Patent ID: 9586358
Date: 2017-03-07
CPC Classifications: B29C

Claim:
1. An apparatus for expansion of plastics material containers, comprising: a conveying device that conveys plastics material containers along a pre-set conveying path; at least one first shaping station arranged on and conveyed by the conveying device, the at least one first shaping station being configured to expand the plastics material containers by acting upon them with a gaseous medium; at least one second shaping station arranged on and conveyed by the conveying device, the at least one second shaping station being configured to expand the plastics material containers by acting upon them with a gaseous medium, the first shaping station and the second shaping station having stretch rods in each case for stretching the plastics material containers to be expanded in longitudinal directions thereof, each said stretch rod having a channel by way of which a gaseous medium is capable of being supplied through the stretch rod to the plastics material containers to be expanded; at least one first gas preparation device that makes a gaseous medium under pressure available at least for a time to the first shaping station, said gaseous medium being supplied at least for a time through the stretch rod to the plastics material containers to be expanded in the first shaping station; and a second gas preparation device fluidly connected to an inner space of the plastics material containers to be expanded in the first shaping station in such a way that a gas flowing between the second gas preparation device and the inner space of the plastics material containers flows between the stretch rod and a wall of the plastics material containers, the first gas preparation device and the second gas preparation device being connected in terms of flow at least for a time by way of the inner space of the plastics material containers arranged in the first shaping station, said second gas preparation device also being connected in terms of flow to a plastics material container present in the second shaping station, wherein pressure ratios of the first gas preparation device and of the second gas preparation device are selected in such a way that a gas flow from the first gas preparation device to the second gas preparation device takes place at least for a time, whereupon whilst the container is produced by preliminary and finishing blow moulding, nevertheless the blow moulding gas does not originate directly from a compressor but it is re-directed such that, the blow moulding gas is conveyed from a compressor into the first gas preparation device, and from there the blow moulding air is conveyed by way of the flushing or stretch rod through the already completely shaped containers to the second gas preparation device, during the pressure and cooling phases.