ADVANCED CONTROL SYSTEM AND METHOD FOR MAKING POLYETHYLENE TEREPHTHALATE SHEETS AND OBJECTS

摘要

A system for making PET objects including a means for reacting a first PET precursor and a second PET precursor to produce a PET melt; a means for flowing the PET melt to a valve having at least two outlets; a means for flowing the PET melt from at least one of the at least two outlets to at least one die forming line and one pelletizing (cutter) line. A means for controlling individually the mass flow of the PET melt in each of the at least two system lines independently of the other and a means for forming the PET objects from the PET melt. The control scheme is a combination of a feed forward system as well as a feedback loop. The entire control scheme is part of the overall system PLC. The fine tuning of the pressure at the outlet of the die forming loop is controllers to less than +/−1 bar to obtain maximum control of formed part.