PURPOSE: To extend the range of packaging paper cut length and improve the grade of high precision and the operating efficiency, by controlling a packaging paper feeding roller drive unit to a speed which corresponds with a pulse sent by a pulse generating unit which generates a pulse with a predetermined cycle, and a signal which is sent from a seal cutter speed detector.

CONSTITUTION: Since a motor 30 runs with a uniform speed, a seal cutter 3 also runs with a uniform speed; and a packaging paper is sealed and cut with a uniform time interval. On the contrary, the feeding speed of a packaging paper 1 changes depending on the cut length. In order to obtain a cut length which is established by a control switch 76, the feeding speed is calculated depending on the data from a ROM 72; a control signal is sent from an output unit 75 to a servo motor 20 to drive a packaging paper feeding roller 2. When the rotation speed of a cutter 3 changes, a control signal which corresponds with this change is made in a controller 7 according to the speed signal which is detected by a cutter speed detector 31; and this control signal is sent to the output unit 75 for the servo motor 20 to operate corresponding with the change; and thus a uniform cut length is maintained.