Accidental Invention: Kevlar

While often associated with high-stakes industries like defense and aerospace, Kevlar has been used in a variety of products, including tires, gloves, sports equipment, and more. The fibrous material that began as an unexpected discovery in a laboratory has gone on to save lives, transform industries, and inspire engineers around the world.

Kevlar, a super-strong synthetic fiber, is a key component in everything from bulletproof vests to racing sails. Kevlar’s durability and versatility make it a go-to material for improving product performance and safety. The story of Kevlar is a compelling blend of scientific curiosity, accidental discovery, and valuable innovation.

An Unexpected Solution

In the mid-20th century, chemist Stephanie Kwolek was employed by the DuPont Company to work on projects involving polymers and low-temperature condensation processes. At one point, she was tasked with finding a new variety of lightweight, durable, and heat-resistant fibers to replace existing steel wires in car tires. During her research, she worked with synthetic polymers (or polyamides), dissolving them in solvents and then running the solution through a machine that would spin it into fiber.

One day in 1965, during her experimentation, Stephanie got an unexpected result. Instead of the typical thick, transparent polymer solutions she had grown accustomed to, this new solution was cloudy and watery. She then spun the mysterious substance and consequently created one of the strongest fibers the world had ever seen.

A Fiber of Many Uses

Following the discovery of Poly(p-Phenylene) Terephthalamide and its valuable traits, DuPont began commercially producing the product under the name Kevlar. While it became a component in radial tires as originally intended, the material also found its way into numerous other applications. Due to the fibers’ impressive toughness (up to five times stronger per weight than steel), durability, and heat-resistant qualities, Kevlar proved useful in other industries, such as defense, aviation, and construction.

Today, one of Kevlar’s most common applications is in protective gear. With its incredible tensile strength, heat tolerance, and resistance to penetration, it has been used to make bulletproof vests, work gloves, and firefighter suits. Kevlar’s remarkable qualities are also used in racecar tires & brake pads, parts for aircrafts, spacecrafts, and boats, and sports equipment like medicine balls, mountaineering ropes, and tennis racquets.

Weaving the Future

Over the years, scientists and engineers have pushed the boundaries of Kevlar’s capabilities. Different formulations and treatments have been developed to enhance its resistance to chemicals, flames, and abrasion, making it suitable for an even wider range of applications. DuPont continues its commitment to invest in constant quality improvements.

As we look to the future, Kevlar’s potential seems limitless. Researchers are exploring ways to integrate the fibers into wearable technology, medical devices, and even lithium-sulfur batteries

Kevlar’s journey from a serendipitous laboratory discovery to a global engineering staple is nothing short of remarkable. With ongoing research and development, the future of Kevlar holds promise for even more groundbreaking applications thanks to its impressive durability and versatility.

If you enjoyed this accidental invention story, you may be interested in reading about Safety Glass, Super Glue, and Silly Putty.

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Accidental Invention: Safety Glass

Safety glass is commonly used in various applications where human safety is paramount. You’ll find it in vehicle windshields, architectural windows, shower enclosures, and computer monitors. As prevalent as this material has become, it’s a wonder to think it was stumbled upon by accident over a century ago.

We interact with glass daily, whether through our windows, eyeglasses, or smartphones. It’s a material so ubiquitous that we often take it for granted.

But safety glass is not your typical glass. Unlike regular glass, which shatters into sharp, dangerous shards when broken, it is designed to minimize injury in case of breakage. It does this by breaking into small, relatively harmless pieces or holding them together in a single sheet despite being cracked.

A Clumsy Discovery

In 1903, a French chemist named Édouard Bénédictus was working with a flask that had contained a dried residue of an alcohol solution of collodion. When he accidentally dropped the flask, he was surprised to see it didn’t shatter into shards as expected. Instead, it broke but held together in one piece.

Bénédictus’s discovery spurred further research into developing this newfound “unbreakable” glass. By 1909, he patented a product he called “triplex,” which consisted of two sheets of glass and a film of cellulose nitrate in between. Eventually, the middle layer was replaced by polyvinyl butyral (PVB) due to its improved strength and ability to maintain clarity. This highly durable material soon took shape as one of the main types of safety glass used today.

Different Types of Safety Glass

Laminated and tempered glass are two distinct types of safety glass, each with its own unique characteristics and advantages. The choice between the two depends on the specific safety and structural requirements of the application.

Laminated Glass

Laminated glass is constructed by sandwiching a layer of vinyl between two or more layers of glass, making it resilient and able to hold together when shattered and preventing it from breaking into sharp, dangerous pieces.

It excels in situations where maintaining the glass’s integrity upon impact is crucial, such as with automotive windshields, architectural windows, and glass doors. It provides protection against collisions and forced entry and even offers sound insulation. Laminated glass maintains its clarity even when cracked or shattered, making it ideal for architectural applications.

Tempered Glass

Tempered glass is made by heating regular glass to a high temperature and then rapidly cooling it, creating internal stresses that make it four to five times stronger than untreated glass. It is strong and designed to break into small, relatively harmless pieces when subjected to significant force, minimizing the risk of large, injury-inducing shards.

This type of glass is often used in applications where safety is important but maintaining structural integrity is not a primary concern. It’s commonly found in shower enclosures, phone screens, and automotive side and rear windows. Tempered glass is more resistant to scratches and other minor damage, making it suitable for everyday applications.

Applications of Safety Glass

Safety glass has become a staple in the construction and manufacturing of many of the items and structures we encounter every day. Some of the most common uses of it are:

1. Automotive Windows and Windshields: Car windshields are a prime example of safety glass. They are designed to stay intact in case of impact, while the passenger windows are designed to break into smaller, less harmful pieces, reducing the risk of injuries during accidents.

2. Large-Scale Architecture: Glass panels and windows in skyscrapers and public buildings use safety glass that can handle severe weather and accidents. It can also be used indoors for flooring, handrails, and viewing partitions.

3. Bulletproof Glass: In situations where extra durability is required, tempered and laminated glass can be combined to create bulletproof glass resistant to ballistic impact. This might be found in banks, government buildings, and military vehicles.

4. Commercial Businesses: Stores often employ safety glass in their doors, windows, and display cases to protect their spaces and expensive merchandise, such as art and jewelry, from potential damage and theft.

5. Residential Buildings: In houses, safety glass can be found in sliding doors, shower enclosures, and skylights. It can also be used in appliances such as oven doors, refrigerator shelves, and computer monitors.

From protecting us on the road to safeguarding us from architectural mishaps and potential injuries, safety glass has become an invaluable material in various applications. As we gaze through our windows, glance at our smartphones, and drive our cars, we can appreciate the hidden safety net that this ingenious invention provides, all thanks to one chemist’s accidental discovery over a century ago.

If you enjoyed this invention story, you might also like these about automatic doors, vending machines, and flushing toilets.

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Accidental Invention: Potato Chips

WARNING: Reading this article may incite a ravenous craving for potato chips. Viewer discretion is advised.

The crunchy, salty, irresistible snack that you know and love was first created nearly two centuries ago. Potato chips are said to have originated from an interaction between a picky restaurant patron and an irritated cook… But is that really where they came from?

The Legend of the Salty Chef

As the story goes, Native and African American chef George (Speck) Crum worked at Moon’s Lake House in Saratoga Springs, New York. One day in 1853, he encountered a particularly fussy eater. Cornelius Vanderbilt had ordered fried potatoes, which he then sent back because they were cut too thick. George, in the act of spiteful pettiness, proceeded to slice a potato as thinly as possible and fry it to a crisp… And Cornelius loved it.

As fun as this story is, historians have mostly debunked it. George Crum still, however, often receives credit for popularizing the snack, as he continued to serve them to enthusiastic patrons.

George’s “Saratoga Chips” quickly became a hit around town and then beyond Upstate New York. In 1860, the chef opened his restaurant, Crum’s House, where each table was served a delicious basket of his famous potato chips. The delicious crisps eventually became quite sought-after throughout the U.S., with the first “Saratoga Chips” being sold in grocery stores in 1895 by William Tappendonby in Cleveland, OH.

Other Cooks in the Kitchen

Over the years, other possible origin stories of the invention of the potato chip have surfaced.

George Crum’s coworker and sister, Catherine Adkins Wicks, also claimed that she was the true inventor of the potato chip. In some versions of the original story, she is said to have been the one who served the thin crips to Cornelius Vanderbilt. In another, Catherine was allegedly peeling potatoes when she accidentally dropped a slice in a pot of boiling fat.

Another Moon’s Lake House employee, “Eliza, the cook,” was claimed to have been making chips as early as 1849. A New York Herald article from the time said her “​​potato frying reputation is one of the prominent matters of remark at Saratoga.” Other restaurant individuals credited with the invention include the owners, restaurant manager Hiram Thomas, and several other cooks.

A different story from Smithsonian Magazine reports that “the earliest known recipe for chips dated to 1817 when an English doctor named William Kitchiner published The Cook’s Oracle, a cookbook that included a recipe for “potatoes fried in slices or shavings.” So, historians have largely agreed that we may, unfortunately, never know the true origin of the chip.

You Can’t Eat Just One

As you can probably guess, the popularity of potato chips grew exponentially, and recipes and production continued to evolve.

In the early 1920s, Herman Lay (name sound familiar?) began making his potato chips and selling them out of the trunk of his car. As he began commercializing the product, rumors spread that the chips had an aphrodisiac quality, which simply bolstered his sales even more.

Smithsonian Magazine also reports that “In 1926, Laura Scudder, a California businesswoman, began packaging chips in wax-paper bags that included not only a ‘freshness’ date but also a tempting boast – ’the Noisiest Chips in the World.’” The new packaging design helped the snack stay fresher and crispier for longer, making them even more popular and allowing them to be mass-marketed.

It wasn’t until the 1950s that potato chips started seeing flavoring, thanks to Irishman Joe “Spud” Murphy. With his founding of Tayto, he developed a manufacturing process that created some of the most popular flavors we still know and love: Sour Cream and Onion, Barbecue, and Salt and Vinegar.

Today, Americans consume about 1.85 billion pounds of potato chips each year, supporting an estimated $10.5 billion industry. Because, in the words of Lay’s 1961 spokesperson Bert Lahr, “You can’t eat just one!”

If you enjoyed this accidental invention story, you might also like the ones about silly putty and Corn Flakes.