Apparatus and method for controlling mass flow in an extrusion die

摘要

An apparatus and method for controlling mass flow in an extrusion die provides cross-directional measurements of at least one property of an extrusion produced by the extrusion die, such measurements being made at a plurality of cross-directional locations that successively span the extrusion. The measurements are assembled to provide cross-directional profiles of the extrusion. A spatial-frequency splitter operates upon the cross directional profiles to separate selected spatial frequency component profiles from each cross-directional profile. A reference profile is provided for representing desired spatial frequency profiles. An error signal generator generates error signals representing the difference between the spatial frequency component profiles and the desired spatial frequency profiles and actuators control mass flow components of the extrusion die in response to the error signals.