Nomex Felt Insulation Properties

Nomex Basics

• According to DuPont, Nomex is an inherently flame-resistant aramid fiber, a strong and stable synthetic fiber similar in feel to nylon. As an insulator, Nomex provides thermal protection, offering resistance to fire and electric arcs. Though a large electrical arc may break Nomex fibers, this non-flammable product will not burn, melt or drip. The aramid fibers of Nomex also resist acid corrosion.

Nomex Felt

• Nomex felt has the appearance and texture of a white felt blanket. The product consists of fibers that are 2 deniers in fineness. Each of these fibers, which are crumpled to creature the texture of felt, measure 3 inches long. DuPont creates Nomex felt by loading aramid fibers into a carding machine, which webs and cross-laps the fibers much like a loom, eventually batting, needling and layering the fibers until the desired thickness is achieved. For thermal stabilization, the felt is heat-set at about 500 degrees Fahrenheit. Generally, Nomex felt comes in thicknesses ranging from 0.125 inch to 0.40 inch.

Applications

• In the form of felt tubes, Nomex may be found as an insulator in electrical systems, wrapping coil forms and lead wires to prevent solder damage. For landscapers dealing with burning leaves and debris, Nomex felt may serve as an insulator for work gloves and coveralls. Most commonly, Nomex felt acts as an insulating layer for protective apparel, such as that worn by firefighters, race-car drivers, forest service employees, petrochemical workers, military personnel and astronauts. This material can also be found in the structural skin of space craft. Nomex felt also lends itself to filtration in the form of filter bags for asphalt-manufacturing facilities.

Pricing and Availability

• At the time of publication, 1 inch of 0.125-inch-thick Nomex felt retails for about $0.75. The thickest Nomex felt -- used to decorate ceramic tile via a process known as sublimation -- retails for about $45 per 14 by 16-inch roll. Retailers as diverse as stunt-work suppliers, heat transfer equipment suppliers and electrical suppliers sell Nomex felt.