CAPACITOR HAVING A HAZY POLYPROPYLENE FILM

摘要

Hazy polypropylene film having a uniformly irregular or raised relief surface is provided for use as a dielectric medium in dielectric liquid impregnated electrical capacitors. In the blown tube process for manufacturing the film, the polypropylene tube emanating from an extruder has a section of the tube controlled in temperature. The temperature control causes continuous and uniform spherulite formation having a crystalline structure on the outer surface of the tube. Subsequent inflation of the tube causes the desired hazy irregularity to occur on the outer surface.