| 摘要 |
<p>In blow molding of containers, a blow pin (11) through which compressed gas, e.g. air, is supplied is inserted into a preform in a mold (4) and then withdrawn. The air pressure is shut off before the blow pin has been retracted appreciably, preferably before it has started on its reverse motion. Before the blow pin is retracted the air pressure is between 30 and 50 bar. An independent claim is also included for the corresponding equipment in which the blow pin motion is controlled mechanically through a cam (17, 43), or pneumatically or electrically. The air is supplied through a valve arrangement (47), optionally electrically controlled.</p> |
