to the above-mentioned embodiment of the heterogeneous adhesive film, the thickness of the EVA adhesive in the mixed adhesive film area 13 can gradually decrease from the EVA adhesive film area 11 side to the POE adhesive film area 12 side; and the thickness of the POE adhesive can gradually decrease from the POE adhesive film area 12 side to the EVA adhesive film area 11 side. Corresponding to this embodiment, in an optional embodiment of the present application, the thickness of the first mixed half-channel 232 gradually decreases from the side close to the first flat half-channel 231 to the side away from the first flat half-channel 231;

[0081] The thickness of the second mixing half-channel 242 gradually decreases from a side close to the second flat half-channel 241 to a side away from the second flat half-channel 241 .

[0082] In addition, the cross-section of the flat pressing channel 25 in this embodiment should also be the same as the cross-section of the heterogeneous adhesive film. In addition, the thickness of the flat pressing channel 25 in this application gradually decreases from the inlet side to the outlet side, and the extrusion pressure exerted on the EVA adhesive integrated structure and the POE integrated structure entering the flat pressing channel 25 gradually increases from the inlet side to the outlet side, thereby ensuring that the two different adhesive material structures are tightly connected together.

[0083] Based on the above discussion, the first feeding channel 21, the second feeding channel 22, the first forming channel 23, the second forming channel 24 and the flat pressing channel 25 in the present application can all be similar to Figure 11 The various columnar pipes in the die head device are spliced together to form; the first feed channel 21, the second feed channel 22, the first forming channel 23, the second forming channel 24 and the flat pressing channel 25 in the die head device of the present application can also be grooved and formed in a solid structure.

[0084] like Figure 10As shown, in another optional embodiment of the present application, the die head device may include:

[0085] The first feeding channel 21 and the second feeding channel 22, the first forming channel 23 and the second forming channel 24, and the flat pressing channel 25 are sequentially distributed in the same inverted cone 20 in three layers, upper, middle and lower.

[0086] The first feed channel 21 includes a first inlet pipe 211 and a first fluid pipe 212, which are both cylindrical and arranged perpendicular to each other. A first fluid outlet 2121 having the same cross-sectional shape as the first forming channel 23 is formed on the wall of the first fluid pipe 212.

[0087] The second feed channel 22 includes a first inlet pipe 211 and a second fluid pipe that are both cylindrical and arranged perpendicular to each other; and two second fluid outlets 2221 having the same cross-sectional shape as the second forming channel 24 are respectively formed on the pipe walls at both ends of the second fluid pipe.

[0088] The first forming channel 23 extends obliquely downward from the first fluid outlet 2121 to the middle area of the inlet of the top end of the flat pressing channel 25;

[0089] The two second forming channels 24 extend obliquely downward from the two second fluid outlets 2221 to the areas on both sides of the inlet of the top of the flat pressing channel 25; and the oblique extension directions of the first forming channel 23 and the second forming channel 24 are opposite;

[0090] The flat pressing channel 25 is a plate-shaped channel extending in the vertical direction, and the discharge port of the flat pressing channel 25 is located at the bottom end.

[0091] like Figure 10 and Figure 13 As shown, in this embodiment, the first feed channel 21 includes a first inlet pipe 211 and a first fluid pipe 212, and the second feed channel 22 includes a second inlet pipe 221 and a second fluid pipe; wherein, the first inlet pipe 211, the first fluid pipe 212, the second inlet pipe 221 and the second fluid pipe are all located in the same horizontal plane; however, in actual application, it is not excluded that the first inlet pipe 211 and the second inlet pipe 221 are respectively located above the first fluid pipe 212 and the second fluid pipe.

[0092] In addition, a first fluid outlet 2121 and a second fluid outlet 2221 are further provided on the pipe wall below the first fluid pipe 212 and the second fluid pipe. It can be understood that the first fluid outlet 2121 and the second fluid outlet 2221 are also connecting ports for the first fluid pipe 212 and the second fluid pipe to communicate with the first molded pipe and the second molded pipe respectively. Therefore, the shape of the first fluid outlet 2121 is the same as the cross-sectional shape of the first molded pipe, and the shape of the second fluid outlet 2221 is the same as the cross-sectional shape of the second molded pipe. Figures 10 to 13 In the embodiment shown, the final heterogeneous film is Figure 2 Taking the die head device corresponding to the illustrated structure as an example, the first fluid outlet 2121 has a flat opening in the middle and wedge-shaped openings on both sides. Accordingly, the second fluid outlet 2221 is composed of a flat opening and a wedge-shaped opening. Furthermore, the two second fluid outlets 2221 on the second fluid conduit are located at either end of the second fluid conduit. The flat opening of each second fluid outlet 2221 is located in the section of the second fluid conduit that extends beyond the first fluid conduit 212, while the wedge-shaped opening of each second fluid outlet 2221 directly faces the wedge-shaped opening of the first fluid outlet 2121.

[0093] Further, if Figure 10 and Figure 14 As shown, the flat pressing channel 25 should be located exactly on the vertical symmetry plane between the first fluid channel and the second fluid channel 222, so that the first molding channel 23 and the second molding channel 24 can extend obliquely from two different directions to the inlet side of the flat pressing channel 25 respectively, so that the colloid structures respectively pressed and formed in the first molding channel 23 and the second molding channel 24 can enter the flat pressing channel 25 together and be extruded and formed in the vertical direction, and output from the discharge port at the bottom of the flat pressing channel 25, thus forming a heterogeneous film.

[0094] Based on the above discussion, the position where the first mixing half-channel 232 and the second mixing half-channel 242 in the first molding channel 23 and the second molding channel 24 are connected to the flat pressing channel 25 must be the position where the EVA glue and POE glue in the mixed film area 13 begin to adhere to each other. Figure 14 In another optional embodiment of the present application, a heating resistor is provided at the position where the first mixing half-channel 232 and the second mixing half-channel 242 communicate with the flat pressing channel 25. The heating resistor 26 is located between the inner walls of the first flat half-channel 231 and the second mixing half-channel 242 adjacent to each other.

[0095] The discharge port of the flat pressing channel 25 is provided with a cooling structure 27 .

[0096] Reference Figure 14During the actual extrusion process of forming the heterogeneous adhesive film, the adhesive surfaces formed by the extrusion of the EOV adhesive and the POE adhesive by the adjacent inner walls of the first mixing half-channel 232 and the second mixing half-channel 242 are heated by the heating resistor 26. This increases the adhesion of the two adhesive surfaces. When the adhesive enters the flat pressing channel 25, the bonding force at the interface 130 where the EVA adhesive and the POE adhesive contact each other is also increased. This helps to improve the tightness of the connection between the POE adhesive and the EVA adhesive in the mixed adhesive film area 13.

[0097] On this basis, in this embodiment, a cooling structure 27 is further provided at the discharge port of the flat pressing channel 25. For example, a cooling water pipe can be provided to fit the edge of the discharge port of the flat pressing channel 25. Cooling water is introduced into the cooling water pipe to cool the output heterogeneous adhesive film, thereby promoting the curing and molding of the heterogeneous structure, and thus avoiding the generation of cracks between the POE adhesive and the EVA adhesive in the mixed adhesive film area 13.

[0098] Based on the above embodiments, the second feeding channel 22 and the two second molding channels 24 can only process and form the POE film areas 12 on the two opposite sides of the EVA film area 11 . In order to be able to process and form the POE film area 12 on the other two sides of the EVA film area 11, in the actual processing process, POE film can be first introduced into the first feed channel 21 and the second feed channel 22 respectively. When the amount of POE glue introduced reaches the amount required to form a POE film area 12, POE glue and EVA glue are jointly introduced into the first feed channel 21, thereby forming an area in which POE glue and EVA glue are mixed with each other in the mixed film area 13. After that, EVA glue is introduced into the first feed channel 21, and POE glue is introduced into the second feed channel 22. Then, EVA glue and POE glue are introduced into both the first feed channel 21 and the second feed channel 22. Finally, POE glue is introduced into the first feed channel 21 together, thereby forming POE glue arranged around the four sides of the EVA film area 11.

[0099] Of course, in practical applications, such as Figure 14As shown, in the present application, it is also possible to consider that the third molding channel 28 and the fourth molding channel 29, which are both flat cylindrical channels, are connected to the flat pressing channel 25, and the third molding channel 28 and the fourth molding channel 29 are respectively connected to corresponding feeding channels, and flexible adhesive materials can be respectively introduced into the third molding channel 28 and the fourth molding channel 29; the third molding channel 28 and the fourth molding channel 29 have the same structure and shape, and are symmetrically arranged with respect to the flat pressing channel 25; thus, in the actual processing process, POE adhesive can be first introduced into the third molding channel 28 and the fourth molding channel 29, and then EVA adhesive and POE adhesive can be respectively introduced into the third molding channel 28 and the fourth molding channel 29 to form a mixed adhesive film area 13, and by changing the direction of the third molding channel 2 8 and the fourth molding channel 29 pass the EVA glue and POE glue pushing and squeezing force, can change the interface 130 between the EVA glue and POE glue in the mixed film area 13; after the mixed film area 13 is formed, the third molding channel 28 and the fourth molding channel 29 can be closed, and EVA glue and POE glue are respectively introduced into the first molding channel 23 and the second molding channel 24. After the EVA glue area and the POE glue film areas 12 on the opposite sides are formed, EVA glue and POE glue can be introduced into the third molding channel 28 and the fourth molding channel 29 again to form the last mixed film area 13. After the mixed film area 13 is formed, POE glue can be further introduced into the third molding channel 28 and the fourth molding channel 29 together, thereby also forming Figure 3 The heterogeneous film shown.

[0100] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply the existence of any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or device comprising a series of elements are inherent to the elements. In the absence of further restrictions, the elements limited by the sentence "comprise one..." do not exclude the presence of other identical elements in the process, method, article or device comprising the elements. In addition, the above-mentioned technical solutions provided in the embodiments of the present application are not described in detail in accordance with the corresponding technical solutions in the prior art to achieve the same principle, so as to avoid excessive elaboration.

[0101] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only intended to help understand the method and core concept of the present invention. It should be noted that those skilled in the art can make various improvements and modifications to the present invention without departing from the principles of the present invention, and such improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. A heterogeneous adhesive film, characterized in that: Used for photovoltaic modules, the heterogeneous adhesive film is formed by co-extrusion of EVA adhesive and POE adhesive, including: An EVA film area, a POE film area provided on at least two opposite sides of the EVA film area, and a mixed film area formed by EVA adhesive and POE adhesive at the junction of the EVA film area and the POE film area; Among them, the EVA glue in the mixed film area and the EVA glue in the EVA film area are interconnected as an integrated structure, and the POE glue in the mixed film area and the POE glue in the POE film area are interconnected as an integrated structure; the surface where the interface between the EVA glue and the POE glue in the mixed film area is located is not perpendicular to the plane where the heterogeneous film is located.

2. The heterogeneous adhesive film according to claim 1, wherein: The thickness of the EVA adhesive in the mixed adhesive film area gradually decreases from one side of the EVA adhesive film area to the side of the POE adhesive film area; The thickness of the POE adhesive in the mixed adhesive film area gradually decreases in a direction from one side of the POE adhesive film area to the side of the EVA adhesive film area.

3. The heterogeneous adhesive film according to claim 1, wherein: The interface between the EVA adhesive and the POE adhesive in the mixed adhesive film area is a sawtooth concave-convex surface or a wavy curved surface.

4. The heterogeneous adhesive film according to claim 1, wherein: The width of the EVA film area is greater than the width of the POE film area; The angle between the plane where the interface of the EVA adhesive and the POE adhesive in the mixed adhesive film area is located and the plane where the heterogeneous adhesive film is located is not greater than 45°.

5. A die head device for preparing heterogeneous adhesive films, characterized in that: For preparing the heterogeneous adhesive film according to any one of claims 1 to 4, comprising: a first feed channel and a second feed channel; a first forming channel connected to the first feeding channel; the first forming channel is a connecting channel formed by a first flat half-channel and two first mixing half-channels located on both sides of the first flat half-channel; Two second forming channels connected to the second feeding channel; each second forming channel is a connecting channel formed by the second flat half channel and the second mixing half channel; A flat pressed channel, wherein the middle area of the inlet of the flat pressed channel is connected to the first forming channel, and the areas on both sides of the inlet of the flat pressed channel are connected to the second forming channel; wherein, one of the first mixing half-channel and one of the second mixing half-channel are commonly connected to the boundary inlet area between the middle area of the inlet and the areas on both sides of the inlet on the flat pressed channel; the surface shapes of the two adjacent channel inner walls of the first mixing half-channel and the second mixing half-channel match each other, and the plane where the two channel inner walls are located and the plane where the flat pressed channel is located are not perpendicular to each other.

6. The die head device for preparing heterogeneous adhesive films according to claim 5, characterized in that: The thickness of the first mixing half-channel gradually decreases from a side close to the first flat half-channel to a side away from the first flat half-channel; The thickness of the second mixing half channel gradually decreases from a side close to the second flat half channel to a side away from the second flat half channel.

7. The die head device for preparing heterogeneous adhesive films according to claim 5, characterized in that: The inner walls of the two adjacent channels of the first mixing half-channel and the second mixing half-channel are mutually engaged serrated inner walls or wavy curved inner walls.

8. The die head device for preparing heterogeneous adhesive films according to claim 5, characterized in that: The width of the first flat half channel is greater than the width of the second flat half channel; An angle between a plane where inner walls of two adjacent channels of the first mixing half-channel and the second mixing half-channel are located and a plane where the flat pressing channel is located is not greater than 45°.

9. The die head device for preparing heterogeneous adhesive films according to claim 5, characterized in that: The first feeding channel and the second feeding channel, the first forming channel and the second forming channel, and the flat pressing channel are sequentially distributed in three layers, upper, middle, and lower, within the same inverted cone; The first feed channel comprises a first inlet pipe and a first fluid pipe which are perpendicularly arranged and both are cylindrical; and a first fluid outlet having the same cross-sectional shape as the first forming channel is formed on the wall of the first fluid pipe; The second feed channel includes a first inlet pipe and a second fluid pipe that are perpendicular to each other and both are cylindrical; and two second fluid outlets with the same cross-sectional shape as the second forming channel are respectively formed on the pipe walls at both ends of the second fluid pipe; The first shaping channel extends obliquely downward from the first fluid outlet to an inlet middle area of the top end of the flat pressing channel; The two second forming channels extend obliquely downward from the two second fluid outlets to the areas on both sides of the inlet at the top of the flat pressing channel; and the oblique extension directions of the first forming channel and the second forming channel are opposite; The flat pressing channel is a plate-shaped channel extending in a vertical direction, and the discharge port of the flat pressing channel is located at the bottom end.

10. The die head device for preparing heterogeneous adhesive films according to any one of claims 5 to 9, characterized in that: A heating resistor is provided at a position where the first mixing half-channel and the second mixing half-channel are connected to the flat pressing channel, and the heating resistor is located between two adjacent channel inner walls of the first flat half-channel and the second mixing half-channel; The discharge port of the flat pressing channel is provided with a cooling structure.

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