Insulating paper for motors and power transformers is a very important insulation material in our electrical products, used in the slot insulation, layer insulation and phase insulation of three-phase motors. Different types of insulating paper should be used for motors of different heat resisting grades. The most commonly used types are DMD, NMN, NHN and other composite insulating paper. With the improvement of insulation performance and heat resistance, TFT composite insulating paper and other new insulating materials come into being.
1. DMD insulating paper (Class B insulation). This kind of insulating paper is a kind of composite insulating material, or DMD for short, produced by calendering a layer of polyester film coated with adhesive.
2. NMN insulating paper (Grade F insulation). This type of insulating paper is a soft composite material consisting of polyester film and Nomex paper, heat resistance grade F(155℃). Good mechanical properties, such as tensile strength, tear resistance and good electrical strength. The surface is smooth and the low-voltage motor is used for automatic off-line production to ensure no fault. It is mainly used for the groove of low-voltage motor, the insulation cover of groove, also can be used as the layer insulation of power transformers or other appliance.
3. NHN insulating paper (Class H insulation). This type of insulating paper is composed of polyimide film and Nomex paper. It is a soft composite material of heat resistance grade H(180℃). It has good mechanical properties, such as tensile strength and tear edge and good electrical strength. It has a smooth surface and adopts automatic logging-off machine to ensure the fault-free NHN in the production of low-voltage motor. It is mainly aimed at the high heat resistance between the motors, the insulating cover used alternately with the insulating cover, and can also be used as power transformers or other appliances for inter-layer insulation.
