Body Armour Materials & Technology
The materials utilised in constructing bullet proof vests’ ballistic panels vary widely from manufacturer to manufacturer. Prior to being sold, all body armour must pass specific tests, meaning that these diverse materials should provide the same levels of minimum threat resistance. Unfortunately, the longterm quality of the body armour piece is not always assured. In particular, vests constructed from Zylon were shown by independent tests to fail after being used only a short amount of time. Evidence that Zylon vests were degrading rapidly after purchase led to their 2005 recall. In selecting a piece of body armour, make sure the vest is constructed from high quality materials such as those described below.
Extremely strong and heat resistant, aramids are a class of synthetic fibres pioneered by DuPont™ in the early 1960s. DuPont™’s meta-aramid Nomax® was supplanted by the para-aramid, Kevlar® in 1973, which revolutionised the body armour industry. In particular, para-aramid materials introduced inherent flexibility and lightweight properties that allowed the development of vests comfortable to the wearer, yet hard wearing and highly protective. Kevlar® and Twaron® are para-aramid materials commonly utilised in bullet proof vests, and have been on the market for three decades.
The chemistry involved in creating aramids typically involves the formation of an AABB polymer through a reaction between carboxylic group and an amine group molecules. Spun together with sulfuric acid, the blended liquid becomes solid and can be marketed in pulp, powder, or fiber form.
Since its development in the early 1970s, Kevlar® production has been refined significantly. The initial Kevlar® 29 was innovative in allowing the manufacture of protective panels that combined flexibility with concealability. The result was a lightweight product that people were comfortable wearing on an everyday basis. In 1988 DuPont™ developed Kevlar® 129 for body armour use, a product that was significantly lighter than its predecessor and had improved ballistic resistance capacities. Kevlar® 129 was even able to resist high-velocity rounds from guns such as the 9mm FMJ. Kevlar® Correctional is the most recently released version of Kevlar®. Introduced in 1995, it protects against knife and other weapon threats, and has led to the production of multi-threat vests that can halt both bullet and stab attacks.
Known as UHMWPE, ultra-high-molecular-weight polyethylene is another common ballistic panel material that is present in a variety of body armour products. With characteristics similar to para-aramids, UHMWPE is a polyolefin composed of extremely long polyethylene chains. There are several techniques of creating UHMWPE, including compression molding and ram extrusion. For the purposes of body armour production, UHMWPE is formed through gel-spinning, which involves creating a gel material by drawing dissolved ethylene through a number of tiny holes. With twin pieces of gel sealed under polyethylene film, a composite is generated that can be manufactured into soft armour ballistic panels, or rigid plates of hard armour. With research demonstrating that UHMWPE strength-to-weight ratios are as much as 40 percent higher than para-aramid fibres, UHMWPE-based body armour made from Spectra® and Dyneema® is increasingly associated with high-end models.
Hard Armour Materials
Forged from metals such as steel, hard armour was traditionally bulky, heavy, and ineffective. Like its soft body armour counterparts, today’s hard armour is constructed from a diverse range of materials. The most common type of hard armour plate utilises ceramic or ceramic composite, frequently incorporating para-aramid backing with a material such as Kevlar®. The least expensive type of hard armour, it is also the heaviest. Monolithic and polyethylene derived hard armour plates are more lightweight than ceramic models, and correspondingly more expensive.
Other hard armour types such as ballistic helmets are typically constructed from a para-aramid base like Kevlar®, and subsequently coated in a rugged thermoplastic resin. The material created is lightweight and thin, offering the wearer maximum comfort over extended periods of use.
What Are The Different Sections Of Body Armour?
All bullet proof vests contain a number of distinct sections. At the most basic, functional level, body armour pieces contain two protective panels housed within a vest carrier, covering the chest and back. Without the insertion of protective panels, the vest is simply a normal piece of clothing that does not protect against threats.
What Are The Different Vest Covers?
Body armour is available with a range of cover types, including natural materials such as cotton, and advanced materials such as Gore-Tex®, CoolMAX®, and Cordura®. While ballistic panels can be sewn into the vest carrier, the industry trend is towards removable panels that can be washed or upgraded as necessary. For example, with the substitution of protective panels, an NIJ Level II vest becomes an NIJ Level IIIa vest.
Utilizing advanced moisture management technologies, CoolMAX® material has thin and lightweight properties that make its use common in many types of performance clothing. CoolMAX® is primarily used for covert vests covers, with the moisture wick system drawing sweat away from the wearer’s body and keeping the skin cool.
The high tenacity fiber technologies in Cordura® make it ideal for use in hard wearing products such as overt vests, which must stand up to the rigors of everyday use.
Gore-Tex® combines waterproof qualities with breathability, and it’s a common technology in consumer products from backpacks to shoes. Gore-Tex® is particularly utilised in bullet proof vest covers worn by police officers throughout the world.