Properties of Ultra-High Molecular Weight Polyethylene (UHMWPE) In Protective Armor
History of UHMWPE
Ultra-High Molecular Weight Polyethylene (UHMWPE) was first created in the 1950’s and became commercialized in the 1970’s clinically as a preferred material for total hip and knee replacements. Rated as the most durable thermoplastic and proven to be 15 times more abrasion-resistant than carbon steel, UHMWPE has since evolved as a preferred material for ballistic protection since 2001.
UHMWPE Current Market
According to a research study by Grand View Research, the global market for Ultra-High Molecular Weight Polyethene (UHMWPE) in 2021 was just shy of $1 billion dollars, but is projected to be around $5 billion by 2028. The protective armor application accounts for nearly 36% of the total global market size for UHMWPE.
Grand View Research indicates, “Ultra-high molecular weight polyethylene (UHMWPE) fibers are gaining increasing acceptance in the military and defense application owing to their several superior properties, such as high chemical resistance excellent impact, and abrasion resistance, highest strength-to-weight ratio, excellent flexibility and comfort, wear resistance, and protection against handgun threats. UHMWPE fibers are widely used in protective armor applications, such as ballistic helmets, frag knits, bulletproof vests, ballistic shields, ballistic plate inserts, and explosion-resistant blanket.”
Overall, the global market for UHMWPE is projected to increase substantially over the next several years, and large portion of this growth will include the use of UHMWPE in protective armor for military and defense applications. More recently, with the volatility of raw material prices and supply chain issues, this may impact the projected market growth for UHMWPE.
Military and Defense Armor
Typically, the U.S. military defense armor is rated by the National Institute of Justice (NIJ) level 4 or greater. Though there’s a variety of different materials and options used to provide level 4 protection, UHWMPE is being incorporated with polymers, ceramic and other ballistic materials which enhances the level 4 protection required by the military.
Performance Analysis of UHMWPE
Strengths:
- Performance – Excellent against Lead Core and mild steel rifle rounds.
- Multi-Hit – Good at absorbing multi-hits in the same general area.
- Weight – Extremely lightweight, especially compared to steel plates.
- Durability – Flex Life Performance Rating of 100. This means greater flexibility without the concern of cracking or tearing.
- Strength – UHMWPE has been cited to be 15 times stronger than steel. Kevlar, for comparison, is noted to be about 7 times stronger than steel.
- Moisture Resistant – UHMWPE is waterproof and therefore will not be weighed down by sweat or liquid absorption.
- Ultraviolet Light Resistance – After 2 full days of UV exposure, UHMWPE lost only 5% of strength, where kevlar for example lost 25%.
- Wearability Temperature – Overall, UHMWPE is a more breathable fabric, making it more comfortable in hotter conditions.
Weaknesses:
- Performance – Weak against hardened steel core ammunition
- Thickness – Generally as thick as ceramic plates
- Temperatures – Can degrade over time in prolonged exposure to temperatures over 70° C (158° F).
- Energy Absorption – Though UHMWPE has an extremely high energy absorption, kevlar has a slightly higher energy absorption rate.
- Cost – Typically more expensive than ceramic or steel.
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