| 摘要 |
PURPOSE:To prevent a waste of time and heat energy for repeating cooling and heating relative to a mold, moreover, reduce the heat contraction by making use of pressurized gas, as it was, supplied for blow-molding a vessel and keeping the configuration during the period of a heat process. CONSTITUTION:When the heat process of a molded vessel is completed, and the pressure of supplying pressurized gas in raised higher than the relief pressure, a safety valve 121 is actuated and opened so as to start exhaust, and the pressurized gas supplied flows as denoted in an arrow so as to cool the molded vessel from inner surface thereof. The pressurized gas to be supplied may be any ordinary temperature gas in the same manner as the blow molding period, and, under certain circumstances, it may be employed the gas cooled lower than ordinary temperature. The flow of the pressurized gas is continued in this manner, and the molded vessel 13 is cooled, and as the molded vessel 13 is substantially cured, a blow valve 7 is closed so as to stop the supply of pressurized gas. Thus, the safety valve 121 may also be closed, however, an exhaust valve 12 is released subsequently, and the pressurized gas within the molded vessel 13 is exhausted so as to make the inner part of the vessel 13 to be ordinary pressure. |
