The silicon photovoltaic module is made up of several layers of raw materials called laminate and the essential accessory materials to make it usable.
The following materials are used to prepare the laminate:
- Glass (modules built in Italy usually use 4mm thick glass)
- Ethylene vinyl acetate - EVA
- Mono or polycrystalline cells
- EVA (elastic compound used in photovoltaic modules to protect photovoltaic cells)
- Glass or Backsheet (bottom cover)
Il glass is used as a base on which a thin EVA sheet is spread.
Above the EVA the photovoltaic cells are positioned facing with the photosensitive side down, then another sheet of EVA is spread and to complete another sheet of glass or a sheet of insulating plastic material.
Il glass is low in iron to ensure greater transparency to sunlight ed it is temperate. A glass of this type allows about 91,5% of the radiation received to pass through.
Everything is sent to the laminator, or oven.
This is a machine in which, after having created the vacuum in a few minutes, a plate, placed in contact, is heated up to 145 ° C for about ten minutes, in order to favor the polymerization of the EVA.
After this time, the finished product is extracted and sent to subsequent processing, having achieved the characteristics required by its installation.
If lamination is done correctly, the laminate is able to resist to the elements for at least 25 / 30 years.
All subsequent processes have the main purpose of making its use more comfortable and practical, actually slightly increasing its resistance over time.
Source: wikipedia.it
