Systems and methods for in-line thermal flattening and enameling of steel sheets
AssigneePolyvision Corporation
InventorKevin Peter Buchanan
Life of this patent
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Abstract
The present disclosure provides systems and methods for in-line thermal flattening and enameling of steel sheets. The systems and methods include an in-line thermal flattening of a feed stock steel sheet and a subsequent enamel coating of the steel sheet. The resulting enamel coated steel sheet has improved flatness compared with other coated steel sheets that are enamel coated but do not undergo the in-line thermal flattening. The systems and methods allow the use of less expensive source materials without sacrificing quality in the finished enameled product.
Claims45
In a method comprising:
- enamel coating a feed stock steel sheet, wherein the enameled coated feed stock steel sheet has a maximum deviation from flat of a comparing distance when a comparing pressure is applied to the enameled coated feed stock steel sheet;
- an improvement to the method comprising:
- thermal flattening the feed stock steel sheet by heating the feed stock steel to a temperature between 300° C. and 700° C., under a tension between 20 MPa and 100 MPa, and in an atmosphere of air, thereby producing a thermally-flattened steel sheet prior to enamel coating, wherein the feed stock steel sheet has a thickness of between 0.1 mm to 1.0 mm and a width of between 0.75 m to 2.0 m;
- and
- enamel coating the thermally-flattened steel sheet on both sides, forming an enameled steel sheet having an enamel coating with a thickness of between 0.01 mm and 1.0 mm on both sides;
- wherein the enamel coated thermally-flattened steel sheet has a maximum deviation from flat of less than the comparing distance when the comparing pressure is applied.
The method of 1 further comprising cutting the enamel coated thermally-flattened steel sheet into individual units.
A method comprising:
- thermal flattening a feed stock steel sheet;
- and
- enamel coating with a two-step, two-fire enameling process the thermally-flattened steel sheet, forming an enameled steel sheet having an enamel coating;
- wherein the two-step, two-fire enameling process comprises:
- applying a first ceramic slurry to at least one side of the thermally-flattened steel sheet having a first side and a second side opposite the first side, forming a first slurried steel sheet having either:
- one surface applied with slurry and the other surface without slurry;
- or
- both surfaces applied with slurry;
- heating the first slurried steel sheet to a temperature between 700° C. and 1000° C. while maintaining the first slurried steel sheet in a catenary position with the first side or the second side pointing upward over a span of between 1.0 m and 40 m and a lateral tension of between 2.0 MPa and 3.0 MPa, forming a first coated steel sheet;
- applying a second ceramic slurry to one side of the first coated steel sheet, the one side is either:
- the surface without applied first ceramic slurry;
- or
- if both surfaces were applied with first ceramic slurry, either one of the surfaces;
- and
- heating the second slurried steel sheet to a temperature between 700° C. and 1000° C. while maintaining the second slurried steel sheet in a catenary position with the first side or the second side pointing upward over a span of between 1.0 m and 40 m and a lateral tension of between 2.0 MPa and 3.0 MPa, forming the enameled steel sheet having an enamel coating on both sides.
Dependencies are inferred from the claim text.