Bag making machine and bag making method

A bag making machine comprising:

• a conveying unit which conveys a multi-layer film in which strip-shaped films are overlapped;
• a side edge sealing device which thermally fuses the films to each other at predetermined intervals in a width direction that is perpendicular to a conveying direction of the multi-layer film;
• and
• an ultrasonic device which is disposed on an upstream side of the side edge sealing device in the conveying direction and softens and crushes a part of a zipper member with ultrasonic waves, the zipper member disposed between the films such that a longitudinal direction follows the conveying direction,
• wherein the side edge sealing device includes:
• a platform which supports the multi-layer film, and
• a heat-generating head which reciprocates between a position adjacent to the multi-layer film and a position separated from the multi-layer film,
• the ultrasonic device includes:
• an anvil which supports the multi-layer film, and
• an ultrasonic horn head which reciprocates between a position adjacent to the multi-layer film and a position separated from the multi-layer film, and
• the heat-generating head and the ultrasonic horn head reciprocate at a same cycle via a link member common to the heat-generating head and the ultrasonic horn.