Dwell time control method and system with automatic pressure switch point adjustment

摘要

A dwell time control system and method for automatically adjusting the selection and timing of a sequence of pressures used to drive the plunger in a parison mold during the parison forming process. The timing of characteristics of the observed press curve from one or more previous parison forming cycles are ascertained and used to control the timing of the changes in pressure during a subsequent parison forming cycle. The timings of these changes of pressure are determined as predetermined percentages of the timings of the characteristics in order to prevent the blow mold from being forced open and in order to prevent the occurrence of an overpressed finish.