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Nomex Flight Suits Provide Better Burn Protection than DCUs

by Flight Learnings

in Uncategorized

Saul Wolf is the SEO of Carter Industries Inc. the official manufacturer of Nomex 27/P fight suits to the US Defense Force.  For further information about Nomex Flight Suits or to purchase the suit visit the Carter Industries website.

Most United States military personnel currently deployed in the desert typically wear a standard uniform called a Desert Camouflage Uniform, DCU for short. Standard DCUs are rugged and hold up well to most of the daily activities of military men and women. This uniform includes pants, an overcoat, and protective headgear. DCUs are made from a blend of 50 percent polyester and 50 percent cotton. They are sewn with a polyester based sewing thread. The blended material is treated with water repellent chemicals and also with insect repellant chemicals. However, the material is not designed to protect against fire or heat higher than what you would expect in the ambient desert temperatures. This last fact is the key to why DCUs cannot be used in military tasks that are at high risk for fire or exposure to weapons that can burn the skin.

Military personnel working in the desert regions of the world are often exposed to exploding Flame Field Expedient (FFE) weapons. These weapons can be made by guerilla soldiers without sophisticated equipment. They contain a thickened fuel that is often still burning when they make contact with the skin of military personnel. These thickened fuels also tend to burn for a long time, even after impact. FFE weapons are also difficult to put out so they can continue to burn the skin long after impact. Severe burns also result from the blasts associated with FFE weapons.

To protect United States military deployed in desert conditions and exposed to FFE weapons, the military uses special flame resistant uniforms. These include special flame resistant uniforms for ground troops and also for pilots. The Nomex flame resistant uniforms use one or a combination of a group of fibers called Nomex fibers. Nomex was developed by and trademarked by DuPont. Nomex fibers have a molecular structure that allows them to withstand temperatures of up to 752 degrees Fahrenheit (400 degrees Celsius). When Nomex fibers are exposed to high temperatures, they do not melt. Instead, they form a protective charred layer that is also self-extinguishing when these fibers are removed from the flames. These charred areas also retain a strong resistance to abrasion and retain much of the original strength of the fibers before they were burned. Nomex fibers are no heavier than the materials used to make the DCUs so they can be easily worn as clothing by military personnel.

If human skin is exposed to temperatures in excess of 111 degrees Fahrenheit (44 degrees Celsius), it will burn significantly. Burns can quickly become life threatening at higher temperatures or longer exposures. They can also be life threatening if they hit at more sensitive areas of the human body such as the chest cavity, throat area, or the face. These types of burns can cause significant damage to the respiratory system very quickly. This is why Nomex materials are the preferred material in military flight suits rather than the standard DCUs. If there is a fire in the small enclosed cockpit of an airplane, with the Nomex flight suit, the pilots were likely die.

A good example of military uniforms that utilize Nomex fibers are CWU 27/P Flight Suits. These one-piece zippered up the front Nomex flight suits are specifically made with Nomex III cloth and Nomex IIIA cloth. This material keeps the flames from burning through for up to ten seconds. Nomex III cloth is made from a blend of 95 percent Aramid fibers and 5 percent Kevlar fibers. Nomex IIIA cloth is made with a blend of 93 percent Aramid fibers, 5 percent Kevlar fibers, and 2 percent P-140 static dissipative fibers. Kevlar fibers hold the Aramid material together at the seams. Nomex flight suits come in two colors: sage green and tan. There are multiple pockets and an adjustable band around the waist with velcro. The Nomex CWU 27/P Flight Suits are very insulating as well and keep the pilots warm in the cockpit which can be quite cold. However, if they are worn outside the cockpit, they are known as being quite warm and too warm in the summertime. Luckily, they are designed to be worn over regular clothing so the pilots can take them off after their flights.

Military pilots and the rest of the cockpit crew are protected from cockpit fires by wearing Nomex flight suits. Race car drivers wear similar suits to protect them from the fires that are started due to crashes. In fact, race car drivers wore suits made out of Nomex decades before they were used in the military. Fire fighters also wear suits made out of Nomex fibers. The material was invented in the sixties but it has been perfected over the decades as the suits and uniforms made from Nomex have been field tested repeatedly in real life situations.

To maximize the effectiveness of Nomex flight suits, it is required that natural fibers be worn under the Nomex uniform. This is because synthetic fibers like polyester and acrylic will melt at relatively low temperatures and will burn the skin quite rapidly even if the Nomex flight suit on the outside is not burning. This is due to the heat transfer. It is also important to have natural fibers which do not melt on under the Nomex uniform in case of a fire. In this situation, the Nomex suit may have to be taken off quickly. It is also suggested that layers of clothing are worn beneath the Nomex flight suit to create layers of air which also insulates the skin from intense heat and flames.

Nomex flight uniforms, Nomex military uniforms for ground troops that are exposed to potentially lethal FFE weapons, and other Nomex uniforms all save lives. Nomex is a form of wearable technology that scientists continue to hone and refine. The military continues to evaluate these Nomex military uniforms and runs burn tests on them in the laboratory with each new uniform that is designed. These tests include the limiting oxygen index test, also called the LOI, which measures the relative flammability. They also run a vertical flame test which directly measures the effect of a methane flame applied to the material for 12 seconds. For comparison purposes, the 50 percent polyester and 50 percent cotton combination of the DCUs burn immediately when this test is performed. In other words, there is a Nomex does a lot to protect the wearer from being severely burned.

 

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