What are some of the recent developments and advancements in technologies aimed at enhancing ballistic protection?
April 2023 marked the launch of Kevlar® EXO™, a product which DuPont heralds as the most groundbreaking aramid fiber innovation in over half a century. Currently, specifics about its performance characteristics are still under wraps, but, in an interview with one of its inventors, it has been disclosed that Kevlar EXO is a chemically modified form of aramid, with improved hydrogen bonding between the molecular chains of its fibers, improved transverse compressive strength, and a reduced defect rate – all of which should translate to superior ballistic performance.
This is a welcome advance, as aramid fibers haven’t come close to hitting their performance ceiling and there ought to be considerable room for improvement. The tensile strength of Kevlar KM2® is roughly ten percent of its theoretical strength (i.e., its maximum attainable tensile strength, derived from its chemical structure). In contrast, the best grades of UHMWPE – currently used in Dyneema® and SpectraShield® – approach 40% of their theoretical tensile strength. Aramid is a material with more potential, but it seems to take a lot more effort to bring that potential out. Kevlar EXO is a step in that direction.
As of this writing, Kevlar EXO is available in rolls for soft armor applications. If it lives up to its “biggest advance in 50 years” billing, it should enable impressively light, thin and flexible soft armor panels. Even if it turns out to be nothing more than a marginal improvement over yesteryear’s aramid materials, its improved flexibility over unidirectional UHMWPE composites should make it an attractive option, especially for law enforcement officers who wear their armor for extended periods of time. Expect Kevlar EXO soft armor products to hit the shelves later in 2023.
Novel Ballistic Products
Another noteworthy trend is the spread of ballistic materials into new product categories.
First, there’s the ballistic fire helmet. Today, in their work as first responders, many firefighters are required to carry two helmets: one ballistic helmet and one fire helmet. This creates a logistical burden and can require firefighters to change helmets in the midst of their response to a crisis. The Department of Homeland Security’s Science and Technology directorate has seen this and, working together with researchers from Texas Tech University, is in the late stages of a much publicized ballistic helmet project for firefighters which should result in a prototype for fielding trials by mid-2023. What’s more, several private companies are aware of this effort and the unmet need it represents, and are likely to throw their hats into the ring before the year is out.
The material construction of this ballistic fire helmet is no secret. Though the ECH, IHPS and most high-end military helmets are now made of UHMWPE composite materials, UHMWPE has poor thermal properties and degrades rapidly at elevated temperatures. Aramid is self-extinguishing, flame-retardant to ~790°F, and can operate for extended periods of time at 660°F, so the ballistic fire helmet of the near future is doubtless going to be made of an aramid laminate in a temperature-resistant resin. What’s less certain, but likely, is that it will also incorporate advanced thermal mitigation strategies – e.g., layers of thermal conductors to spread heat across the entire helmet shell and layers of insulators to prevent that heat from affecting the helmet’s wearer.
Another example of this spread is in riot armor. Today, riot armor is much like football armor or motocross armor in that it’s only rated for blunt impact protection and is not intended to hold up against bullets, knives or spikes. The newly released Adept Armor NovaSteel Breastplate is a riot armor torso and shoulder protector – and a drop-in replacement for existing riot armor torso/shoulder parts – which is rated for blunt impact, NIJ Knife-3, NIJ Spike-3, and ballistic performance to NIJ IIIA/HG2, with a light up-armor ballistic plate which brings it up to III+/RF2.
Though it is unlikely to result in new products for 2023, there has been much recent research into soft armor design strategies. There are two trends, distinct but very closely related.
First, there’s a push towards sustainable composites made of natural materials – particularly those derived from kenaf, flax, bagasse, and pineapple leaf. These high-strength natural fibers can be combined with aramid or UHMWPE layers in laminate armor systems and these hybrid systems purportedly perform quite well. What’s more, high-strength natural fibers can be as much as 95% cheaper than the high-tech synthetics they replace. (Bagasse, in particular, is an industrial waste product.) Natural fibers have already made inroads into the automotive market – the BMW i3, among other makes and models, utilizes kenaf fiber composite panels – and it is increasingly likely that the armor industry will follow suit with low-cost Level II and IIIA body armor panels partially or wholly derived from natural fiber composite materials.
The other trend follows studies from PEO Soldier and Purdue University. Their research program found that the top few layers – i.e., the threat facing side – of laminate soft armor panels don’t necessarily contribute to the ballistic performance characteristics of those panels. In one experiment, they compared prototype soft armor shoot packs against a variety of FSP threats. Their baseline “traditional” soft armor panel was made of 22 layers of aramid; one of their competing test systems was made up of eight layers of cotton fabric over 14 layers of aramid. Those two systems performed identically. (The performance difference between them against 9mm steel fragments at common handgun velocities was less than one percentage point.)
The discovery in question isn’t new; it’s a few years old – but 2023 has seen it tested and advanced, with different research groups replacing UHMWPE or aramid layers in soft armor panels with everything from polycarbonate (five) to a wide range of natural fibers, including some of those previously mentioned.
All told, we’re on the threshold of potentially significant innovations in soft armor systems.
Another safe prediction is that as ballistic materials get lighter and thinner, they’re going to become more ubiquitous. 2023 brings ballistic fire helmets and ballistic riot armor, and it’ll be interesting to see how Kevlar EXO is implemented by armor designers in 2023, 2024 and beyond.
Jake Ganor is a materials scientist, armor engineer and a designer of ballistic shields. His company, Adept Armor (ade.pt), is pioneering next generation armor systems. His book, Body Armor and Light Ballistic Armor Materials and Systems, is now available on Amazon.