| 摘要 |
<p>BALLOON BLOW PLASTIC MOLDING This invention covers the core rod or parson pin of a blow mold machine with a rubber tube or balloon so that the plastic is supported internally during a blow molding operation. The fluid that blows the molding inflates the balloon and has contact with the inside of the balloon instead of with the plastic of the parison. Cooling fluid circulates inside the balloon so that the molding is cooled from both sides to shorten the cycle. Higher pressure fluid can be used without risk of rupturing the molding and blowing can, therefore, be carried out at a lower temperature where the plastic has begun to crystallize and can be oriented for greater strength.</p> |
