METHOD AND APPARATUS FOR BLOW MOLDING HOLLOW ARTICLES

摘要

A method and apparatus for blow molding plastic articles which utilizes one or more fixed needles and one or more micro vents associated with a blow mold cavit y. Each needle has a first passage associated therewith through which vacuum is supplied to pull the molten plastic about the needle and a second passage therein through which air u nder pressure is introduced to tear the plastic and blow the article to the confines of the mo ld which has been closed about the plastic parison. Micro vents facilitate exhausting air which i s about the parison. Preferably the second passage for compressed air is provided by a central bore a nd the first passage for the vacuum is provided by an annular space about the fixed needle. I n a modified form, the fixed needle comprises dual air passages. Provision is made for utiliz ing plural molds with controls for supplying air and vacuum.