Choosing a bulletproof vest

The number of people versed in weapons has sharply increased, the Internet is actively discussing armored vehicles, comparing characteristics and buying uniforms for the Ukrainian army. We live in an environment where Personal Protective Equipment is becoming in popularity on a par with smartphones and laptops. Bullet-proof vests are bought and chosen, at times, completely without delving into the essence, without understanding the terms, which is fraught with sad consequences as a result of their use. And if the wrong smartphone is just a pointless waste of funds, then a mistake when buying Personal Protective Armor can be fatal.
Protection from bullets was needed by a person after the appearance of muskets. Heavy cuirasses and armor, which saved from the blow, were unable to withstand the new enemy, which was the bullet. The tactics of fighting have changed, new methods of defense were required. The original plates and bibs were heavy and uncomfortable, depriving the infantry of the maneuverability. And so a new area in scientific research was born, dedicated to the creation of a comfortable body armor for a soldier that would provide sufficient protection, be comfortable and not weigh too much.
It should be noted right away that completely different types of SIBZ fall under the generally accepted term "body armor". Bullet-proof vests can be in the form of ready-made sets with plates or separate covers, for hidden or outdoor wearing, modular or with a sewn-on set of pouches. For each case, you can choose the most suitable option.
The same applies to plate materials. Initially used metal materials are now forced to make room, as effective and lightweight materials have appeared: Kevlar, ultra-high molecular weight high-density polyethylene (UHMWPE), ceramics and cermets. You can find out more about body armor on the http://platecarrierguide.com.
Protection standards
What can we say about the standards of protection, which are regulated differently in each country. In the United States, the classification created by the National Institute of Justice (NIJ) is used, in Russia there is GOST, in Ukraine certification is carried out using DSTU 4547, which, unlike foreign documents, is not publicly available. But if you collect information from specialized sites, you can draw up a comparative table in which you can show the differences between the protection classes defined in different countries.
With GOST standards in Russia, it is more and more difficult, since the new GOST adopted in 2014 differs significantly in calibers and types of weapons from domestic ones, so it is rather difficult to compare our standard with the Russian one. And in principle, such comparative tables always do not look very correct, allowing only an approximate estimate of the characteristics of a particular protection class, while at the same time finding out their approximate analogue in other countries.
The main materials from which SIBZ were made, until recently, were Kevlar and metals (titanium, steel). Later, ceramics were added to them, and now the "squeak of fashion" - UHMWPE (ultra high molecular weight high density polyethylene).
Reservation injury
Usually people, when they see the test results, evaluate the bulletproof vest in the key "pierced / not pierced". But even if the bulletproof vest is not pierced, the kinetic energy of the bullet must go somewhere. In the case of a metal plate, this energy will be transferred to the person on whom this plate is worn, as a result of which the so-called zabronevaya (over-barrier) injury will be inflicted. For example, a shot from a conventional PM pistol with a bullet speed of 315 m / s can be compared to the blow of a 2-kg sledgehammer. And the consequences can be very different, depending on the type of ammunition, range, angle of impact and place of impact. Everything can end up as light abrasions, bruises and hematomas, but in severe cases there may be broken ribs, ruptured blood vessels and damage to internal organs.
When testing for over-the-counter injury, the bulletproof vest is placed on ballistic plasticine, and after shooting, the recesses left on it are examined. In the United States, for example, a dent of up to 44 mm is allowed, with a 10% chance of death. It should be understood that an unbroken vest in one out of ten cases can still mean death.
Naturally, the developers themselves are not limited to the armor plates, supplying the finished product with additional layers for the safety of the owner. This is, first of all, the amortization and climatic backing, which minimizes the damage to the armor, and also provides sufficient ventilation.
Aromatic polyamide aka Kevlar
Kevlar thread was developed by DuPont back in the 70s of the last century. With the same mass, the Kevlar thread turned out to be 10 times stronger than steel. Initially, aramid fiber was planned to be used for reinforcing automobile tires, but later it began to be used in a wide variety of fields.
Kevlar has excellent ballistic characteristics, however, the cost of producing aramid fibers is quite high, and such ballistic fabric will not resist against serious ammunition, therefore, the boundary use of Kevlar is 1-2 protection class, where pistol bullets are mainly a threat. And for this, of course, a multilayer fabric is used.
Subsequently, alternative developments of synthetic fibers with high mechanical and thermal strength appeared. In fact, all of these "nomexes" and "twarones" are the same aromatic polyamide as Kevlar, just developed by other companies and have slightly different characteristics.
Alas, aramid fiber will not help much if you use a knife or an awl against it. It is difficult to cut it, but to pierce it is easy. The threads simply diverge, so you will have to use something more serious to protect against the knife. In addition, Kevlar does not tolerate moisture, wet fiber loses up to 40% of its strength, although after drying it restores its properties.
But where stealth and mobility are needed, soft armor will come in handy. A vest made of aramid fiber is easy to hide under a suit, and it does not hinder movement, since it bends well.
Heavy metal
In army body armor, which should protect against more serious rifle cartridges, metal plates are used, which are made of titanium and special types of steel. The main attractive qualities of metals are their relatively low cost, increased strength and the ability to withstand multiple hits. But they also have disadvantages, among which the main one is the mass. You can wear a bulletproof vest that weighs about 8-10 kilograms only for a short time, and if you add other equipment here, then the mass will be much larger.
In addition, steel plates are dangerous due to debris flying away after being hit by a bullet, which can touch limbs or the head. Here you can remember about light alloys of aluminum or titanium, which help to avoid fragments and protect against serious damage to the armor, but such materials are much more expensive, and the lightness also has a downside - it is impossible to make a high-class armor plate based on such alloys. But it is possible to solve the issue of fragments and armor steel - it is enough to provide the plate with an anti-splinter coating, which is the same aramid fiber.
Ceramics
Combating the weight of steel-plate body armor has led to the development of ceramic plates capable of withstanding armor-piercing bullets. Actually, the main task of a light, but extremely durable ceramic plate is reduced to the destruction of the bullet and the absorption of its energy.
Unfortunately, ceramics, stopping the projectile, cracks themselves, so the reuse of the plate, which has already been hit, is very undesirable, since the next time it will not be able to perform its functions, but will simply pass the bullet further. And further behind the ceramics, a traditional metal plate is usually installed, which makes it much easier to stop the remnants of a bullet that has lost energy.
At the moment, three types of ceramic panels are widely used, which use aluminum oxide, boron carbide and silicon carbide. Alas, carbide panels are not cheap and their mass production (for arming the army, for example) is therefore difficult.
SVMPE
The scary acronym stands for Ultra High Molecular Weight High Density Polyethylene. Yes, you are not mistaken - the most promising and modern material for armor plates is polyethylene. Only it is very durable and, of course, lightweight.
Extruded polyethylene is suitable for use in class 3 body armor, but it costs much more than conventional armor steel, and has some flammability problems. In addition, while providing the same protection, the polyethylene plate will be significantly thicker than steel. Considering that the first three classes of protection can provide vests for concealed wearing, replacing their armor plates with polyethylene is quite problematic, since its thickness in this case grows to an unacceptable 20 mm, where it is already difficult to hide something.
Currently, armor plate and vest manufacturers are combining available materials to get the best results. The best is taken from each type of armor to compensate for the disadvantages of the other type. You can't walk around so much in hidden-wearing bulletproof vests, therefore, combined plates with ceramics and metal can most often be found in army large bulletproof vests that are worn over uniforms.
Avoiding fakes
There are cases when unscrupulous sellers, under the guise of armor plates, sold forgeries that did not have any protection. To prevent this situation from happening to you, be careful about choosing a brand, demand a certificate. It is also advisable to look at the samples shot and test reports - excessive exactingness and meticulousness in this case should not bother anyone, since you are buying a thing that can save the life of you or someone who will wear a bulletproof vest.