It is a specific object of the invention to provide a bag making machine which will minimize undesirable effects caused by discontinuation of a bag making operation.
The moment a start signal is given to resume the operation of the bag making machine, the sequencer 19 drives the servo motor 14 of the intermittent feeder 2 to return the thermoplastic web 1 to its pre-interrupt position. Thus, as seen in FIG. 1, the drive roller 11 and nip roller 12 rotate in the arrow "c" direction to return the thermoplastic web 1 into the bag making station 3. When the thermoplastic web 1 is fed by a length set by the digital switch 16 of the digital pack 17 via a feedback pulse from the encoder 13, the servo motor 14 stops, returning to the state shown in FIG. 2 (A).