Photovoltaic glass is one of the key materials for solar cell modules, mainly used to protect the cells and increase the light transmittance. Its production process mainly includes the following steps:
1. Raw material preparation
A. Main raw materials: quartz sand, soda ash, limestone, dolomite, crushed glass, etc.
B. Ingredients: Mix the raw materials in a certain proportion to ensure the light transmittance, strength and weather resistance of the glass.
C. Additives: Add clarifying agents, oxidants, etc., to remove bubbles and enhance UV resistance.
2. Melting and forming
A. High-temperature melting: The mixed raw materials are heated in A kiln to 1500-1600℃ and melted into a uniform glass liquid.
B. Clarification and homogenization: By using high temperature and clarifying agents to remove bubbles, the composition of the glass liquid becomes uniform.
C. Forming process:
a. Rolling method: The glass liquid is pressed into shape by rolling rollers to form flat glass with special patterns on the surface.
b. Float method: The glass liquid floats on the tin liquid to form the shape, making the surface flatter, but subsequent treatment is required to enhance the light capture capacity.
3. Annealing
A. Annealing furnace: The formed glass is slowly cooled to eliminate internal stress and prevent cracking.
B. Temperature control: The cooling rate must be precisely controlled to ensure the mechanical strength of the glass.
4. Coating treatment
A. Objective: To enhance the light transmittance of glass.
B. Coating process:
A. Sol-gel method: Nano-coatings such as silica are applied to the surface of glass, and then a porous anti-reflective film is formed after high-temperature curing.
b. Magnetron sputtering method: By vacuum sputtering for film coating, it offers better uniformity but is more expensive.
5. Tempering treatment
A. Physical tempering: Heat the glass to A temperature close to its softening point, then rapidly cool it with cold air to form a compressive stress layer on the surface, thereby enhancing its strength.
B. Performance Requirements: It must meet standards such as impact resistance and wind pressure resistance.
6. Cutting and edge processing
A. Cutting: According to the size requirements of the components, use diamond tools to cut the glass into the specified size.
B. Edge grinding: Chamfer or polish the edges to prevent stress concentration and installation damage.
7. Cleaning and inspection
A. Cleaning: Remove surface dust, oil stains, etc., to ensure the adhesion for subsequent packaging.
B. Quality Inspection:
a. Light transmittance, thickness, surface defects.
b. Impact resistance test and weather resistance test
8. Packaging and Shipment
A. Packaging: Shockproof materials are used to separate the glass sheets to prevent damage during transportation.
B. Application: Delivered to solar module manufacturers for lamination and packaging.
