| 摘要 |
<p>METHOD AND APPARATUS FOR BLOW MOLDING A method and apparatus utilizing preform and final blow molds for forming molecularly oriented thermoplastic articles. According to the method, an extruded tubular parison is positioned within the pre-form blow mold and blown to a pre-form configuration. The blown pre-form is then conveyed, while suspended from a moveable carrier, through a thermal conditioning chamber and the temperature of the pre-form is adjusted to within the range for molecular orientation. Next, the thermally conditioned pre-form is conveyed by the moveable carrier to a final blowing station where the pre-form is blown to the configuration of the final article. In a first disclosed embodiment the carrier is a blow pin which is inserted into the tubular parison at the pre-form molding station prior to the first molding operation. In the second embodiment, the carrier is a tubular projection telescopically inserted into the blown pre-form prior to entry of the pre-form into the thermal conditioning chamber, and the pre-form is blown to its final shape by a blow tube inserted through the carrier. In both embodiments, the carriers are used to convey successive pre-forms in a continuous molding operation.</p> |
