Friday, 20 June 2014

Why Kevlar Is Stronger Than Nylon?

You mean besides reinforcing the tyres on the Batmobile? (True Bat-Fact – look it up).


For those not in the know, Kevlar (or Poly-paraphenylene terephthalamide, to give the material its scientific name) is a very tough and durable man-made fibre. It was first developed in 1965 by Polish-American scientist Stephanie Kwolek and has been commercially used around the world since the early 1970’s. Today, Kevlar is available in several grades, which are used for different tasks and exhibit greater, or lesser, tensile strength as well as flexibility and tenacity.


Since its introduction in 1971, Kevlar has been used for body armour (i.e. bullet proof vests), army helmets/protective gear, car and bicycle tyres (I once had a set, actually), protective clothing, paraglider suspension lines, shoe tread, headphones, musical instruments (strings and drumskins), fire resistant clothing, kitchenware (for its non-stick properties), cables and ropes, brake pads in cars, smartphone casing and even wind-turbines.


According to DuPont, Kevlar’s parent company,


“It’s about resilience, strength, saving the day, and helping keep people safe from harm —DuPont™ Kevlar®. DuPont™ Kevlar® aramid fiber is used to make a variety of clothing, accessories, and equipment safe and cut resistant. It’s lightweight and extraordinarily strong, with five times the strength of steel on an equal-weight basis. Best known for its use in ballistic and stab-resistant body armor, Kevlar® brand aramid fiber has shown its own heroism in helping to save the lives of thousands of people around the world. And since its invention over 40 years ago, things have only gotten better. DuPont™ Kevlar® continues to take on new challenges, with our scientists continuously innovating and working on a range of new opportunities through collaborations with communities, industrial manufacturers, and governments. Together we’re bringing the strength and durability of Kevlar® to so much more. The result? Kevlar® aramid fiber is now successfully used in everything from vehicles and industrial clothing to fiber optics and city roads. And we’re only getting started”.


The discovery of this wonderful material is actually quite an interesting story. Back in 1964, Kwolek’s group was searching for a way to make tyres stronger, but also a little bit lighter. Apparently, the by-products of their solutions were usually thrown away, but Kwolek saw potential in one of them, as it had formed a type of liquid crystal, something that had never been seen in their polymers before. She tested the strength of the new material and discovered that it was extremely strong. The rest, as they say, is Wikipedia.


Oh, Happy New Year, by the way! :)