Bulletproof glass, also known as bullet-resistant glass, is designed to stop bullets. Typically, it’s constructed from a strong, transparent material like polycarbonate thermoplastic or layers of laminated glass. Polycarbonate layers are often sandwiched between regular glass sheets.
When a bullet strikes, it might penetrate the outer glass layer, but the robust polycarbonate layer halts its progress before it can breach the inner glass. Laminated glass, another type of bullet-resistant glass, comprises multiple glass sheets bonded together with a liquid rubber.
One-way bulletproof glass represents an advancement in this technology, commonly used in armored vehicles. This specialized glass resists incoming fire from the outside but allows occupants to return fire through the glass.
One-way bulletproof glass consists of two layers: a brittle outer layer and a flexible inner layer. When a bullet impacts the outer layer, it shatters a portion of it, dissipating the bullet’s energy across a wider area. This slowed-down bullet is then stopped by the flexible inner layer.
Conversely, when a bullet is fired from the inside, it strikes the flexible layer first. Because the bullet’s energy is concentrated on a smaller area, it passes through the flexible layer. The brittle outer layer then shatters outward as the inner layer flexes, allowing the bullet to exit.