Method of producing extremely thick insulation coating on surface of electrical steel

Patent metadata

Field	Value
Publication number	US-9406416-B2
Application number	US-201114348357-A
Country	US
Kind code	B2
Filing date	Dec 14, 2011
Priority date	Oct 17, 2011
Publication date	Aug 2, 2016
Grant date	Aug 2, 2016

Abstract

A method of producing an extremely thick insulation coating on a surface of an electrical steel, comprises the following steps: 1) preparing a coating liquid—stirring sufficiently the coating liquid for 0.1˜4 hours, with the viscosity of the coating liquid being within 10˜80 S; 2) coating a strip steel—using a double-roller or a tri-roller coating machine, wherein the film thickness and evenness can be controlled by adjusting different parameters; 3) baking the coating—using three sections, that is, a drying section, a baking section and a cooling section, to bake the coating, wherein the temperature in the drying section is 100˜400° C., the temperature in the baking section is 200˜370° C.; the time in the whole drying and solidification section is 33˜144 seconds, wherein the time in the drying section is 9˜39 seconds, and the baking time is 24˜105 seconds; wherein in the baking process, the strip steel having been coated is conveyed in a non-contact way, in particular, the strip steel is conveyed by blowing pressure-adjustable air onto the lower surface to make it float; the air pressure is 0˜2000 Pa; the wet film is kept out of contact with the furnace rollers before it is solidified, guaranteeing that the surface of wet film is intact; 4) online detecting the film thickness.

First claim

The invention claimed is:

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.

2. The method of producing an extremely thick insulation coating on a surface of an electrical steel according to claim 1 , characterized in that the method further comprises step 4): online detecting of the film thickness using an online detection method to continuously detect the film thickness on both the upper surface and the lower surface of the strip steel, and by comparing the result of the film thickness during the online detection with a target thickness, adjusting the coating machine in due time to achieve the target thickness, so as to ensure a uniform film thickness.

3. The method of producing an extremely thick insulation coating on a surface of an electrical steel according to claim 1 , characterized in that in the step 1) of preparing the coating liquid, the solvent for adjusting the viscosity comprises ethylene glycol butyl ether or butyl glycol.

4. 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 until thoroughly mixed, 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 tri-roller coating machine, in two coating ways, said two coating ways comprising co-current coating and counter-current coating, wherein in the tri-roller coating machine, both the speed ratios of a coating roller and a pick-up roller are 0.2˜1.2; and the pressure between the two rollers is 0.1˜10 KPa; the gap between the pick-up roller and a metering roller is 80˜150 μm;
3) baking the coating using burner nozzles to provide heated air, wherein the heated air circulates through a vertical circulation bellow, drying the wet film on the surfaces of the strip steel and solidifying the 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., 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 any furnace rollers before the wet film is solidified, so as to guarantee that the surface of the wet film is intact.

5. The method of producing an extremely thick insulation coating on a surface of an electrical steel according to claim 4 , characterized in that the method further comprises step 4): online detecting of the film thickness using an online detection method to continuously detect the film thickness on both the upper surface and the lower surface of the strip steel, and by comparing the result of the film thickness during the online detection with a target thickness, adjusting the coating machine in due time to achieve the target thickness, so as to ensure a uniform film thickness.

6. The method of producing an extremely thick insulation coating on a surface of an electrical steel according to claim 4 , characterized in that in the step 1) of preparing the coating liquid, the solvent for adjusting the viscosity comprises ethylene glycol butyl ether or butyl glycol.

Assignees

• Lu Yongqiang
• Lv Chunguo
• Wang Zhicheng
• Chen Bin
• Chen Xiao
• Xie Shishu
• Baoshan Iron & Steel

Inventors

• Lu Yongqiang
• Lv Chunguo
• Wang Zhicheng
• Chen Bin
• Chen Xiao
• Xie Shishu

Classifications

• B05D2202/10

  based on Fe · CPC title

• C09D5/08

  Anti-corrosive paints · CPC title

• B05D5/12 Primary

  to obtain a coating with specific electrical properties · CPC title

• H01F1/18

  with insulating coating · CPC title

• B05D3/0413

  Heating with air · CPC title