Rain-X kontra Ombrello,
aus der Providence Journal Company vom 19.10.97.
 

Windshield coatings do keep the rain away

By KEN MINGIS
Journal-Bulletin Staff Writer

Yes, as it turns out, using a windshield coating like Rain-X or Visionblade really does let you see out of your windshield better in bad weather.

A study conducted earlier this year by the University of Michigan's Transportation Research Institute shows that applying windshield coatings helped drivers see better in wet weather -- both during the day and at night, according to James R. Sayer, one of the institute's lead researchers.

And that, the study said, can lead to better reaction times while driving.

Sayer, in a brief telephone interview, said the "hydrophobic glass coatings," as they are known, act as wax does on a car's paint; they repel water on glass by causing it to bead up and blow off the windshield as you're driving down the street.

The repellent effect lasts anywhere from one to six months, depending on how often it rains, and can help keep windshields clear of ice, dirt and even bugs. (Roadway grit, ground into the windshield by a car's windshield wipers, tends to scrape the chemicals off, which is why they must be regularly reapplied.)

Simulated-storm testing

According to Sayer, the Transportation Research Institute study showed that drivers, on average, could see 34 percent better with coated windshields than without. He stressed the idea, however, that those results could vary in day-to-day driving conditions.

In the test, 32 drivers were seated in a car, with water and wind blown onto the windshield to simulate driving in a moderate rainstorm at 37 miles an hour with the wipers on low. The drivers then had to identify letters on a chart to determine how well they could see, Sayer said.

Results included in the study show that all of the drivers reported being able to see better, both in simulated daytime driving and nighttime driving. The study also showed that older drivers fared better than younger drivers, and said they could see better -- especially during nighttime driving conditions.

The study did not determine which of several products now on the market and available to consumers is better -- largely, Sayer said, because the chemical make-up of them is similar.

Neither did the study delve into how long the coatings last, he said, although he noted that the longer the chemicals are on the windows, the less likely they are to be effective.

A crucial difference

But that hasn't stop manufacturers from using the study to tout their products in an effort to get car and truck owners to regularly apply the coatings to their windshields.

Rain-X, which calls itelf "the invisible windshield wiper" and has been on the market for 24 years, and Visionblade, which is made by STP, are both applied in a similar manner. After cleaning the windshield, you rub the coatings onto the glass, let them dry slightly, then wipe them off with a clean cloth.

"We take the university study as being a difinitive work that confirms what we have pioneered to the world since 1973," said Howard Ohlhausen, president of Unelko Corporation, which makes Rain-X. "We have always claimed that Rain-X can make the difference between seeing and not seeing the road, other vehicles and pedestrians.

"We are absolutely delighted that a univeristy saw fit . . . to make an independent evaluation," Ohlhausen said. "The most critical finding is that it reduces the reaction time of motorists during inclement weather. . . . (That) can make the major difference between accident or no accident, life or death."

Distinguishing the proucts

Bob Howard, of PPG Industries Glass, agrees with the study's findings. PPG makes automobile glass and a hydrophobic coating known as Aquapel*, which is not available at retail but is offered through auto service stores and glass replacement shops.

"I believe it shows there is a real potential for hydrophobic glass coatings to provide better driving safety through better response time and better visual acuity -- which is the ability to see objects in the rain and in the rain at night," Howard said.

Not surprisingly, Howard argued that Aquapel* and Visonblade -- which uses PPG's formula -- work better than other products, such as Rain-X. (Visionblade also tends to be more expensive.)

He acknowledged that the products generally work the same way, but said PPG's formula lasts longer, and therefore is cheaper to use in the long run than other coatings.

Long-lasting versus user-friendly

"What it does in layman's terms is it changes the chemistry of the glass surface so that rather than being attractive to water, it's unattractive to water," he said. "So it beads up and can't stay on the glass and runs off.

"Glass . . . tends to attract water," Howard said. "This changes that chemistry and bonds to the glass.

"We've conducted both lab tests and field tests where we've compared our products with other products," Howard said. "That's why I believe our(s) offer greater potential -- because they're going to be performing for a longer period of time.

Ohlhausen, not surprisingly, begged to differ. He argued that Rain-X is better because it is easier to apply.

"That is not to say (others) don't perform, or will not do as well as Rain-X does,"he said. "To reflect on the difference between the Rain-X technology and variations thereof offered by PPG and others, it all gets down to whether a hydrophobic coating is user-friendly or not.

Why it's easy

"When we say user-friendly, Rain-X is a material that can be applied througout the year . . . as long as the surface is reasonably dry," he said. "It's unaffected by a variation in temperature and humidity.

"The other ones have a limited shelf life and they can build up," he said. "With Rain-X, you could put 22 coats on and when you're done, you still have only one (on the glass).

"And once you open theirs, you must use it within 30 minutes," Ohlhausen said. "With Rain-X, you can start and stop (the application) to your heart's content. With theirs, if you don't get it all on the first time, that's all she wrote."

* Ombrello wird in der USA unter dem Namen Aquapel vertrieben