Fiber Group: Aramid

Composition
A manufactured fiber in which the fiber forming substance is a long-chain synthetic polyamide in which 85% of the amide linkages are attached directly to two aromatic rings.

Characteristics
Aramid fibers are best characterized by their excellent thermal and strength properties. Aramid fibers do not ignite, melt or drip, making them excellent choices for flame resistant applications. Para-aramids exhibit high heat resistance comparable to that of meta-aramids. The primary distinction between each variation is the superior strength and modulus of para-aramids. Various brands of aramids include: Kevlar®(para), Nomex®(meta), Twaron®(para) and Technora®(para).

Common applications
Critical component in protective flame-resistant clothing, harnesses and helmets required for aerospace, military, first responders, and industrial safety equipment. The hazards addressed by personal protective equipment (PPE) include physical, electrical, heat, arc-flash, chemicals, biohazards and airborne particulate matter.

PARA-Aramid Performance Properties

Meta-aramid Performance Properties

Flame Resistant Vs Flame Retardant Explained
Flame-resistant fibers are materials that have flame resistance as part of their chemical structures. Aramid fibers are inherently flame-resistant fibers. The actual structure of the fiber itself is not flammable. For inherently flame-resistant fibers, the protection is built into the fiber itself and can never be worn away or washed out. In the case of Nomex®, when exposed to flame, the aramid fiber swells and becomes thicker, forming a protective barrier between the heat source and the skin. This protective barrier stays supple until it cools, giving the wearer vital extra seconds of protection to escape.

Flame-retardant treated fabrics are made flame-resistant by the application of flame-retardant chemicals. A chemical additive in the fiber or treatment on the fabric is used to provide some level of flame retardancy. During a fire, chemically dependent fabrics rely on a chemical reaction to extinguish the flame.

When assessing the use of one of the other, keep in mind that flame-resistant fibers have inherent flame-resistant properties that cannot be washed out or damaged through exposure to chemicals in the workplace or laundering. Flame-retardant treated garments, however, may be damaged by chlorine bleach, the combination of hydrogen peroxide (“oxygen bleach”) with hard water, or exposure to oxidizing chemicals in the workplace.