Strip coating machine with thickness control

摘要

A continuous strip coating machine has top and bottom applicator rolls and a backup roll adjacent the top applicator roll. A lift roll to lift the strip of material and thus vary the angle of wrap of the strip about the bottom applicator roll is provided. The use of the lift roll in turn varies the pressure between the strip and the roll and thus the thickness of the coating applied to the strip bottom. Thickness may be measured indirectly by measuring pressure of the strip on the applicator roll. Thickness may also be measured directly. Oscillations of the strip in a drying oven may also be sensed and compensated for. Feedback control is used with the thickness measuring techniques to control the coating thickness by varying angle of wrap, relative speed between the applicator roll and strip, and/or nip pressure between the applicator roll and a transfer roll that transfers coating material to the applicator roll.