Stephanie Louise Kwolek

Stephanie Louise Kwolek

1923 – 2014

Invented Kevlar Fiber

Major Field of Study:  Chemistry

Specific Accomplishment:  Invented Kevlar Fiber

Home Town:  New Kensington, Pennsylvania

Youth Activities:  Became interested in science through studying nature with her father, John Kwolek, a naturalist.

Bachelor’s Degree:  Carnegie Institute of Technology, Bachelor of Science, Chemistry, 1946

Engineering and Science Achievements:  

Stephanie Louise Kwolek invented Kevlar (poly-paraphenylene terephthalamide), a para-aramid synthetic fiber with exceptional strength-to-weight properties.  Five times stronger than steel of the same weight, Kevlar is perhaps best known for its use by law enforcement in bullet-proof vests.  In 2006, the International Association of Police Chiefs estimated that the lives of 3,000 policemen had been saved since 1987 through the use of body armor.  Kevlar’s many other applications range from tennis rackets to gloves, to over-stressed bridge reinforcements.

The discovery came when Kwolek was working for DuPont during the 1964/65 time frame on developing a light-weight fiber for radial car tires.  Her experimentation with polymers had produced a low-viscosity, cloudy solution that would normally have been discarded, since conventional polymer solutions are typically highly-viscous and translucent.  Nonetheless, Kwolek called for continued processing or “spinning” of the solution into a solid fiber, and she was rewarded when it was shown that the resulting strand was extraordinarily strong and would not break when nylon normally did.

Additional Details:

Hired by DuPont shortly after graduating from college in 1946, Kwolek spent her entire career with that firm until her retirement in 1986.  Among her other accomplishments, she obtained 28 patents and was instrumental in the development of the heat-resistant fiber Nomex, a prominent component of firefighter protective clothing.

After retirement, she continued to consult for DuPont and served on the National Academy of Sciences as well as the National Research Council.  She was also active in tutoring high school students and encouraging young women to embark on careers in science.

Kwolek received numerous awards, including the National Medal of Technology, IRI Achievement Award and the Perkin Medal.


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Pearce, Jeremy “Stephanie Kwolek, Inventor of Kevlar is Dead at Ninety, New York Times, 20 June 1014, retrieved from 

“Obituary:  Carnegie Mellon Alumna and Hall of Fame Inventor Stephanie Kwolek Dies at 90,” Carnegie Mellon University News, 20 June 2014, retrieved 18 July 2016 from

“Kwolek, Stephanie Louise,” Pennsylvania Center for the Book,” retrieved 18 July 2016 from

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“Survivor’s Club Salutes 3000th Law Enforcement Officer Saved by a Protective Vest, DuPont web site retrieved 18 July 2016 from


Stephanie Kwolek. Wikipedia.