Patent ID: 9406416
Filing Date: 2016-08-02
CPC Classification: B05C,B05D,C09D,H01B,H01F

Claim Text:
1. A method of producing an extremely thick insulation coating on a surface of an electrical steel, comprising the following steps: 1) preparing a coating liquid by stirring the coating liquid for 0.1˜4 hours, then according to an original viscosity of the coating liquid, diluting the coating liquid with pure water or solvent to make sure that the viscosity of the coating liquid is within 10˜80 S; 2) coating a strip steel by coating an upper surface and a lower surface of the strip steel with the coating liquid using a double-roller coating machine in two coating ways, said two coating ways comprising co-current coating and counter-current coating, wherein in the double-roller coating machine, both the speed ratios of a pick-up roller and a coating roller are 0.2˜1.5, and the pressure between the two rollers is 1˜50 KPa; 3) baking the coating using burner nozzles to provide heated air, wherein the heated air circulates through a vertical circulation bellow, drying a wet film on the surfaces of the strip steel and solidifying a wet film; baking the coating in three sections, said three sections comprising a drying section, a baking section, and a cooling section, wherein the temperature in the drying section is 100˜400° C., and the temperature in the baking section is 200˜370° C.; the time in the whole drying and baking sections is 33˜144 seconds, wherein the time in the drying section is 9˜39 seconds, and the time in the baking section is 24˜105 seconds; wherein a coating with film thickness of 2˜10 μm is finally formed, wherein in the baking process, the strip steel having been coated is conveyed in a non-contact way, in which the strip steel is conveyed by blowing pressure-adjustable air onto the lower surface of the strip steel to make the strip steel float; the air pressure is adjustable within 1˜2000 Pa according to the thickness of the strip steel; wherein the wet film is kept out of contact with a furnace roller before the wet film is solidified, so as to guarantee that the surface of the wet film is left intact.