Polyolefin synthetic resin in-mold foam molding method

Abstract

Objects of the invention is to provide a practical, novel foam molding apparatus wherein mold surfaces are devoid of air orifices, and to provide an in-mold foam molding apparatus and method for the reduction of cooling time for molded articles. A mold cavity 4 is filled with prefoamed beads comprising a polyolefin synthetic resin; these are heated and fused with steam; and the molded article is cooled, during which cooling process the pressure of the foamed resin against the molds 2, 3 as it is cooled is successively measured by means of a bearing pressure sensor, and when the pressure of the foamed resin against the molds has reached a pressure predetermined for the particular molded article, cooling of the molded article is terminated, the molded article is released from the mold, and the molded article is then set in a fixture to stabilize the shape of the molded article.

Dependencies are inferred from the claim text.