A METHOD TO FIND OPTIMAL AUXILIARY INJECTION GATE LOCATIONS FOR SUCCESSFUL MOLD FILLING IN RESIN TRANSFER MOLDING PROCESS

摘要

There are various choices for gate and vent locations in a mold in Liquid Injection Molding processes. One can find optimal gate locations that will fill a mold succesfully under nominal conditions without any dry spots. No control actions are needed. However, disturbances such as uncertainty in the fiber preform permeability, variations in the resin viscosity, and racetracking of the resin along the mold walls, may create unexpected and unanticipated flow patterns that could result in a defective part, because they may lead to regions of fiber preform that do not get covered with resin. This paper presents a method to change the flow pattern by switching the injection gate to a different optimal location that will prevent incomplete filling. A method, the trigram method, is proposed to locate the optimal gate location. The method is demonstrated with two examples.