How can bulletproof glass achieve impact resistance through material stacking?

2025-05-15 15:44:50

1、 Multi layer composite structure design

Bulletproof glass adopts a "hard soft hard" laminated system:

Outer high-strength glass (thickness 5-20mm): usually tempered soda lime glass or borosilicate glass, with a Mohs hardness of ≥ 6.5, which consumes the kinetic energy of the bullet and changes its trajectory through fragmentation;

Intermediate viscoelastic interlayer (PVB/EVA/polyurethane, thickness 0.76-3.04mm): absorbs shock waves and adheres to glass fragments, and a single layer of PVB can absorb about 30% of kinetic energy;

Inner layer tough material (polycarbonate PC, thickness 10-50mm): utilizing high elongation at break (>100%) to stretch and deform, preventing the penetration of the projectile.

2、 Energy dissipation synergy effect

Stress wave interference: The fragmentation of the outer glass causes transverse stress waves, which interfere and cancel out with the longitudinal shock waves of the warhead;

Interlayer impedance difference: The density difference between glass (density 2.5g/cm ³) and PC (1.2g/cm ³) causes shock waves to reflect and attenuate at the interface, with an energy attenuation rate of up to 60%;

Plastic deformation energy storage: The PC layer absorbs energy through molecular chain stretching, and a single layer of 10mm PC can withstand ≥ 800J kinetic energy impact.

3、 Protection level and material configuration

UL 752 Level 3: Using "12mm glass+1.52mm PVB+12mm glass+10mm PC", it can withstand 9mm handgun bullets (kinetic energy 500J);

EN 1063 BR6 level: "20mm glass x 3 layers+3.04mm PVB+25mm PC", can defend against 7.62mm rifle bullets (kinetic energy 3500J).

Summary: By combining gradient materials, the kinetic energy is gradually attenuated, and interlayer impedance matching and viscoelastic energy dissipation are key factors. The comprehensive protection efficiency is more than 10 times higher than that of single-layer glass.

Bullet Proof Glass

Thickness: 19mm,21mm,25mm,35mm,40mm,68mm,etc

Type:Composite bullet proof glass of glass and polycarbonate,one-way bullet proof glass,etc

Size:Max:2440×7000mm;Min:100×100mm

More product details:https://longboglass.com/product/20.html