| 摘要 |
PURPOSE:To provide a sandwich molding process by which to manufacture a plastic molded product with adequate strength maintained on the installed part and outstanding performance such as crack prevention. CONSTITUTION:A main system and an installed part are provided and the main system is composed of a core layer of a hard resin material B and a skin layer of a soft resin material A, while the installed part is covered by a skin layer of a soft material at least on one of the surfaces. In addition, in a cavity for the molding of the installed part, a molding die equipped with a slide core 3 which stops at a position for molding the plate thickness of the installed part and at an intermediate position for molding the smaller thickness of the plate, is used. The slide core has a liner pin for the molding of a through hole, and with this slide core set to the intermediate position, the amount of a soft material after deduction of an equivalent to a hard material is injected. In addition, the hard material is injected into the soft material and if the injection process is almost completed, the internal pressure rises, pushing the slide core backward to a position for the formation of the plate thickness for the injection of the hard material. The hard material is injected into the cavity for the remaining installed part to allow the hard material to flow up to an area near the tip of the installed part. |
