Monday, January 5, 2009

The Spectra vs. Kevlar Discusion

By Marcos Santana

Over the years, many improvements have been made in military and police garments to increase safety and create bullet proof body armor that is both comfortable and protective. However, in the past, being safe has meant a certain amount of bulk and discomfort, as well as added weight and mass for soldiers and officers facing combat on the battle fields and in urban wars. The use of Kevlar, a registered trademark of DuPont, has made body armor lighter and easier to work with, but flexibility has still been a problem.

A new material is changing the face of bullet proof gear for soldiers and police officers. The new substance is called SPECTRA and is a lot stronger, flexible and lighter than KEVLAR. The advantages seem to be obvious but what are they exactly and how do the security forces benefit from SPECTRA ?

Let's first examine the structure of each of the two materials. Kevlar is a high strength, high performance fiber that, despite its many years of use in bullet proof clothing, is still not entirely understood. The best description of how it is believed to function is that the molecules form into sheets that then stack themselves around the center of a fiber like spokes. The idea behind using this as a bullet proof material was to stack several layers of the material together in a weave pattern.

In the past when bullets had less velocity and were not constructed from extremely hard materials, Kevlar did a fine job. When a bullet hit a bullet proof vest the different layers of Kevlar reduced the velocity and flatted the bullet while braking layer after layer. This was a very effective way to stop those bullets but today bullets are made of harder materials and the technically very advanced weaponry give the bullets a very high speed.

Due to these improvements in weaponry we are back to the point of the bulky, heavy and less flexible bullet proof material because the only solution to this advanced weaponry penetrating completely the vests is by adding more and more layers of Kevlar to the fabric.

Spectra is a completely different technology. The material is about 40% lighter than Kevlar, making it more comfortable from the start. On top of that, it is not a woven structure, meaning that several layers are not necessary, further reducing weight and bulk. - 15995

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