August 06, 2023 5 min read
Ultra-high molecular weight polyethylene, or UHMWPE, has revolutionized ballistic protection.
Discovered by accident in a lab in 1963, it took 30 years before this hydrocarbon polymer first made its way into a working, military-issued French helmet, followed by broad acceptance as a ballistic material of choice. Today, UHMWPE composites are widely used in modern military helmets, various other tactical helmets, and armor plates.
By providing “higher ballistic protection at a reduced weight,” UHMWPE composites have proven more effective than predecessor materials, current competitors, and many theoretical replacements.
Hard Head Veterans proudly presents our series on ultra-high molecular weight polyethylene (UHMWPE) composites in armor and helmet design.
Chemist and ballistic researcher Jake Ganor of Adept Armor details this material's chemistry, history, manufacturing, and future. We also explain modern helmet construction, the crucial quality control processes, and how headgear is tested and assigned ballistic protection levels.
Table of Contents:
Polyethylene is the simplest hydrocarbon polymer—a repeating chain of two hydrogen atoms bonded to a carbon.
At a smaller molecular weight and size, this material is used for things like plastic shopping bags and drink bottles. But heavier chains and finer fibers—well-aligned—make up ultra-high molecular weight polyethylene, which has incredible strength and friction and impact resistance.
Variants of UHMWPE comprise truck-bed liners, hydraulic bearings, and marine fenders, where durability is key. But when manufacturers take processing a step further by adding resins and limiting structural imperfections, UHMWPE gets tough enough to stop bullets and other projectiles—all at a pretty light weight.
Read this blog to learn more about the chemistry of UHMWPE, the resins and manufacturing that make ballistic protection possible, and why glass and other seemingly weak materials are way stronger than you might think:
Dutch scientists didn’t realize the potential of what they accidentally discovered during a series of experiments in 1963.
UHMWPE fibers were strong but formed in unusable clumps until an innovative process 15 years later made industrial production possible. What followed was 15 more years of research and contractual struggles before the first modern military helmets entered service.
The French military was the first player in the game, and its 1993 Spectra Helmet still holds up well in terms of performance. This innovative headgear and proof of concept paved the way for UHMWPE’s use in ceramic body armor plates and today’s ballistic and tactical helmets used by both the US military and private buyers.
Learn about the long, strange trip of ultra-high molecular weight polyethylene—from discovery to ballistic protection:
Ultra-high molecular weight polyethylene may be strong, but creating modern combat helmets from it is not easy. Sheets must be shaped into an oval helmet shell, often forming wrinkles that initiate weak points or make the material unusable. And since UHMWPE is expensive, so is every wasted effort.
Manufacturers developed processes, also used with aramids, to handle these challenges. They cut composite sheets into darted pinwheel patterns, position these shapes to make even seams, and fuse them with heat and pressure.
But even these methods create seams and specific points on a helmet that are weaker than others—the crown is stronger than the sides, front, and rear. And end-users want more robust protection where projectiles will most likely hit.
Read this blog to discover common and alternative manufacturing approaches—including “deep drawing,” which can build a seamless helmet but creates more material waste:
UHMWPE has come to dominate ballistic protection products, often in concert with aramids and always with resins, due to its low weight and excellent performance. But what's on the horizon for future helmets and armor?
Among the theoretical candidates are Zylon® fibers, new aramid derivatives, M5 fiber, and carbon fiber nanotubes.
But Zylon faces seemingly insurmountable obstacles after manufacturers faced recalls and lawsuits due to degradation with everyday use. Aramid derivatives haven’t reported better performance results than UHMWPE. And M5 is denser and has a lower projected specific tensile strength. Carbon nanotube fibers have exciting potential, but this promise is still theoretical because nanomaterial tech isn’t advanced enough.
Check out armor researcher Jake Ganor’s review of the primary candidates for tomorrow’s ballistic protection, including why he thinks UHMWPE is here to stay and improve with evolving production techniques:
The challenges of making modern military helmets aren’t limited to those involved with UHMWPE. Aramid or polyethylene fibers must combine with stiff resins in just the right way to conform to shape and avoid imperfections that compromise protection. That’s why Hard Head Veterans and other quality providers source only the best materials from well-vetted suppliers.
These manufacturers of ballistic fibers conduct quality control (QC) and testing procedures, ideally augmented by secondary assessments before and after the raw materials make their way into finished helmets.
Learn how Hard Head Veterans and our suppliers do it, including checks of fiber ply orientation/stacks, resins, dimensions, and weight, plus realistic performance tests:
How do tactical helmet end-users know they are getting adequate protection? Thankfully—given the stakes, if it fails—well-established testing and standards ensure headgear performs as advertised.
The gold standards for ballistic protection derive from dedicated military contract testing and the National Institute of Justice (NIJ), which issues vital industry benchmarks for helmets and armor. NIJ assessment criteria result in the protection levels touted with gear, such as Levels I, II-A, II, and III-A.
But what do those levels and other standards practically mean? This blog explains the tests and what they safeguard against, including specific ammunition types, resistance to penetration (RTP), backface deformation (BDF), blunt impact performance, fragmentation performance, and more:
Hard Head Veterans stays on top of helmet research to ensure we provide the best protection possible. Readmore blog posts, and be sure tocheck out our gear, including a selection ofthe best tactical helmets andessential helmet accessories.