Electromagnetic wire is one of the main raw materials for electric motors.A wire used for winding or coiling.There are many kinds.According to its section shape,it can be divided into three types:round line,flat line and stripline.The cross-section of circular and flat lines has the same standard size.The cross-sectional size of the strip wire can be customized by the wire manufacturer according to design requirements.According to the characteristics and uses of the insulation layer,it can be divided into four categories:enameled wire,wrapped wire,inorganic insulation wire,and special type.

　　1.Enamelled wire:

　　The coating of enameled wire should be uniform,smooth,and covered(with few pinholes).The wire diameter and film thickness should comply with Chinese standards.The performance of enameled wire is determined by the paint film and generally includes the following items:

　　(1)Mechanical properties.The paint film should have scratch resistance,elasticity,and appropriate softness and elongation to ensure that it can withstand the effects of friction,bending,stretching,and compression during winding,embedding,stretching,and forming without damage.

　　(2)Electrical performance.The main reason is the high breakdown voltage of the paint film.The enameled wire used for high-frequency and high-voltage motor windings requires a small film loss angle tangent.For enameled wires with a diameter less than 0.5,the number of pinholes is an important indicator for evaluating their electrical performance.Many motor manufacturers have equipped thin film continuity testers to detect the number of pinholes in the incoming inspection of electromagnetic wires.

　　(3)Thermal performance.This includes the softening and breakdown,thermal aging,and thermal shock performance of the paint film.Softening and breakdown performance refer to the heat resistant deformation ability of the paint film under pressure;Thermal aging performance refers to the ability of a paint film to maintain elasticity after a short period of thermal action;Thermal shock performance reflects the ability of the paint film to withstand thermal shock(quenching,quenching)without cracking during baking,dipping or overload operation.

　　(4)Chemical properties.Indicates the corrosion resistance of the paint film to chemical substances such as acids,alkalis,salt mist,organic solvents,or refrigerants.