process and apparatus for electrostatically pinning a dielectric film to a moving surface which is electrically conducting and connected to a grounded fixed potential comprising a corona wire fed with a direct current and a semi - cylindrical metal counter - electrode connected to a potential which is approximately equal to the potential of the moving surface . when extruding a molten mass of polymer onto a cooling surface , a substantial increase in the speed of application is observed . the best results are obtained when the radius of the counter - electrode is approximately equal to the distance between the corona wire and the moving surface .