| 摘要 |
<p>PROBLEM TO BE SOLVED: To improve the utilization factor of a low grade resin material and to obtain a homogeneous multilayer resin molding by a method in which a virgin resin material to be a skin layer is extruded while being melted, and the low grade resin material to be a core layer is extruded while the viscosity of the resin is increased to the limiting viscosity equivalent to that of the virgin material, laminated in a molten state, and injected into a mold. SOLUTION: Recycled PET flakes are heated/vacuum-deaerated in the chamber of a twin-shaft continuous kneader 24 to have a prescribed water content, added with a chain extending agent from a drug supply means 35, heated/kneaded/vacuum- deaerated by a kneading rotor, and subjected to viscosity increasing treatment to be improved to a prescribed limiting viscosity value. Molten PET flakes for a core layer are injected from an injection cylinder 25 to the laminated die head 12 of a mold clamping device 4, simultaneously from the first injection unit, a virgin PET resin for a skin layer is injected from the die head 12, both are laminated in the shape of a sandwich, a prescribed quantity is measured, and a cold parison for a bottle is obtained and blow-drawn. In this way, the utilization factor of a low grade resin material is improved, and a homogeneous multilayer resin molding is obtained.</p> |
