Flexible Insulation Material Solutions

Nomex is an aramid paper that provides thermal resistance and mechanical strength in an insulation system. Mylar is a polyester (PET) film that provides the primary dielectric barrier. In most motor and transformer insulation systems, they work together as a laminate rather than independently. NMN (Nomex/Mylar/Nomex) is the most common construction, where Nomex handles the thermal and mechanical load and Mylar provides the electrical insulation performance.

Nomex 410 is rated for continuous thermal exposure at 220 degrees Celsius, which places it in the Class H thermal classification under IEC 60085. It is one of the most widely specified high-temperature synthetic papers in motor and transformer manufacturing worldwide.

Standard Mylar (PET film) is rated for continuous service up to approximately 105 to 130 degrees Celsius depending on grade. Kapton (polyimide film) handles continuous service at 220 degrees Celsius and above. When the thermal class of the insulation system exceeds what PET film can sustain, or when the equipment design requires a higher dielectric performance at elevated temperature, Kapton is the correct specification.

NMN uses polyester (Mylar) film as the dielectric core between two layers of Nomex aramid paper. NKN substitutes polyimide (Kapton) film for the core, giving it a higher thermal rating. NMN is sufficient for most Class H insulation systems. NKN is specified when the design requires performance above the thermal limit of polyester film, such as in high-duty-cycle motors or specialized transformer designs.

Yes. We convert flexible laminate materials to customer-specified widths and lengths from standard roll stock. If you have dimensional requirements for slot liners, layer insulation, or phase separators, our team can quote slit-to-width and cut-to-length supply from our stocked laminate grades.

Felt layers serve a mechanical rather than electrical function. They cushion conductors during the winding process, fill gaps between conductors and the slot wall, and absorb vibration in service. The primary dielectric protection comes from the film or laminate insulation, while the felt layer protects that insulation from abrasion and mechanical stress.

Both are made from aramid fiber, but they have different structures and serve different functions. Nomex paper is a compressed, dense sheet material used as a primary thermal and mechanical insulation component. Aramid felt is a lighter, more open fibrous material used for cushioning and gap filling. They are not interchangeable in an insulation system.

Yes. We work directly with motor and transformer OEMs to supply flexible insulation materials to custom dimensions, laminate constructions, and thickness specifications. Contact our team with your thermal class, voltage rating, and dimensional requirements to discuss standard or custom supply options.