History of bulletproof vest

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Principle originally been developed since the Middle Ages. Starting from the knights (knight) with the iron cloak, which can reduce a sword stab wounds or sores shooting arrows. 

Unfortunately, with the development of firearms, protection becomes useless.

Bulletproof armor (bullet proof vest) or ballistic armor (ballistic vest)??
Clothes "Bulletproof" is divided into two, namely the Soft and Hard Body Armor Body Armor.

Soft body armor
in daily tasks or duties undercover (undercover) police / detektiv prefers a lightweight bulletproof clothing. 

Picture: Bulletproff_vest 

Picture: ballistic_vest (designed for civilian / Incognito)

Soft body armor is now generally made ​​of fibers aramid (aramid fibers). 

Picture: molecular bonds aramid 

Image: Woven fiber is commonly known in the market as Kevlar

The Kevlar layer thickness of less than 1 mm, the standard generally consists of up to 32 layers of clothes and can weigh up to 10 kg.

Aramid (Kevlar)
This material was found in 1964 by Stephanie Kwolek , an American chemist, who worked as a researcher at DuPont company. 

Picture: Stephanie Kwolek
Aramid is the abbreviation of the word aromatic polyamide. Aramid has a structure strong, tough (tough), has a good damping properties (vibration damping), resistant to acids (acid) and bases (leach) and besides it can withstand heat up to 370 ° C, so it is not flammable. 
Due to its Such, aramid is also used in aircraft, tanks, and aerospace (rocket). products marketed known as Kevlar. Kevlar weighs a light, but 5 times stronger than steel.

Working Principle Plus Anti Bullets
principle works is by minimizing the kinetic energy burst of bullets , by using kevlar layers to absorb the energy rate and break it wide clothes, so the energy is not enough to make a bullet can penetrate clothing. 
In rate of energy absorbing bullets, armor (kevlar) that suppress deformed inward (shock wave), the pressure will be passed into that of the user's body. 
limit maximal suppression into no more than 4.4 cm (44 mm). 
If the limit is passed, then the user will have clothes injuries (injuries of internal organs) , which would endanger the safety of life. 
See the picture below. 

Picture: Absorption rate of energy that causes a layer of kevlar bullet deformation. 

Picture: Deformation pressing kevlar body armor users. 
Analogues such as ball speed which can be held by a net. Goal nets consisted of a series of straps that are connected to each other. If the ball was caught by netting the goal, then the rate of energy (kinetic) ball will be absorbed by the goal nets, which causes the rope around him grew longer (extend) and then the pressure (pull) the rope will be streamed to the goalposts. 
Picture above shows that the assumption shirt wearers Bulletproof can be spared entirely from injury produced by fire is one!
should be stressed once again that the main function of a bullet proof armor is to stop a bullet!! So the bullet did not get into the wearer's body armor, which can cause death. 
Often caused " pressure "had been inflicted bullet, dress wearer will suffer a contusion (blunt force trauma) until fracture. 

Picture: blunt force trauma . 
Obviously injuries are also depending on the type used clothes. This suggests that the term shirt / vest (bullet proof vest) is incorrect, the correct term is clothes / ballistic vests (ballistic vest)!

Hard Body Armor 

Image: SWAT team.
By adding a layer of soft body armor, can be produced hard body armor. 
Generally layers of ceramic (Al2O3 "Alumina"), sheet metal or composite. 
shape is thick and heavy make no comfort, to rarely imposed in daily tasks. Only in specific high-risk tasks, such as military or SWAT team operation will be charged. 

Image: American soldier 

Pictures: SWAT team 

Picture: details bulletproof armor (hard body armor) 

Image: Hard body armor
worn Depends layer will affect the level ( level) body armor.

Level Plus Ballistic
armor ballistic standards of the most widely used is the standard NIJ (National Institute of Justice) America. Under this standard, ballistic armor is divided into several levels (level), that is the level I, II-A, II, III-A, III, and IV. Level I is the lowest level, only clothes can withstand bullet caliber (diameter) small. 
details see the image below. 

Picture: ballistic armor abilities 

Picture: level hack protection capabilities against bullets 

Figure: Level II Vest (5-YEARS-OLD) Shot from 18 "(46 cm)
Starting level III armor will be fitted with iron plates , so being able to withstand shotgun!! 

Image: Plate iron front (left) and rear (right) 

Picture: Polster of a type of plastic (polymer) to reduce the effect of "stress" (shock wave) bullets. 

Picture Effect "pressure" generated bullets, clothes left without Polster, Polster right clothes with.
By using current materials, the higher the level of security provided (the higher level), the more thick and heavy clothes to be worn.'s certainly a shortage of material. 
Top On this basis, the scientists and the military is still developing a new material that is lighter and stronger.

Other material
kevlar addition, other materials being developed are: 
Vectran is a liquid crystal polymer (liquid crystal polymer). Fiber has a strength of up to two-fold compared with kevlar. 

Picture: vectran

Yarn Spiders (Spider Silk) 

Pictures: of spiders and webs
Spider thread protein molecule consists of a long bond. This thread does not only have the ability to withstand extreme loads , but also at the same time has a very high elastic properties , can be drawn up that extends as much as 40%. 
elastic properties are derived from a small liquid droplets found in the thread, which when viewed form like a string of pearls or beads.

Image: spider webs
inside each grain has a reserve this thread, if there is prey falls into cobwebs, thread the beads will be automatically drawn out, so that the nets will not break!

Picture: Association of molecular threads of the spider.

Figure: Structure of spider silk .

In Canada, a company engaged in the field of biotechnology Nexia and the American military has succeeded in synthesizing spider silk from goat's milk. Goat previously manipulated 
(transgenic) with genetic spiders, so that it produces milk containing spider silk proteins. In one liter there are 1-2 grams of protein threads. 
Having processed (wet spinning) can be produced yarn with size 10-60 micro meter diameter, this replica is certainly far greater than native spider silk which has a diameter of 2.5 to 4 micro meter. 
synthesis Spider thread is called biosteel.

In Germany, Dr.Thomas Scheibel researchers from the University of Munich (Technischen Universität München) succeeded as the first person in the world who can solve the information contained in the genetic code of spider thread, so the thread can be produced by labor (artificial). 
By manipulating the genetic bacteria (one liter of liquid bacteria), can produce one gram of fabric yarn (powder). This process takes several days. Spider thread is proved up to five times stronger than kevlar (20 times stronger than steel threads) and of course lighter. 
country Germany has also managed to make the machine knitter spider thread, most likely in the coming years, there will be market ballistic armor made ​​of spider silk.

Picture: Dr.Thomas Scheibel

CNT (Carbon Nanotubes)
candidate next material is CNT. Discovered in 1991 by Professor Sumio Iijima of Japan.

Picture: Professor Sumio Iijima.
CNTs is the composition of the elements carbon (C), which is very small "nano" (0.000 000 001) and is shaped like a pipe (tube), whose walls are arranged like a honeycomb.