Bullet-proof jacket

The bullet-proof jacket is equipment mainly intended to protect the thorax, the abdomen and the back against the shooting of firearms by absorbing the impact. The waistcoats are manufactured with tightened woven fibers, mainly the Kevlar. This type of waistcoat can then protect that which carries it against the projectiles of handguns, from shotguns as well as the Shrapnel S of certain explosives like the grenades. One can slip of the plates of metal or ceramics into small pockets envisaged for this purpose in the front and the back of the waistcoats in order to allow him to stop bullets the such 5,56 mm NATO, but by increasing few kilos the weight of the waistcoat. The police forces generally carry the waistcoat alone, while the metal or ceramics plates are used by the national armies or the special forces of police intervention, such American SWAT or GIGN French.

Overall picture

Plates of metal (steel or titanium), of ceramics or Polyéthylène provide an additional protection to the level of the vital bodies. They allow an effective protection against all the ammunition of handguns (except some exceptions) and the majority of rifles. These “tactical bullet-proof jackets” became a standard in the military field, because the traditional bullet-proof jacket does not offer enough resistance against the projectiles of rifles of attack, weapons which the military forces are generally likely to face. CRISAT NATO (Collaborative Research Into Small Arms Technology-North Atlantic Treaty Organization) recommends the plates of Titane.

Contrary to the metal armours of the two World wars, the modern bullet-proof jackets do not deviate the balls, but stop the projectiles rather by absorbing the kinetic energy which they release, and by redistributing it on the greatest portion of the possible body. It is a little the same principle of the rackets in snow, which distribute the weight of the person on more a large surface so that it does not penetrate the layer of snow. For the waistcoat, it is thus the kinetic energy of the ball which is redistributed, so that it does not penetrate the body. Moreover, this phenomenon deforms a little the ball, which decreases its capacity of penetration. It should be known that in spite of the fact that the bullet-proof jacket prevent the projectiles from penetrating, the body nevertheless absorbs the energy deployed by the ball, which can cause internal traumatisms. Even if most of the time one leaves with a blue there, the impact can cause serious wounds a such internal bleeding, tears on the level of fabrics or of the fractures at the coasts.

The majority of the bullet-proof jackets offers a limited protection against the arrows, the spades with ice, the stabs, the ammunition whose point is frayed or the ammunition perforating. Since the energy deployed by this type of object is distributed on a very restricted surface, they can cross certain bullet-proof jackets. Waistcoats are however especially designed to counter the sharp objects the such knives - they are mainly used by the prison warders. Materials the such Dyneema (an alternative to the Kevlar) offer a greater protection against the blades.

The bullet-proof jackets, without the addition of plates of protection, do not offer practically any protection against the ammunition of rifle or even certain ammunition of gun fired by rifles, because their speed and their capacity of penetration are much higher. The only exception is the .22 Long Riffles, which are stopped by the bullet-proof jackets, and this, even if it is drawn by a rifle.

History

Silk jacket

The first ancestors of the bullet-proof jacket were made of silk. They resembled medieval clothing matelassés made up from 18 to 30 layers of clothing in order to offer a minimal protection against the arrows. In 1881, George Emey Goodfellow, a doctor of Arizona, attended a duel of firearm between two men. By examining one of the two adversaries, he discovered that the silk handkerchief of the man had somewhat slows down the ball which had touched it. Doctor Goodfellow documented several other cases where silk fabrics would have protected from the people of a wound by ball.

In Chicago, a man of the name of Casimir Zeglen used the discovery of Goodfellow, to develop one of the first bullet-proof jackets towards the end of the year 1800. Very expensive, the made silk waistcoat could stop the slowest balls drawn by handguns with blasting powder. The waistcoat could cost in the 800 $ US in 1914, which would be equivalent to 15.000 $ in 2005. June 28th, 1914, Franz Ferdinand, the archduke of Austria, carried one of these jackets at the time of his assassination. However, it could not protect it from the ball of .32 ACP STATES drawn by Gavrilo Princip which reached it with the neck.

Steel drill plates

During the First World War, the United States developed several types of armor, including “Brewster Body Shield”, made of a steel and chromium, nickel alloy. This armor could stop the balls of the Lewis Mark I, which could reach the speed of 820 m/s. However, this armor was cumbersome and very door (18 kilos). Another type of armor was conceived in February 1918 by the Metropolitan Museum off Art. This drill plate, based on an armor of the 15th century, weighed twelve kilos, but was considered too noisy and constraining. A waistcoat overmeasure, fact of steel in scales attached to a leather lining weighing five kilos, was also developed. Being adjusted with the body, she was regarded as more comfortable than the other types of armor.

Upholstered waistcoat

Towards the end of the year 1920 and the beginning of 1930, members of criminal groups of the United States started to wear stuffed cotton clothing. Much less expensive than the steel armours, these waistcoats could absorb the impact of ammunition of handguns the such .22 Long Riffles, .25, S&W .32 Length, .380 ACP STATES and the .45 ACP STATES which travelled at speeds approaching 300 m/s. Several police services as the FBI obtained a more powerful ammunition then, the .357 Magnum, in order to answer these waistcoats.

Second world war

With the beginning of the Second world war, the United States developed armours for the infantry, but the majority of the models were too heavy and forced too the movements. Moreover, these armours were incompatible with the existing equipment. The company Wilkinson Sword in parallel developed a waistcoat the proof Shrapnels of the Flak ( Fl ug' A' bwehr' K' anone ) German for the pilots of the RAF ( Royal Air Force ). These waistcoats, facts of plates of manganese inserted in a ballistic nylon jacket developed by the Dupont firm, could not however stop a ball.

The Japanese army produced also some types of armor for the infantry during the Second world war, but they do not transfer the utility of it. The attempts of the American army began again in the middle of 1944, with the production of several types of armor such T34, T39, T62E1 and M12.

The Red Army developed as for it named models SN-38, SN-39, SN-40 and SN-42. “ S talynoi NR agrudnik ” being translation of “steel Waistcoat” and the number representing the year of design. Only the SN-42, fact of two plates of steel pressed, started production finally. Of a 2 mm thickness and a weight of 3,5 kilos, it was provided to SHISBr (Genius of combat), to Tankodesantniki (of the infantrymen embarking on the tanks at the time of an attack) and to certain brigades of armoured tanks. The armor SN protected against from the balls of the MP-40 German, drawn with more than 100-125 meters, which gave an important advantage at the time of urban battles (as in Stalingrad). Despite everything, its weight made it unusable for the infantry to foot and the 7.92x57 mm drawn by the Mauser Karabiner 98k, and MG42 crossed it easily.

1960 to 1980

During the War of Korea, several new waistcoats were produced for the American army, of which M-1651 which made a great improvement to the level of the weight. However, it was not very effective on the level of protection against the balls and the shrapnels. The waistcoats of the war of Vietnam used various nylon combinations, of new ceramics able to block the bullets, of material and glass fiber used in the steel armours of the Second world war and the war of Korea.

In 1968, “American Body Armor” was founded and produced a nylon combination covered with several steel plates. This type of waistcoat was sold by the company of firearm Smith & Wesson, under the name of “Barrier vest” for the police force.

Into the middle of the years 1970, Dupont Corporation introduced synthetic fiber of Kevlar, which was conceived to reinforce the tires. The Institute National off Justice subjected this new material to a methodical evaluation, in order to be able to check if the Kevlar could firstly stop a projectile, and to determine the number of layers necessary to arrive there. To ballast Shubin, which was named coordinator of this evaluation, provides report/ratio which approved finally that the Kevlar (as material) could provide a good protection, which was light and could be comfortably carried by the policemen systematically, and thus save lives.

In 1975, Richard A. Armellino, the founder of American Body Armor, marketed a waistcoat entirely made of Kevlar, named K-15, including/understanding 15 layers of Kevlar as well as a ballistic steel plate of 5" x8" vertical with the height of the heart. This type of plate is used still today in the modern waistcoats, in order to decrease the internal traumatisms on the level of the heart and the sternum.

In 1976, Richard Davis, the founder of Second Chance Body Armor, developed the first bullet-proof jacket of the company entirely made of Kevlar. Named “Model Y”, the light weight of this waistcoat enabled him to become the new form of daily protection for the modern police forces. In the middle of the years 1980, one estimates whereas between a third and half of the police officers in patrol of the United States carries the waistcoat in a regular way. In 2006, in the USA, more than 2000 police officers saw their life saved by their waistcoat, thus proving the relevance of the bullet-proof jacket like part of standard equipment of the police force.

1990 to 2000

The light waistcoat of Kevlar has imperfections however, because the large fragments or the projectiles having a high swiftness transfer enough from kinetic energy to cause wounds, which can prove to be serious and even mortals. Thus To arrange it Body Armor was developed by the American soldiers in 1994. It was the second modern American bullet-proof jacket being able to stop a bullet, while remaining enough light to be carried by the infantrymen on the ground. The waistcoat of US Rangers is however heavier than the PASGT ( Personal Armor System for Ground Troops ) carried by the regular infantry, in addition to less effectively protecting the shoulders and the neck.

Since the years 2000, new the Interceptor Multi-Threat Body Armor System became the standard of the American army by replacing the PASGT. The waistcoat of Kevlar Interceptor offers a protection against the shrapnels, the automatic shootings of 9 mm or lower gauge. Plates SAPI ( Small Arms Protective Insert ), made of ceramics to the thorax and the back, provide an increased protection of the vital bodies against the threats of 7.62x51 NATO.

Materials

Since 1970, several new fibers and methods of manufacture of the bullet-proof jackets made their appearance, simultaneously with the Kevlar. One distinguishes two big families from fibers in the modern manufacture of the bullet-proof jackets.

Firstly, para-aramides (Poly-para-phenylene téréphtalamide) which gathers mainly the Kevlar of Dupont, the Twaron of Teijin and the GoldFlex of Honeywell. Twaron and the Kevlar are materials very resembling the level of the performances. The manufactoring process of the Kevlar using of the phosphotriamide hexamethylic carcinogen, a war of patent followed between Dupont and Akzo (Twaron d' Arko was bought by Teijin in 2000). Finally, today Dupont must pay substantive patent law in Akzo to be able to use their methods of protection, and this, in spite of many research on behalf of Dupont to find an alternative. GoldFlex as for him is more resistant and flexible device which its candidates, but there thus remains more expensive and less attractive.

The second type of fiber includes/understands the fibers high-strength polyethylene like Spectra of Honeywell, Dyneema of DSM and Zylon de Toyobo. Spectra and Dyneema have characteristics very close to Twaron and Kevlar. However, the Zylon lost its certificate of the Institute National off Justice (NIJ) which approves its use in the bullet-proof jackets, because a research showed that it lost its capacitées antibalistiques much more quickly than any other material. This research was started in 2003 after the death of the police officer Tony Zeppetella de Oceanside and the serious wounds of the police officer ED Limbachers de Forest Hills, who carried both of the made waistcoats of Zylon.

Standards of performance

The NIJ provides a certificate of the level of protection offered by the various bullet-proof jackets sold in the United States. The higher the note given by the NIJ is, the more the waistcoat is powerful. If the NIJ does not provide a certificate or reforms it, the product cannot be sold any more on the American territory.

the swiftness given is the swiftness which the ball at the time of the impact and not at the time of the exit has of the gun.
the maximum kinetic energy is only one approximation in order to provide a general idea of the quantity of energy that each type of waistcoat can absorb. This figure is founded only on the energy usually deployed by such types of ammunition, but is not the official figure.

Types III and IV must be equipped with metal or ceramics plates to be able to reach their level of protection. The waistcoats can be supplemented articulated plates protecting the top from the thighs, called “Jupe”. The weight of the bullet-proof jackets lies between 2 and 4 kg for classes I, IIA, II and IIIA and between 5 and 7 kg for classes III and IV.

Future developments

If the bullet-proof jacket saves much life, the protection which it offers still limits to the thorax. It results from it from many wounds to the members, being able to lead to an amputation. The American army thus develops a new type of bulletproof armor. Composed of a bullet-proof jacket including/understanding of the larger skirts in order to offer a protection increased to the level of the shoulders and thighs, of a helmet, legging and protect-arm, it would make it possible to decrease the number of serious wounds largely. However, this type of armor remains still heavy and very cumbersome, so much on the level of mobility of the soldiers, but also in the shooting (the larger skirts on the level of the shoulders gènent the shooting), although certain soldiers are ready to make sacrifices on this level in order to profit from an increased level of protection. If the application of this type of armor is completely inadequate for the infantry, it could be used for the terrestrial crews of vehicles.

The silk of spider

The silk of spider is more than 10 times more resistant than steel and 3 times more than the Kevlar. Various tests of domestication of the spiders failed. If the worms with silk are for a long time domesticated by the man, the spiders have the annoying practice of entredévorer when they are withdrawn from their territory. An important test was tried in the years 1960 by the American army, which tried to find a new means of protecting their troops at the time of the War from Vietnam. Although the experiment was a failure, they could nevertheless identify Nephila claripes, which produced 7 types of silk, including one ultra-resistant. Plusieures years later, technological advances made it possible to insulate the genes which code the proteins which form the silk of spider and to insert them in a bacterium. It is into 1990 that Lewis, thanks to a financing of the army, identified two genes necessary. The US Army Soldier and Biological Chemical Chommand in Natick and the University of Wyoming tried to produce sufficient quantities of them by obliging bacteria to produce proteins. However, the results were insufficient, as well on the level of the quantity as of quality. If the silk of spider is so strong, it is thanks to the repetitive nature of two of its genes, but the bacteria cut the sequence by thus decreasing the resistance of produced silk.

In 1993, Turner, a geneticist and researcher from the McGill university in Montreal, discovered similarities between silk-producing glands of the spiders and the glands mammaires of the goats. After 3 years of research within the Nexia company, the scientists succeeded in producing great quantities of silk of spider while inserting 2 genes in glands mammaires of goats. Collected milk thus contained proteins, which, once purified by the scientists of the army, were introduced into small tubes where they formed ultra-resistant silk, very near to natural silk.

Since, Nexia is owner of firm containing a dozen genetically modified goats, raised with more than 1000 other healthy individuals.

The projections of the army on named silk “Biosteel”, created thanks to proteins of Nexia, are rather discrete. However, one can suppose the preparation of many benchmarks of silk in the future replacement of the Kevlar. Indeed, Biosteel contains many advantages. If the Kevlar is manufactured containing oil and that it requires chemical processes in its manufacture, Biosteel requires to him an infrastructure of production much less heavy and expensive. In addition to its best performances, Biosteel is as lighter and flexible device as the Kevlar. There remain however question marks as for the longevity of such a silk in addition to its capacity to resist hot summer dayss, which could be less low than the Kevlar. However, Biosteel is dedicated to a great future on the level of the bullet-proof jacket. Even if its exact antibalistic capacities are still unknown (at least publicly), one can envisage the reduction marked in the weight of a bullet-proof jacket makes entirely of Biosteel. Even if it would be astonishing that the use of this new fiber makes it possible to completely separate metal or ceramics plates, it would certainly make it possible to decrease by them their thickness and thus their weight. It would also make it possible to return the project of bulletproof armor of the American army much more mobile.

The nanotechnology

Several nanotechnologies also were born in the last years. Firstly, of the nanoparticules inserted in the waistcoat could react to the pressure applied by a ball to the material and harden sufficiently to block the latter. It would result from it a flexible armor which could deviate the balls as would do it a steel armor, but with a weight lighter than the modern waistcoats. Another technology is presented by the ApNano company like a rigid nanocomposite, based on Tungsten Disulfide, able to resist the impact of 250 tons per square centimeter, while remaining in good state. A test of the material under an isostatic pressure by a French team allots to him even resistant of 350 tons per square centimeter. The development of a bullet-proof jacket made up of silk of spider and nanotechnology was started with the current of 2006 for a potential marketing. One can think of a traditional waistcoat where the Kevlar would be replaced by of Biosteel and the plates of ceramics by a material nanotechnologic.

In a future a little more remote, the Nanotube S of carbon which offer resistances nearly 100 times larger than steel and a weight six times less for the same quantity, could replace the ceramics plates even more effectively. Moreover, the nanotubes could extremely probably be directly fixed on fibers in order to increase their resistance, while not decreasing their flexibility. However, their production remains too expensive to consider it in a near future.

Legislation

The possession of bullet-proof jacket is legal in the majority of the countries of the world. There exist exceptions such as for example in Australia or in Germany. The people condemned for crimes violent one see themselves prohibiting their possession with the the United States.

External bonds

standards of protection of the NIJ

Simple: Bullet-proof vest

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