| 摘要 |
PURPOSE:To obtain a molded body excellent in strength by a structure wherein thick-walled reinforcing parts are provided at the important positions of the hollow molded body. CONSTITUTION:Before the filling of molten thermoplastic resin, which is injected in the cavity 6 of a mold 5, gas under pressure is forced in the cavity 6 in order to produce a hollow part 1 in the molten thermoplastic resin. Next, by locally squeezing the hollow part 1 through the protrusion of some part of the mold 5 in the cavity 6 so as to locally weld the front surface part 2 and the rear surface part 3 under the condition that the hollow part 1 of the obtained hollow molded part is pinched between the parts 2 and 3 in order to form thick-walled reinforcing parts 4. |
