20.06.2022
Various ballistic materials are used in the manufacture of protective plates and covert body armor for bulletproof vests. The main ones are Kevlar, polyethylene, ceramics and metal. And the way to test the quality of armor plates is a shot. The most common shapes of plates are rectangle, rectangle with rounded corners and irregular hexagon. In addition, armor plates come in flat and anatomic shapes.
When a bullet hits a Kevlar armor plate, it penetrates a "network" of very dense fibers. They absorb and dissipate the impact energy transmitted to the vest from the ball, which deforms and flattens in the process.
The additional energy is absorbed successively by each layer of material until the ball is stopped.
Because the fibers work both all together and in each individual layer, it helps to prevent so-called blunt trauma to internal organs. Currently, there is no such material to make an armor vest a single layer. The more layers, the stronger the kevlar package, the higher the velocity of the fired bullet has to be to penetrate it. Thanks to its flexibility and low weight, Kevlar is indispensable for neck and groin protection.
Kevlar is good against soft lead balls as well as blunt (rounded) shell balls.
Kevlar Properties:
Polyethylene is often confused with Kevlar, but it is a completely different material. Polyethylene is a special ultra-high density ballistic material. In English, such polyethylene is called "high-modulus or high performance polyethylene" (abbreviation - HM PE or HP PE).
Polyethylene armor panels are simple in their design, but difficult to manufacture. They consist of a large number of layers of polyethylene fibers and film that are pressed together using high pressure.
Polyethylene has high strength, using it to produce rigid armored panels of class III (according to the U.S. system). At the same time, polyethylene armor panels will protect against any kind of cold steel weapon. Since polyethylene is afraid of fire, B-32 armor-piercing cartridges with a special thermal composition are dangerous for polyethylene armor plates - when hitting an obstacle or a target, such balls form a lot of sparks.