In this process, the polymer melt is extruded through an annular die to a rising continuous tube which is cooled by an air ring and is simultaneously axially stretched and circumferentially ring and is simultaneously axiall stretched and circumferentially inflated by the take-up force,f, and the internal bubble pressure,respectively, until the freezeline height, L, is reached (see Fig1). Consequently, with the help of thecollapsing frames and nip roll,the solidified film bubble is changed from the bubble shape to alay-flat tube of film. The obtained biaxilly oriented polymer film has mechanical, physical, and optical properties(e.g.tensile strength, tear resistance,heat seal characteristic, transparency) that are desirable in daily used products,such as carrierbags,wrapping foils, garbage, medical films or as electrolytic membranes (where polylefines, ps,pvc pa respresents typical film blowing poylmers)