Preparation method of impact-resistant high-strength double-plated tempered photovoltaic glass

Abstract

The invention discloses a preparation method of impact-resistant high-strength double-plated tempered photovoltaic glass, and belongs to the technical field of photovoltaic glass production and processing, a whole set of 2.0 mm photovoltaic glass production and processing technology is established through the working procedures of burdening, melting, forming, annealing, cutting, stacking, edging, film plating, tempering and the like, and when a double-plated tempered 2.0 mm photovoltaic glass product is produced, the impact-resistant high-strength double-plated tempered photovoltaic glass product is produced, the production cost is reduced, and the production efficiency is improved. By controlling the thickness of the photovoltaic glass in the forming production of the photovoltaic glass and controlling the film layer thickness of the first coating film in the double-coating film coating processing of the photovoltaic glass, the furnace temperature curve process in the tempering processing is greatly improved, and the tempering size performance is ensured to reach the standard while the tempering safety performance is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of photovoltaic glass production and processing, and in particular to a method for preparing impact-resistant high-strength double-plated tempered photovoltaic glass. Background Art

[0002] Solar photovoltaic cells are used to convert sunlight directly into electricity. Photovoltaic glass, located on the outermost layer of the front surface, is directly exposed to sunlight, utilizing its extremely high transmittance (>94.0%) to provide light energy to the cells. The manufacturing process of photovoltaic glass includes batching, melting, forming, annealing, cutting, stacking, edging, coating, and tempering.

[0003] During the photovoltaic glass forming process, the thickness specification of 2.0mm photovoltaic glass is: 2.00±0.15mm. In actual production, in order to reduce costs, negative management is usually adopted, that is, the thickness is controlled within 2.00~1.90mm.

[0004] Photovoltaic glass coating: can effectively improve the solar transmittance of the glass surface, thereby improving the conversion efficiency and output power of photovoltaic cells.

[0005] During the double-plating process of photovoltaic glass, the standard thickness of one coating layer is: 80±15nm. In actual production, in order to ensure the transmittance gain of the coating, it is usually managed thicker: that is, the thickness of one coating layer is controlled at 80~95nm.

[0006] During the tempering process of photovoltaic glass, based on the requirements of safety performance, photovoltaic glass must undergo tempering processing (forming compressive stress on the surface of photovoltaic glass and tensile stress inside photovoltaic glass) to achieve the purpose of surface strengthening.

[0007] The table for judging the quality and safety performance of 2.0mm photovoltaic glass tempering is as follows:

[0008]

[0009] In the existing production of double-coated tempered 2.0mm photovoltaic glass, the impact resistance can meet the safety performance requirements of small balls not being broken, but cannot meet the safety performance requirements of medium balls not being broken.

[0010] This application improves the impact strength to a higher level: meeting the safety performance requirement of the ball not being broken. Summary of the Invention

[0011] In view of the deficiencies in the prior art, the present invention provides a method for preparing impact-resistant, high-strength, double-plated tempered photovoltaic glass.

[0012] Based on the above objectives, the present invention adopts the following technical solutions:

[0013] A method for preparing impact-resistant, high-strength, double-coated tempered photovoltaic glass comprises the following steps: feeding uniformly mixed glass raw materials into a tank furnace to be melted into glass liquid, hydraulically rolling the glass into shape, and then annealing the glass plates to obtain glass plates, cutting, stacking, and edge grinding the glass plates before double-coating them, tempering them in a tempering furnace after the double-coating, and cooling them after exiting the tempering furnace to obtain finished photovoltaic glass. During rolling forming, the thickness is controlled to be 2.00-2.10 mm, during double-coating, the thickness of the first film layer is 70±5 nm, and the thickness of the second film layer is 120±15 nm, and the temperature curve of the tempering furnace is as follows: the furnace inlet temperature is 540-560° C., the high-temperature zone temperature is 700-720° C., and the tempering time is 96-102 seconds.

[0014] Furthermore, the glass raw material comprises, by mass percentage, SiO2 70-75%, Na2O 10-15%, CaO 7-10%, MgO3-5%, Al2O3 0.1-1%, and Fe2O3 in the glass raw material is ≤150ppm.

[0015] Furthermore, the temperature at the feeding port in the pool furnace is 1400-1450°C, the temperature in the middle of the dissolving pool is 1550-1600°C, and the temperature at the calender inlet is 1100-1200°C.

[0016] Furthermore, annealing is carried out in an annealing furnace, which is provided with a heat preservation zone and a non-heat preservation zone from front to back. The length of the heat preservation zone is 35 to 40 meters, the temperature at the entrance of the heat preservation zone is 570 to 590 degrees Celsius, and the temperature at the exit of the heat preservation zone is 285 to 305 degrees Celsius. The running speed of the glass sheet in the annealing furnace is 10 to 14 meters per minute.

[0017] Furthermore, the composition of the coating solution used for the first coating layer is, by mass percentage, 1-methoxy-2-propanol 1-5%, ethanol 1-5%, silicon dioxide 3-5%; water 3-8%; nitric acid 0.1-0.5%; sodium hydroxide 0.1-0.5%; and isopropyl alcohol 80-90%.

[0018] Furthermore, the coating solution used for the second coating layer is composed of, by mass percentage, 1-methoxy-2-propanol 1-5%, ethanol 1-5%, water 5-10%, nitric acid 0.1-0.5%, methyl acrylate 0.5-1.5%, potassium persulfate 0.05-0.2%, polyethylene glycol 0.1-0.5%, mercaptoethanol 0.1-0.5%, sodium hydroxide 0.2%, and isopropyl alcohol 80-90%.

[0019] Furthermore, the length of the tempering furnace is 48 to 60 m, and the average running speed of the glass sheet in the tempering furnace is 36 to 38.4 m / min.

[0020] Furthermore, the cooling means that the glass sheet of the tempering furnace enters the high-pressure air grid at a speed of 45 to 51 m / min, and the pressure of the high-pressure air in the high-pressure air grid is 9000 Pa to 13000 Pa.

[0021] Furthermore, the operating speed during photovoltaic glass coating is 15 to 18 m / min.

[0022] Furthermore, the molecular weight of the polyethylene glycol is 200-6000.

[0023] Compared with the prior art, the present invention provides a method for preparing impact-resistant, high-strength, double-plated, tempered 2.0mm photovoltaic glass, which has the following beneficial effects:

[0024] 1. The preparation method of the impact-resistant, high-strength, double-plated tempered 2.0mm photovoltaic glass lays the foundation for improving the safety performance of tempered glass by controlling the thickness of the photovoltaic glass during the molding production of the 2.0mm photovoltaic glass.

[0025] 2. The preparation method of the impact-resistant, high-strength, double-coated tempered 2.0mm photovoltaic glass controls the thickness of the first layer of coating in the double-coating process of the 2.0mm photovoltaic glass, thereby significantly improving the furnace temperature curve of the tempering process. While improving the safety performance of the tempering, it can also ensure that the tempering dimensional performance meets the standards.

[0026] 3. The preparation method of the impact-resistant high-strength double-coated tempered 2.0mm photovoltaic glass can improve the impact strength to the safety performance requirement of the medium ball without breaking by adjusting the furnace temperature curve and heating time during the tempering process, while the tempered size performance meets the standard.

[0027] 4. The preparation method of the impact-resistant, high-strength double-plated tempered 2.0mm photovoltaic glass has established a complete set of 2.0mm photovoltaic glass production and processing technology. When producing double-plated tempered 2.0mm photovoltaic glass products, by controlling the thickness of the photovoltaic glass in the photovoltaic glass molding production and the thickness of the first layer of coating in the photovoltaic glass double-plating processing, a significant improvement in the furnace temperature curve process in the tempering processing can be achieved, while improving the safety performance of the tempering and ensuring that the tempering size performance meets the standards. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a structural schematic diagram of a calender of the present invention;

[0029] In the figure: 1. Glass liquid; 2. Glass plate; 3. Calendering roller.

[0030] Figure 2 It is a schematic structural diagram of the coating machine of the present invention;

[0031] In the figure: 4, coating liquid; 5, coating roller; 6, photovoltaic glass.

[0032] Figure 3 Schematic diagram of the tempering furnace process-furnace temperature curve of the present invention;

[0033] In the figure: horizontal axis: 30 zones of the tempering electric heating furnace; vertical axis: furnace temperature setting value; red line: upper furnace temperature; blue line: lower furnace temperature.

[0034] Figure 4 This is a photo of the finished product of the double-coated tempered 2.0mm photovoltaic glass made by the present invention. DETAILED DESCRIPTION

[0035] The following is a clear and complete description of the technical solutions in the embodiments of the present invention, with reference to the accompanying drawings. It is obvious that the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts are within the scope of protection of the present invention.

[0036] Example 1

[0037] A method for preparing impact-resistant, high-strength, double-plated, tempered 2.0mm photovoltaic glass, the process is as follows:

[0038] (1) Ingredients: The raw material formula for photovoltaic glass, calculated by mass percentage, is: SiO2 72.5%, Na2O 14.0%, CaO 8.7%, MgO 3.9%, Al2O3 0.90%, with Fe2O3 ≤ 150ppm. The various raw materials are homogenized and weighed (using electronic scales with automatic calibration and drop adjustment to achieve a dynamic accuracy of over 1 / 2000), then enter the mixer, undergo moisture control and iron removal, enter the furnace hopper, and then pass through the feeder before entering the tank furnace.

[0039] (2) Melting: The prepared batch materials are added into the pool furnace. Inside the pool furnace, the temperature of the feeding port is 1410℃, the temperature in the middle of the dissolving pool is 1560℃, and the temperature at the entrance of the calender is 1120℃. Complex physical and chemical changes occur in the pool furnace. After stirring and clarifying, the materials are melted into qualified glass liquid and supplied to the molding production through the channel.

[0040] (3) Molding: Figure 1 As shown, the glass liquid 1 flowing out of the channel is drained to the calender through the lip brick, and is pressed and cooled by the upper and lower calendering rollers 3 to form a glass plate 2 with a thickness of 2.00 to 2.10 mm (adjusted by the pressure of the calendering rollers). The glass plate 2 is sent to the annealing furnace at a running speed of 11.0 m / min.

[0041] (4) Annealing: The annealing furnace is an all-steel electric heating and air-cooling type. It is equipped with a heat preservation zone and a non-heat preservation zone from front to back. The length of the heat preservation zone is 37500mm, and the length of the non-heat preservation zone (open air) is 26750mm. By setting the temperature of each zone in the heat preservation zone (the heat preservation zone is evenly divided into five zones, and the heat preservation zones from front to back are A1 zone 581℃, A2 zone 552℃, B zone 448℃, and C zone 295℃), a certain annealing curve is formed to eliminate and balance the internal stress of the glass sheet caused by uneven temperature during the forming process.

[0042] (5) Cutting and stacking: The annealed glass sheets are cut longitudinally and transversely by longitudinal cutting machines and cross-cutting machines to obtain semi-finished original sheets with qualified length and width dimensions. The sheets are automatically unloaded and stacked by robots and provided to the processing steps for production.

[0043] (6) Edge grinding: Using mechanical grinding method, the photovoltaic glass original sheet automatically completes the grinding of the long and short sides to the set size, and the chamfer grinding of the four corners to the set size (grinding wheel processing speed for edge grinding: 15.0m / min).

[0044] (7) Double-layer coating process: using roller coating method, such as Figure 2 As shown, the coating liquid 4 is used to complete the double-layer standard thickness coating (adjusted by the coating roller speed; the first layer thickness is 70±5nm, the second layer thickness is 120±15nm) on the surface of the photovoltaic glass 6 through the reverse rotation of the coating roller 5, thereby improving the transmittance of the photovoltaic glass. The transmittance increase of the double-plated product can reach 2.4%. The running speed of the glass plate in this process is 15.0m / min.

[0045] Among them, the coating solution used for the first layer of coating is composed of, by mass percentage, 3% 1-methoxy-2-propanol, 3% ethanol, 3.6% silicon dioxide, 5% water, 0.2% nitric acid, 0.2% sodium hydroxide, and 85% isopropyl alcohol; the coating solution used for the second layer of coating is composed of, by mass percentage, 3% 1-methoxy-2-propanol, 3% ethanol, 7% water, 0.2% nitric acid, 1% methyl acrylate, 0.1% potassium persulfate, 0.3% polyethylene glycol (PEG-200), 0.2% mercaptoethanol, 0.2% sodium hydroxide, and 85% isopropyl alcohol.

[0046] (8) Tempering process: Photovoltaic glass is continuously fed into the tempering furnace at a conveying speed of 36.4 m / min. The tempering furnace adopts electric heating, such as Figure 3As shown in the figure, the total length of the tempering furnace is 60 meters, which is evenly divided into 30 zones. The temperature at the furnace entrance is 540-545°C, the temperature in the high-temperature zone (i.e., zones 19-27) is 710-715°C, and the total heating time of the tempering furnace is 99-100 seconds, completing the softening of the entire photovoltaic glass. The temperature of the photovoltaic glass is about 700°C when it is out of the furnace; then it enters the high-pressure wind grid at a transmission speed of 48.0m / min, and the high-pressure air (pressure of 11000Pa-11500Pa) is used to complete the rapid cooling of the photovoltaic glass surface (when leaving the high-pressure wind grid, the temperature of the photovoltaic glass is about 220°C); during the cooling process, the surface of the photovoltaic glass shrinks rapidly, generating compressive stress, and the middle layer of the photovoltaic glass cools slowly and has no time to shrink, forming tensile stress, so that the photovoltaic glass obtains higher strength and completes tempering.

[0047] Through the above process, a qualified double-coated tempered 2.0mm photovoltaic glass product is obtained with a transmittance of 94.1% to 94.2%. Figure 4 shown.

[0048] The criteria for judging the excellent rate, qualified rate and unqualified rate of the impact strength (drop ball) test are as follows:

[0049]

[0050]

[0051] 1. During conventional production of double-coated tempered 2.0 mm photovoltaic glass: in step (2), the average thickness of the glass plate 2 is 1.97 mm, and the range is 0.12 mm (measured at intervals of 250 mm along the short side, with a total of 50 groups of samples); in step (7), the average thickness of one layer of the film during the double-coating process is 85 nm (measured at a point 200 mm from the front, with a total of 50 samples) (after double-coating, the transmittance gain is 2.4%); in step (8), the tempering furnace inlet temperature is 500° C., the upper temperature of the high-temperature zone is 705° C., the lower temperature is 700° C., and the tempering furnace heating time is 102 seconds. Other conditions are the same as in Example 1.

[0052] Impact resistance: (falling ball) small ball qualified rate is 100%, excellent rate is 90%; (falling ball) medium ball qualified rate, as shown in Table 1 below.

[0053] Table 1

[0054] 21st 22nd 23rd 24th total Number of ball drops 17 18 13 5 53 6 broken 0 2 3 4 1 10 Good quality rate 11.76％ 16.67％ 30.77％ 20.00％ 18.87％ 6 broken 2 11 4 3 3 21 6 broken 3+ 2 5 2 0 9 Pass rate 23.53％ 50.00％ 61.54％ 40.00％ 43.40％

[0055] 2. When the double-coated tempered 2.0 mm photovoltaic glass is produced according to the control of the present invention: in step (2), the average thickness of the glass plate 2 is 2.04 mm, and the range is 0.10 mm (measured at intervals of 250 mm along the short side, with a total of 50 groups of samples); in step (7), the average thickness of one layer of the film in the double-coating process is 68 nm (measured at a point 200 mm away from the front, with a total of 50 samples), and after double coating, the transmittance gain is 2.3%; in step (8), the inlet temperature of the tempering furnace is 540°C, the upper temperature of the high-temperature zone is 715°C, the lower temperature is 710°C, and the heating time of the tempering furnace is 99 seconds.

[0056] Impact resistance: (falling ball) small ball qualified rate is 100%, excellent rate is 100%, (falling ball) medium ball qualified rate, as shown in Table 2 below.

[0057] Table 2

[0058] 8th 9th 10th 11th 12th total Number of ball drops 12 14 12 12 9 59 6 broken 0 6 2 7 3 4 22 Good quality rate 50.00％ 14.29％ 58.33％ 25.00％ 44.44％ 37.29％ 6 broken 2 0 1 0 1 1 2 6 broken 3+ 1 0 0 1 0 2 Pass rate 91.67％ 92.86％ 100.00％ 83.33％ 88.89％ 93.22％

[0059] From the data in Table 1 and Table 2, it can be seen that the present application increases the thickness of the original glass plate, reduces the thickness of the first coating layer, and adjusts the temperature of the tempering furnace to produce impact-resistant and high-strength double-coated tempered 2.0mm photovoltaic glass.

[0060] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing impact-resistant high-strength double-coated tempered photovoltaic glass, characterized in that: The process is as follows: the evenly mixed glass raw materials are sent into the pool furnace and melted into glass liquid. The glass is hydraulically rolled and then annealed to obtain a glass plate. The glass plate is cut, stacked, and edged before being double-coated. After double-coating, it is tempered in a tempering furnace and cooled after leaving the tempering furnace to obtain a finished photovoltaic glass product. During rolling forming, the thickness is controlled to be 2.00~2.10 mm. During double-layer coating, the thickness of the first layer is 70±5 nm, and the thickness of the second layer is 120±15 nm. The temperature curve of the tempering furnace is: the furnace inlet temperature is 540~560℃, the high temperature zone temperature is 700~720℃, and the tempering time is 96~102 seconds.

2. The method for preparing the impact-resistant high-strength double-coated tempered photovoltaic glass according to claim 1, characterized in that: Calculated by mass percentage, the glass raw material composition is: SiO2 70~75%, Na2O 10~15%, CaO 7~10%, MgO3~5%, Al2O3 0.1~1%, and Fe2O3 in the glass raw material is ≤150ppm.

3. The method for preparing the impact-resistant high-strength double-plated tempered photovoltaic glass according to claim 1, characterized in that: The temperature at the feeding port of the pool furnace is 1400~1450℃, the temperature in the middle of the dissolving pool is 1550~1600℃, and the temperature at the calender entrance is 1100~1200℃.

4. The method for preparing the impact-resistant high-strength double-plated tempered photovoltaic glass according to claim 1, characterized in that: Annealing is carried out in an annealing furnace, which is equipped with a heat preservation zone and a non-heat preservation zone from front to back. The length of the heat preservation zone is 35~40m, the temperature at the entrance of the heat preservation zone is 570~590℃, and the temperature at the exit of the heat preservation zone is 285~305℃. The running speed of the glass plate in the annealing furnace is 10~14 m / min.

5. The method for preparing the impact-resistant high-strength double-plated tempered photovoltaic glass according to claim 1, characterized in that: The composition of the coating solution used for the first coating layer is, in percentage by mass: 1-methoxy-2-propanol 1-5%, ethanol 1-5%, silicon dioxide 3-5%; water 3-8%; nitric acid 0.1-0.5%; sodium hydroxide 0.1-0.5%; and isopropyl alcohol 80-90%.

6. The method for preparing the impact-resistant high-strength double-plated tempered photovoltaic glass according to claim 1, characterized in that: The composition of the coating solution used for the second coating layer is as follows, in percentage by mass: 1-methoxy-2-propanol 1-5%, ethanol 1-5%, water 5-10%; nitric acid 0.1-0.5%; methyl acrylate 0.5-1.5%; potassium persulfate 0.05-0.2%; Polyethylene glycol 0.1~0.5%; Mercaptoethanol 0.1~0.5%; Sodium hydroxide 0.2%; Isopropyl alcohol 80~90%.

7. The method for preparing the impact-resistant high-strength double-plated tempered photovoltaic glass according to claim 1, characterized in that: The length of the tempering furnace is 48~60 m, and the average running speed of the glass sheet in the tempering furnace is 36~38.4 m / min.

8. The method for preparing the impact-resistant high-strength double-plated tempered photovoltaic glass according to claim 1, characterized in that: The cooling process refers to the glass sheets in the tempering furnace entering the high-pressure air grid at a speed of 45-51 m / min, where the pressure of the high-pressure air in the high-pressure air grid is 9000 Pa-13000 Pa.

9. The method for preparing the impact-resistant high-strength double-plated tempered photovoltaic glass according to claim 1, characterized in that: The operating speed during photovoltaic glass coating is 15~18 m / min.

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