Model predictive temperature control of an extruder

This paper presents a temperature control concept for a highly efficient and thus well isolated extruder without active cooling. Heat is supplied via heating bands. The heat is removed mainly by the transport of the granulate or by the melt. Based on a finite volume model for the heat distribution in an extruder, a model predictive control for the extruder barrel is designed. The heat flow between the barrel and the melt is measured with the help of a disturbance observer so that it can be taken into account in the control concept. The model predictive control calculates suitable temperature trajectories for the heating bands to achieve desired temperature profiles in the extruder. The suitability of the proposed control concept for extrusion startups, operating point changes and disturbance scenarios is proven by simulations but above all by experiments.