Preparation and Properties Study on Highly Filled EVA Functional Composite Film
|School||East China University of Science and Technology|
|Keywords||EVA Highly Filled Functional Composite Film Property|
As a new type of solar cell encapsulation materials, Ethylene vinyl acetate copolymer (EVA) film comes to crosslink during packaging, and finally forms the gel which has homogeneous structure, high light transmission and good sealing; in the PV modules, the film in using process can effectively prevent the crystalline silicon cells from being corroded by gas, water, dust, etc. EVA film has a poor thermal conductivity, in the process of service, high temperature and ultraviolet easily maked it age. Through adding thermal conductive and insulating fillers, some properties of composite film could be effectively improved, such as the thermal conductivity, and the temperature of the battery module would be reduced; but with the increase of filling quantity, the processing and molding of film were difficult.This article mainly studied the preparation and properties of highly filled EVA functional composite film.To achieve the preparation of highly filled film which fitted for the requirements of the packaging, through the study of rheological properties and the optimization of molding process, and the action of liquidity of composite system was improved. Finally the composite film with uniform thickness could be prepared by hot pressing molding method, etc, and the volume content of the filler could as high as 0.5.By testing the heat-conducting and insulating property of filling system, and the results showed that the thermal conductivity of composite film got very good ascension, and its insulation performance didn’t distinctly drop after the filling, so the modification of film with functional fillers is successful. During the study of the mechanical properties、adhesive properties and the thermal stability of the film, it was found that in a certain range of filler content, the adhesive properties could meet packaging requirements, and the thermal stability improved.The tensile strengths and tensile elongation of composite film decreased.