A continuous to intermittent device and method for moving the interior of a machine for the production of flexible packaging bags forward

摘要

Device (100) apt to change the forward movement of a film (12) into a machine (10) from continuous mode to intermittent mode for producing bags (1) for packaging and the like, comprising a dandy roll (20) mounted movably backwards and forwards between a feed calender (21) which operates in continuous mode and a transport calender (22) which operates in intermittent mode, the dandy roll (20) moving towards said transport calender (22) when the latter is operating, in order to feed the film (12) and moving in the opposite direction when the transport calender (22) is stopped in order to recover the input film coming from the feed calender (21), wherein a servomotor (50) is provided for the movement of said dandy roll (20), and wherein at least one load cell (55) is provided along the path of the film (12) apt to continuously monitor the tension applied to the film (12) and to instantly change the torque applied to the motor (50).