Kevlar is used in a number of applications, be it in industry, law enforcement or in general consumer products. The products made with Kevlar are part of daily life, eveb though we can't always see their relationship to Kevlar.

There are lots of desirable properties associated with Kevlar. It is extremely resistant to punctures and tension because it is woven so strongly. It is also resistant to chemical products and shrinking. It conducts very little electricity. Since this polymer is so durable, it can't be torn either.

Kevlar is used extensively in the production of certain tires, especially bicycle tires. These tires are superior to others as they can be driven on after they have been punctured because they tend to keep their shape. For this reason that can be a lot safer than conventional tires. The Kevlar tire technology has been applied to aeroplane, car, racing vehicle and truck tires. Before the arrival of Kevlar tires, other anti-puncture tires were offered for sale. However, these tires were so heavy and expensive that they couldn't be used or produced practically.

Another use for this material is in the production of sporting goods. Some components of Kevlar are used in an array of rackets, such as tennis, badminton and squash rackets. Canoes and kayaks were also improved when Kevlar technology was applied there. They are now more durable during impacts.Kevlar is also used in a variety of skis, snowboards, skateboards, gloves, helmets and shoes.

Bulletproof Vests

One of the most popular applications for Kevlar is with bulletproof vests. Over the years, bulletproof vests have saved countless lives of military personnel, other law enforcement officers and civilians alike. To date it has saved more than 2,749 police officers. Thanks to the invention of Kevlar, bulletproof vests will continue to do so for years to come.

Bulletproof vests are very simple. They consist of a carrier, plastic film and Kevlar. In order to be successful at stopping projectiles, there must be layers of material. These layers are made of Kevlar and plastic film. The plastic film surrounds the woven Kevlar to aid in the energy transmission and absorption. The layers are then placed between the outer shells, also called the carrier. The carrier is what you would see if you saw someone wearing the vest.

If you have ever played hockey, then you should already have somewhat of an idea of how body armour works. Just like the hockey net, Kevlar is woven into a pattern. The pattern is interlaced which gives it the look of little squares when observed with a microscope. This interlaced pattern gives Kevlar the ability to absorb and distribute the impact of the projectile along the vertical and horizontal fibres, just like the hockey net disperses the puck's energy.

When a projectile makes contact with the vest, the kinetic energy is dispersed along the woven Kevlar layers. The first layer softens the impact by using the woven pattern's horizontal and vertical tethers. When the projectile hits a vertical tether, every horizontal tether is pulled. This distributes some of the projectile's energy along its tightly woven tethers before the layer breaks. The next layer then absorbs the energy and the process continues until the kinetic energy is zero. Since most non-armour piercing bullets are lead and lead is a soft metal, the bullets that come into contact with the vest deform further reducing the bullet's energy. This is called "mushrooming".

Since sound travels so quickly through Kevlar, (up to three times faster that nylon) the energy is quickly displaced over the entire vest. The time it takes for a vest to stop a projectile is in the low microseconds and if the vest is successful, the wearer is only left with some blunt trauma, a bruise.

Bulletproof vests are not perfect. There are bullets that can pierce them and the name given to them are armour-piercing bullets. These bullets are made of steel and they do not "mushroom" when they come in contact with the Kevlar. The armour-piercing round literally punches a hole through the Kevlar. To make the bullet even more effective, some bullets are coated with Teflon, a plastic with excellent lubricating characteristics. If a bullet is coated with Teflon, it is exposed to less friction as it comes in contact with the vest, giving it a greater chance of piercing the armour and killing the wearer. To compensate for armour piercing and Teflon coated bullets, the number of layers must be augmented and the spaces between the fibres reduced, thus creating a more effective energy transmission.