AutoTech Daily
May 2, 2002
The new Lincoln Navigator SUV will be the first U.S-built vehicle to use laminated glass for its front side windows, according to supplier PPG Industries. The application also is the first in the world to use PPG's thinner glass design, which allows automakers to install laminated sidelights in the same door channel used for tempered windows. The Aviator is due late this summer.
Pittsburgh-based PPG says it has provided laminated sidelights to several luxury cars in Europe and a handful of vehicles in Mexico in recent years. Europeans favor the system for its sound-deadening properties, while consumers in Mexico and other developing countries are attracted to its improved strength over tempered glass. Similar to the laminated glass used in windshields, the new sidelights sandwich a layer of polyvinyl butyral between two pieces of heat-strengthened glass. This reduces outside noise heard in the passenger compartment by as much as 6 decibels and takes potential intruders about 20 times as long to break through than traditional tempered glass, PPG says.
In the past, laminated side windows were at least 4.2 mm thick to maintain edge strength and optical requirements. PPG says manufacturing improvements have allowed it to reduce thickness to 3.8 mm—the same thickness as conventional tempered glass— by shaving 0.2 mm from each of the two glass layers. The PVB layer wasn't changed. Matching the thickness of tempered glass means the new windows can be used in existing models without redesigning the door system.
Laminated glass is about 10% lighter than the same size piece of tempered glass. The PVB layer also makes it easier to include solar reflective coatings that reduce heat loads and ultraviolet light. On the downside, laminated glass is four to five times as expensive as tempered glass—or about $20 more per window. Despite the cost penalty, PPG expects laminated sidelights to grow to more than 500,000 vehicles worldwide by 2004. PPG says it has contracts to supply the system to DaimlerChrysler, Ford and GM on 2003 models, and as a rear window for an unidentified European automaker.
Posted with permission from AutoTech Daily.
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