| 摘要 |
PURPOSE:To make it possible to mold the neck part of a bottle having a structure, in which the interface between functional resin and main resin is intermingled, by a method wherein the functional resin is injected radially in a cavity and, after that, the injection of the main resin is started again, when the functional resin reaches the wall surface of a core mold. CONSTITUTION:Polyethylene terephthalate 26, for example, is injected from a main resin not runner nozzle 4 through a main resin gate 6 and filled in a cavity, which is formed between a core mold 1 and a cavity mold 3. When the flow front of the polyethylene terephthalate reaches the underside of the support ring of a parison, the main injection is temporarily stopped and at the same time the injection of U-polymer 25 is started through a secondary gate 12, which is located at a position corresponding to the outer peripheral part of the support ring of the parison. After the arrival of the U-polymer to the wall surface of the core mold 1, the injection of the polyethylene terephthalate is re-started so as to allow the main resin to flow in the U- polymer layer and at the same time to allow the U-polymer to flow in the cavity in order to form a thick neck part side layer and neck part tip layer made of U-polymer. |
