Patent attributes
In a method of microcellular injection molding, a polymer and a supercritical fluid are processed. A condition of processing the polymer and/or the supercritical fluid is adjusted to control a weight of a plastic part and/or a surface characteristic of a plastic part produced. In another method of producing a plastic part using microcellular injection molding, a polymer is heated and melted and a supercritical fluid is added thereto. The resulting mix is a single-phase polymer-gas solution comprising the polymer and the supercritical fluid. The polymer and/or the supercritical fluid are adjusted to control the weight of the plastic part and/or a surface characteristic of the plastic part. Once adjusted, the melted polymer with the supercritical fluid is injected into a mold. Upon injecting the melted polymer and supercritical fluid, a pressure drop causes the supercritical fluid to nucleate in the melted polymer, thereby causing nucleation of bubbles.