Dureflex® A4700 films for greater security

Bullet-resistant glass (BRG), also known as bulletproof or ballistic glass, is made from transparent materials designed to withstand bullets. Beyond protecting occupants in vehicles, bulletproof glass is essential in high-security environments, such as banks, store checkouts, government buildings, anti-intrusion applications and severe weather protection. 

The most common types of bullet-resistant glass use acrylic and polycarbonate (PC) due to their optical clarity and light weight relative to glass. 

Optical clarity in security glazing applications is essential, so the undesirable effects of hazing or yellowing of polymer materials are considered unacceptable. Aliphatic TPU interlayers offer high levels of weather resistance, maintaining their clarity throughout the lifetime of laminated transparencies. 

Patriot Armored Systems LLC. utilizes Dureflex® A4700 aliphatic polyurethane film for security glazing interlayer applications. As a leader in glass and polymer lamination, specializing in architectural, bullet-resistant, and security glazing, Patriot serves a diverse customer base including government institutions, military vehicles, and manufacturers of architectural and ballistic glazing systems. Therefore, their standards and customization requirements for weatherability, puncture and impact resistance are elevated.

Covestro developed Dureflex® A4700 to meet the high demands of the bullet-resistant glazing market, focusing on durability, UV-resistance, and optical clarity in adhesive applications for glass-clad and glass-plastic laminates including polycarbonate (PC) and acrylic (PMMA). The absence of plasticizers ensures optimal performance, while the glass-plastic clad construction helps reduce weight.

Dureflex® A4700 can be laminated via standard autoclave processing by using vacuum technology and is formulated for bonding PC-to-PC, PC-to-glass, and acrylic-to-glass laminations. The elasticity of this TPU Film allows for bridging different materials, compensating for varying temperature-related expansions.

For ballistic threats, the film’s puncture and impact resistance slows bullet penetration and retains glass shards. This feature is crucial for security glazing, protecting inhabitants from debris. 

These benefits make Dureflex® A4700 suitable for many applications, including armored vehicles, aircraft canopies, security for retail, residential, and government buildings. It's also ideal for weather-resistant architectural glazing, such as hurricane and tornado-proof windows.