US Patent 7325489 Process for controlling torque in a calendering system

A method for controlling a calendering system having a first roll and a second roll is disclosed. The first roll has a first roll torque controller and a first roll speed controller. An exemplary method comprises the steps of: (a) setting said first roll at a desired process speed with said first roll speed controller; (b) determining a target torque of said first roll; (c) contactingly engaging said first and second rolls; (d) measuring an actual torque of said first roll; (e) comparing said target torque and said actual torque; and, (f) adjusting a speed of said first roll with said first roll torque controller to maintain said target torque of said first roll according to said comparison of said target torque and said actual torque.