The sealing material used for solar modules is generally silica gel. As shown in the figure, it is a special silica gel product for solar modules. Its main function is: not only for the bonding, fixing and sealing of solar panels, but also for sealing and wiring the aluminum frame of photovoltaic modules. The bonding and sealing of the box and the TPT/TPE backplane, as well as the sealing of solar lamps, etc., play a role in protecting the crystalline silicon wafers from pollution and oxidation.
Silicone products for solar modules
The use of silica gel as a sealing material for solar modules has the following excellent characteristics.
①Neutral curing at room temperature, white, paste-like, fast deep curing.
②Good sealing, strong adhesion, good adhesion to aluminum, tempered glass, TPT/TPE backing material, junction box plastic PPO/PA, and no corrosion.
③It is resistant to aging, ultraviolet radiation, moisture-proof and waterproof.
④ High and low temperature resistance (65～230℃), resistance to hail impact, resistance to humidity, cold and heat.
⑤Excellent weather resistance, long-term exposure to the outdoors will not turn yellow and maintain good adhesion.
⑥Non-toxic, non-corrosive, non-polluting and environmentally friendly.
⑦The process is simple, convenient, easy to operate, and the cost is very low.
Some companies also use double-sided tape and foam instead of silica gel.
Pay attention to the following matters when using special silica gel for solar modules.
①The bonding surface should be pretreated. Use solvents such as isopropanol, acetone or methyl ethyl ketone to remove all grease and contaminants that affect bonding, and keep all surfaces clean and dry. The bonding of certain specific plastics requires special surface treatment, for example, polypropylene and PTFE require chemical corrosion or plasma treatment to achieve the best bonding.
②How to use: Apply neutral sealant on the pretreated surface, and then quickly cover the other side that needs to be bonded. When exposed to moisture, at room temperature and 50% relative humidity, the surface of the sealant will crust within 10 to 15 seconds. The excess sealant can be easily scraped off with a knife before the surface is skinned.
③Curing time After the cured surface is formed, the curing will continue to deepen from the surface. The curing thickness of the neutral sealant is about 3.3mm within 24h (under room temperature and 50% relative humidity). The deeper part where the air is difficult to reach, the curing time will be longer. The curing time will also be prolonged under low humidity conditions. Before handling and packaging the bonded parts, wait patiently (for enough time) to ensure that the integrity of the sealant is not affected.
④Validity period and storage When the neutral sealed collagen package is not opened, the sealant has a validity period of 9 months from the date of production (conditions: the storage temperature is below 27℃, and the storage place is in a cool and dry place). Since the neutral sealant reacts easily with moisture in the air and solidifies, the sealant container should be tightly sealed when not in use. During storage, blocking seals are easily formed on the sealant cylinder or tube end. These seals can be easily cleaned without affecting the remaining components.
⑤ Matters needing attention before curing Although the silicone is completely cured, it is non-toxic, but before curing, avoid contact with eyes and children, and keep the working environment well ventilated.
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