Bulletproof glass is a composite material made from glass (or acrylic glass) and high-quality engineering plastics through a special processing method. It is usually a transparent material, such as PVB/polycarbonate fiber thermoplastic (generally Lexan resin, also known as LEXAN PC RESIN). It has the appearance and light transmission behavior of ordinary glass, providing a certain degree of protection against small arms fire. The thickest PC sheets can reach 136 mm in thickness and 2166 mm in width, with an effective lifespan of up to 6664 days.

Structural Composition

**Load-bearing Layer:** This layer is the first to withstand impact and break. It generally uses thick, high-strength glass, capable of destroying the bullet or altering its shape, rendering it unable to continue its journey.

**Transition Layer:** This layer generally uses organic adhesive materials with strong adhesion and good light resistance, absorbing some of the impact energy and stopping the bullet's advance.

**Safety Protection Layer:** This layer uses high-strength glass or high-strength transparent organic materials, possessing good elasticity and toughness. It absorbs most of the impact energy and ensures that the bullet cannot penetrate this layer.

Basic Classification

Based on the level of protection offered, bulletproof glass can be divided into two types: safety type and life-safety type.

Safety type bulletproof glass, after being shot, produces no shrapnel on its non-impact surfaces, posing no harm to the human body. Life-safety type bulletproof glass, after being shot, produces shrapnel on its non-impact surfaces, but the bullet cannot penetrate the glass, potentially causing secondary injury.

Bulletproof glass has different requirements for its ballistic protection capabilities depending on the type of firearm. Bulletproof glass is divided into three main series: first, aviation bulletproof glass; second, bulletproof glass for vehicles and ships; and third, bulletproof glass for banks. The thickness ranges from 18mm to 40mm.

Protective Principle

In bomb and accidental explosion events, bomb-resistant glass can minimize the direct damage caused by the extremely high load of the blast wave and the high-speed flying glass fragments, reducing the repair costs of attacked facilities or facilities around the blast center. Even under conditions where the load generated by the blast wave energy increases dramatically, several times or even tens of times, bomb-resistant glass remains impenetrable, with a glass retention value RET≈1. Once a single pane of glass (including float glass, tempered glass, and insulated glass) breaks, as long as the critical breaking pressure RET is slightly exceeded, it will quickly drop below 0.3, causing glass fragments to scatter and resulting in penetrating damage.