TYPES OF BALISTIC SHIELDS
We would like to devote the first article to the absolute basics - that is, the types of personal ballistic shields. This knowledge is all the more important because it concerns equipment on the effective operation of which the life and health of the user depends. With this knowledge, you will be able to decide what type of shielding you need and what will work best in a given situation.
The simplest division of ballistic shields is, by design, soft shields, hard shields and hybrids formed from a combination of the two systems.
SOFT BALLISTIC SHIELDS
They are usually made of para-aramid fibers (e.g. Kevlar, Twaron) or UHMWPE or high molecular weight polyethylene (e.g. Dyema, Spectra). The essence of their operation is the absorption of energy through high deflection of the flexible and tear-resistant material, which thus does not have to be heavy.
Soft ballistic shields should be used where the benefits of wearing comfort outweigh those obtained from a high level of safety. Note that shields of this type are used only to protect against low velocity and energy projectiles (pistol ammunition), since higher energy projectiles even if stopped will cause very serious internal injuries.
Additional advantages of soft ballistic shields are their large surface area, flexibility, light weight and often resistance to additional exposures such as cutting and stabbing with a knife or pick. At the same time, it should be remembered that shields of this type do not like moisture and, in particular, human sweat and thus are packaged in airtight (non-breathable) covers, which significantly reduces the comfort of the user.
Soft covers, due to the need for a lot of expensive materials, are relatively expensive.
Their properties deteriorate over time and usually after 5-7 years they no longer provide sufficient protection.
HARD BALLISTIC SHIELDS
They are made of materials capable of absorbing high energy with little deflection.
Among them, we distinguish betweenhomogeneous shields made of compressed UHMWPE and para-aramid or high hardness steel, and composite shields, which also contain ceramic elements in their construction.
Homogeneous hard shields made of UHMWPE and para-aramid allow a significant leap in shield resistance compared to soft ballistics, but they also have significant limitations - they perform very badly when confronted with high-speed bullets. The .223 5.56 5.45 caliber bullets show considerable effectiveness in defeating them.
They are much better at stopping soft and slow .308 or 7.62×39 caliber bullets, which have high energy due to their weight. Of course, they don't stand a chance against anti-tank ammunition with a hard sharp core.
Among the advantages is undoubtedly the very low weight while keeping in mind that good ballistics of this type must be expensive due to the large amount of high-quality material used-otherwise there is the possibility of serious and fatal injuries due to the so-called backface deformation (BFD), to which we will devote a separate article, as it is one of the three most important mechanisms of injury due to the impact of the bullet on the ballistic shield.
It should also be remembered that although they have the ability to stop many bullets, in the area of impact the material has already been weakened and may not necessarily stop another bullet or properly absorb the energy. Typical backface deformation in this class is about 40mm for .308 caliber Less deflection is shown by para-aramid casings and more by UHMWPE.
Homogeneous hard shields made of steel are one of the oldest types of shields used against propelling weapons. Steel of suitable quality (preferably dedicated armor steel) has excellent energy absorption properties and, thanks to its high stiffness, also distributes the impact energy over the entire surface of the ballistic plate.
Among the disadvantages of steel, of course, we can include the lack of resistance to hard core anti-tank ammunition and its weight. However, it should be borne in mind that with the right quality steel, the weight of a ballistic plate equipped with an effective shrapnel retention system is 2700-3300g, depending on the degree of resistance and shape.
The aforementioned anti-shrapnel system must be an integral part of a steel ballistic shield, since it protects the wearer from bullet fragments that shatter on the plate. Such a system cannot be replaced by rubber bands, adhesive tape bands, pockets and similar inventions glued onto the steel.
Ballistic shields made with steel technology are budget-friendly and have the longest shelf life. When well protected and stored, they are essentially eternal.
They have the smallest backface deformation of all designs amounting to a few dozen millimeters with an impact energy of 4000-4500J and therefore very high and appropriate for .308 .30-06 or 7.62x54r calibers.
They exhibit the highest ability of all types to effectively stop a large number of hits including those occurring very close together.
HARD COMPOSITE (CERAMIC) BALLISTIC SHIELDS
This group of ballistic shields provides the highest degree of protection and features the highest degree of design complication. In a nutshell, the ballistic plate in this case consists of a front very hard and brittle ceramic layer- designed to break up the projectile (including anti-tank) and distribute the energy of its impact over a large area.... and a rear layer to absorb impact energy and prevent excessive deflection.
For ceramics, the main materials are Al2O3 aluminum oxide, SiC silicon carbide and B4C boron carbide. The absorbing materials are the para-aramid fibers and UHMWPE mentioned earlier.
Because of the use of ceramic, this type of plate, although often sold by many manufacturers as "multihit" and so certified, should be considered by the user more as a way to stop one very dangerous anti-tank projectile (for example, 7.62x54r B-32M) and possibly a chance to stop more that do not hit the area of the cracked ceramic.
Note that the NIJ-certified Class IV ceramic has resistance to the virtually non-existent and WWII-era .30-06 M2 AP bullet, which is much weaker than the 7.62x54r B-32M used here.
A minimum backface deformation of no more than 20mm (some standards allow 44mm) should also be considered just as important as not allowing the board to puncture.
The weight of stand-alone ceramic plates increases with the degree of resistance and should be assumed to be in the range of 2,500-3300g.
The price depends on the quality and type of materials used - plates made of SiC are, at the same degree of resistance, about 15% lighter than those made of Al2O3 and five times more expensive, while those made of B4C are about 20% lighter and seven times more expensive - dedicated mainly to institutional users.
Shelf life is mainly defined as 5-7 years.
HYBRID PERSONAL BALLISTIC SHIELDS
This type of shield, also called ICW ( in conjunction with ) abroad, is nothing more than a combination of a hard ( steel, ceramic ) ballistic plate and a soft ballistic shield.
The idea behind such a solution is to be able to adjust the level of protection to the external situation, and the example of a police officer who wears a light and flexible Kevlar vest on a daily basis, which protects him from a knife, broken bottle or pistol bullet over a large area, but when the situation requires it, he can by adding a dedicated hard plate (weighing less than a standalone plate) achieve a higher level of protection.
Why dedicated? Because the components of this system are for use only in the configuration in which they were designed. We can't use any hard plate and put it together with any soft cover.
This is especially important because there are many ICW hardboards on the market that are sold without soft inserts-because these have most simply expired and the hardboards in question have simply become a troublesome waste.
What's more- the sheathing of the whole system should also be adapted to this. Thus, it may turn out that the hard board is inadequately (or even not at all!) supported by the soft insert
It may turn out that such a board, in order for the system to absorb energy, needs class IIIA soft ballistics and not class II (we will write another article about classes of protection). So as a rule of thumb here is that the system is bought together or strictly according to the manufacturer's recommendations. It is then a very good solution for daily multi-hour service in low-risk conditions.
We hope that this article will give you the basis to choose the best product to meet your expectations on your own.
Greetings!
BC ARMS Team
