Mothers of Invention (Part 1)

May is National Inventors Month. In Part 1 of our two-part Mothers of Invention blog, we present three remarkable women inventors whose ideas have become part of our everyday world.
From the mundane to the complex, their inventions prove that no idea is too small to make a difference. Read on to be inspired! And check out our previous blogs on Chieko Asakawa, Josephine Cochrane, Katalin Kariko, Kitty Perkins and Vesta Stoudt – all remarkable women who made remarkable inventions.

Changing the World One Diaper at a Time: Marian Donovan (1917-1998)

In a world before disposable diapers and modern washers and dryers -- before the 1960s -- life with baby meant piles of dirty laundry. Nappies, as they were sometimes called, were rectangles of cotton cloth which were neither leak nor odor proof. Changing baby usually involved a change of clothing and often bedsheets as well.
Starting around the late 1940s, some mothers, against their doctors’ advice, put rubber pants over their baby’s nappies to avoid leaks, but rubber was rough on an infant’s delicate skin and often caused rashes. In 1946, Marian Donovan, the daughter of an inventor father and a mother of two and ultimately three children living in suburban Westport, Connecticut, thought there had to be a better solution.

One day the lightbulb in her head went off as she stood in her bathroom. Looking at her shower curtain, she thought, why not use a lighter waterproof material to contain the mess inside the diaper? She began testing her idea by cutting up shower curtains and whipping up designs on her sewing machine.

It took a few years of experimenting during which she visited a hospital in New York City to measure babies. Her friends’ babies became beta testers for the prototypes of her designs. She tried a variety of materials before settling on a moisture proof parachute nylon.

The final beta version had an insert for a cloth diaper and snaps around the waist, eliminating the need for “safety pins,” which despite the name, were tricky to use on squirming babies.

Donovan took her idea to manufacturers who were making the rubber pants, but they brushed her off. As she told Barbara Walters in a 1975 interview, “I went to all the big names that you can think of, and they said ‘We don’t want it. No woman has asked us for that. They’re very happy, and they buy all our baby pants.’” Their ‘thanks- but- no -thanks’ response was no surprise given the fact that men ran manufacturing companies and most men never changed diapers.

Having grown up in an inventor family, Donovan was familiar with rejection. So she wasn’t deterred. With her father’s help and advice, “I went into manufacturing myself,” she said.

Donovan did her own marketing and sales as well. In 1949, Donovan’s “boater” diaper cover debuted at Saks Fifth Avenue in New York City. Sold in four sizes and three colors for $1.95, the ads with a drawing of a happy baby, proclaimed, “Mothers! The Boater is a seep-proof diaper cover…the three-dimensional boater is shaped to keep the moist diaper from pressing against a baby’s skin. Easy adjustable snaps, four inner flaps which hold a diaper in position with a pin. Easy to launder.”

One year later, after more than a million dollars in sales, the product was such an unexpected hit that retail execs were nearly speechless. As the astonished president of Saks wrote to Donovan. “It is not often that a new innovation in the infants wear field goes over with the immediate success of your boaters.”

In 1951, two years after its introduction into the market, Donovan was awarded a patent for her creation. Later that year she sold her invention to the Keko Corporation for $1 million, the equivalent of more than $10 million today.

Having figured out the leakage problem with a waterproof pouch, Donovan wanted to improve the diaper itself. Her next invention was a paper diaper, but again her idea was dismissed and ridiculed by paper manufacturers who called it “unnecessary and impractical.” In 1961, Proctor and Gamble and engineer and inventor Victor Mills bought her idea and went on to create Pampers, the first widespread disposable diaper on the market. Today 95% of American parents use disposable diapers which is a multi-billion dollar industry.

Marian Donovan’s inventive genius didn’t begin and end with the diaper. By the time she died in 1998, she was the holder of 20 patents for inventions that included a dental floss, a zipper tag and a clothing organizer. In 2015, she was inducted posthumously into the National Inventors Hall of Fame.

The Mother of Kevlar, A Magic Fiber that Saves Lives: Stephanie Kwolek (1923-2014)

Nearly six decades ago, Stephanie Kwolek invented Kevlar, a wonder fiber that is best known as the lifesaving protective material in bulletproof vests worn by soldiers and police officers. It’s still considered one of the most versatile, tough and adaptable materials ever made and is used in hundreds of consumer and industrial products. Yet most people aren’t aware of how it works and few know about the woman who created it.

Like most inventions, the creation of Kevlar began by trying to solve a problem. In the 1960s, radial tires were the heavyweights of the tire industry. Unlike the original rubber tires, a ring of steel was added to radials to make them tougher. Radials also had thicker tread, so they lasted longer and could also withstand the heat generated by long rides.

But steel, the very thing that made radials superior, was heavy. It also slowed down the car and often created a rougher ride. A decade before the gas crisis of the early 1970s, there were already concerns about gas shortages and fuel economy. The challenge was how to replace the steel with something lighter.

In 1965, Stephanie Kwolek was halfway through her 40-year career as a chemist for DuPont, a big chemical company best known for inventing Nylon®, the first synthetic fiber. Born in a suburb of Pittsburgh, Kwolek had wanted to be a fashion designer and teacher at one time before she fell in love with science and chose to study chemistry at the Carnegie Institute of Technology. She wanted to be a doctor, but with no money for medical school, she accepted what she thought was a temporary job at DuPont, investigating the relatively new field of polymers. Fascinated by the fibers, she forgot all about becoming a doctor and the temporary job eventually turned into a career. Polymers are substances comprised of large molecules that bond together in a chain-like chemical structure. Wool, silk, DNA, proteins and cellulose are naturally occurring polymers. Nylon®, Teflon,® and most plastics are synthetic polymers created in labs.

At DuPont’s Experimental Station in Wilmington, Delaware, her bosses asked Kwolek to find the next generation high performance polymer that would create a new and improved radial tire. She took four common elements, carbon, hydrogen, nitrogen, and oxygen and began experimenting with them in her lab. In one of her attempts, she created a thin milky solution that became shiny when stirred. It was unlike the clear syrupy texture of the polymers she had worked with. Another chemist might have tossed the solution out, but instead, Kwolek’s curiosity drove her to keep working with it.

Normally, the next step in polymer development would be to convert the liquid polymer into fibers. To do that, Kwolek needed to wet-spin the solution in a machine called a spinnert. The liquid is forced through tiny holes, creating strands which are then spun. It’s much like how cotton candy is made but instead of spinning sugar, molecules are rotating at super high speeds.

The technician who ran the spinnert objected to her request to use the machine. He contended the solution was too watery and thin to be spun. Even though Kwolek had filtered the solution, he thought there were particles in the solution that would clog the machine. He finally relented and the results astounded everyone.

“It spun beautifully. It was very strong and very stiff, unlike anything we had made before,” Kwolek said in an interview for the Boston Museum of Science in 1996. “I knew that I had made a discovery! I didn’t shout Eureka! But I was very excited…we were looking for something new, something different and this was it!”

More research found that this remarkable solution Kwolek created had unique superpower properties. Kevlar® is five times stronger than steel wire yet is lightweight. It can withstand temperatures up to 450F degrees before melting and temperatures as low as – 320F degrees; it resists acid, water and can tolerate exposure to ultraviolet radiation.

All these properties made it perfect for an array of military, industrial and consumer products that would eventually be developed, including space suits, space shuttle components, aircraft bodies, ship hulls, construction materials, first responder and military clothing, gloves, shoes and equipment, welder’s gloves, skis, tennis racquets and motorcycle helmets.

Out of all the applications using her invention, Kwolek says she is most proud of the Kevlar bullet proof vest that has saved thousands of lives of police officers and soldiers since it was introduced in 1976. “I was fortunate enough,” she said, “to do something that would be of benefit to mankind.”

For many years, until she retired in 1986, Kwolek led DuPont’s Polymer Research team. In 1966, she and her colleague, Paul Morgan. were awarded a patent for Kevlar®. In 1995, she was inducted into the National Inventors Hall of Fame and awarded the National Medal of Technology.

The Mother of the Coffee Filter: Melitta Bentz (1873 –1950)

If you lived more than a century ago, making coffee at home was often a hot mess. There were no such things as paper filters until 25 year- old Amelie Auguste Melitta Bentz, a homemaker and mother of three children in Dresden, Germany came up with the idea.

In the early 1900s in Europe and the United States, the two most popular ways of brewing coffee were either through a percolating process or boiling the coffee in cloth filters – both unsatisfactory methods that over-extracted the flavor out of the beans, leaving a bitter taste and left grounds floating in the liquid. Brewing was a pretty primitive process and cleaning up the grit and grounds in the pot was a chore Bentz detested.

Like the millions of Americans today who can’t live without their daily caffeinated buzz, Bentz was a coffee lover. She asked herself: what would it take to get a clear and robust cup of coffee?

One day, as the story goes, she ripped off a piece of her son’s ink blotter, a thick absorbent paper used to dry ink, and fashioned it into a makeshift filter. She took a brass pot, punched holes into the bottom, placed the blotter filter into it, added coffee grounds and placed the pot over a larger pot before pouring boiling water into the contraption.

The coffee that dripped into the pot was closer to what she was dreaming of: clear and free of any coffee grounds and with a strong, aromatic flavor. Best of all-- there were no messy grounds to clean-up. In one stroke, Bentz had a cup of clean coffee by developing new method of making coffee: drip brewing. This is the way most of us make coffee at home today.

She shared her “perfect coffee enjoyment” with friends and family. In July 1908, she filed and received a patent from the Berlin Patent Office for a coffee filter with a domed underside, recessed bottom and inclined flow holes." The patent launched her entrepreneurial venture, a company, called “M. Bentz.”

Bentz was the daughter of a bookseller and publisher and granddaughter of brewery owner. She knew what it took to start a business. She found filter paper and began making 50 filters in the family’s five room apartment. Her husband, a department store manager in Dresden, set up a display with demonstrations on how the filters worked. Her sons filled a handcart with filters and accompanied Bentz as she went from store to store marketing them.

It didn’t take long for people to become fans of Bentz’ coffee filters. The homegrown business became a bona fide operation with employees making filters and filling orders. Bentz continued to innovate. Her next inventions were a ‘pour over’ kit consisting of a metal water distributor, a filter holder and sieve. The simple paper filter wasn’t just a game changer for making coffee at home. Drip and pour over coffee ultimately replaced percolation in coffee shops, restaurants and led to the coffee renaissance of modern-day culture around the world.

Bentz’ company prospered for about a decade before the first of two world wars disrupted its operations. During World War I, paper became scarce and imported coffee beans were banned in Germany. Her husband and one of her sons were drafted to fight. In World War II, the government took over her manufacturing plants for wartime production. Despite the struggles, the company never dissolved and after 1945, it revived. When Bentz and her husband retired from day-to-day operations, she turned it over to her sons. The company patented its cone-shaped paper design and the iconic red and green graphic logo now associated with all Melitta products today.

Family members still run the billion-dollar global company which produces 50 million filters a day along with coffee, coffee makers and related products. Thanks to Melitta Bentz, millions of coffee lovers around the world enjoy a smooth cup of joe every day.

© 2024 Alice Look

Executive Producer, Remarkable Women Stories