Abstract: A surface treatment apparatus for a metal sheet has a blasting device for blasting solid particles having an average particle diameter of 300 ?m or less onto the metal sheet which is continuously transferred, a blast chamber in which the blasting device is disposed, and cleaning means provided at the downstream side of the blast chamber for cleaning a surface of the metal sheet. At an inlet side of the blasting device, a deposits removing device for removing deposits on the surface of the metal sheet may be provided.

Abstract: A surface treatment apparatus for metallic sheet has at least one centrifugal blasting machine to blast solid particles having 30 to 300 ?m of mean particle diameter against the continuously traveling metallic sheet. The blasting machine is structured by a centrifugal rotor having a rotation axis. The line of intersection between the plane vertical to the rotation axis and the plane of the metallic sheet is positioned in parallel to or at 45° or smaller angle to the travel direction of the metallic sheet.

Abstract: A surface treatment apparatus for a metal sheet has a blasting device for blasting solid particles having an average particle diameter of 300 ?m or less onto the metal sheet which is continuously transferred, a blast chamber in which the blasting device is disposed, and cleaning means provided at the downstream side of the blast chamber for cleaning a surface of the metal sheet. At an inlet side of the blasting device, a deposits removing device for removing deposits on the surface of the metal sheet may be provided.

Abstract: The method for manufacturing galvanized steel sheet has a step of adjusting the surface texture thereof by blasting solid particles against the surface thereof. The surface texture is defined by at least one parameter selected from the group of parameters consisting of mean roughness Ra on the surface of steel sheet, peak count PPI on the surface of steel sheet, and filtered centerline waviness Wca on the surface of steel sheet. The galvanized steel sheet has a surface in dimple-pattern texture.

Abstract: The method for manufacturing galvanized steel sheet has a step of adjusting the surface texture thereof by blasting solid particles against the surface thereof. The surface texture is defined by at least one parameter selected from the group of parameters consisting of mean roughness Ra on the surface of steel sheet, peak count PPI on the surface of steel sheet, and filtered centerline waviness Wca on the surface of steel sheet. The galvanized steel sheet has a surface in dimple-pattern texture.

Abstract: The method for manufacturing galvanized steel sheet has a step of adjusting the surface texture thereof by blasting solid particles against the surface thereof. The surface texture is defined by at least one parameter selected from the group of parameters consisting of mean roughness Ra on the surface of steel sheet, peak count PPI on the surface of steel sheet, and filtered centerline waviness Wca on the surface of steel sheet. The galvanized steel sheet has a surface in dimple-pattern texture.

Abstract: A method for supplying rolling oil for cold rolling is provided wherein emulsion rolling oil is supplied using both: (i) a first rolling oil supply system for sypplying the emulsion rolling oil to a roll and a steel sheet being rolled in a recirculation mode, and (ii) a second rolling oil supply system for supplying the emulsion rolling oil to only the front and back surface of the stell sheet. The emulsion rolling oil supplied by the first and second supply systems comprise an emulsifier of a same type and concentration, and the second supply system is controlled so that an average particle diameter of emulsion is larger than an average particle diameter of emulsion of the first supply system. The emulsion of the second supply system, which has not stuck onto the steel sheet being rolled, is then joined to the emulsion of the first supply system.

Abstract: A method for supplying rolling oil for cold rolling comprises the steps of: supplying emulsion rolling oil using a first rolling oil supply system supplying the emulsion rolling oil to a roll and a steel sheet in a recirculation mode and a second rolling oil supply system supplying the emulsion rolling oil to only the front and back surface of the steel sheet, wherein the emulsion rolling oil, which is added with an emulsifier of the same type and concentration with respect to the amount of oil as those of the emulsifier of the first supply system and controlled so that the average particle diameter of emulsion is larger than that of emulsion of the first supply system, is supplied from the second supply system; and joining the emulsion of the second supply system to the emulsion of the first supply system.