Trosifol® Spallshield® CPET in a class of its own when it comes to occupant protection and spall retention
Occupant protection is both a functional and ethical prerequisite in many glazing applications. Very few materials offer the performance and longevity of Trosifol® Spallshield® CPET, which is why it is seen in security and transportation applications around the world – in architecture, vehicles and railway rolling stock.
Originally developed in answer to the need for antilacerative or ‘friendly’ windshields in the automotive segment – and subsequently used by GM on 300,000 toptier cars in 1986 through 1988 – Trosifol® Spallshield® CPET is a two-layer composite structure comprising polyester (PET) film and hard-coat, which provides an inner shield that helps to protect occupants from glass spalling and lacerations.
This film is highly durable, chemically resistant, and virtually indistinguishable from glass. Because these laminates are glass/plastic composites, they combine the best features of glass with those of plastic, resulting in glazing, which is very lightweight, thin and strong.
Panel fabrication uses a standard lamination process, where Trosifol® Spallshield® CPET is laminated to a ply of PVB interlayer. As a result, the final panels also feature the enhanced functional characteristics bestowed by PVB, including post-breakage glass retention, enhanced safety from accidental impacts, long-term durability and excellent optical visibility.
One company with a broad experience of anti-spall applications is Prelco Group, which for 65 years has been designing and manufacturing innovative glazing and window solutions for commercial and institutional buildings, high-rise apartment buildings and vehicles; for both private and public sectors, including mass transit and defense.
According to Patricia McLean, Vice-President of Industrial Sales at Prelco: “One application that highlights the industry’s requirements for driver protection using a film composite is from the Montreal inter-city transit system STM (Société de transport de Montréal). The technical specification for its new subway windscreens – in cars designed and built by Bombardier – defines a custom impact requirement, the pass/fail criteria for which is that there shall be no penetration through the inner surface of the windshield by either the object striking the windscreen or any resulting glass fragments (spall).
“Toronto’s Commuter Train (GO-Transit Bi-Level Enhanced vehicle), also built by Bombardier, saw recent redevelopment too,” McLean continues, “with a small square windscreen being replaced by a much larger, Spallshield® equipped panel, which not only give the drivers a much better field of view, but also makes the trains look sleeker and more contemporary. In both instances the screens meet the U.S. Federal Railroad Administration’s 49 CFR Part 223 safety glazing standards for locomotives, passenger cars and cabooses.