METHOD OF CONTROLLING EXTRUSION MOLDING

摘要

PURPOSE: To enable temperature control for the manufacture of extrusion molding profiles. CONSTITUTION: The cyclic control of extrusion molding is disclosed and the molding velocity is controlled so that the strand exit temperature is as constant as possible and equal to the prescribed theoretical trajectory. The trajectories of the molding velocity and the strand exit temperature in respective cycles are measured and the dependence of the strand exit temperature on the molding velocity is determined with respect to entire course of time of a cycle (k). According to the dependence and the time trajectory of the molding velocity in the cycle (k), the molding velocity trajectory of the following cycle (k+1) is determined so that the control error and the control expenses are as low as possible and, after completion of the molding cycle (k+1), the proper process is inductively iterated for every subsequent molding cycle until the whole molding program is completed. This process is especially suited for the manufacture of extrusion molding (in particular for the extrusion of aluminium or aluminium alloy) having low and/or wavelength dependent emmissivity and/or variable surface characteristics.