Kevlar vs. UHMWPE: What's the Difference?

Kevlar and UHMWPE (Ultra-High Molecular Weight Polyethylene) are both high-performance synthetic fibers widely recognized for their exceptional strength-to-weight ratios and amazing resistance to impact and abrasion. While they share a lot of similarities, there are distinct differences between the two materials that you’ll need to know in order to pick the right one for what you want in your riding gear.

Closeup of Kevlar material

What is Kevlar?

Kevlar, developed by DuPont in the 1960s, is an aramid fiber renowned for its extraordinary strength. It is composed of long-chain polymers with rigid molecular structures that provide an incredible amount of tensile strength. Kevlar is often used for its resistance to high temperatures, as in bulletproof vests, helmets, and body armor for motorcycle riders as well as military and law enforcement. Kevlar is also used in the aerospace and automotive industries because of its invaluable strength and heat resistance.

Closeup of UHMWPE material, image from namilong.com

What is UHMWPE?

UHMWPE is a high-strength, lightweight polyethylene fiber that is also extremely durable and impact resistant. It was first introduced commercially in the 1970s and has since gained a ton of popularity for its strength and flexibility. UHMWPE is created by aligning the polymer chains during a gel-spinning process that results in a material with high tensile strength. Like Kevlar, it’s used in the manufacture of bulletproof vests, protective gloves, but is also used in making ropes and sails because of its strength, light weight, and resistance to chemicals and UV radiation.

Wear alone as a mesh summer riding jacket or as an armored base layer below any other apparel of your choosing. This zip-up is made of extremely durable power-stretch UHMWPE material, which is 15 times STRONGER than STEEL, in the most vulnerable areas.

What’s the Difference?

One of the main differences between Kevlar and UHMWPE is their molecular structures. Kevlar has a more rigid and crystalline structure, making it highly resistant to penetration and cutting forces. It is fantastic at absorbing and distributing impact energy, making it ideal for situations that would require protection against ballistic threats. UHMWPE has a more flexible and elongated molecular structure, meaning it has incredible impact resistance and the ability to dissipate energy very effectively. It is particularly useful for situations that would require flexibility and protection against sharp objects, such as cut-resistant gloves or knife-proof vests.

Another important distinguishing factor is their density. Kevlar has a higher density compared to UHMWPE, resulting in slightly heavier finished products. UHMWPE might be appealing for motorcyclists to reduce the bulk that Kevlar-lined gear may add. While this might be important in some other very specific situations where weight is a key factor, the difference in density is generally negligible for most uses.

In addition, UHMWPE is waterproof and won’t be weighed down by liquid absorption. This makes UHMWPE ideal for use in tents and backpacks which may be used in wet or humid conditions. On the other hand, Kevlar can absorb up to 3.5% of its own weight in water! A UHMWPE jacket would remain comfortable for longer in hot and humid weather for motorcycle riders and would provide some water resistance if there's unexpected rain.

Ultraviolet light resistance is also an essential factor in the lifespan of heavy-duty fibers that spend a lot of time outside or in the sun. Kevlar will lose up to 25% of its material strength after two days of UV exposure, while UHMWPE loses only up to 5%. This is an important distinction for manufacturing products that are used outdoors.

Kevlar and UHMWPE also have different thermal properties. Kevlar can withstand higher temperatures without significant degradation, which means that it maintains its strength and integrity even in extremely hot conditions. For this reason it is perfect for flame-resistant clothing or protective equipment for firefighters. UHMWPE has a lower melting point and may deform or lose strength at higher temperatures. However, UHMWPE is a less popular choice to be worn in cooler temperatures because it does not have as impressive insulation capabilities as Kevlar.

In terms of cost, Kevlar is generally more expensive than UHMWPE. The production process and the raw materials involved contribute to its higher price point. UHMWPE is often chosen for situations when cost is most important without compromising on strength and durability.

Both Kevlar and UHMWPE are amazing materials that have changed the world and have made many industries and activities safer– especially within the world of motorcycles. Both offer protection from different kinds of threats, but knowing their key distinctions is important for choosing which will function best for your needs. The Pando Moto Commando Mesh UHM Jacket uses UHMWPE instead of Kevlar and claims to be 15x stronger than steel! In terms of comfort and wearability in comparison to the Kevlar-lined Sherpa Trucker Jacket, we’ll let you be the judge!