Application of Digital Control Techniques to a Laboratory Extrusion Process

Extruders are now routinely controlled with digital computer systems and algorithms. In this study, we have installed, debugged, and demonstrated an advanced control algorithm for individual temperature-zone control of a laboratory single screw extruder. The algorithm: ¿ adjusts the parameters of a resident first-order plus deadtime process model with a linear least squares estimator, ¿ adapts the controller parameters to achieve a prespecified closed-loop setpoint response (Dahlin´s method) and ¿ is in use in a polymer processing research laboratory, installed on a DEC PDP 11/23 system.