The Study Of Key Technologies Of High Transparent BOPP Film

Biaxially Oriented Polypropylene (BOPP) takes polyolefin resin and additive as main raw materials, processed by a special extrusion technics, has a function of high lustrousness and low haze.The transparency of BOPP film is mainly reflected by two parameters, light transmittance and haze. This paper studied the film that made on some kinds of process by using the different synthesis technology of the raw material of PP, transparent agent and surface layer's anti-conglutination. The result showed that the raw material of PP of gas-phase synthesis because of having ruleless PP and much less impurities that produce the better film. Different transparent agents not only have different crystallization rates of PP and crystalloid morphology, but also have different effect of optical properties. Using two kinds of transparent agents with certain proportion can obtain the lower haze film. In addition, the anti-conglutination which added on surface layer to prevent film's adhesion should be chose with close or the same refraction coefficient with PP.When mass production of BOPP, the different production process make a large influence on crystallization rate of PP and crystalloid morphology, so the correlative processing temperature(extrusion temperature and casting temperature) also been researched. The result indicated that extruded melt's temperature should be controlled at about 230℃and casting temperature be controlled at the temperature when smaller crystal generate at the soonest, so as to avoid producing bigger crystallization.