Preparation And Characterization Of EVA Film For Encapsulanting PV Modules

Ethylene-Vinyl acetate copolymer (EVA) was used to prepare EVA films for encapsulanting PV modules. Vavious additives, including curing agents, coupling agent, antioxidants, were added to EVA by melt extrusion for obtaining modified EVA, and then the modified EVA particles was molded to form EVA films.The cross-linking kinetics of EVA encapsulation film were studied from the perspective of crosslinking agent, and processes of using three generations of cross-linking agents were compared, the results showed that luperoxTBEC is by far the most suitable cross-linking agent. Based on this, the influence of cross-linking degree on anti-aging and adhesive property was verified and discovered that the advisable crosslinking degree must between 75%-83%.The influence of silane coupling agent on the film adhesive property was investigated. At the same time, the effects of coupling agent for glass transmittance measured. It's concluded that when the amount of silane coupling agent was 0.4%, it can not only improve the adhesive property of EVA film, but also can effectively improve the optical transmittance of EVA film on glass.In order to explore the reasons of EVA film becoming yellow during outdoor using, Three tasks were mainly made:firstly, the factors that influence the anti-aging ability were investigated using the methods of speeding up the climate aging, then we measured the change of transmittance of EVA film in different climate. At last, the FTIR and TG of EVA film were analyzed both before and after aging.In conlusion, suitable antioxidants can obviously increase the anti-wet and heat ability of EVA film. Phosphate ester antioxidants are the most suitable. Ultraviolet absorption agent and light stability agent have the synergistic effect and can obviously increase the anti-ultraviolet light aging ability of EVA film.