Production method for pleated film, and production method of pleated packaging body

A production method for a pleated film, comprising:

• an introduction step for moving an elongated film for use as a packaging body in a longitudinal direction of the film and introducing the film into a gap part between a pair of pleat-forming plates disposed with a gap therebetween so that an upstream-side inner surface and a downstream-side inner surface of the film oppose each other;
• a fixing step for fixing the film to the pair of pleat-forming plates;
• and
• a pleat-forming step for forming a pleat extending in a latitudinal direction of the film by closing the gap between the pair of pleat-forming plates,
• wherein sealing bars are provided on the pair of pleat-forming plates on opposing surfaces of the pair of pleat-forming plates, and
• the introduction step is performed using at least one of following methods (A) to (C):
• (A):
• a method in which the film is introduced into the gap between the pair of pleat-forming plates so that the upstream-side inner surface and the downstream-side inner surface of the film oppose each other by blowing air from the inner surface side of the film;
• (B):
• a method in which the film is introduced into the gap between the pair of pleat-forming plates so that the upstream-side inner surface and the downstream-side inner surface of the film oppose each other by suctioning gas from the atmosphere through a suction member disposed on the outer surface side of the gap part between the pair of pleat-forming plates;
• and
• (C):
• a method in which the film is introduced into the gap between the pair of pleat-forming plates so that the upstream-side inner surface and the downstream-side inner surface of the film oppose each other by a pair of rollers disposed on the outer surface side of the film.