Low-Energy Injection Molding Process by a Mold with Permeability Fabricated by Additive Manufacturing

This paper describes the improvement of flow length and realization of low-energy molding in the injection molding process, by focusing on the injection mold with permeability fabricated by additive manufacturing. The mold is equipped with a sintered body with permeability, which is used as a mold insert. The inside of the sintered mold insert is structured so that the permeability should not be degraded, even if the thickness is increased. With respect to the effect of the sintered mold insert with permeability, the flow length and low-energy molding are evaluated by the filling rate of a thin section of moldings, and the electric energy of the injection molding machine that drives the screw in the injection process. Through fundamental experiments, the mold using the sintered mold insert with permeability was found to improve the flow length. The electric energy of the injection molding machine in the injection process is reduced by 6%--13% compared with the sintered mold insert without permeability.