METHOD FOR CONTROLLING SUCKING-BACK OF INJECTION MOLDING MACHINE

摘要

PROBLEM TO BE SOLVED: To improve a quality and a productivity of a molding by reducing an unevenness of a residual amount and an unevenness of a weight due to a change in a resin pressure in a screw after a metering (plasticizing) step. SOLUTION: A method for controlling sucking-back of an injection molding machine comprises the steps of previously obtaining an optimum resin pressure P after metering step at each resin, measuring the resin pressure before starting an injection, controlling next sucking-back amount until the measured resin pressure becomes equal to the optimum resin pressure P, and setting the resin pressure after the metering step at the time of an automatic operation to the optimum resin pressure P.