Temperature Measurement in Heating Cylinder of an Injection Molding Machine

Abstract

The effects of molding conditions, such as the set temperature of the band heaters and the screw rotation rate, on the temperature history and distribution in the heating cylinder have been studied by measuring the barrel temperature and the temperature at the screw surface. The temperature history at the screw surface during the molding process was measured by using a thermocouple telemetry system. The measured results were compared with the set temperatures of the heaters. Representative PP and PS resins were used in the experiments.The observed temperature distribution along the screw axis indicates a steep temperature rise at the feed zone, and it differs largely from the set values. The set temperature at the feed zone notably affects the temperature of the polymer melt in the compression and metering zones. The results obtained in this study will be useful for an optimum design of the heating cylinder and also for the construction of a CAE model.