You may have heard the term “bulletproof” to describe glass before. You’ve probably also heard that the phrase is more correctly expressed as “bullet resistant” glass. While the fired projectiles can still damage the glass itself, this is actually by design. The more energy the glass can take from the bullet, the less there is to harm you. However, there is a little more to this type of security glass than that. Let’s take a look at the concept of one-way bullet resistant glass, and where bullet resistant glass originated from.
The humble Prince Rupert’s Drop is the first time that science had an inkling of the strength potential of glass. The drop was discovered by glass blowers in the 17th century. When molten glass is dropped into cold water, the outer shell hardens very rapidly. The inner part of Prince Rupert’s drop cools at a much slower rate. As it cools down, the inside pulls on the outside, creating a large tensile strength.
Bullet resistant glass received its second great idea from Edouard Benedictus in 1903. The chemist dropped a vial containing a solution that left a plastic layer on the glass. While the vial broke, it did not shatter at all. The origins of bullet resistant glass may have been accidental, but the research invested in since is anything but accidental.
Polycarbonate materials form the basis of most modern bullet resistant glass, the strongest of which is BallistiMAX. When glass and polycarbonate are laminated, the result is robust bullet resistant glass. Ballisitglass has created a unique blend of polycarbonate that has superior strength. Because of the way that polycarbonates are manufactured, they provide increased flexibility. Glass, on the other hand, is brittle. How these two materials work together can be exploited to great benefit.
While glass is an integral part of the product, polycarbonate and acrylic make up the bulk of the materials for one-way bullet resistance glass. The concept of “one-way” is a simple one: the side that stops the bullets needs to flatten the bullets out to increase the surface area. A flat bullet does exponentially less damage than a sharp one. Once flattened, the rest of the energy dissipates into the cracking glass and the flexible layers behind it.
Let’s flip the scenario now to the person on the other side. With BallistiMAX, the defender on the other side of the glass can fire shots that make it through the flexible layers first. Since they punch right through, the bullet is not flattened at all. The bullet, still sharp, punches through the rest of the layers. It leaves the glass with enough energy to create damage on the assailant’s side.
Bullet resistant glass should be installed in businesses where they carry items of high value such as banks, jewelry stores, precious metals processors, and firearm stores. Other places that are high risk can include places of worship, government buildings, and schools.
If you are considering installing bullet resistant glass in your establishment, call us today at 954-612-6640. We offer a wide range of security products to protect both property and people. Learn which ones suit the needs of your property best.