| 摘要 |
1,017,673. Producing wide flat films. SOC. EDISON. Sept. 1, 1964 [Sept. 2, 1963], No. 35780/64. Heading B5B. Wide film sheet of synthetic thermoplastic material is continuously produced by continuously and progressively bringing into contact with one another along a narrow longitudinallyextending zone two tubular films, continuously and progressively welding the films together along that zone, and either before or after the welding step, continuously slitting one film longitudinally adjacent and parallel to one side of the zone and continuously slitting the other film longitudinally adjacent and parallel to the other side of the zone so that the joined films can be opened out to form a single sheet having a width substantially equal to the sum of the peripheries of the tubular films. Wide flat films may be similarly continuously produced by continuously welding together, slitting and opening out three or more tubular films. The flat films thus produced have a width substantially equal to the sum of the peripheries of all the tubular films. |
