| 摘要 |
PURPOSE:To obtain the titled product small in internal strain and high in the shape accuracy of a lens surface by a method wherein a cavity mold, a core mold are heated up to the glass transition point - melting point, resin is injected into their cavities, then, the runner gate is cut off and cooled under pressure. CONSTITUTION:The core mold 6 and the cavity mold 7 are closed. When injection resin (such as acryl resin etc.) is heated up to the glass transition point or melting point, the resin 9 is injected into the cavity 8 and when the resin is melted, the core mold 6 and the cavity mold 7 are moved into the cylinder of the movable mold 1 or the fixed mold 3 so that the volume of the cavity 8 is not changed to separate the resin 9 in the cavity 8 from the runner 2. While taking caution that the temp. difference does not occur between the surface and the inner part of the resin 9, either one of the molds 6, 7 is moved by the cylinder pressure, the resin 9 is compressed and cooled at the rate of 5-20 deg.C/min to obtain the desired product. |
