| 摘要 |
<p>PURPOSE: To prevent burst or extremely uneven thickness by molding a preform for a polycarbonate container by blow molding at above a specified temperature of an outer surface immediately before the blow molding. CONSTITUTION: A polycarbonate container 10 is formed out of a polycarbonate resin by injection stretch blow molding. The polycarbonate container has a circular shape in cross section consisting of a neck part 14 including a mouth 12 at an upper end, a shoulder part 16 which is continued from the neck part 14 and gradually expands, a barrel part 18 which is continued from the shoulder part 16 and extends downward, and a bottom 20 at the lower end which is continued from the barrel part 18. Here, temperature of an outer surface of a preform immediately before blow molding is made to be 180 deg.C or above, the temperature of the preform is heightened so as to easily expand the whole, so that uneven thickness is restrained, thickness distribution is almost uniformed, and defective molding such as burst can be eliminated. In this case, when the temperature is below 180 deg.C, distribution of thickness is unstable and thickness is largely uneven, which are undesirable.</p> |
