Successful development of silicon steel sheet insu

Successful development of silicon steel sheet insulating paint for large motors

successful development of silicon steel sheet insulating paint for large motors

October 15, 2002

there are basically two kinds of silicon steel sheet insulating paint used in the field of motor industry in China: traditional pure organic paint and

water-soluble semi inorganic paint, but neither of them can pass the Franklin burning loss test, fail to meet international standards, and directly affect the cooperative production with foreign countries Joint bidding and export of products

wanjiasai, Xiaolangdi, etc

Franklin burn test method is to burn the coated insulating paint film on the silicon steel sheet with a flame, and then measure the leakage current of the residual part of the paint film after burning

, which should be less than a certain value but not reach the value that can be used by everyone. The purpose is that when the iron core is overheated, there is still enough resistance between the punching pieces to ensure good insulation between the pieces and prevent the expansion of short circuit between the pieces. This is the internationally recognized test standard

, which is adopted by most foreign companies. The main indicators are that under the conditions of advanced production technology of various polyurethane raw materials in China, the leading output is (150 + 5) ℃, the pressure is

5.2mpa, and the voltage is 5V (DC), the average value of inter chip leakage current measured is not greater than 0.2A, and the maximum value is not greater than 0.6A

pure organic paint can not meet this requirement, and only some inorganic filler can be added. However, the content, fineness, precipitation of inorganic filler and its compatibility with organic components must be solved. The content is too low to meet the requirements, and the high volume

is easy to cause precipitation. Finally, the preferred content is 5%? 30％。 Low fineness has an impact on the burning loss test, and high fineness has an impact on the paint film thickness, which is finally confirmed as 2? five μ m。 Compared with organic materials, inorganic fillers have a larger proportion, which inevitably leads to sedimentation. Only by adding an appropriate amount of suspending agent can we alleviate the sedimentation problem, and the mixing during use is also easy to complete. The adopted

organic and inorganic materials have poor compatibility. Finally, a suitable treatment agent is selected to solve the compatibility problem.

the 550MW generator of Ertan Power Station, the largest in China, recently produced by Harbin electric machinery factory, has applied this new semi non

machine silicon steel sheet paint, and sent the punching sample to ge Canada for comprehensive test and certification. The appearance, thickness, Franklin burning The test results of punching, bending, etc. show that all of them are qualified, and even most of the key indicators

far exceed the standard value. In addition to hydro generators, this paint has been used on various AC motors