PREPARATION OF MULTI-CHAMBER TYPE HOLLOW MOLDED ARTICLE

PURPOSE:To inexpensively and integrally mold a multi-chamber type molded article having a plurality of hollow regions, by performing blow molding in such a state that both cavities of a plurality of unit hollow molded articles are communicated to each other. CONSTITUTION:A cylindrical parison 9 extruded from an extrusion nozzle 8 is supplied between a first mold 11 in which a first hollow molded article 10 provided with a hole 15 by drilling and a second mold 13 and both molds 11, 13 are moved to perform mold clamping. In the next step, when pressure gas is blown into the parison 9, the parison 9 expands to be contacted with the first mold 11, the second mold 13 and the surface 14 of the first hollow molded article 10 under pressure. At this time, the vicinity of the hole 15 provided to the surface 14 of the expanded parison 9 is locally expanded and bursted by the injection of the pressure gas to communicate a cavity B and a cavity A. Therefore, a second hollow molded article 16 having a desired shape is molded without deforming the shape of the surface 14 of the first hollow molded article 10 to be integrated with the first hollow molded article 10.