摘要 |
<p>METHOD AND APPARATUS FOR MOLDING EXPANDABLE POLYSTYRENE This invention relates to improvements in molding expandable polystyrene, particularly for molding high density tubular parts, in which the molding tool is made with a sintercore metal on each side of the mold cavity, and which has an internal vacuum chamber, external steam jackets, and compressed air means capable of communicating with both the interior vacuum chamber and the exterior steam jacket. The process sequence comprise the steps of (l) applying a vacuum to the inner chamber of the mold, (2) filling the mold with expandable polystyrene beads, (3) charging the jacket with steam, said vacuum being maintained in the inner chamber during steps 2 and 3 to improve mold filling and steaming through the sintercore, (4) cooling the jacket with compressed air, or a water mist and (5) removing the jacket and then the molded article, with the article removal being assisted by application of compressed air to the inner chamber of the mold.</p> |