A dwell time control system and method are disclosed for automatically adjusting the selection and timing of a sequence of pressures (p1,p2,p3) used to drive the plunger in a parison mold during a 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 (tp 2 , tp 3 ) of the changes in pressure (p1 to p2, and p2 to p3) 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 parison mold from being forced open and in order to prevent the occurrence of an overpressed finish.
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