| 摘要 |
PURPOSE:To make it possible to blow mold a parison without developing flash by quickly inserting the parison in a cavity under the condition that the temperature of the parison is prevented from lowering by a method wherein a pair of split mold main parts of split molds are drawn near with a gap, which is the specified times as large as the diameter of the parison, and, after that, the parison is inserted by lowering it along a cavity and finally the molds are closed so as to blow mold the parison by forcing pressurized fluid in the parison. CONSTITUTION:In a pair of split molds 1 consisting of split mold main parts 5 and split mold upper parts 8 and split mold lower parts 10, both of which are just on the upper parts and the lower parts of the split mold main parts 5, a pair of split mold main parts 5 of the split molds 1 are drawn near with a gap (l), which is about 1-1/3 times the diameter of a parison 13. Under the state as just mentioned above, the parison 13 is inserted in a cavity 4 from the upper end opening of the cavity 4 by lowering it along the inner surface of the cavity 4. After the split mold main parts 5, the split mold upper parts 8 and the split mold lower parts 10 are closed each other, pressurized fluid is forced in the parison 13 in order to blow mold it. If the gap (l) for inserting the parison is too large, the parison 13 is off the cavity. If the gap (l) is too small, no effect of the gap develops. The preferable gap is about 1-1/3 times the diameter of the parison 13 or about 15mm ordinarily in the case for molding, for example, the duct for automotive air conditioner. |
