Method and apparatus for blow molding hollow articles

Abstract

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 cavity. 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 under pressure is introduced to tear the plastic and blow the article to the confines of the mold which has been closed about the plastic parison. Micro vents facilitate exhausting air which is about the parison. Preferably the second passage for compressed air is provided by a central bore and the first passage for the vacuum is provided by an annular space about the fixed needle. In a modified form, the fixed needle comprises dual air passages. Provision is made for utilizing plural molds with controls for supplying air and vacuum.

Dependencies are inferred from the claim text.