NMN Insulation Material for Electric Motors

In the field of motor insulation, NMN is a highly balanced three-layer composite insulation material. Its full name i...

In the field of motor insulation, NMN is a highly balanced three-layer composite insulation material. Its full name is Nomex^®/ Polyester Film / Nomex^®. It is constructed by bonding two layers of Nomex paper with a center layer of Mylar (polyester film).
Essentially, it combines the thermal resistance of Nomex with the high dielectric strengthof polyester film.

1. Structure Breakdown (N-M-N)

Outer Layers (N – Nomex): Provide thermal stability, tear resistance, and excellent resin absorption (facilitating the penetration of insulating varnish).
Inner Layer (M – Mylar/PET): Located in the center, it provides superior electrical breakdown strength and mechanical support.

2. Core Characteristics

Thermal Class: Rated as Class F (155°C) or Class H (180°C), depending on the specific adhesive and Nomex grade used.
Superior Mechanical Properties: Extremely tough and resistant to folding and tension, making it ideal for automatic winding machines and manual insertion.
Electrical Reliability: The polyester film ensures high dielectric strength, maintaining stable insulation even in humid environments.
Compatibility: Excellent bonding capability with various types of motor impregnating varnishes.

3. Primary Applications

NMN is commonly used in critical parts of small and medium-sized motors:
Slot Insulation: Placed within the stator slots to prevent contact between the windings and the iron core.
Phase Insulation: Used to isolate different phases of the windings.
Inter-turn/Layer Insulation: Used as padding between layers in certain large coils.

4. Comparison: NMN vs. DMD vs. NHN

5. Buying and Usage Tips

Thickness Specifications: Common thicknesses include 0.15mm, 0.20mm, 0.25mm, 0.30mm, etc. Selection should be based on the precise gap of the motor slot.