Invention Geek – The Invention of Kevlar

Question from No Name:

When was the bulletproof vest invented? Or should I say Kevlar?

Kevlar was another accidental invention among many others throughout history that has saved thousands of lives. The fabric was originally intended to replace steel belting in the tires of vehicles. A member of DuPont’s Pioneering Research Laboratory, Stephanie Kwolek, first developed the synthetic material in 1965. Kwolek was awarded patent number 3,819,587 in 1974 for “Wholly aromatic carbocyclic polycarbonate fiber having orientation angle of less than about 45º.”

Kwolek had been hard at work developing new polymer solutions when she stumbled onto one that behaved in a way no other solution had before. The particular liquid separated into two distinct layers: one was clear and yellow, and the other was cloudy, shiny, and much thinner than other mixtures. It poured like water, which was also uncharacteristic.

Kwolek and technician Charles Smullen tested the liquid further, spinning it to fibers and ultimately discovering the material’s remarkable capabilities. The substance was lightweight, stronger than steel, chemical, flame, and high cut resistant.

Under DuPont, Kwolek’s material underwent testing as a bullet resistant fiber. DuPont first began marketing Kevlar in 1971 as bulletproof, protective body armor.

Today, Kevlar is used in many other products, including helmets, spacecraft shells, skis, and suspension bridge cables.

…all thanks to another “Happy Accident.”