Windshields and automotive glass have become a curious thing as of late. These days, even windshields are targets for advanced technology.
The problem is that light from the sun attacks on two fronts — direct solar rays that go straight through the windshield and re-radiated infrared light that doesn't escape the vehicle once it is absorbed. This second offender creates a greenhouse-like effect in the cockpit.
Ultraviolet light causes things to fade — interior components such as leather, plastic consoles and dashboard vinyl. They break down, start to decompose and become weaker from constant exposure. Next is infrared light — that's where heat comes from. And heat, in most engineering environments, is a bad thing.
Guardian Automotive deals with these basic principles daily at its new Science and Research Technology Center in Carleton, MI. The company's targeting two primary areas of technology for windshields and has developed some fairly fantastic advances. The first is in heat-reduction windshields that reduce the above-noted effects.
The other up-and-coming technology is water-repellant hydrophobic coatings, says Scott Thomsen, director of science and technologies.
Guardian's infrared reflective (IRR) SilverGuard glass has an infrared emission rate of 48% — it actually contains a thin coating of silver in the 13-layer proprietary laminate. That's a 23% reduction in the amount of light and heat introduced into a vehicle's cockpit via a more conventionally tinted windshield. This is opening up all kinds of possibilities, says Mr. Thomsen. But Europe seems to be benefiting the most from IRR and its heat-reducing, sun-blocking properties.
Europe offers the perfect environment for IRR technology for volume production. Small-displacement gasoline and diesel engines with relatively little power to spare, fewer average miles driven per year and temperate climates reduce the penetration rate of air conditioning in European vehicles.
In fact, if a European buyer specifies air conditioning, it's probably coupled with some kind of infrared-reduction glass product, says Mr. Thomsen.
Certainly Europe is where Guardian's IRR technologies are taking hold.
“It's on the current Opel Zafira, and we've been selected for the Opel Corsa, the/Porsche (SUV) — and three others are pending with European OEMs,” says Steve R. Markevich, automotive group vice president.
It appears that North America is next in line for IRR.
“In the U.S., automakers that make Windstar-like vans are looking at IRR glass so they don't have to install second air conditioning units into those vans,” says Mr. Markevich.
The National Renewable Energy Lab (NREL) in Golden, CO, also is interested in this sort of energy-reduction technology. “We're trying to impact the whole country to reduce fuel consumption and pollution,” says John Rugh, senior mechanical engineer-NREL Center for Transportation Technologies and Systems. “We haven't put out any formal documentation on it, but in vague terms, yes, we do see a reduction in peak soak temperatures with infrared reflective glass.”
“Peak soak” is the temperature that automakers have to design air conditioning systems. A reduction in peak soak means a reduction in the size and energy draw of compressors, evaporator cores and blower motors. This, in turn, leads to an overall weight savings, as well as a downstream reduction in fuel consumption and pollutants.
And fans of that wonderful aftermarket water-repelling treatment, Rain-X, take note: Guardian also has developed what it calls a “hydrophobic” windshield that is tough as nails and repels water like a duck's back.
Hydrophobic technology for side-door glass already is well represented in production vehicles. It's standard equipment, for example, on this year's Lexus GS430.
But up to this point, no one has been able to design a water-resistant windshield coating that doesn't get eventually worn away by the action of the windshield wipers, says Mr. Thomsen.
Guardian, though, seems to have made the breakthrough with a test windshield that has more than 1 million wipe cycles and no signs of coating corrosion. Diamond Guard, as Guardian calls the coating, is scratch- and abrasion-resistant because of materials and the chemical vapor deposition process by which it is produced. The biggest question seems to be what a windshield like that is worth, says Mr. Thomsen.
“We're working with an OEM to quantify chips, digs and scratches and how they play out with warranty work to determine the windshield's value,” says Mr. Thomsen. “The cost itself (for the Diamond Guard technology) won't be prohibitive.”
In the end it will be stringent cost/benefit analysis on the part of the automakers as to if and when you'll see Diamond Guard and other laminate technologies on new vehicles. But with groups like NREL and the Environmental Protection Agency lobbying for better fuel economy and less noxious effluents — and a perpetual raising of the bar, so to speak, for luxury car equipment — chances are good that windshields are about to get better.