Abstract: 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.

Abstract: A process for the manufacture of a plastic part, the process comprising providing a polymer, heating the polymer, introducing a gas or supercritical fluid into the polymer, mixing the polymer and the gas to produce a first melt, extruding the first melt, pelletizing the extruded first melt to form pellets, transforming the pellets into a second melt, and molding the second melt to form the plastic part. In pelletizing the first melt, individual cells of gas are included in the resulting pellets. Before the cells can nucleate, the polymer is solidified to keep the gas contained therein. After the polymer is pelletized, the pellets are considered to be unfoamed. In molding the second melt to form the plastic part, nucleation of the cells is initiated through favorable process conditions and/or additional cell nucleating agents, thereby resulting in the second melt being foamed.

Abstract: 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.