| 摘要 |
PURPOSE:To prevent that a monomer spouts out of an air vent hole or the air vent hole is clogged with a polymer by detecting the monomer rising through the air vent hole provided to a casting mold at the time of the reactive injection molding of metathesis polymerizable monomer in the presence of a polymerization catalyst system to close the upper end of the air vent hole. CONSTITUTION:Air vent holes 8a, 8b are provided to the upper mold 5b of a mold 5 so as to respectively communicate with the reservoir 6 of the lower mold 5a of the mold 5 and the cavity provided to the cavity of the boss part of the upper mold. Tubes 10 made of fluoroplastic is fitted in the air vent holes 8a, 8b in a liquidtight state in an extractable manner. A resin detector 11 such as an electrostatic capacity sensor is fixed in the vicinity of the insertion part of each of the tubes 10 and a solenoid valve 12 opening and closing each of the tubes 10 is provided to each of the tubes 10 on the upper side of the resin detector 11. When the detector 11 detects the resin in each of the tubes 10, each of the solenoid valves 12 is closed. When the mold 5 is opened after a resin is injected in the mold 5, the resin in each of the tubes 10 is taken out in the state connected to a molded product and no resin remains in the air vent holes 8a, 8b. |
