11 Properties of Nomex papers for electrical insulation tasks
For over 50 years, designers and manufacturers of transformers, generators, motors and other electrical equipment have relied on Nomex paper's unique combination of properties to optimize performance, increase reliability and extend the life of their products. DuPont branded Nomex products offer high electrical, chemical and mechanical integrity. This makes them ideal for a wide variety of electrical insulation applications such as: B. slot insulation , slot closure , slot closure and phase insulation in electric motors and generators, layer insulation in transformers and molded parts as housing insulation in other electrical equipment.
11 properties characterize Nomex papers:
- Inherent Dielectric Strength
- Mechanic solidity
- High temperature resistance
- High chemical compatibility
- High radiation resistance
- flame retardancy
- Insensitivity to moisture
- Suitable for low temperatures
- good punchability
- good coatability
- good deformability
Inherent dielectric strength of Nomex papers
At high density, Nomex allows short-term electrical stresses from 18 kV/mm to 34 kV/mm (460 V/mil to 870 V/mil), depending on product type and thickness.
Mechanical strength of Nomex papers
Nomex High-Density products have high mechanical toughness, tensile strength and abrasion resistance, and are also flexible (with reduced thickness).
High temperature resistance of Nomex papers
Temperatures up to 200°C have little or no effect on the electrical and mechanical properties of Nomex products. The useful properties of Nomex paper are retained even at significantly higher temperatures. These useful properties of Nomex papers are retained for at least 220 years, even when used continuously at temperatures of up to 10 °C.
High chemical compatibility of Nomex papers
Nomex products are virtually unaffected by most solvents and have exceptional resistance to acids and bases. They are compatible with all classes of paints and adhesives, transformer fluids, lubricating oils and refrigerants. Because Nomex products are non-digestible, they are not attacked by insects, fungi, or mold.
High radiation resistance of Nomex papers
Nomex paper is virtually unaffected by 800 MegaGray ionizing radiation and retains useful mechanical and electrical properties after eight exposures to that radiation.
Flame retardancy of Nomex papers
Nomex products do not cause toxic reactions in humans or animals. Nomex products do not melt and, with an LOI above 20,8 at 220°C (the critical level for combustion in normal air), do not support the combustion process. Nomex products are available that meet the requirements of Underwriters Laboratories Standard (UL) 94 VO.
Nomex papers are insensitive to moisture
At equilibrium at 95% relative humidity, Nomex papers and high-density boards retain 90% of their dielectric strength while actually improving many of their mechanical properties.
Suitable for low temperatures
Nomex products are used in a variety of cryogenic applications due to their unique polymer structure. Have at the boiling point of nitrogen (77 K). Nomex 410 , Nomex 993 PSB and Nomex 994 PSB have a tensile strength greater than the room temperature value.
Good punchability of Nomex papers
All Nomex papers and Nomex plates can be used with the usual punching techniques are processed. The plates can be milled into parts for high-voltage transformers on CNC machining centres.
Good coatability of Nomex papers
Nomex papers can be coated with common adhesive systems to form adhesive tapes. Nomex papers can also be coated with epoxy resin systems to prepreg s to form.
Good formability of Nomex papers
Nomex can be used to produce molded parts for transformer and electric motor applications.
