The heat resistance of enameled wire is an important indicator, especially for motors and components or windings with temperature rise requirements, which directly affects the design and use of electrical equipment. If enameled wire with higher heat resistance and supporting materials can be used, greater power can be obtained without changing the structure, or the size and weight can be reduced while keeping the power unchanged, and the consumption of non-ferrous metals and other materials can be reduced.

The thermal shock test is to study the heat tolerance of the enameled wire film under mechanical stress. In the thermal shock test, the extended film itself will shrink due to heat, but the wire bonded to the film prevents this shrinkage. The film strength of different types of enameled wires is different, and the strength of various films decreases to different degrees as the temperature rises.

Chemical resistance includes resistance to acid, alkali, salt spray, moisture, oil, solvent, refrigerant, radiation, etc. During the coil impregnation process, the enameled wire must not only withstand thermal shock and softening breakdown tests, but also be able to withstand the erosion of solvents such as toluene, xylene, petroleum solvents, and oil in the impregnation varnish.