| 摘要 |
PURPOSE:To obtain lovely cutting at the perforation provided at right angles with the longitudinal directing of a film, by a method wherein after the film has been oriented appropriately in the longitudinal and lateral directions at the temperature of more than a softening point and less than a fusion point, stretched 1-20% in the longitudinal direction futher at the temperature of less than the softening point. CONSTITUTION:A film 2 is obtained by extruding molten resin through an annular die 1 and oriented appropriately in a longitudinal and lateral directions at the temperature of more than a softening point and less than a fusion point of resin by an inflation method. Then the film 2 is led to rolls 3... at the temperature of less than a softening point of the resin and stretched 1-20% in the longitudinal direction through a difference between circumferential speeds of rolls each. Perforation 4 are applied to the obtained tubular film 2 at right angles with a longitudinal direction of the film 2 at appropriate intervals, which is made into one side or both side opening according to necessity. Then an article 5 to be packed is packed, formed into a tubular state and shrinkage package is performed by heating the same under a nonrestrictive state. |
