Other

Katsuya Sakaba

Masao Kamiguchi

Tatsuhiro Uchiyama

Shusaku Nishiyama

Ikushi Takasaki

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( ) to Pr(N) for one shot is stored as reference pressure data Pr ( ) to Pr (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 to obtain the detected pressure data Pr( ) to Pr(N). Waveforms of the detected pressure data Pr( ) to Pr(N) and reference pressure data Pr ( ) to Pr (N) are graphically represented so that variation of the molding condition is observed. It is assumed that if there are any differences, a problem resides in the resin, while if there is no difference but the defective molding occurs, the problem resides in a mold.

Method for determining molding characteristic and injection molding machine

A resin flow analysis in a die is performed by CAE or the like to obtain a resin pressure curve at a resin inlet port or a resin pressure curve at a nozzle end portion of a molding machine. Injection (air shot) is performed while a nozzle is separated from a die, so that an injection pressure curve Pa to be detected at this time is obtained. From the injection pressure curve and the resin pressure curve, an injection pressure command curve serving as a molding condition in mass production is obtained. The resin pressure curve obtained by the resin flow analysis is compensated by the injection pressure curve in an air shot for a time lag and pressure loss caused by the mechanical elements of an injection molding machine, so that molding conditions in mass production can be easily obtained. In addition, a pressure loss at the nozzle portion is also obtained, so that an injection pressure command curve is obtained from the pressure loss, the injection pressure curve, and the resin pressure curve.

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Otsu, Japan

Katsuya Sakaba