Countless militaries, government agencies, banks, and other businesses use bulletproof glass in their efforts to safeguard staff and property. But who invented bulletproof glass?
This protective material isn’t the result of a single invention; with origins in the 17th century, it has evolved over time as scientific innovations (as well as a few happy accidents) led us to the many types of bulletproof glass we rely on today.
The Earliest Iterations of Tempered Glass
The bulletproof glass timeline begins in the mid-1600s. Named after Prince Rupert of the Rhine, Prince Rupert’s Drops were the first iteration of fortified glass. Scientists found that a rapid hardening effect occurred when dropping molten glass into cool water, resulting in teardrop-shaped bits of glass. The rounded end of the teardrop was incredibly strong and able to withstand impact.
The drops, while lacking useful applications themselves, did indicate that glass could be fortified, inspiring further research into how to improve glass’ durability and strength. In 1935, Rudolph A. Seiden received a tempered glass patent. This advancement in tempered glass served as an initial step in ultimately developing bulletproof glass for high-impact applications.
The First Iteration of Laminated Glass
French chemist Edouard Benedictus accidentally discovered laminated safety glass in 1903—a discovery that paved the way for modern bulletproof glass.
While performing experiments in England, Benedictus dropped a glass vessel containing a liquid nitrate solution. Instead of shattering as expected, the beaker merely cracked. The solution had created a layer of plastic within the flask, preventing the glass from shattering. In 1909, Edouard Benedictus filed a patent in France for laminated safety glass, and in 1914, he filed a patent in the U.S.
In the World Wars, the military used his technique to create laminated, somewhat bullet-resistant glass. Though it wasn’t fully bulletproof, manufacturers utilized laminated safety glass in World War I for plane windshields, aviation glasses, and gas masks. By the end of WWII, high-durability safety glass was developed for rugged applications in warzone transport vehicles.
The First Patented Bulletproof Glass
While tempered glass is strong and laminating the glass reduces the explosion of glass shards, it is still tough to make a usable bulletproof product with just these three ingredients. The number of layers and the resulting thickness make it prohibitively heavy for most applications.
To get around these limitations, scientists began experimenting with alternatives to glass. In the 1930s, a chemist created the first acrylic resin, and in the 1950s, two polymer chemists independently developed polycarbonate. These plastics are both transparent alternatives to glass, with different properties that allow them to better disperse a bullet’s kinetic energy.
In 1982, the first U.S. patent for bulletproof glass was officially granted to Jacques Sauret and Gerard Grosse. The authors described their bulletproof pane as “a substantial improvement in the resistance to impacts over other bullet-proof panes.” The patent describes a bulletproof window made up of several layers, including multiple laminated panes of glass using a film of polyvinyl butyral (PVB), at least one sheet of polycarbonate, and a relatively thick layer of PVB.
This configuration is the basis for modern bulletproof glass.
Modern Bulletproof Glass
Today, bulletproof glass is often made of layers of tempered glass, polycarbonate, or acrylic resin, sandwiched together with sticky urethane films. These layers are glazed together in a high-pressure oven called an autoclave.
There are many different styles of modern bulletproof glass based on application and protective capabilities. There are different levels of transparency and light transmission, tinting, one-way mirrors, and more. Today, consumers have more effective, beautiful bulletproof glass options than ever before.
Depending on the application and level of ballistic protection, the thickness and weight of bulletproof glass can still provide challenges for both installation and overall structural engineering. However, as technology and science progress, panes of bulletproof glass have gotten thinner and easier to work with, but there can be trade-offs to these advancements. Working with an experienced bulletproof glass provider like Bullet Guard is a great way to ensure you’re getting the protection you need without compromising structural integrity or aesthetics.
If you are interested in adding ballistic protection to your facility, take a deeper dive into the different bulletproof window glazing options by downloading our free infographic, Bulletproof Glazing 101. This handy guide will help you understand the properties of different types of modern bulletproof glass.
Bulletproof Glass and Barrier Products From Bullet Guard
At Bullet Guard, we design, manufacture, and install standard and custom bullet-resistant and bulletproof products, using the latest in ballistic barrier technology. We are industry experts on the various styles of bulletproof windows, doors, enclosures, transaction systems, and fiberglass panels.
We understand that most ballistic barriers require a custom solution, and offer unparalleled customer service to help our clients choose the best products for their application. It can be challenging to choose the right ballistic protection that maximizes safety, cost-efficiency, and aesthetics, so please don’t hesitate to reach out to us with any questions. Contact us today to learn more about our fabrication capabilities or to request a quote.