Patent ID: 8980146
Filing Date: 2015-03-17
Classification: B29C,B29L

Abstract:
1. A method of automatically adjusting pressure in an injection molding process to adapt for variations in the flowability of a molten plastic material, the method comprising: (a) during a first injection molding cycle of an injection molding run, injecting a first shot of the molten plastic material into a mold cavity at a first cycle injection pressure; (b) during the first injection molding cycle, measuring a first time for the molten plastic material to reach a flow front sensor that is configured to sense the presence of a flow front of the molten plastic material at a particular location in the mold cavity; (c) a first comparing of the first time to a predetermined target time to determine a first comparison result; (d) determining a second cycle injection pressure, based, at least in part, on the first comparison result; and (e) during a second injection molding cycle of the injection molding run, subsequent to the first injection molding cycle, injecting a second shot of the molten plastic material into the mold cavity at the second cycle injection pressure.