Kevlar cannot be easily cut or punctured, due to the chain links that form the fibers of this material. That means even more protection for police and military applications.
In addition, it makes Kevlar the ideal material for a variety of gloves, where workers handle sharp objects. This chemical is made from creating a chemical reaction between an acid and a chemical solution containing nitrogen and hydrogen. This process results in chemical chains composed of hydrogen, carbon, oxygen, and nitrogen. These chains are incredibly strong on their own. The spinning process orients all of the chains to be parallel, while enabling the hydrogen bonds on the sides of the chain to act as a glue, keeping the chains together.
As such, the chains are incredibly strong in tensile strength along the length of the chain, and the hydrogen bonds form incredible tensile strength perpendicular to the orientation of the chains. Most Kevlar vests are rated for a service life of 5 years.
Bulletproof vests and ballistics materials may be damaged more quickly if they are constantly used, used outdoors where they may be exposed to ultraviolet rays , or not kept clean since debris may penetrate the material, causing it to weaken. Offering strength under heat, Kevlar protects against thermal hazards up to degrees Farenheit. This combination of unusual properties makes Kevlar useful for a broad range of applications, such as ballistic vests, cut-resistant gloves and blast and flame barriers.
Kevlar has also boosted sports gear performance. Applications in that vein include bicycle tires that are virtually flat-free and puncture-resistant; running shoes that maximize the energy output of runners; boats that are lighter and more damage-tolerant; and durable lightweight sails that tolerate high winds and saltwater. Originally published on September 30, Sign up for our email newsletter. Already a subscriber? Sign in. Thanks for reading Scientific American. Kevlar actually starts out as a thin, watery liquid, but when it hardens it forms incredibly tight chemical bonds.
It takes a lot of energy to make a Kevlar thread stretch. Another similar thread is called Dyneema, which is a polyethylene-based plastic made through a slightly different process. Those tough Kevlar threads are then spun into a yarn that looks like cord or string.
That cord is so strong that it finds uses in many industries, including the manufacture of fabrics used in bulletproof panels. Kevlar is very similar to another product that firefighters and race car drivers are familiar with called Nomex , which is used in fire protective clothing.
To make the fabrics used in bulletproof panels that Kevlar yarn is woven into a fabric sheet. Paul May University of Bristol. Kevlar is well known as the material from which bullet-proof vests and body-armour is made. But it can be used in many more applications, such as bicycle tyres, yacht sails, ropes, and brakepads. It can do this because, despite it being a fibre, it has an extremely high stength-to-weight ratio, often qiuoted as being 5 times stronger than an equal weight of steel.
It is actually a trademark of the chemical company DuPont , who first synthesised it in In anticipation of a gas shortage, in the DuPont research group led by Kwolek began searching for a new lightweight but strong fibre to use for tyres. One day in , while trying to dissolve one of her polymers, something strange happened. She reported:.
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