| 摘要 |
PURPOSE:To obtain a hollow molding having excellent strength and a wide applicability, having reinforcing ribs in its inside, by a method in which a cylindrical parison is extruded from the die of molds and then molded by blowing. CONSTITUTION:A cylindrical parison 3 is extruded from the ring die 1 of molds, and at the same time a rib 6 is projected from an extrusion nozzle 5 for rib, provided to the die 1, into the parison 3. The molds 2 are clamped and the parison 3 is expanded and molded by blowing air from an air jet nozzle 4 provided to the die 1 to obtain an aimed molding. In this case, two or more ribs 6 are preferably formed without lapping on parallel lines in the opening and closing direction of the molds. |
