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US3932683A Expired / Lapsed US ⏱️ 0.0 years remaining

Control of coating thickness of hot-dip metal coating

Assignee: Inland Steel Co
•
Filing: 1972-10-10
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Granted: 1976-01-13
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Expires: 1992-10-10
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Abstract

Abstract Objectionable ripple formation in continuous hot-dip coating is avoided by using a single set of blowing nozzles and directing the gas streams downwardly against the strip at an angle between the strip and the center line of the gas stream of from about 0° to about 45°, preferably from about 20° to about 40°. The technique is particularly useful at low line speeds of 150 feet per minute or less, especially at high coating weights of 1.5 ounces per square foot or more.

Inventors

  • 👤 Norman A. Robins
  • 👤 Frank H. Bugajski

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-09 07:55
CPC Classifications
C; C23; C23C; C23C2/00; C23C2/14; C23C2/16; C23C2/18; C23C2/20

Claims Analysis

Total Claims: 9
Claim 1
Independent Claim 116 words
In a continuous hot-dip coating line wherein a metal strip is passed through a molten coating bath at a line speed not greater than about 150 feet per minute and is withdrawn vertically from the bath between a pair of gas blowing nozzles for impinging only a single stream of gas against each side of said strip and thereby controlling the coating thickness, the improvement which comprises directing the gas stream from each of said nozzles generally downwardly against the strip at an angle between the strip and the center line of the gas stream of not more than about 40°, whereby to eliminate or substantially minimize ripple formation on the surface of the coated product.
Claim 2
Dependent Claim 116 words
In a continuous hot-dip coating line wherein a metal strip is passed through a molten coating bath at a line speed not greater than about 150 feet per minute and is withdrawn vertically from the bath between a pair of gas blowing nozzles for impinging only a single stream of gas against each side of said strip and thereby controlling the coating thickness, the improvement which comprises directing the gas stream from each of said nozzles generally downwardly against the strip at an angle between the strip and the center line of the gas stream of not more than about 40°, whereby to eliminate or substantially minimize ripple formation on the surface of the coated product.
Claim 3
Dependent Claim 18 words
The improvement of claim 1 further characterized in that said angle is from about 20° to about 40°.
Claim 4
Dependent Claim 22 words
The improvement of claim 1 further characterized in that said line speed is from about 40 to about 100 feet per minute.
Claim 5
Dependent Claim 30 words
The improvement of claim 1 further characterized in that the line is operated so as to obtain a coating weight of not less than about 1.5 ounces per square foot.
Claim 6
Dependent Claim 44 words
The improvement of claim 1 further characterized in that said line speed is from about 40 to about 100 feet per minute and the line is operated so as to obtain a coating weight of not less than about 1.5 ounces per square foot.
Claim 7
Dependent Claim 29 words
The improvement of claim 1 further characterized in that the line is operated to obtain a coating weight of from about 1.5 to about 3 ounces per square foot.
Claim 8
Dependent Claim 55 words
The improvement of claim 1 further characterized in that said line speed is from about 40 to about 100 feet per minute and the line is operated so as to obtain a coating weight of from about 1.5 to about 3 ounces per square foot, and said angle is from about 20° to about 40°.
Claim 9
Dependent Claim 31 words
The improvement of claim 1 further characterized in that said strip is steel and said coating bath is a metal selected from the group consisting of zinc, aluminum, and alloys thereof.

References Cited (Backward Citations)

US3681118A Cited
US3406656A Cited
US3459587A Cited
US3607366A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1979-01-12 1979-07-14 1980-01-13 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1983-01-12 1983-07-14 1984-01-13 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1987-01-12 1987-07-14 1988-01-13 $7700.00 Window Closed / Lapsed

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