Abstract: The injection molding is known to be the most effective process for producing discrete plastic parts of complex shape to the highest precision at low cost. The placement of a gate is one of the most important variables of the total mold design, because it influences the manner in which the plastic flows into the mold cavity. Through the study of the flow behavior of melt front, an optimal problem for single gate location of injection molds is constructed which is based on the introduction of the equivalent flow length concept. The objective is to obtain a balanced filling pattern by the minimization of the difference of equivalent flow length among the fundamental flow paths. A genetic algorithm is used to search optimal gate location. The models analyzed demonstrate that the proposed method can obtain the optimal gate location within minimum time.

Key words: Equivalent flow length, Filling pattern, GA’s, Injection molding