Method for manufacturing electrical steel self-adhesive coating in laboratory

Abstract

The invention discloses a method for manufacturing an electrical steel self-adhesive coating in a laboratory. The method comprises the following steps: performing single-sided coating on the surface of a non-oriented electrical steel substrate without a surface insulating coating after complete annealing by adopting a small-sized electric coating machine, controlling the thickness of the coating to be 1.5-3.0 microns, putting a sample coated with the coating into an air dry oven at the temperature of 180-210 DEG C, baking for 80-100 seconds, taking out the sample, naturally cooling at room temperature, and taking out the sample to obtain the non-oriented electrical steel substrate with the surface insulating coating. And laminating the sample coated with the self-adhesive coating under the pressure of 1-3MPa, continuously curing for 1-3 hours at the curing temperature of 160-210 DEG C, and measuring that the T stripping value reaches 4.0 N / mm or above.

Description

Technical Field

[0001] The invention relates to the technical field of special coatings, in particular to a method for preparing a self-adhesive coating for electrical steel in a laboratory. Background Art

[0002] In the existing motor manufacturing process, after the silicon steel is punched and stacked, it is usually fastened into an iron core by welding, bolting or riveting. However, the above connection methods may have the following problems: (1) The magnetic properties of the iron core will deteriorate at the welding or riveting points, which will affect the operating efficiency of the motor; (2) Only a part of the iron core is fastened, which is prone to generate noise during magnetization resonance; (3) The iron core is only partially fixed, which cannot be used in working conditions with high fastening requirements and is not suitable for micro motors.

[0003] In order to solve the problems that may exist in the above-mentioned welding, bolt connection or riveting methods, the core laminations are currently fixed by coating a self-adhesive coating on the surface of electrical steel, so that the core can be fixed on the entire surface, the fixing strength is improved, the magnetic performance is less damaged, the size of the motor can be smaller while achieving the same effect, and the vibration and noise of the silicon steel sheet in the core can be effectively reduced. The self-adhesive coating can be specifically divided into three states according to its use process: liquid, activated and passivated. Among them, the activated state is generally achieved in a steel plant. The specific operation process is to apply the coating in a liquid state to the surface of the silicon steel, and then undergo certain drying process conditions to make the coating in an activated state; then, the coating in the activated state is heated and pressurized by the motor user to achieve mutual bonding to achieve a passivated state. Among them, whether the self-adhesive coating can achieve mutual bonding and reach a certain strength in the motor user is directly related to the coating state after coating in the steel plant.

[0004] The inventor used a laboratory platform to carry out research on the coating and drying process of self-adhesive coating for non-oriented electrical steel, completed the control of the activation state of the self-adhesive coating for non-oriented electrical steel under laboratory conditions, and produced a self-adhesive coating with excellent bonding properties, laying a practical foundation for actual industrial production and opening up a new path for the laboratory development of self-adhesive coating technology.

[0005] The present invention provides a method for preparing a self-adhesive coating for electrical steel in a laboratory. By using a laboratory platform to carry out research on the coating and drying process of the self-adhesive coating for non-oriented electrical steel, the activation state of the self-adhesive coating for non-oriented electrical steel is controlled under laboratory conditions, and a self-adhesive coating with excellent bonding performance is obtained, which lays a practical foundation for actual industrial production and opens up a new way for the laboratory to develop the self-adhesive coating process. Summary of the invention

[0006] The purpose of the present invention is to provide a method for preparing a self-adhesive coating for electrical steel in a laboratory in view of the above problems.

[0007] The object of the present invention is achieved as follows: A method for preparing a self-adhesive coating for electrical steel in a laboratory, comprising the following steps: Step 1: Sampling: Cut a non-oriented electrical steel substrate without a surface insulating coating after complete annealing as a sample; Step 2: Sample shearing: Use a shearing machine to shear the sample to a size of 70-90 mm × 260-320 mm in the transverse direction × rolling direction; Step 3: Grinding burrs: Use sandpaper to grind the burrs on the edge of the sheared sample so that the burr height is less than 0.01 mm; Step 4: Use white gauze dipped in alcohol to clean the side of the sheared sample to be coated; Step 5: Use a coating machine to apply the self-adhesive coating liquid to a single side of the sheared sample, the coating roller is a stainless steel wire rod with a diameter of 8-10 mm, the groove depth of the wire rod is 0.13-0.17 mm, and the self-adhesive coating The solid content of the liquid is controlled at 25-40%, the viscosity is 20-30S, the coating speed is less than 5m / min, and the thickness of the coating is controlled at 1.5-3.0μm; Step 6: Place the shear specimen with one side coated with the coating in a blast drying oven at a temperature of 180℃~210℃ for baking, and the baking time is 80-100S. During the coating baking process, the humidity in the blast drying oven must be ensured to be less than 50%; Step 7: Take out the sample and cool it naturally at room temperature; Step 8: Cut the shear specimen coated with the self-adhesive coating into a coating specimen of 25mm×200-250mm, and then stack the coating specimen under a pressure of 1-3MPa, and continuously cure it at a curing temperature of 160-210℃ for 1-3 hours, and the measured T peel value reaches 4.0N / mm or more.

[0008] The thickness of the non-oriented electrical steel substrate is 0.35-0.65 mm and the specification is 260-320 mm×260-320 mm.

[0009] The beneficial effects of the present invention are as follows: the present invention provides a method for preparing a self-adhesive coating for electrical steel in a laboratory. By using a laboratory platform to carry out research on the coating and drying process of the self-adhesive coating for non-oriented electrical steel, a self-adhesive coating with excellent performance is prepared under laboratory conditions, laying a practical foundation for actual industrial production, and opening up a new way for the laboratory to develop the self-adhesive coating process. DETAILED DESCRIPTION

[0010] The present invention provides a method for preparing a self-adhesive coating of electrical steel in a laboratory. The method comprises the following steps: 1. Sampling: cutting a non-oriented electrical steel substrate without a surface insulating coating after complete annealing, with a thickness of 0.35-0.65 mm and a specification of 300 mm×300 mm. 2. Sample shearing: using a shearing machine to shear the sample to a size of 80 mm×300 mm in transverse direction×rolling direction. 3. Grinding burrs: in order to reduce the influence of burrs on the coating roller during the coating process, the burrs on the edge of the sheared sample are polished with sandpaper to make them less than 0.01 mm. 4. Using white gauze dipped in alcohol to clean the side of the substrate to be coated. 5. The self-adhesive coating liquid adopts EB548 purchased from Rembrandt Company. 6. The solid content of the self-adhesive coating liquid is controlled at 25-40%, and the viscosity is 20-30S; 7. A small electric coating machine is used for single-sided coating, and the coating roller is a stainless steel wire rod with a diameter of 10 mm, and the groove depth of the wire rod is 0.15 mm. 8. To ensure the uniformity of the coating surface, the coating speed is less than 5m / min. 9. The thickness of the coating is controlled at 1.5~3.0μm. 10. Place the sample coated on one side in a blast drying oven at a temperature of 180℃~210℃ for baking, and the baking time is 80~100S. Use a stopwatch to time, and the time when the sample is placed in the oven and the oven door is closed is recorded as the starting time, and the time when the baking is completed and the sample is taken out is recorded as the end time. 10. During the coating baking process, the dehumidification function of the oven should be turned on to ensure that the humidity is less than 50%. 11. The removed sample is cooled naturally at room temperature. 12. Cut the sample coated with the self-adhesive coating into 25mm×200mm, overlap it at a pressure of 1~3MPa, and continuously cure it at a curing temperature of 160~210℃ for 1~3 hours. The measured T peel value reaches more than 4.0N / mm. Example 1

[0011] The non-oriented electrical steel substrate without surface insulation coating after complete annealing was cut into 80mm (transverse) × 300mm (rolling direction), and the burrs on the edge of the sheared sample were polished with sandpaper to be less than 0.01mm. The side of the substrate to be coated was cleaned with white gauze dipped in alcohol. The solid content of the self-adhesive coating liquid was controlled at 30%, and the viscosity was 25S. A small electric coating machine was used for single-sided coating. The coating roller was a stainless steel wire rod with a diameter of 10mm, and the groove depth of the wire rod was 0.15mm. The coating speed was less than 5m / min, and the thickness of the coating was controlled at 2.0μm. The sample with one side coated was placed in a blast drying oven at a temperature of 200℃ for baking, and the baking time was 90S. Use a stopwatch to time the sample. The time when the sample is placed in the oven and the door is closed is recorded as the start time. The time when the sample is taken out after baking is recorded as the end time. During the coating baking process, the dehumidification function of the oven should be turned on to ensure that the humidity is less than 50%. The taken out sample is cooled naturally at room temperature. The sample coated with the self-adhesive coating is cut into 25mm×200mm, laminated at a pressure of 1-3MPa, and continuously cured at a curing temperature of 160-210℃ for 1-3 hours. The measured T peel value reaches 5.0N / mm. Example 2

[0012] The non-oriented electrical steel substrate without surface insulation coating after complete annealing was cut into 80mm (transverse) × 300mm (rolling direction), and the burrs on the edge of the sheared sample were polished with sandpaper to be less than 0.01mm. The side of the substrate to be coated was cleaned with white gauze dipped in alcohol. The solid content of the self-adhesive coating liquid was controlled at 25%, and the viscosity was 20S. A small electric coating machine was used for single-sided coating. The coating roller was a stainless steel wire rod with a diameter of 10mm, and the groove depth of the wire rod was 0.15mm. The coating speed was less than 5m / min, and the thickness of the coating was controlled at 1.8μm. The sample with one side coated was placed in a blast drying oven at a temperature of 180℃ for baking, and the baking time was 80S. Use a stopwatch to time the sample. The time when the sample is placed in the oven and the door is closed is recorded as the start time. The time when the sample is taken out after baking is recorded as the end time. During the coating baking process, the dehumidification function of the oven should be turned on to ensure that the humidity is less than 50%. The taken out sample is cooled naturally at room temperature. The sample coated with the self-adhesive coating is cut into 25mm×200mm, laminated at a pressure of 1-3MPa, and continuously cured at a curing temperature of 160-210℃ for 1-3 hours. The measured T peel value reaches 4.5N / mm. Example 3

[0013] The non-oriented electrical steel substrate without surface insulation coating after complete annealing was cut into 80mm (transverse) × 300mm (rolling direction), and the burrs on the edge of the sheared sample were polished with sandpaper to be less than 0.01mm. The side of the substrate to be coated was cleaned with white gauze dipped in alcohol. The solid content of the self-adhesive coating liquid was controlled at 40%, and the viscosity was 30S. A small electric coating machine was used for single-sided coating. The coating roller was a stainless steel wire rod with a diameter of 10mm, and the groove depth of the wire rod was 0.15mm. The coating speed was less than 5m / min, and the thickness of the coating was controlled at 2.8μm. The sample with one side coated was placed in a blast drying oven at a temperature of 210℃ for baking, and the baking time was 100S. Use a stopwatch to time the sample. The time when the sample is placed in the oven and the door is closed is recorded as the start time. The time when the sample is taken out after baking is recorded as the end time. During the coating baking process, the dehumidification function of the oven should be turned on to ensure that the humidity is less than 50%. The taken out sample is cooled naturally at room temperature. The sample coated with the self-adhesive coating is cut into 25mm×200mm, laminated at a pressure of 1-3MPa, and continuously cured at a curing temperature of 160-210℃ for 1-3 hours. The measured T peel value reaches 4.8N / mm.

[0014] The above description is only a specific embodiment of the present invention, but the structural features of the protection scope of the present invention are not limited thereto. Any changes or modifications made by any technician in the field of the present invention are all covered by the patent scope of the present invention.

Claims

1. A method for producing a self-adhesive coating for electrical steel in a laboratory, characterized in that: The following steps are involved: Step 1: Sampling: Cut the non-oriented electrical steel substrate without surface insulation coating after complete annealing as the sample; Step 2: Sample shearing: Use a shearing machine to shear the sample to a size of 70-90 mm x 260-320 mm in the transverse direction and rolling direction; Step 3: Grind burrs: Use sandpaper to grind the burrs on the edge of the sheared specimen to a height of less than 0.01 mm; Step 4: Use white gauze dipped in alcohol to clean the side of the shear specimen to be coated; Step 5: Use a coating machine to apply the self-adhesive coating liquid to a single side of the shear specimen. The coating roller is a stainless steel wire rod with a diameter of 8 to 10 mm. The groove depth of the wire rod is 0.13 to 0.17 mm. The solid content of the self-adhesive coating liquid is controlled at 25 to 40%, the viscosity is 20 to 30 seconds, the coating speed is less than 5 m / min, and the thickness of the coating is controlled at 1.5 to 3.0 μm. Step 6: Place the shear specimen with one side coated in a blast drying oven at a temperature of 180℃~210℃ for 80~100S. During the coating baking process, the humidity in the blast drying oven must be less than 50%; Step 7: Take out the sample and cool it naturally at room temperature; Step 8: Cut the shear specimen coated with the self-adhesive coating into a coating specimen of 25 mm × 200-250 mm, and then laminate the coating specimen under a pressure of 1-3 MPa, and continuously cure for 1-3 hours at a curing temperature of 160-210°C, and measure a T peel value of more than 4.0 N / mm.

2. A method for producing a self-adhesive coating for electrical steel in a laboratory according to claim 1, characterized in that: The thickness of the non-oriented electrical steel substrate is 0.35-0.65 mm and the specification is 260-320 mm×260-320 mm.