| 摘要 |
PURPOSE:To severely control the disposition of an intermediate layer by coaxially disposing inner layer, the intermediate layer and outer layer resin passages from a center toward an outward direction in a hot runner, initially injection molding the inner layer and the outer layer resin, and coinjecting the intermediate layer resin by slightly delaying in a laminar flow in which the compression force of the circumferential direction is sufficiently alleviated, and early finishing the injection. CONSTITUTION:An inner layer resin passage 54, an intermediate layer resin passage 55 and an outer layer resin passage 56 are coaxially disposed in this sequence from a center toward an outward direction in a hot runner 50, and the inner layer resin and the outer layer resin are initially injected. After a slight delay, the intermediate layer resin is coinjected in the shape of a laminar flow that the circumferential compression force is sufficiently alleviated and sandwiched by the inner and outer layer resins, and the injection of the intermediate layer resin is stopped prior to the end of the injection. The inner and outer layer resins are eventually injected. Thus, since the intermediate layer resin is controlled in a laminar flow thereby to regularly feed the resin layers, the position and disposition of the intermediate layer can be severely controlled in the molded piece. |
