How bullet resistant is polycarbonate?

A transparent sheet that can stop a bullet? It seems unlikely at first—more like a contradiction in terms than a practical solution. Yet polycarbonate defies expectations. Its unique combination of toughness and clarity has made it a go-to material in ballistic protection systems where visibility cannot be compromised.

Understanding how bullet resistant polycarbonate truly is requires examining its inherent properties, its role within laminated systems, and the standards that define its protective capabilities.

Why Polycarbonate Resists Ballistic Impact

Polycarbonate doesn’t stop a bullet by being harder than the projectile. Instead, its ballistic resistance comes from its ability to absorb and redistribute energy. When struck, the material flexes rather than fractures. Thus, the kinetic energy of the bullet is transformed into deformation across a wider area. This response reduces the likelihood of penetration and prevents the dangerous fragmentation typical of brittle materials like glass.

The effectiveness of polycarbonate is due to a combination of physical properties:

• Impact strength: Polycarbonate offers up to 250 times the impact resistance of glass. Therefore, it's ideal for applications where high-energy impacts are a concern.

• Elongation before failure: The material stretches considerably before tearing. Its flexing helps it absorb and dissipate energy from ballistic threats.

• Dimensional and thermal stability: This characteristic enables the panel to retain its shape and structural strength during repeated stress and the heat produced by ballistic impact.

These qualities allow polycarbonate to serve as a core material in bullet-resistant glazing, especially at lower threat levels.

How Polycarbonate Performs in Laminated Systems

On its own, a sheet of polycarbonate offers limited protection against firearms. Its true bullet resistance is realized when it’s part of a laminated structure designed to absorb, disperse, and contain the energy of ballistic threats.

Each layer in a laminate has a specific function:

• The outer layer: Disperses the initial force of impact.

• The intermediate polycarbonate layers: Deform to absorb momentum and reduce projectile velocity.

• The internal anti-spall layer: Captures any debris that could be ejected from the rear side of the panel.

By varying the number and thickness of these layers, laminates can be tailored to stop increasingly powerful rounds. In this context, polycarbonate is a key part of the system.

Thickness and the Limits of Resistance

Bullet resistance in polycarbonate depends directly on its thickness and configuration:

• At 1 inch, polycarbonate laminates are capable of stopping 9mm rounds, qualifying for UL 752 Level 1.

• At 1.25 inches, the material can stop a .44 Magnum round, corresponding to UL Level 3. This is generally the highest level of ballistic protection achieved using polycarbonate alone.

• Above 1.375 inches, protection against rifle fire requires adding materials like glass, polyurethane, or aramid fibers to the system.

The more polycarbonate is used, and the more effectively it's integrated with other materials, the greater the system’s resistance to ballistic threats.

Placement Within the UL 752 Ballistic Standard

To determine how bullet resistant a system is, it must be tested against recognized benchmarks. The UL 752 standard evaluates materials by firing multiple rounds from specific firearms and assessing their ability to stop penetration and prevent spall.

Polycarbonate glazing systems can achieve the following ballistic ratings as a standalone or core material:

• Level 1: 9mm FMJ handgun, 3 shots

• Level 2: .357 Magnum, 3 shots

• Level 3: .44 Magnum, 3 shots

Beyond these levels, polycarbonate is used in combination with other materials in hybrid systems that meet higher-level threats:

• Levels 4–5: Rifle fire, including 7.62mm FMJ rounds

• Levels 6–8: Higher-velocity rifle fire, such as from AR-15s and AK-47s

• Levels 9–10: Armor-piercing rounds, notably up to .50 caliber

Within these advanced ballistic systems, polycarbonate may not serve as the primary barrier. However it contributes significantly to the overall protection by absorbing energy, preventing spall, and reducing weight.

What to Consider When Specifying Polycarbonate for Ballistic Use

To ensure polycarbonate performs as expected, a range of design and environmental considerations must be addressed:

• UV protection: Coatings are required to prevent yellowing and preserve optical clarity.

• Scratch resistance: Hard-coated surfaces are recommended for areas with frequent contact or cleaning.

• Structural integration: Proper framing and anchoring are essential to support the laminate's weight and allow it to absorb ballistic energy.

• Threat alignment: The configuration must match the expected threat level to provide appropriate and efficient protection.

These factors help ensure the long-term reliability and performance of polycarbonate glazing systems.

So, How Bullet Resistant Is Polycarbonate?

Polycarbonate provides substantial bullet resistance when used within properly engineered laminates. It's effective at stopping handgun rounds, with systems capable of meeting UL Level 3 performance at approximately 1.25 inches of thickness. For higher-caliber threats, it maintains an important role as part of composite solutions, contributing flexibility, strength, and safety.

At Action Bullet Resistant, we design and supply ballistic protection systems incorporating polycarbonate for applications where visibility and defense must go hand in hand. Whether you're protecting a storefront, office, or secure facility, our team can help you choose the right configuration to meet your security needs. Contact us today to learn how polycarbonate can be used to protect with strength and clarity.