摘要 |
PURPOSE:To improve smoothness of the surface of a molded product, by a method wherein a parison is extruded, mold clamping is performed and air is sucked into the parison under a state where inner surface of a mold forming a cavity of a blow mold is heated directly from a cavity side and a temperature is raised. CONSTITUTION:When a mold is under a breaking state, a heating unit 2 is introduced within the mold, blow mold 1 is clamped, the outside 2a of the heating unit 2 abuts against the inner surface of the mold, heated directly and a temperature is raised. Then when the inner surface 3a of the mold becomes a state of a temperature rise by a fixed temperature, the mold is broken, the heating unit 2 is removed by actuating a heating unit introducing and taking-out mechanism 5, a parison 7 is extruded swiftly through an extrusion head 6 and the parison 7 is pinched by mold clamping. Air is blown into the parison through an air blowing port 8, the parison 7 is expanded and pressed against the inner surface 3a of the mold. The mold is cooled with a refrigerant flowing within a refrigerant circulation path 9 provided in the blow mold 1, after cooling resin, the mold is broke and a molded product 10 is taken out. |