Abstract
In a previous work dealing with the parameters influencing the calibration/cooling stage of profile extrusion, it was concluded that the two main objectives of the calibration stage are conflicting, i.e. conditions leading to a high efficiency will generally promote high temperature gradients at the same location, and vice versa. The exceptions were the reduction of the extrusion velocity and splitting the calibrator into several units, separated by annealing zones. Therefore, the only obvious way to improve the cooling performance of the calibrator without compromising the production rate is the division of the total cooling length into several independent units. In the present work, an optimisation methodology (encompassing a numerical simulation code, an objective function and an optimisation routine) is used to optimise the lengths of the individual cooling units and of the annealing zones existing between them with a view to improve the cooling performance of the calibration/cooling stage.