Preparation equipment and method of photovoltaic front plate

Abstract

The invention relates to the technical field of photovoltaic modules, and provides equipment and a method for preparing a photovoltaic front plate. After glass fiber cloth is unwound, resin powder scattering, dipping, film covering, pre-crosslinking curing, embossing, post-crosslinking curing and sizing are continuously carried out in a transmission state, and the photovoltaic front panel is obtained. The impregnation comprises the steps of melt impregnation, heating and pressurizing, thickness control and first cooling in sequence; and the curing degree of the pre-crosslinked and cured resin is 30-60%. According to the preparation equipment and method provided by the invention, continuous production of the photovoltaic front plate can be realized, the production efficiency is high, the energy consumption is low, the energy is saved, and the obtained product is good in thickness uniformity, high in light transmittance and strong in binding force of a functional film, and has a wide application prospect.

Description

Technical Field

[0001] The present invention relates to the technical field of photovoltaic modules, and in particular to equipment and a method for preparing a photovoltaic front panel. Background Art

[0002] Photovoltaic power generation utilizes the photovoltaic effect at the interface of semiconductors to directly convert sunlight into electricity. It primarily consists of three main components: photovoltaic modules (solar panels), a controller, and an inverter. The photovoltaic front sheet, a crucial component of a photovoltaic module, is primarily made of transparent glass. Its primary function is to protect the photovoltaic cells from environmental influences (such as rain and sandstorms) while allowing sunlight to pass through, enabling the cells to effectively convert light into electricity. Currently, the mainstream product for photovoltaic front sheets is low-iron tempered embossed glass, produced using a specialized embossing machine to create a custom pyramidal pattern on ultra-clear glass. However, this low-iron tempered embossed glass is heavy and complex to produce.

[0003] Photovoltaic front panels made from fiberglass cloth and polymer films are lightweight, easy to install and transport, and are increasingly being used, particularly in the packaging structures of lightweight components. Related art discloses methods for making lightweight photovoltaic front panels using fiberglass cloth. These methods involve first preparing a resin solution using solvents, resins, curing agents, and modifiers. This resin solution is then applied to the surface of the fiberglass cloth to produce an impregnated fiberglass cloth. The cloth is then cut, and the cut impregnated fiberglass cloth and polymer film are then pressed together using a press. This method is complex to operate, has low production efficiency, and produces a product with poor thickness uniformity. Summary of the Invention

[0004] In view of this, the present invention provides a photovoltaic front sheet preparation device and method. The photovoltaic front sheet preparation method provided by the present invention is simple to operate, can achieve continuous production of photovoltaic front sheets, has high production efficiency, and the resulting product has good thickness uniformity, high light transmittance, and strong bonding strength of the functional film.

[0005] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions: The present invention provides a method for preparing a photovoltaic front plate, comprising the following steps: After the glass fiber cloth is unwound, the resin powder is continuously sprinkled, impregnated, coated, pre-crosslinked and cured, embossed, post-crosslinked and cured, and shaped in a transmission state to obtain the photovoltaic front panel; The impregnation comprises sequentially performing melt impregnation, heating and pressurizing, thickness control, and first cooling; The curing degree of the resin after the pre-crosslinking curing is 30-60%.

[0006] Furthermore, the unwinding tension of the glass fiber cloth is 0-50N; the resin powder includes one or more of epoxy resin powder, acrylic resin powder, polyolefin resin powder, polyester resin powder and resin-based composite powder; and the average particle size of the resin powder is 1-1000µm.

[0007] Furthermore, the melt impregnation temperature is 80-160° C., and the time is 10-30 min; the melt impregnation is performed in a melt impregnation oven; and exhaust is performed during the melt impregnation process; The heating and pressurizing are carried out by a heating and pressurizing roller group, the temperature of the heating and pressurizing roller group is 80~180℃, and the air gap is 0.15~5mm; the thickness control is carried out by a thickness control roller group, the temperature of the thickness control roller group is 80~180℃, and the air gap is 0.1~4mm; the first cooling is carried out by a first cooling roller group; the temperature of the first cooling is below 90℃.

[0008] Furthermore, the functional film used in the lamination is a weather-resistant film, an anti-reflection film, a UV cutoff film or a water-blocking film; the unwinding tension of the functional film is 0~50N; the lamination is carried out under the action of a laminating roller group, the temperature of the laminating roller group is 50~150℃, and the line pressure is 20~150N / mm.

[0009] Furthermore, the pre-crosslinking curing is carried out in a pre-crosslinking curing oven, which includes an upper oven and a lower oven, the temperature of the upper oven is 120-180° C., and the temperature of the lower oven is 100-130° C.; the pre-crosslinking curing time is 2-30 min.

[0010] Furthermore, the embossing is performed by an embossing roller set, wherein the upper roller temperature of the embossing roller set is 80-190° C., and the lower roller temperature is 70-150° C.; Preheating is performed before post-crosslinking and curing, and the preheating temperature is 40-150°C; The post-crosslinking curing includes a first stage and a second stage, wherein the temperature of the first stage is 100-190° C. and the time is 10-90 min, and the temperature of the second stage is 100-150° C. and the time is 10-90 min; the post-crosslinking curing is carried out in a post-crosslinking curing oven; After the post-crosslinking and curing, a second cooling is performed; the second cooling is performed by a second cooling roller group, and the temperature of the second cooling is below 90°C.

[0011] Furthermore, the shaping includes sequentially performing tempering and third cooling; the tempering is performed by a tempering roller group, and the third cooling is performed by a third cooling roller group; The tempering temperature is 80-130° C., the time is 1-20 min, and the pressure is 0-50N; the third cooling temperature is below 90° C., the time is 1-30 min, and the pressure is 0-40N.

[0012] The present invention also provides a preparation equipment for the photovoltaic front panel used in the preparation method described in the above scheme, comprising a pre-treatment module, a coating device, a pre-crosslinking curing oven, an embossing roller group, an embossing roller group, a post-crosslinking curing device, and a shaping device arranged in sequence along the conveying direction of the glass fiber cloth; the pre-treatment module can sprinkle resin powder on the unwound glass fiber cloth, and heat and pressurize, control thickness and perform a first cooling in sequence after melt impregnation; the coating device has a coating unwinding roller and a coating roller group arranged up and down, the surface of the coating roller group is provided with a staggered roller, which can separate the product after the first cooling from the coating unwinding roller The film released by the roller is pressed and connected; the pre-crosslinking and curing oven arranged at the end of the laminating device includes an upper oven and a lower oven, and the laminated product passes between the upper oven and the lower oven; the embossing roller group is arranged at the end of the pre-crosslinking and curing oven, which includes an upper roller and a lower roller, and the upper roller and the lower roller can emboss the pre-crosslinked and cured coated glass fiber cloth; the post-crosslinking and curing device includes a first preheating roller, a post-crosslinking and curing oven and a second cooling roller group which are sequentially arranged at the end of the embossing roller group; the shaping device is located at the end of the second cooling roller group, and includes a tempering roller group and a third cooling roller group.

[0013] Furthermore, the pretreatment module includes a melt impregnation device, a heating and pressure roller group, a thickness control roller group and a first cooling roller group arranged in sequence along the transmission direction of the glass fiber cloth; the melt impregnation device includes a melt impregnation oven and an exhaust roller group; a unwinding device and a powder sprinkler are provided at the front end of the melt impregnation oven, the unwinding device can unwind the glass fiber cloth and transport it to the melt impregnation oven, and the powder sprinkler can sprinkle resin powder on the glass fiber cloth located between the melt impregnation oven and the unwinding device.

[0014] Furthermore, it also includes a plurality of conveying devices, which are respectively located at the front end of the pretreatment module, between the pretreatment module and the laminating device, between the laminating device and the pre-crosslinking curing oven, between the pre-crosslinking curing oven and the embossing roller group, between the embossing roller group and the post-crosslinking curing device, and between the post-crosslinking curing device and the shaping device; the conveying device includes a horizontally arranged active drive roller and a driven drive roller, and the active drive roller and the driven drive roller are connected by a closed conveyor belt, and the conveyor belt includes a release layer, a heat-conducting diffusion layer and an anti-slip layer arranged in sequence from the outside to the inside. Through the layered structure of the conveyor belt, the side of the conveyor belt that contacts the active drive roller and the driven drive roller will not slip, and the transmission process is more stable. The release layer and the heat-conducting diffusion layer can achieve uniform and stable heat on the surface of the conveyor belt, ensuring that the resin powder is heated and melted evenly, so that the product is infiltrated, cured, and has uniform performance, ensuring uniform product performance and quality.

[0015] The present invention provides a method for preparing a photovoltaic front panel, comprising the following steps: after unwinding a fiberglass cloth, continuously performing resin powder sprinkling, impregnation, laminating, pre-crosslinking and curing, embossing, post-crosslinking and curing, and shaping in a transmission state to obtain the photovoltaic front panel; the impregnation comprises sequentially performing melt impregnation, heating and pressurizing, thickness control, and a first cooling; and the degree of curing of the resin after the pre-crosslinking and curing is 30-60%. The present invention uses solid resin powder as a raw material, and after sprinkling the resin powder on the surface of the fiberglass cloth, continuously performs each subsequent step, omitting the resin liquid preparation process, is suitable for continuous production, can significantly improve production efficiency, reduce production energy consumption, save energy, and the resulting product has good thickness uniformity, high light transmittance, and strong binding force of the functional film. At the same time, the present application sets the embossing step between the pre-crosslinking curing and the post-crosslinking curing, and by controlling the curing degree of the pre-crosslinking curing, the embossing can be effectively carried out; furthermore, the embossing step of the traditional method is usually carried out by a pressing machine, which is inconvenient to operate and cannot achieve continuous production. The present invention uses an embossing roller group for embossing, which can realize embossing during the transmission process of the glass fiber cloth, with simple operation and high efficiency.

[0016] In addition, the present invention can further guarantee the performance of the product obtained by continuous production and ensure the stable progress of the production process by controlling the process parameters of each step.

[0017] In addition, the present invention uses a coating roller group for coating, which can improve the flatness and thickness uniformity of the product and improve the bonding strength between the functional film and the glass fiber cloth. Moreover, the traditional method usually requires covering the surface of the glass fiber cloth with a layer of adhesive film and using the adhesive film to composite the glass fiber cloth and the functional film. The method of the present invention can omit the use of the adhesive film.

[0018] The present invention also provides a preparation device for a photovoltaic front panel. The equipment provided by the present invention can realize the continuous production of photovoltaic front panels, has high production efficiency, high automation level, and broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A schematic diagram of a photovoltaic front panel manufacturing apparatus according to one embodiment of the present invention; Figure 2 A schematic cross-sectional view of a conveyor belt according to one embodiment of the present invention; Figure 3 This is a schematic diagram of the first cooling roller assembly in a pressed state according to one embodiment of the present invention; Figure 4 A schematic front view of a laminating roller assembly according to one embodiment of the present invention; Figure 5 A schematic top view of a laminating roller assembly according to one embodiment of the present invention; Figure 6This is a process flow chart for preparing a photovoltaic front panel according to the present invention.

[0020] In the figure: 1-unwinding device, 2-powder spreading machine, 3-first preheating roller, 4-melt impregnation oven, 5-exhaust roller group, 6-heating and pressure roller group, 7-thickness control roller group, 8-first cooling roller group, 9-film unwinding roller, 10-film coating roller group, 11-pre-crosslinking and curing oven, 12-embossing roller group, 13-second preheating roller, 14-post-crosslinking and curing oven, 15-second cooling roller group, 16-tempering roller group, 17-third cooling roller group, 18-thickness gauge, 19-trimming machine, 20-cutting machine, 21-conveyor belt, 2101-release layer, 2102-thermal diffusion layer, 2103-anti-slip layer, 22-glass fiber cloth. DETAILED DESCRIPTION

[0021] The present invention provides a method for preparing a photovoltaic front plate, comprising the following steps: After the glass fiber cloth is unwound, the resin powder is continuously sprinkled, impregnated, coated, pre-crosslinked and cured, embossed, post-crosslinked and cured, and shaped in a transmission state to obtain the photovoltaic front panel; The impregnation comprises sequentially performing melt impregnation, heating and pressurizing, thickness control, and first cooling; The curing degree of the resin after the pre-crosslinking curing is 30-60%.

[0022] The present invention has no special requirements for the glass fiber cloth, and any cloth well known to those skilled in the art can be used.

[0023] In the present invention, the unwinding tension of the glass fiber cloth is preferably 0~50N, specifically 0N, 5N, 10N, 20N, 25N or 50N; the resin powder includes one or more of epoxy resin powder, acrylic resin powder, polyolefin resin powder, polyester resin powder and resin-based composite powder; in the present invention, the resin-based composite powder is preferably the strontium titanate nanomaterial in ZL202310776712.1; specifically, the raw materials for preparing the strontium titanate nanomaterial include a base material and a dispersant, and the mass of the dispersant is 0.05~0.2% of the mass of the base material; in terms of mass fractions, the base material includes the following raw materials for preparation: powder 50-90 parts of resin, 10-50 parts of curing agent, 0-20 parts of antioxidant, 0.05-0.2 parts of catalyst, 0-10 parts of surface adjuster, 0-20 parts of light stabilizer, 0.05-5 parts of strontium titanate nano-additive, wherein the strontium titanate nano-additive is a mixture of octahedral strontium titanate, hexahedral strontium titanate and irregular strontium titanate, and the mass ratio of the octahedral strontium titanate, hexahedral strontium titanate and irregular strontium titanate is 3-4:4-6:1-2; the particle size of the matrix material is 30-150 μm; the dispersant includes one or more of aluminum oxide, fumed silica and glass microbeads, and the particle size of the dispersant is 2-8 μm.

[0024] In the present invention, the average particle size of the resin powder is preferably 1 to 1000µm, specifically 5µm, 10µm, 50µm, 60µm, 100µm, 200µm, 300µm, 500µm or 1000µm; the present invention controls the particle size of the resin powder within the above range, which can improve the uniformity of the resin powder on the surface of the glass fiber cloth, is beneficial to the uniform melting and infiltration of the resin, and is beneficial to the control of the thickness of the product; in a specific embodiment of the present invention, the resin powder is preferably sprinkled by a powder sprinkler, and the unwound glass fiber cloth passes under the powder sprinkler, and the powder sprinkler evenly sprinkles the resin powder on the surface of the glass fiber cloth.

[0025] In the present invention, the impregnation includes sequentially performing melt impregnation, heating and pressurizing, thickness control, and first cooling; before the melt impregnation, the powdered glass fiber cloth is preferably preheated, and the preheating temperature is preferably 40-150°C, specifically 50°C, 70°C, 80°C, 100°C, 120°C, or 150°C.

[0026] In the present invention, the temperature of the melt impregnation is preferably 80-160° C., specifically 100° C., 120° C. or 140° C., and the time of the melt impregnation is preferably 10-30 min, specifically 15 min, 20 min or 25 min. The melt impregnation is preferably carried out in a melt impregnation oven, and the melt impregnation time is specifically calculated based on the time it takes for the glass fiber cloth with resin powder on its surface to pass through the melt impregnation oven. Exhaust is preferably performed during the melt impregnation process, specifically by providing an exhaust roller group inside the melt impregnation oven to exhaust the gas between the molten resin and the glass fiber cloth during the melt impregnation process, thereby fully ensuring that the molten resin has high fluidity. Multiple groups of small pressing rollers are continuously rolled multiple times to fully exhaust the gas between the resin and the glass fiber cloth, thereby accelerating the resin infiltration into the glass fiber.

[0027] In the present invention, the heating and pressurizing are preferably performed by a heating and pressurizing roller group. The temperature of the heating and pressurizing roller group is preferably 80~180℃, specifically 100℃, 120℃, 150℃ or 160℃. The air gap of the heating and pressurizing roller group is preferably 0.15~5mm, specifically 0.3mm, 0.45mm, 1mm, 2mm, 3mm or 4.5mm. In a specific embodiment of the present invention, the air gap of the heating and pressurizing roller group is preferably set according to the specifications of the target product. The present invention uses heating and pressurizing to completely penetrate the glass fiber cloth with the molten resin and achieve preliminary surface flattening.

[0028] In the present invention, the thickness control is preferably performed by a thickness control roller group, the temperature of the thickness control roller group is preferably 80~180℃, specifically 100℃, 120℃, 150℃ or 160℃, the air gap of the thickness control roller group is preferably 0.1~4mm, specifically 0.5mm, 0.3mm, 1mm, 1.5mm, 2mm or 3mm; the first cooling is preferably performed by a first cooling roller group; the temperature of the first cooling is preferably below 90℃, preferably 10~90℃.

[0029] In a specific embodiment of the present invention, the glass fiber cloth with resin powder on its surface is preheated and then sequentially passes through a melt impregnation oven (an exhaust roller group is provided in the melt impregnation oven), a heating and pressure roller group, a thickness control roller group, and a first cooling roller group under the action of a conveyor belt; in the melt impregnation oven, the resin powder melts at a high temperature and initially infiltrates into the glass fiber cloth; the exhaust roller group exhausts the molten resin-glass fiber cloth structure; the molten resin is then completely impregnated into the glass fiber cloth by the heating and pressure rollers and the surface is initially flattened; the resin is then gradually pressed to the target thickness of the melt impregnation stage by the thickness control roller group; and then the resin-glass fiber cloth is demolded from the conveyor belt by the first cooling roller group.

[0030] In the present invention, the coating is specifically a functional film coated on the surface of the resin-glass fiber cloth obtained after the first cooling; the functional film used for the coating is preferably a weather-resistant film, an anti-reflection film, a UV cut-off film or a water-blocking film, and the functional film is a polymer film, specifically preferably an ETFE film, a PVDF film or a PVF film; the unwinding tension of the functional film is preferably 0~50N, specifically 0N, 5N, 10N, 20N, 25N or 50N; the coating is preferably carried out under the action of a coating roller group, the temperature of the coating roller group is preferably 50~150℃, specifically 60℃, 80℃, 120℃ or 140℃, and the line pressure is preferably 20~150N / mm, specifically 30N / mm, 50N / mm, 80N / mm or 120N / mm. Before laminating, the resin-glass fiber cloth after the first cooling is preferably preheated, and the preheating temperature is preferably 100-150° C., specifically 100° C., 120° C., 140° C., or 150° C. In a specific embodiment of the present invention, after the resin-glass fiber cloth after the first cooling is demolded from the conveyor belt, it continues to be conveyed, passes through the laminating roller group, and is laminated with the functional film to obtain a coated glass fiber cloth.

[0031] In the present invention, the pre-crosslinking and curing is preferably carried out in a pre-crosslinking and curing oven, and the pre-crosslinking and curing oven preferably includes an upper oven and a lower oven. The temperature of the upper oven is preferably 120-180°C, specifically 130°C, 150°C or 160°C, and the temperature of the lower oven is preferably 100-130°C, specifically 110°C or 120°C; the pre-crosslinking and curing time is preferably 2-30 min, specifically 5 min, 10 min or 15 min, and the pre-crosslinking and curing time is preferably calculated based on the time it takes for the coated glass fiber cloth obtained after coating to pass through the pre-crosslinking and curing oven. During the pre-crosslinking and curing process, the temperature is raised again to increase the crosslinking and curing degree of the resin, increase the bonding strength between the functional film and the resin, and soften the resin in preparation for embossing. In the present invention, after the pre-crosslinking and curing, the curing degree of the resin in the obtained pre-crosslinking and curing material is 30-60%, thereby keeping the resin in a highly elastic state. In the present invention, the upper surface of the coated glass fiber cloth is a functional film. During subsequent embossing, the resin on the upper surface does not directly contact the upper roller of the embossing roller group. The present invention controls a relatively high upper oven temperature to make the upper surface of the resin in a highly elastic state, thereby increasing the bonding strength between the functional film and the resin and softening the resin, thereby facilitating surface embossing. At the same time, the resin on the lower surface of the coated glass fiber cloth will directly contact the lower roller of the embossing roller group during subsequent embossing. The present invention controls a relatively low lower oven temperature to ensure that the lower surface of the product is better demoulded from the lower roller of the embossing roller group.

[0032] In the present invention, the embossing is preferably performed using an embossing roller assembly. The upper roller temperature of the embossing roller assembly is preferably 80-190°C, specifically 100°C, 130°C, 150°C, or 180°C, and the lower roller temperature is preferably 70-150°C, specifically 80°C, 90°C, or 120°C. The gap between the upper and lower rollers in the embossing roller assembly is preferably 0.1-1.2 mm. The present invention utilizes the embossing roller assembly to heat-press the desired pattern onto the surface of the functional film, and controls the thickness of the product by controlling the gap between the embossing rollers. Furthermore, the present invention provides a release treatment on the lower roller surface of the embossing roller assembly, enabling demolding at a high temperature of 130°C (with a demolding force of <1 N / cm) and a demolding angle of 30-90°. The release treatment is preferably performed by applying a release coating or performing an ultra-finished mirror finish. The release coating is preferably a non-sticky material coating, more preferably a polytetrafluoroethylene coating. The ultra-finished mirror finish preferably has a roughness (Ra) of less than 0.01 μm.

[0033] In the present invention, before the post-crosslinking and curing, the embossed material is preferably preheated, and the preheating temperature is preferably 45-150°C, specifically 50°C, 70°C, 80°C, 100°C, 120°C or 150°C.

[0034] In the present invention, the post-crosslinking curing preferably includes a first stage and a second stage, the temperature of the first stage is preferably 100~190°C, specifically 120°C, 150°C, 160°C or 180°C, the time of the first stage is preferably 10~90min, specifically 20min, 40min, 60min or 80min, the temperature of the second stage is preferably 100~150°C, specifically 110°C, 120°C or 130°C, the time of the second stage is preferably 10~90min, specifically 20min, 40min, 60min or 80min; the post-crosslinking curing is preferably carried out in a post-crosslinking curing oven.

[0035] In the present invention, a second cooling is preferably performed after the post-crosslinking and curing; the second cooling is preferably performed by a second cooling roller set, and the temperature of the second cooling is preferably below 90°C, preferably 10-90°C.

[0036] In a specific embodiment of the present invention, after the embossed product is preheated, it passes through a post-crosslinking curing oven and a second cooling roller group in sequence under the action of a conveyor belt. In the post-crosslinking curing oven, it is heated again to increase the crosslinking of the resin to the target curing range of the product, and then passes through the second cooling roller group to demold the post-crosslinking curing material and the conveyor belt.

[0037] In the present invention, the shaping preferably includes tempering and third cooling in sequence; the tempering temperature is preferably 80-130°C, specifically 100°C or 120°C, the tempering time is preferably 1-20 min, specifically 3 min, 5 min or 15 min, and in a specific embodiment of the present invention, the tempering time can be calculated by the vehicle speed and the contact area between the product and the tempering roller group; the tempering pressure is preferably 0-50N, specifically 5N, 10N, 30N or 45N; the tempering is preferably carried out by the tempering roller group, and the third cooling is carried out by the third cooling roller group; the third cooling temperature is preferably below 90°C, more preferably 10-90°C, and the third cooling time is preferably 1-30 min, specifically 2 min, 5 min or 20 min; in a specific embodiment of the present invention, the third cooling time can be calculated by the vehicle speed and the contact area between the product and the third cooling roller group; the third cooling pressure is preferably 0-40N, specifically 5N, 10N or 30N. The present invention releases the internal stress of the product through tempering and the third cooling to achieve product shaping.

[0038] In the present invention, after the third cooling, it is preferred that the obtained product is subjected to thickness measurement, cutting and screening and classification. In a specific embodiment of the present invention, the product after the third cooling passes through the thickness measurement section, the cutting section and the screening and classification section in sequence. The thickness uniformity of the product is detected in the thickness measurement section, and the thickness control system is automatically / manually adjusted to achieve stable thickness control; in the cutting section, the trimming position, width and cutting length of the target product are automatically / manually adjusted to cut out the specified product specifications as required; in the screening and classification section, the target product screening standard is input into the defect detection system, and the product is automatically judged and screened according to the standard after defect detection, and the product is classified and placed by a robot.

[0039] In a specific embodiment of the present invention, the transmittance of the prepared photovoltaic front panel is 88~93%, the thickness deviation is ≤±10%, the peeling force of the functional film is >5N, and the tensile strength of the photovoltaic front panel is 20~200N / 10mm.

[0040] The present invention also provides a preparation device for the photovoltaic front plate used in the preparation method of the above scheme, referring to Figure 1 Its structure includes a melt impregnation oven 4, an exhaust roller group 5, a heating and pressing roller group 6, a thickness control roller group 7, a first cooling roller group 8, a laminating device, a pre-crosslinking and curing oven 11, an embossing roller group 12, a post-crosslinking and curing device, a tempering roller group 16 and a third cooling roller group 17, which are arranged in sequence along the conveying direction of the glass fiber cloth 22. The crosslinking and curing box and the melt impregnation oven 4 are both known structures. A post-processing module is also provided at the end of the third cooling roller group 17. The post-processing module includes a thickness gauge 18, a trimming machine 19, a cutting machine 20, an inspection machine and a manipulator using mature and known structures. The post-processing module can measure the thickness and trim the product, and cut it to the required length. After passing the inspection, the product is transferred to the storage device by a manipulator. The front end of the melt impregnation oven 4 is provided with an unwinding device 1 and a powder spreading machine 2. The unwinding device 1 and the powder sprinkler 2 are both known structures, so they will not be described in detail. The unwinding device 1 can unwind the glass fiber cloth 22 and transport it to the melt impregnation oven 4. The powder sprinkler 2 can sprinkle resin powder on the glass fiber cloth 22 located between the melt impregnation oven 4 and the unwinding device 1. A second preheating roller 13 is provided at the front end of the melt impregnation oven 4, which can preliminarily preheat the product after powdering. The melt impregnation oven 4, the exhaust roller group 5, the heating and pressure roller group 6, the thickness control roller group 7, and the first cooling roller group 8 can sprinkle resin powder on the unwound glass fiber cloth 22, and heat, pressurize, control thickness and perform the first cooling in sequence after melt impregnation. The coating device has a coating unwinding roller 9 and a coating roller group 10 arranged up and down. A heating oven is provided before and after the coating roller group 10, which can control the temperature of the product before and after coating respectively. Figure 4 and Figure 5As shown, the surface of the laminating roller group 10 is provided with staggered rollers, which can hot-press and bond the product after the first cooling with the film released by the laminating unwinding roller; specifically, the laminating roller group 10 has a pre-hot-pressing laminating roller group and a post-hot-pressing laminating roller group. The surface of the pre-hot-pressing laminating roller group adopts a special staggered roller design, combined with the smooth surface design of the post-hot-pressing laminating roller group, to achieve efficient exhaust and bonding between the film and the resin layer; when working, the pre-hot-pressing laminating roller group forms an air channel at the staggered roller stripes after pressing, and the post-hot-pressing laminating roller group expels the gas from the air channel. The pre-crosslinking curing oven 11 provided at the end of the coating device includes an upper oven and a lower oven, and the coated glass fiber cloth passes through the upper oven and the lower oven; the embossing roller group 12 is provided at the end of the pre-crosslinking curing oven 11, which includes an upper roller and a lower roller, and the upper roller and the lower roller can emboss the pre-crosslinked cured coated glass fiber cloth; the post-crosslinking curing device includes a first preheating roller 3, a post-crosslinking curing oven 14 and a second cooling roller group 15, which are sequentially provided at the end of the embossing roller group 12; Figure 3 As shown, the first cooling roller group 8, the second cooling roller group 15 and the third cooling roller group 17 of this embodiment have the same structure, including cooling rollers arranged in an upper and lower staggered manner, and the cooling rollers are all mature and known structures; the first cooling roller group 8, the second cooling roller group 15 and the third cooling roller group 17 all adopt an upper and lower staggered pressure cooling roller arrangement, which effectively increases the contact area between the cooling roller group and the glass fiber cloth, improves the cooling effect, and avoids damage to the product due to direct pressure during the cooling process, especially for resins that harden after cooling, which can avoid cooling damage.

[0041] In one embodiment, in order to ensure smooth transmission of the glass fiber cloth 22 between various devices, a plurality of conveying devices are designed. The conveying devices are respectively located at the front end of the pretreatment module, between the pretreatment module and the laminating device, between the laminating device and the pre-crosslinking curing oven 11, between the pre-crosslinking curing oven 11 and the embossing roller group 12, between the embossing roller group 12 and the post-crosslinking curing device, and between the post-crosslinking curing device and the shaping device; in one embodiment, the conveying device includes a horizontally arranged active drive roller and a driven drive roller, and the active drive roller and the driven drive roller are connected by a closed conveyor belt 21. During the transmission between two adjacent processing sections, the glass fiber cloth is located on the conveyor belt 21, thereby achieving its smooth transmission.

[0042] In one embodiment, in order to achieve uniform and stable heat on the surface of the conveyor belt, ensure that the resin powder is heated and melted evenly, make the product evenly infiltrated, cured, and have uniform performance, and ensure uniform product performance and quality, this embodiment adopts a special multi-layer structure in the conveyor belt 21 of the prepreg section and the curing section. The multi-layer structure of the conveyor belt 21 includes a release layer 2101, a thermal diffusion layer 2102, and an anti-slip layer 2103, which are sequentially connected from the outside to the inside by a temperature-resistant thermally conductive adhesive to achieve high-strength bonding between layers. Among them, the release layer 2101 can be formed by a high-temperature resistant fabric surface that can be coated with fluorine (such as Teflon) or coated with silicon release treatment (such as silicone oil release agent); the thermal diffusion layer 2102 can be a single or multiple excellent thermal conductive metal wires (copper, aluminum, silver, etc. or alloys) uniformly woven in the longitudinal and transverse directions (the metal wire diameter is 100-2000µm), or it can be a uniform layer of excellent thermal conductive materials such as graphene, which can prevent the uneven heating of the resin caused by possible uneven heating of the oven. When the conveyor belt is unevenly heated, the heat can quickly diffuse to the low-temperature area to compensate for the temperature difference and ensure temperature uniformity, thereby achieving surface temperature uniformity of the release layer 2101. Figure 2 As shown, Figure 2 The middle arrow indicates the direction of heat diffusion; the anti-skid layer 2103 is in direct contact with the active transmission roller and the driven transmission roller to prevent slipping between the active transmission roller and the driven transmission roller. It adopts a structure of a rubber material with certain elasticity and high temperature resistance plus an anti-skid cloth, so that the anti-skid layer has both certain elasticity and anti-skid. Its elasticity applies a certain pressure value between the anti-skid layer and the guide roller during operation, further improving the anti-skid effect.

[0043] The following combination Figure 1 The process of preparing the photovoltaic front panel of the present invention is described in detail: the glass fiber cloth 22 is unwound by the unwinding device 1 and passes under the powder sprinkler 2. The powder sprinkler 2 sprinkles the resin powder on the surface of the glass fiber cloth 22. Then, it passes through the second preheating roller 13 for preheating under the conveying action of the conveyor belt 21, and then enters the melt impregnation oven 4 for melt impregnation. During the melt impregnation process, the exhaust is carried out by the exhaust roller group 5. After the melt-impregnated product is conveyed out of the melt impregnation oven 5, it passes through the heating and pressure roller group 6, the thickness control roller group 7 and the first cooling roller group 8 in sequence. The resin-glass fiber cloth is demolded from the conveyor belt by the first cooling roller group 8. Afterwards, the resin-glass fiber cloth is pressed and connected with the functional film unwound by the coating roller group 10 and the coating unwinding roller 9, and the obtained coated glass fiber cloth enters the pre-crosslinking curing oven 11 for pre-crosslinking curing, and then passes through the embossing roller group 12 for embossing, and then passes through the first preheating roller 13 for preheating, and then enters the post-crosslinking curing oven 14 for post-crosslinking curing, and then cools the second cooling roller group 15, and then passes through the tempering roller group 16 for tempering, and then passes through the third cooling roller group 17 for cooling, and then passes through the thickness gauge 18 for thickness measurement, the trimming machine 19 for trimming, and the cutting machine 20 for cutting to obtain the photovoltaic front panel of the present invention.

[0044] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0045] The photovoltaic special powder used in the following examples was prepared according to the method in Example 1 of ZL202310776712.1. By controlling the sieve mesh number, photovoltaic special powders with average particle sizes of 60±5µm and 300±10µm were obtained, which were used in Examples 1 and 2, respectively.

[0046] Example 1 use Figure 1 The equipment used in the preparation of photovoltaic front panels is as follows: Figure 6 As shown, the specific preparation method is as follows: The glass fiber cloth is unwound to the lower part of the powder spreading machine 2 with an unwinding tension of 3N, and the photovoltaic special powder (particle size of 60±5µm) is evenly sprinkled on the surface of the glass fiber cloth 22; then, under the action of the conveyor belt 21, it is preheated by the second preheating roller 13 and enters the melt impregnation oven 4 for melt impregnation, and is exhausted by the exhaust roller group 5, and then passes through the heating and pressure roller group 6, the thickness control roller group 7 and the first cooling roller group 8 in sequence to demould the resin-glass fiber composite material from the conveyor belt; the temperature of the second preheating roller 13 is 50℃, and the melt impregnation The temperature of the oven 4 is 160°C, and the time for passing through the melt impregnation oven 4 is 20 minutes; the exhaust roller group 5 is designed inside the melt impregnation oven 4, with a total of 6 groups of small pressing rollers. After continuous multiple rolling, the gas between the resin and the glass fiber cloth is fully discharged, accelerating the resin to impregnate the glass fiber; the temperature of the heating and pressure roller group 6 is 160°C, the air gap is 0.45mm, the temperature of the thickness control roller group 7 is 160°C, the air gap is 0.35mm, and the first cooling roller group 8 cools the temperature of the resin-glass fiber composite material to below 80°C.

[0047] The ETFE film is unwound with an unwinding tension of 5N. The resin-glass fiber composite material passes through the first cooling roller group 8 and is preheated in an oven in front of the coating roller group (preheating temperature is 100°C). Then, it is hot-pressed and bonded to the ETFE film under the action of the coating roller group. The temperature of the coating roller group 10 is 150°C and the line pressure is 50N / mm. The coated material enters the pre-crosslinking and curing oven 11. The upper oven temperature of the pre-crosslinking and curing oven 11 is 150°C, and the lower oven temperature is 110°C. The time for passing through the pre-crosslinking and curing oven 11 is 15 minutes. Then, it is embossed by the embossing roller group 12. The upper roller temperature of the embossing roller group 12 is 150°C, the lower roller temperature is 100°C, and the gap between the upper roller and the lower roller is 0.3mm.

[0048] The embossed material is preheated by the first preheating roller 3 under the action of the conveyor belt 21 and then enters the post-crosslinking curing oven 14, wherein the temperature of the first preheating roller 3 is 60°C, and the post-crosslinking curing oven 14 is divided into two sections, the temperature of the front section is 150°C, and the temperature of the rear section is 140°C. The embossed material takes 30 minutes to pass through the front section of the post-crosslinking curing oven 14, and 30 minutes to pass through the rear section of the post-crosslinking curing oven 14; the material passing through the post-crosslinking curing oven 14 is cooled to below 80°C by the second cooling roller group 15, and demolded from the conveyor belt, and then passes through the tempering roller group 16 and the third cooling roller group 17 in turn, the temperature of the tempering roller group 16 is 130°C, and the pressure is 10N, and the temperature of the material is cooled to below 80°C by the third cooling roller group 17, and the pressure of the third cooling roller group 17 is 10N.

[0049] The material passing through the third cooling roller 17 is measured by a thickness gauge 18 for thickness detection and adjustment, and then is trimmed by a trimming machine 19 and cut into specified product specifications by a cutting machine 20. Then it goes to the screening and classification section, and the target product screening standards are input into the defect detection system. After the product is defect-detected, the system automatically judges and screens it according to the standards, and classifies and places it by a robot.

[0050] Example 2 use Figure 1 The photovoltaic front panel is prepared using the equipment in the process. The specific preparation method is as follows: The glass fiber cloth 22 is unwound to the lower part of the powder spreading machine 2 with an unwinding tension of 10N, and photovoltaic special powder (average particle size of 300±10µm) is evenly sprinkled on the surface of the glass fiber cloth 22; then, under the action of the conveyor belt 21, it is preheated by the second preheating roller 13 and enters the melt impregnation oven 4 for melt impregnation, and is exhausted by the exhaust roller group 5. After that, it passes through the heating and pressure roller group 6, the thickness control roller group 7 and the first cooling roller group 8 in sequence to release the resin-glass fiber composite material from the conveyor belt; the temperature of the second preheating roller 13 is 60℃ The temperature of the melt impregnation oven 4 is 180°C, and the time for passing through the melt impregnation oven 4 is 30 minutes; the exhaust roller group is designed inside the melt impregnation oven 4, with a total of 6 groups of small pressing rollers. After continuous multiple rolling, the gas between the resin and the glass fiber cloth is fully discharged, accelerating the resin to impregnate the glass fiber; the temperature of the heating and pressure roller group 6 is 160°C, the air gap is 1.2mm, the temperature of the thickness control roller group 7 is 150°C, the air gap is 1.05mm, and the first cooling roller group 8 cools the temperature of the resin-glass fiber composite material to below 80°C.

[0051] The ETFE film is unwound with an unwinding tension of 10N. The resin-glass cloth passing through the first cooling roller group 8 is preheated in an oven in front of the laminating roller group (preheating temperature is 100°C), and then hot-pressed and bonded to the ETFE film under the action of the laminating roller group 10. The temperature of the laminating roller group 10 is 150°C and the line pressure is 60N / mm. The laminated material enters the pre-crosslinking and curing oven 11. The upper oven temperature of the pre-crosslinking and curing oven 11 is 170°C, and the lower oven temperature is 120°C. The time for passing through the pre-crosslinking and curing oven 11 is 30 minutes. After that, it is embossed by the embossing roller group 12. The upper roller temperature of the embossing roller group 12 is 160°C, the lower roller temperature is 120°C, and the gap between the upper roller and the lower roller is 1.0mm.

[0052] The embossed material is preheated by the first preheating roller 3 under the action of the conveyor belt 21 and then enters the post-crosslinking curing oven 14, wherein the temperature of the first preheating roller 3 is 50°C, and the post-crosslinking curing oven 14 is divided into two sections, the temperature of the front section is 165°C, and the temperature of the rear section is 150°C. The embossed material takes 35 minutes to pass through the front section of the post-crosslinking curing oven 14, and 25 minutes to pass through the rear section of the post-crosslinking curing oven 14; the material passing through the post-crosslinking curing oven 14 is cooled to below 80°C by the second cooling roller group 15, and demolded from the conveyor belt, and then passes through the tempering roller group 16 and the third cooling roller group 17 in turn, the temperature of the tempering roller group 16 is 130°C, and the pressure is 5N, and the temperature of the material is cooled to below 80°C by the third cooling roller group 17, and the pressure of the third cooling roller is 5N.

[0053] The material passing through the third cooling roller 17 is measured by a thickness gauge 18 for thickness detection and adjustment, and then is trimmed by a trimming machine 19 and cut into specified product specifications by a cutting machine 20. Then it goes to the screening and classification section, and the target product screening standards are input into the defect detection system. After the product is defect-detected, the system automatically judges and screens it according to the standards, and classifies and places it by a robot.

[0054] The transmittance, thickness, thickness deviation, and peeling force between the ETFE film and the resin-glass fiber cloth layer of the photovoltaic front panels prepared in Examples 1 and 2 were tested. The results are shown in Table 1.

[0055] Table 1 Performance test results

[0056] According to the results in Table 1, it can be seen that the photovoltaic front sheet prepared by the present invention has good thickness uniformity, high light transmittance, strong bonding force of the functional film, and high tensile strength of the sheet.

[0057] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A method for preparing a photovoltaic front panel, characterized in that: The following steps are involved: After the glass fiber cloth is unwound, the resin powder is sprinkled, impregnated, coated, pre-crosslinked, embossed, post-crosslinked, and cured, and the photovoltaic front panel is obtained in a transmission state; The impregnation comprises sequentially performing melt impregnation, heating and pressurizing, thickness control and first cooling; The curing degree of the resin after the pre-crosslinking curing is 30-60%.

2. The preparation method according to claim 1, characterized in that: The unwinding tension of the glass fiber cloth is 0-50N; the resin powder includes one or more of epoxy resin powder, acrylic resin powder, polyolefin resin powder, polyester resin powder and resin-based composite powder; the average particle size of the resin powder is 1-1000µm.

3. The preparation method according to claim 1, characterized in that: The temperature of the melt impregnation is 80-160°C, and the time is 10-30 minutes; the melt impregnation is carried out in a melt impregnation oven; exhaust is performed during the melt impregnation process; The heating and pressurizing are carried out by a heating and pressurizing roller group, the temperature of the heating and pressurizing roller group is 80~180℃, and the air gap is 0.15~5mm; the thickness control is carried out by a thickness control roller group, the temperature of the thickness control roller group is 80~180℃, and the air gap is 0.1~4mm; the first cooling is carried out by a first cooling roller group; the temperature of the first cooling is below 90℃.

4. The preparation method according to claim 1, characterized in that: The functional film used in the lamination is a weather-resistant film, an anti-reflection film, an ultraviolet cut-off film or a water-blocking film; the unwinding tension of the functional film is 0~50N; the lamination is carried out under the action of a laminating roller group, the temperature of the laminating roller group is 50~150℃, and the line pressure is 20~150N / mm.

5. The preparation method according to claim 1, characterized in that: The pre-crosslinking curing is carried out in a pre-crosslinking curing oven, which includes an upper oven and a lower oven, the temperature of the upper oven is 120-180° C., and the temperature of the lower oven is 100-130° C.; the pre-crosslinking curing time is 2-30 minutes.

6. The preparation method according to claim 1, characterized in that: The embossing is performed by an embossing roller group, wherein the upper roller temperature of the embossing roller group is 80-190° C., and the lower roller temperature is 70-150° C.; Preheating is performed before the post-crosslinking and curing, and the preheating temperature is 40-150° C.; The post-crosslinking curing includes a first stage and a second stage, wherein the temperature of the first stage is 100-190°C and the time is 10-90 min, and the temperature of the second stage is 100-150°C and the time is 10-90 min; the post-crosslinking curing is carried out in a post-crosslinking curing oven; After the post-crosslinking and curing, a second cooling is performed; the second cooling is performed by a second cooling roller group, and the temperature of the second cooling is below 90°C.

7. The preparation method according to claim 1, characterized in that: The shaping includes tempering and third cooling in sequence; the tempering is performed by a tempering roller group, and the third cooling is performed by a third cooling roller group; The tempering temperature is 80-130° C., the time is 1-20 min, and the pressure is 0-50N; the third cooling temperature is below 90° C., the time is 1-30 min, and the pressure is 0-40N.

8. The photovoltaic front panel preparation equipment used in the preparation method according to any one of claims 1 to 7, characterized in that: include: A pretreatment module, which can sprinkle resin powder on the unwound glass fiber cloth, and then heat and pressurize, control thickness and perform the first cooling in sequence after melting and impregnation; A film coating device, comprising a film coating unwinding roller and a film coating roller group arranged up and down, wherein the surface of the film coating roller group is provided with staggered rollers, which can press and connect the product after the first cooling with the film released by the film coating unwinding roller; A pre-crosslinking curing oven provided at the end of the film coating device, comprising an upper oven and a lower oven, and the film coated product passes between the upper oven and the lower oven; An embossing roller group is arranged at the end of the pre-crosslinking curing oven, and comprises an upper roller and a lower roller, and the upper roller and the lower roller can emboss the pre-crosslinked and cured coated glass fiber cloth; A post-crosslinking and curing device comprises a first preheating roller, a post-crosslinking and curing oven and a second cooling roller group which are sequentially arranged at the end of the embossing roller group; The shaping device is located at the end of the second cooling roller group and includes a tempering roller group and a third cooling roller group.

9. The photovoltaic front panel manufacturing equipment according to claim 8, characterized in that: The pretreatment module comprises a melt impregnation device, a heating and pressure roller group, a thickness control roller group and a first cooling roller group which are sequentially arranged along the transmission direction of the glass fiber cloth; the melt impregnation device comprises a melt impregnation oven and an exhaust roller group; a unwinding device and a powder sprinkler are arranged at the front end of the melt impregnation oven, the unwinding device can unwind and convey the glass fiber cloth to the melt impregnation oven, and the powder sprinkler can sprinkle resin powder on the glass fiber cloth located between the melt impregnation oven and the unwinding device.

10. The photovoltaic front panel manufacturing equipment according to claim 8, characterized in that: It also includes multiple conveying devices, which are respectively located at the front end of the pretreatment module, between the pretreatment module and the laminating device, between the laminating device and the pre-crosslinking curing oven, between the pre-crosslinking curing oven and the embossing roller group, between the embossing roller group and the post-crosslinking curing device, and between the post-crosslinking curing device and the shaping device; the conveying device includes a horizontally arranged active transmission roller and a driven transmission roller, the active transmission roller and the driven transmission roller are connected by a closed conveyor belt, and the conveyor belt includes a release layer, a heat-conducting diffusion layer and an anti-slip layer arranged in sequence from the outside to the inside.

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