Method for determining molding characteristic and injection molding machine

摘要

An injection is carried out under a certain molding condition with a nozzle in an injection molding machine left open to sample an injection pressure Pr in every certain cycle for storing. Detected pressure data Pr(0) to Pr(N) for one shot is stored as reference pressure data Pr0(0) to Pr0(N). When defective molding occurs or when a resin lot is changed or the like, the injection is carried out with the nozzle left open under the same molding condition as that used in obtaining the reference pressure data and obtain the detected pressure data Pr(0) to Pr (N). Waveforms of the detected pressure data Pr(0) to Pr (N) and reference pressure data Pr0(0) to Pr0(N) are graphically represented so that variation of the molding condition is observed. It is assumed that if there are any differences, a problem presumably resides in resin, while if there is no difference but the defective molding occurs, the problem presumably resides in a mold. <IMAGE>