The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 05, 2001
Filed:
Jun. 20, 2000
Sachihiro Iida, Tokyo, JP;
Takahiro Sugano, Tokyo, JP;
Kawasaki Steel Corporation, Hyogo, JP;
Abstract
A molten metal is deposited on the surfaces of a metal strip by continuously dipping the metal strip in a coating bath. The metal strip is lifted at a constant speed while supported with a pair of upper and lower support rolls in the coating bath. The coating weights of the molten metal deposited on the surfaces of the metal strip are adjusted by wiping the molten metal with gases from gas wiping nozzles disposed above the surface of the coating bath. The metal strip is advanced while supported with a pair of upper and lower touch rolls, wherein the metal strip is advanced by setting the distance L between the upper support roll disposed in the coating bath and the lower touch roll disposed outside the coating bath within the range determined by a formula L≦80×T×W,/V, where L: distance between the upper support roll in the coating bath and the lower touch roll outside the coating bath (mm), V: line speed of the metal strip (m/min), T: tension imposed on the metal strip (kgf/mm,), and W: target coating weight per one side of the metal strip (g/m,). The stable quality of the metal strip can be obtained by reducing the variation of the coating weights of the molten metal deposited on the surfaces of the metal strip at all times regardless of the change of the operating conditions under which continuous hot dip galvanizing operation is carried out. Further, a coating cost can be greatly reduced by preventing the excessive deposition of the molten metal.