| 摘要 |
PURPOSE:To provide a molding device which can manufacture a synthetic resin hollow molded body of good surface properties and even wall thickness. CONSTITUTION:A molding device is provided with a molding cavity 4, a gate 5 communicated with said cavity 4, a mold 1 provided with an overflow chamber 7 communicated with the cavity 4 through an outflow path 6, and a gas blowing mechanism 8 blowing gas into molten synthetic resin R injected into the cavity 4 through the gate 5 to form a hollow section in said molten synthetic resin R. An outflow make-and-break mechanism 26 for closing the outflow path 6 until the molten synthetic resin R is filled in the cavity 4 and opening the outflow path 6 during the operation of the gas blowing mechanism 8 is annexed. Injection pressure is sufficiently applied to the molten synthetic resin R in the cavity 4 to make the surface properties of a hollow molded body good, and also gas pressure is applied evenly in a hollow section to uniformize the wall thickness of the hollow molded body. |
