An extrusion blow moulding machine for forming a bottle having a calibrated neck finish from an extruded parison, including a blow pin assembly comprising a blow pin tip that comprises a plurality of orifices around the circumference of the blow pin and adjacent the base of the bottle neck to help spread the parison material around the neck and assist in cooling and oval cut-outs positioned in line with the parting line of the mold to receive excess material and reduce push-down of excess material at the base of the bottle neck.
Containers and other hollow articles are frequently formed by blow molding. The blow molding process involves providing a tube of heated and softened plastics material (parison) about which a two-piece mold is closed. Air or another gas is introduced under pressure into the parison to expand it against the walls of the mold, forming the desired hollow article. Such blow molding machines can be of various types, the most common of which are extrusion-blow mold machines and injection-blow molding machines.