| 摘要 |
PROBLEM TO BE SOLVED: To provide an injection/expansion molding method by which it is possible to control not only the expansion ratio but also the thickness of a hardened layer, and also mold an expanded product best-suited for a used application and further, restrain the property dispersion of the expanded product, so that the failure rate of the finished product is reduced. SOLUTION: This injection/expansion molding method comprises the steps to inject a molten resin 9 into a cavity 6 formed in a mold 1, and expand the molten resin 9 by moving a movable half 5 of the mold 1 after the resin injection/packing process. In this method, the internal temperature of the mold 1 is detected by means of a mold temperature sensor 10, then the internal resin temperature 9a of the cavity 6 is estimated based on the actual measurements of the detected temperature, and the inching of the mold 1 is delayed until a temperature at which the expansion-molded product with a specified expansion ratio and a specified hardened layer thickness can be obtained. Further, after that resin temperature is reached, the movable half 5 of the mold 1 is moved backward. |
