US 12,442,065 B2
System and method for coating of continuous sheets of metal
Owen Pearcey, Highvale (AU)
Assigned to Hatch Ltd.
Filed by HATCH LTD., Mississauga (CA)
Filed on Feb. 19, 2021, as Appl. No. 17/180,192.
Prior Publication US 2022/0267885 A1, Aug. 25, 2022
Int. Cl. C23C 2/20 (2006.01); C23C 2/00 (2006.01); C23C 2/40 (2006.01)
CPC C23C 2/00348 (2022.08) [C23C 2/00344 (2022.08); C23C 2/20 (2013.01); C23C 2/40 (2013.01); C23C 2/51 (2022.08); C23C 2/52 (2022.08); C23C 2/524 (2022.08)] 16 Claims
OG exemplary drawing
 
1. A method for a sheet coating process, the method comprising:
a) submerging a sheet in a coating bath of coating material;
b) contacting the sheet in the coating bath with a main roll and a correcting roll to alter the direction of the sheet and alter a crossbow in the sheet;
c) measuring distances from a select location at or near a set of air knives to a plurality of points simultaneously on the sheet transverse to the direction of travel of the sheet and downstream of the correcting roll;
d) determining by measurement the crossbow in the sheet based on the distance measurements from step c);
e) prior to submerging the sheet in the coating bath, providing a crossbow modeling curve, the crossbow modeling curve comprising solutions for a correcting roll position that provides a minimum crossbow or a zero crossbow in the sheet; and
f) changing the correcting roll position relative to the main roll based on the distance measurements and the crossbow modeling curve to impart a correction in the sheet to provide a minimum crossbow or a zero crossbow in the sheet.