Plastic bottle forming machine with modular design

Abstract

Machine system for continuous formation of molecularly oriented plastic bottles by blowing heat-conditioned parisons comprising a modular unit including a parison forming section for simultaneously forming a plurality, preferably four, of parisons in injection molds, each mold having a neck ring assembly; a blowing or bottle forming section for simultaneously blowing the same number of bottles in blow molds as there are parisons in the parison forming section, and an invert arm assembly having a plurality of arms constructed and arranged between said parison forming section and bottle forming section so that the extreme end of each invert arm will retain the neck ring assembly of the injection mold, and in a first position the arms and neck rings are in operable association with the parison injection molds and in a second position are in operable association with the blow molds. In the method of operation, the arms of the invert arm assembly retain the neck rings of the parison forming molds, the parisons are simultaneously molded, the invert arm and neck ring assembly inverted, i.e., rotated 180 degrees, depositing the formed parisons and neck rings in operable association with an open blow mold. After blow mold closing, the neck rings are opened and the invert arms carrying the neck rings are again inverted, i.e., rotated 180 degrees in the opposite direction, to the first invert movement, and the cycle begins again. The machine system provides for rapid manufacture of bottles, is compact, and makes efficient use of machine components.