The Characteristics of photovoltaic PV film
Photovoltaic PV film as a part of one of the materials for solar panels encapsulations, the main role is to adhesive solar cells, solar temper glass and solar backsheet together. According to the actual application requirements of solar PV modulels in the premise of ensuring the transmission performance of the module can isolate the external water vapor, extend the life of the solar module, protect the battery, and package it into a solar module that can output direct current.
PV solar film in general should have high transparency, high adhesion, good weather resistance and easy storage, good sound insulation effect, low melting point, easy flow and other excellent performance characteristics.
The production of photovoltaic solar film is usually based on resin (EVA, POE) as the main material, through the addition of crosslinking agents, thickeners, antioxidants, light stabilizers, through melting extrusion, salivation into the film to get the finished product. Photovoltaic film is mainly divided into EVA film, POE film, EPE film and so on.
EVA film includes transparent EVA film and white EVA film two kinds, transparent EVA film has high light transmittance, UV moisture and heat yellowing resistance, snail line resistance, good adhesion and other characteristics, but poor reflection, high water permeability, easy to produce PID (potential potential induced attenuation) phenomenon, resulting in battery module power decline; The white EVA film is used for the packaging of the lower side of the photovoltaic module cell, which can make the sunlight reflect twice to the surface of the battery, improve the power generation efficiency of the solar module, and the disadvantage is that the price is higher. Compared with EVA film, POE film has higher water vapor barrier rate, weather resistance and stronger anti-PID performance, and its water vapor transmittance is only 1/8 of EVA film, which can effectively reduce PID effect, mainly used for single-crystal PERC (emitter and back passivation battery) double-sided, N-type battery package. EPE film, namely "EVA-POE-EVA" three-layer composite structural film, belongs to co-extruded POE film, which not only has the high water resistance and high PID resistance of POE film, but also has the lamination process characteristics of the double glass component of EVA film with high yield. Suitable for PERC double-sided double glass, N-type double-sided double glass and other photovoltaic modules with high weather resistance requirements.
