The Extrusion Process Is A Multivariable System

Adaptive and Multivariable Control

The extrusion process is a multivariable system where product qualities (e.g. extrudate dimensions) and process parameters (e.g. melt temperature and pressure) need to be controlled within a tight tolerance by manipulating appropriate process variables (e.g. screw speed, power to the die and barrel heaters, take-up speed, etc.). Once the control of separate components of the extrusion line has been achieved, one should look into the regulation of the entire system using multivariable control methods. Since the extrusion process is highly nonlinear, adaptive control may offer great potential benefits. Improvements or advances in measuring techniques and better understanding of the process from steady-state and dynamic models will make it possible to institute more effective and realizable adaptive control schemes.