Patent ID: 6221305
Filing Date: 2001-04-24
Classification: B29C,B29L

Abstract:
In an extrusion blow molding machine, a method for forming a bottle having a calibrated neck finish comprising the steps of:(a) extruding a tubular parison over a fixed blow pin,(b) controlling the wall thickness of the parison to provide sufficient material to fill the neck area of the bottle,(c) closing a mold on the parison after it has been received on the blow pin, such that the closing action of the mold segments serves to compress the material of the parison forcing it to conform to the mold on the outer diameter of the neck and around the blow pin for the inner diameter of the neck, and(d) introducing a gas through the blow pin, and distributing the gas through a plurality of orifices around the circumference of the blow pin and near the base of the neck in a manner that tends to spread out material in the neck.