METHOD OF MOLDING CROSS-LINKED FOAMED COMPOSITIONS

摘要

A method for injection-molding a cross-linked, foamed composition including the introduction of an inert gas from an inert gas supply unit (3) into a mold chamber (1) of a preheated mold (2) to evacuate air and oxygen from the mold chamber. A mixture of a resin, a cross-linking agent and a chemical blowing agent are introduced into the mold chamber after the inter gas has evacuated air and oxygen from the mold chamber. The inert gas is evacuated from the mold chamber while the mixture substantially fills the mold chamber. The mixture is heated within the mold chamber to a temperature sufficient to thermally decompose the chemical blowing agent. The temperature of the mixture is maintained within the mold chamber until the resin substantially forms a cross-linked composition. The mold is opened and cross-linked composition foams to produce a finished product that is free of oxidation.