In the field of electrical insulation, 6640 NMN insulation paper has become one of the most trusted materials used in electric motors and transformers. Known for its excellent combination of thermal stability, dielectric strength, and mechanical durability, NMN (Nomex® + Mylar® + Nomex®) flexible composite insulation is a preferred choice for many electrical equipment manufacturers worldwide.
6640 NMN flexible composite insulation paper is made by laminating polyester film (Mylar) between two layers of Nomex® paper produced by DuPont™. This unique three-layer structure integrates the best properties of both materials — the mechanical strength and smooth surface of polyester film, and the excellent thermal resistance and electrical insulation performance of Nomex® aramid paper.
Typical thicknesses of NMN insulating paper are 0.10/0.13/0.15/0.18/0.20/0.22/0.25/0.30/0.35 (mm), with the specific thickness depending on the insulation class and application requirements. It is widely used in Class F (155°C) insulation environments.
1. Outstanding Thermal Stability
NMN insulation maintains its performance under long-term exposure to high temperatures, making it ideal for motors and transformers that operate continuously in demanding environments.
2. Excellent Electrical Strength
The Mylar layer provides superior dielectric strength, ensuring reliable interlayer and slot insulation in electric motors and transformers.
3. Good Mechanical Toughness and Flexibility
The Nomex outer layers improve flexibility and resistance to mechanical stress during motor winding and assembly.
4. Strong Resistance to Moisture and Chemical Agents
NMN insulation paper resists aging, moisture absorption, and common industrial chemicals, guaranteeing stable performance even under humid or contaminated conditions.
Because of its balance of mechanical, electrical, and thermal properties, 6640 NMN insulation paper is widely used in multiple insulation parts of electric motors and transformers, such as:
• Slot liners and slot wedges in low- and medium-voltage motors
• Phase and interturn insulation
• Interlayer insulation in transformers and generators
• Layer insulation for dry-type transformers and electromagnetic coils
• Die-cut and formed insulation components
In electric motor production, NMN flexible composite material ensures the stability of the winding system and reduces the risk of short circuits, thereby extending the motor’s service life.
Compared with other flexible insulation materials like 6520 polyester film composite or DMD insulation paper, NMN insulation paper offers significantly higher temperature resistance and better mechanical strength. Its structure allows excellent adhesion and compatibility with epoxy resins and impregnating varnishes, improving bonding during motor assembly and ensuring long-term reliability.
Manufacturers seeking high-performance motor insulation materials choose NMN for its balance of cost, durability, and insulation efficiency.
High-quality 6640 NMN insulation paper is manufactured under strict quality control to meet IEC 626, GB/T 5591.3.1, and UL E345672 standards. Each batch undergoes dielectric breakdown, tensile strength, and thermal aging tests to ensure consistent performance in all applications.
In today’s energy and automation industries, 6640 NMN insulation paper plays a critical role in guaranteeing the safety, efficiency, and longevity of electric motors and transformers. Whether used as slot insulation, phase insulation, or interlayer barriers, its advanced composite structure delivers unmatched protection under high temperature and voltage conditions.
For motor and transformer manufacturers looking for reliable flexible composite insulation materials, NMN Nomex Mylar Nomex insulation paper remains the preferred solution for long-term, stable performance.
