Bullet proof glass is made of thick glass sheet and a sandwiched layer of...................
🔬 Understanding Bulletproof Glass Construction
Bulletproof glass, more accurately known as ballistic glass or bullet-resistant glass, is not a single piece of glass. It is a strong, transparent composite material made by bonding multiple layers of different materials together. The goal is to create a material that can absorb and dissipate the immense kinetic energy of a projectile without being penetrated.
Laminated Structure: The construction is a laminate, or a "sandwich," of alternating layers of a hard, brittle material (glass) and a soft, tough material. The question asks to identify this soft, energy-absorbing interlayer.
⚖️ Detailed Analysis of the Options
Let's analyze the role of each potential interlayer material.
(c) High strength plastic
Why it's correct: This is the essential energy-absorbing component. The interlayer is typically made from a tough, transparent thermoplastic like Polyvinyl Butyral (PVB) or, for higher levels of protection, Polycarbonate.
How it works: When a bullet strikes, the outer layer of hard glass shatters, blunting the bullet and spreading its energy over a wider area. The soft, tough plastic interlayer then stretches and deforms, absorbing the remaining energy like a catcher's mitt. It also holds the shattered glass fragments together, preventing spalling. Multiple layers of glass and plastic are used to defeat higher-caliber threats.
(a) Steel & (b) Stainless steel
Why they're incorrect: Steel is used for armor plating, but it is opaque. The entire purpose of bulletproof *glass* is to provide transparent protection. Sandwiching a layer of steel would defeat this purpose entirely.
(d) Chromium plate
Why it's incorrect: Chromium plating is an extremely thin surface coating used for decoration, corrosion resistance, and hardness. It has no structural or ballistic-resistant properties and could not function as a thick, energy-absorbing layer in a laminate.
💡 Study Tips for Composite Materials
- Bulletproof Glass = A Sandwich: The most important concept is that it's a layered composite: Hard Layer (Glass) + Soft Layer (Plastic) + Hard Layer (Glass).
- Glass Shatters, Plastic Stretches: Remember the roles. The glass is brittle and designed to break to spread the impact. The plastic is tough and designed to stretch to absorb the impact.
- Transparency is Key: Any option that is opaque (like steel) can be immediately eliminated when discussing transparent armor like glass.