Abstract: A film or fibrous web which has been stretched by moving at least two laterally spaced first longitudinal portions gripped by a first gripping means along at least two arcuate divergent paths formed jointly by at least two radially disposed first pulleys and endless belt means trained arcuately therearound, is further stretched by moving at least two laterally spaced second longitudinal portions adjacent to the first longitudinal portions gripped by a second gripping means along at least two arcuate divergent paths contiguous to the first arcuate divergent paths, respectively, formed jointly by at least two second pulleys, respectively, disposed downstream of and close to the first pulleys in coplanar relation thereto and second endless belt means trained arcuately therearound. The film while being stretched is heated to a temperature suitable for stretching with heated air and the like, or is softened by immersing in a bath of solvent or plasticizer.

Abstract: A method of slitting a continuous thermoplastic film comprises advancing the film longitudinally at a first speed along a peripheral surface of a roll rotating at a peripheral speed equal to or slightly greater than that of the film, and slitting the film while being advanced by pressing cutting edges of a rotating cutter against the peripheral surface of the roll. In order to prevent the cutting edges from being worn out and to form slits of uniform size and shape, the peripheral surface comprises an elastic layer of polymeric material, the cutting edges are heated above a temperature at which the film starts melting, the film and the elastic surface layer are cooled along their contacting surfaces with a cooling liquid, and the cutting edges are rotated at substantially the same peripheral speed as the roll. The invention also includes an apparatus for carrying out the method.

Abstract: A method and apparatus for stretching a thermoplastic polymer film in which the opposite selvages of the film are gripped by gripping means and are stretched transversely during heating by moving the selvages along two divergent arcuate paths lying in the same plane and extending over a predetermined circumferential range from a quater to a half of the full circumference of the circle containing the arcuate paths. In order to avoid drawbacks in the existing equipment such as irregular molecular orientation in and rupture of the film, the longitudinal travel of the film while being stretched is controlled by controlling means so that the central web portion is advanced by substantially the same distance as the gripped film selvages, whereby the amound of longitudinal movement of the film is held always constant throughout the width of the film.

Abstract: A method for shaping a tubular film in a downward and wet manner is provided in which an extruded tubular film is coagulated in contact with a coagulation liquid which flows down along the inside surface of a cylindrical composite perforated wall composed of a cylindrical perforated wall and cylindrically piled up circular rings of coiled wire provided in a single layer and in contact with the inner surface of said cylindrical perforated wall, provided in a negative pressure chamber connected to the lower part of a coagulation liquid-supplying pool; in this coagulation, coagulation liquid is fully utilized by mixing with a reflux coagulation liquid formed when a part of coagulation liquid once flows out through said wall and is collected in a plurality of coagulation liquid-collecting weirs provided around the outer surface of said wall, and then flows again through said wall to the inside thereof; and said film is drawn downward while being supported on the inner surface of said wall by friction due to sucti