How does a bulletproof vest work?
You've seen it more than once in a movie. This scene where one of the characters is shot, but miraculously, he survives thanks to the bulletproof vest hidden his t-shirt. The equipment thus plays its role wonderfully since, in fact, it is intended to protect the chest, abdomen and back from an armed attack, by absorbing the impact of the bullet. But what the writers make of it, is it really realistic, or just a cinematic fantasy?
Bulletproof vest: well-chosen materials
In fact, the secret of the effectiveness of bulletproof vests lies in their composition: they are made of a ceramic plate of approximately one centimeter, and another of polyethylene (high density fibers) of the same thickness. Combined, these two materials would be more effective than a 13 millimeter steel plate. This could preserve the body of an ammunition. But the damage to the body would be quite different.
As you can imagine, the wave caused by the impact of a bullet is extremely violent on our organs. The lesions are certain. But with a ceramic and polyethylene alliance, the shock is attenuated... or even reversed! First, the cartridge will be slowed down in its course by the ceramic, to finally encounter the layer of polyethylene. And this is where all the magic of this technology operates.
In contact with the polyethylene therefore, the wave will turn around, because it propagates faster than the ball. She will therefore counter the course of the latter... and crush her by opposing her path. A mind-blowing result: the projectile is "shriveled". But the feeling is not trivial either. In addition, there are different types of bulletproof vests, more or less rigid depending on the weapon they have to counter.
Short history of the bulletproof vest: more and more efficient
Today, bulletproof vests are made with tightly woven fibers, mainly Kevlar. Something to protect the wearer from projectiles from handguns and rifles, as well as shrapnel (objects filled with bullets or fragments of metal projected at the time of the explosion) or certain explosive devices (for example , pomegranates). But this equipment was not always designed like this.
The first ancestors of these protections were made of silk or linen. It was from the First World War that the United States began to develop more advanced armor, like the Brewster Body Shield, an alloy of nickel, chromium and steel. Then in the late 1920s and early 1930s, members of American criminal gangs wore cotton-filled clothing.
It was then in the mid-1970s that DuPont Corporation introduced the synthetic Kevlar fiber, initially designed to reinforce tires. It becomes the reference in the matter. The only weak point, it is only able to secure the trunk. The American army has therefore been developing new technologies. Spider silk, for example, is said to be ten times stronger than steel and three times stronger than Kevlar.
Nanotechnologies are now also part of this race for progress, with the aim of one day making soldiers a kind of all-powerful Avengers. There you go, now you know everything!
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