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March/April 2004

 2004The State of Plastic Sidelites Part IV
Vast Possibilities Exist for Polycarbonate and Trilaminate Sidelites
by Leslie Shaver

While polycarbonates do have some hurdles to cross before they are approved for use in the sidelites of new American cars, it does not mean they can’t be found in American vehicles. As a matter of fact, they can be found in some interesting places, such as sun and moon roofs, the Corvette top and the body panel under the trunk in the Mercedes C203. NHTSA even mandated them for use in the rear quarter windows in some cars. However, few American car manufacturers have taken advantage of this option as of yet.

“The criteria was that they could not be in a place where they obscured the driver’s vision,” said a source from the National Highway Transportation and Safety Administration (NHTSA). “We did allow the exception for the area behind the C pillar, but, so far, no one has taken us up on it.”

In Europe, Frank Hoefflin of Exatec said governments are allowing many more things with polycarbonates in design. One example he points to is the French company Peugot, which has used polycarbonates in some inventive ways to reclaim market share in the country. Other companies in Europe, where Hoefflin said regulators are ahead of Americans in accepting polycarbonates, are also benefiting from these plastics.

“European manufacturers are interested in pushing the design envelope,” he said. “Europeans have used polycarbonates in redesigns and as key selling points.”

Still, he admits Europeans are not allowing polycarbonates in sidelites.

For proof of what polycarbonates can do, Hoefflin points to the roof of a minivan. With glass, he said, this roof can only be straight. However, polycarbonates add to the styling potential by giving engineers the option to add curvatures to the roof—either from left or right or back to front.

“There are significant limitations for glass windows,” he said. “With polycarbonates, you can mold them into any shape you want.”

If polycarbonates could get past the NHTSA hurdles in the United States, car manufacturers may welcome them with open arms. But there are other reasons for excitement with polycarbonates, as well—specifically their potential for weight savings. In an era in which every manufacturer is attempting to make cars more fuel-efficient by reducing their weight, this cannot be discounted. 

Then there is the issue of manufacturing. Hoefflin said that polycarbonates could actually make the manufacturing process more efficient. For proof of this, he points to the backlite of the Chevrolet Trailblazer, which has a number of attachments on the glass. Many of these are put on manually, he said. However, polycarbonates would allow manufacturers to mold these parts in during the production process.

“The OEM can take some of the cost out of the manufacturing process [by using polycarbonates] because it does not have to pay workers to put attachments into windows,” he said.

Into The Future
While both polycarbonates and laminated sidelites have advanced during the past few years, there remain questions about how widespread these glazings will be utilized. While polycarbonates have NHTSA hurdles to cross, market forces dictate the future of laminated sidelites primarily.

Tom Hagen, GM’s total integration engineer for glass and mouldings, said he sees laminated plastic sidelites becoming more prevalent in high-end cars, where consumers may be more concerned about noise and would have the money to pay for the extra protection they offer.

“More and more windows in luxury cars and SUVs will come with advanced side glazing,” he said.

However, Hagen thinks competition among auto manufacturers will dictate whether these glazings eventually slide into more economical automobiles. He said it mainly will depend on the market and whether or not people with less expensive cars will care enough about noise control and the other benefits of laminated glass to pay a 400- to 500-percent increase over tempered glass for them. If one manufacturer finds there is a demand in these parts on the market, the others probably will follow.

“The question will be if you need laminated sidelites to move ahead of the competition or whether you just need them to keep up,” Hagen said.

If the market forces dictate that laminated glass becomes standard in more vehicles and polycarbonates cross their NHTSA hurdles, there is no doubt that consumers and glass technicians will see changes in the vehicles coming off the lines in the future. As for now, all they can do is become more educated about these technologies and prepare for their arrival.

Laminated Glazings May Mean Few Adjustments

With car manufacturers increasingly looking to laminated sidelites as an option in their new vehicles, you do not need a crystal ball to see that auto glass installers and repair technicians will soon have to know how to deal with these new sidelites. While laminated glass and tempered glass are very different in their structure and the benefits they offer to drivers, their effects on auto glass installers and repair technicians will be surprisingly similar to those of tempered glass.

Still, there could be some differences, even among various types of laminated glass. For instance, Dave Zenda, master auto glass installer for Klein-Dickert in Madison, Wis., noted that some of the newer sidelites he has encountered, specifically ones with thermo-paned glass, are much heavier than their tempered predecessors. This can cause some problems for installers. In one case, he said he needed two installers to set the window in the door—with one steadying the sidelite while another attached it.

This may increase labor costs for the shop. And, in a climate where it’s hard enough for shops to get anything other than a flat fee for labor, it may be difficult to convince insurance companies that these costs need to be covered.

“The problem is getting insurance companies to pay for extra time,” Zenda said. 

But Zenda admits the thickness of the glass and the PVC will vary. In fact, Solutia makes a laminated sidelite that it says is actually lighter than tempered glass. Because of this, auto glass technicians will notice little difference between the weight of these sidelites and basic tempered glass.

Another possible problem Zenda noted was that laminated sidelites would be more likely to crack if an auto glass installer tightened bolts too hard into them. However, the manufacturers have solved this problem by putting attachments onto the glass that connect to the car. 

“If you were clamping the glass directly into the door, torques would have to be monitored,” said Tom Hagen, total integration engineer for glass and mouldings for General Motors. 

One major benefit to laminated glass is that it is not as messy to install as tempered glass with fewer shards of glass hanging around after the installation, according to Steve Coyle, technical training manager for the Performance Achievement Group (PAG), an auto glass training school in Madison, Wis. 

“It will reduce the time for technicians to do the job because you don’t have to clean up all of the tempered glass,” he said. “That would be really nice because it’s time-consuming. It’s sometimes even longer than 20 minutes depending on the type of vehicle you are working on. The access inside the door can be real difficult sometimes. It makes it hard to get the glass out.”

It stands to reason that, since they are laminated like windshields, newer sidelites can be repaired. However, this is not necessarily the case, Hagen said.

“Windshields have annealed glass,” he said, “but the side glazing is heat strengthened. It will fracture much like tempered glass.”

This means repair technicians won’t be able to do much other than remove scratches.

Without having repair as a real option, auto glass shops will usually have to buy new sidelites when a laminated one breaks. As most people with glass and auto manufacturers will tell you, this can be an expensive proposition. Jay Pyper, director of Northern American market development for Solutia Inc., the St. Louis-based manufacturer of tempered interlites said OEM tempered sidelites could cost anywhere from $400 on the Chrysler Pacifica to almost $2,000 on some BMW models. For his part, Hagen estimates that laminated sidelites will be about 400 to 500 percent more compared to tempered glass. 



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