A cloudy, milky white substance instead of a clear one

Stephanie Kwolek (Kensington, Pennsylvania, July 31, 1923)

Stephanie Kwolek was born in 1923 in Pennsylvania, on the east coast of the United States. Her father was a nature lover, who traveled with her through the fields and the woods; together they collected leaves and flowers and seeds, which they stuck in large books.

From her mother she got the love for sewing and fabrics. She drew all kinds of clothes and sewed them together with her mother. She thought of becoming a fashion designer. Her father died when she was ten, in the depths of the Great Depression that ravaged America.

Her mother had to work in the factory and little Stephanie's future did not look so bright.

When she got older, she wanted to become a GP: 'Do something good for people.' She earned a degree in chemistry and biology. But she had no money to continue her studies. She thought: I'll first work in chemistry for a few years, just for the money, and then continue my medical studies.

By chance she ended up in 1946, at the age of 23, at the chemical giant Du Pont de Nemours. She would stay there for forty years. In photos with her male colleagues, it is striking how small she was in stature, 1.55 meters, but she turned out to be the most beautiful researcher.

She herself said: 'Over the years it turned out that I saw things that other people did not see. If an investigation doesn't go the way I expect, I never give up, I fight back, I keep looking and trying to see if there isn't something…”

That's how it went on that strange day in 1964. Her team had been instructed to look for a tougher plastic to reinforce car tires. For months Stephanie Kwolek combined, mixed, heated and cooled chemicals.

One day, her jars produced a strange, cloudy, milky-white liquid instead of the clear, as it should be. She walked over to the man who had a machine for pulling the mixtures into threads.

But he said: 'There are pieces in it, they will clog my machine.' She took out the pieces and kept nagging the man to do the spin test. Out of misery he gave in and lo and behold: you could certainly draw threads from it.

It later turned out that Stephanie Kwolek had discovered a miraculous material: a fabric that was as light as a feather and five times stronger than steel. Under water even twenty times stronger than steel.

The fabric was named kevlar (an arbitrary word), best known today for its use in body armor. But Kevlar has more than 200 applications; for example, it is in radial tires, skis, and safety helmets.

Stephanie Kwolek remained with DuPont until she retired in 1986. She immediately bought a new sewing machine with her premium. She still possesses the love of making clothes and likes to work in the garden, with her father's love of nature.

Kevlar has earned DuPont hundreds of millions of dollars.

Has Stephanie become wealthy? 'No', she says, 'that's often how it goes when you work for a company. But across the street from me lives a man who works for the FBI.

Every now and then he rings my doorbell; he always has a policeman with him whose life was saved by a bulletproof vest.

And then the FBI man says, "Look, here's the woman who saved your life." The feeling of having really contributed to the well-being of humanity is more important to me than millions of dollars.'

She has since been awarded many times. In 1995, she was inducted into the U.S. Inventors Hall of Fame, as the fourth woman among 119 inventors. In addition to great gentlemen such as Thomas Edison, Henry Ford, Graham Bell and Louis Pasteur.
(See also: gore-tex, nylon, teflon, tupperware)