Molding device having heat transfer chambers insulated from each other for molding expandable thermoplastic resin particles

摘要

A mold for polystyrene has two spaced dies receiving the polystyrene therebetween. The wall of each die has two superposed independent chambers, one a heating chamber and the other a cooling chamber adjacent the die surface. Passages from the heating chamber pass through the cooling chamber and through the die surface and do not communicate with the cooling chamber. The opening of the passages in the die surface may be partially closed by nozzles.