Patent ID: 7803311
Filing Date: 2010-09-28
Classification: B29C,Y02P

Abstract:
1. Method for molding a container from a thermoplastic material, comprising pre-blowing a heated parison by supplying low-pressure blowing air from a low-pressure air supply, completing the blow molding by subsequent supply of high-pressure blowing air, supplying the high-pressure blowing air flowing out of the completely blow-molded container to the low-pressure air supply via a reversing mechanism during a transitional phase, performing a pressure monitoring in the area of the low-pressure air supply, after the transitional phase venting the container with respect to an ambient pressure, and controlling the pressure in the low-pressure air supply by varying the duration of the transitional phase, the method further comprising detecting an actual pressure value in the low-pressure air supply, and ascertaining the duration of the transitional phase by comparison of the actual pressure value with a setpoint pressure value for the low-pressure air supply to create a low-pressure equilibrium in the area of the setpoint value, converting the quantity of the duration of the transitional phase thereby obtained into a signal that is relayed to the reversing mechanism, and switching the reversing mechanism between a first switching state, wherein the low-pressure blowing air flows from the low-pressure blowing air supply into the container, and a second state, wherein the high-pressure blowing air is allowed to flow out of the container into the low-pressure air supply, on the basis of the relayed signal.