Model reference optimal steady-state adaptive computer control of plastics extruder processes (2)

Feedback and feed forward control strategies are used to hold the melt temperature and pressure at die inlet within close tolerances using control actions calculated via process models and applied by a hierarchical cascade controller. The methodology is described by reference to a specific 40 mm diameter screw plastics extruder fitted with a variable geometry annular blow molding die head, processing specific polymers. However, the control procedures are completely general and can be applied to any extruder-die combination.