Technology Behind Light Weight Bullet-Proof Jackets

Cops wearing bullet proof jackets

As bullet proof jacket is used to save body from bullets as suggested by its name. It is being used till centuries, only the difference lies in its construction. Initially, it was made of iron and its weight was very heavy. As technology stepped its way forward, researchers created bulletproof vests of fabric!

Firstly, I want to make this clear that in today’s world we are commercially using bullet proof jackets made of different types of fabrics sandwiched to produce a light weight vest which can save our body from bullets.

The formation of light weight bullet proof fabrics started after the discovery of Kevlar fiber by Du-pond. Kevlar is a para-aramid synthetic fiber. It was developed by Stephanie Kwolek in 1965 and was commercialized in 1970 as a replacement to steel in tires. Its tensile strength to weight ratio is five times more than steel making it five times stronger than steel.

Not only the fiber itself responsible for bullet proof property but also the way it is weaved plays a crucial role. A bulletproof jacket consist of a vest shaped sheet of advanced plastic polymers that are composed of many layers of Kevlar or Twaron and spectra shield over it bonded with resins such as Kraton and then sealed between two sheets of polyethylene. Panel is also inserted in it. Panel gives protection but not much comfort. It is placed between the shells of fabric. To make fabric absorbent for sweat, it is coated with absorbent material like Kumax from its inner surface.

The basic principle behind his vest is dissipation of energy when a bullet hits on it. Energy of bullet is dissipated and due to the strength of material used, bullet is restricted to penetrate to even touch wearer’s body. Although, energy is only dissipated it can cause internal injury to the person wearing it. Chances of injury remains there just the chance of being hit by bullet reduces. Energy is dissipated in a larger area and hence restricting bullet to penetrate through it.

The combination of high performance fibers with the weave makes it possible to restrain such a force. As the force is being split into a larger area, it penetrates some layers and doesn’t allow bullet to reach the body. Vest can prevent bullet penetration but still both the vest and wearer can absorb bullet’s energy. To impart more strength to the fabric, plates of polyethylene, ceramic steel can be used for protecting vital areas.

To overcome this problem, now bullet proof jackets are being made with non-Newtonian fluids. This fluid is packed inside Kevlar body of textiles. This not only reduces the weight of jacket but also it acts as a much better life saver. Non-Newtonian fluid hardens when an external force is applied to them resulting in restriction of bullet’s energy to even penetrate vest and reach towards the person’s body. This not only restricts the bullet but also bullet is collected in a layer of vest which can easily be removed and can be used for evidence.

This is the basic idea how a bullet proof fabric is formed. There are many advancements and researches going on to improve this fabric to make it more effective and efficient!