Plastic Windows to Get Closer Look

PARIS – Among the technical features of the Citroen DS5 coming to the market this fall are polycarbonate quarterlites from Freeglass of Germany, a leading contributor to renewed industry interest in weight saving.

Freeglass has 80% of the plastic-glazing market, Managing Director Rym Benyahia says in an interview, although that percentage could change rapidly with the awarding of a single project because the market segment is so small.

Freeglass says polycarbonate windows cut weight, expand design flexibility in models such as Smart EV.

Freeglass’ predecessor company, Schefenacker , started the segment in 1998 with fixed quarterlites on the Smart Fortwo. Production of that vehicle has continued for 13 years “with no problems of yellowing,” Benyahia says.

This year Freeglass, now a subsidiary of mineral-glass supplier Saint Gobain Sekurit, is celebrating 10 years in the business.

Plastic weighs half as much as glass, but the material costs more than twice as much. Freeglass and its competitors sell the process to tackle the cost problem: Clear plastic windows are made by injection molding, which permits interesting shapes that glass can’t match and permits integration of other parts.

OEM interest in polycarbonate windows has gone through three stages, says Benyahia. Interest during Freeglass’ first five years was great, especially in Germany and the rest of Europe, but tailed off as weight savings disappeared as a priority. The last new Freeglass project before the DS5 was the ‘06 Mercedes-Benz G-wagon.

The auto makers’ renewed focus on weight savings began three years ago when oil prices touched $150 a barrel and governments began tightening future fuel-efficiency rules.

“There was again an increase in interest in light solutions, and plastic can save 6-9 kg (13.2-19.8 lbs.) in a sunroof,” says Benyahia. “New contracts that have been awarded will be coming to the market soon.”

This year, Freeglass will provide not only the DS5 windows but also a wind-deflector in a German sports car, he says. Next year, Freeglass has three polycarbonate-glazing projects, including a high-volume B-segment European car.

Benyahia counts on research and development for continuing improvements in plastic windows that will keep them competitive. Main material suppliers Sabic Innovative Plastics and Bayer MaterialScience have been refining their products and selling plastic glazing to OEMs.

“We are really pushy with the chemists, looking for other transparent polymers,” says Benyahia. “We are looking for one that doesn’t need any coating. And we are working with coating suppliers.”

Freeglass uses a wet coating process that deposits a layer of silicon on the plastic so the surface is harder. While such a coating can last for 10 years or more in a fixed window, it isn’t enough to protect moving windows or those with wipers.

Freeglass also is turning toward its mineral-glass mother company for ideas.

The material suppliers use dyes to absorb solar infrared heat, says Benyahia. “But as engineers, we know that the energy has to go somewhere. We are looking for a reflective solution.

Saint Gobain Sekurit has a system of layers that block infrared. Our strategy is to be able to migrate the technology to plastic. Many demands from the electric-vehicle side associate weight and infrared.”

The EV push is fertile ground for plastic glazing because less mass means more range or smaller batteries, and less heat reaching the cabin means less demand on the air conditioning.

“The success of cars like the Smart and Mini will be a key trend to follow,” he says. “You can’t persuade people to buy electric cars without giving something extra in terms of style and attractiveness. Weight saving is there (with polycarbonate glazing), but the design features would be the most important” and design possibilities are greater with plastic.

While looking to Europe to remain the leader in plastic glazing, Freeglass believes Asia will become the next biggest market.

“Chinese OEMs and the Japanese have a very high interest” in polycarbonate glazing, Benyahia says. “In China, they are looking for a local supplier, and there are no existing valid solutions.”

So Freeglass is planning to set up there, probably through a joint venture with a Chinese supplier that knows the market.

In North America, “I am very interested in what is the strategy of Ford and General Motors,” Benyahia says. They are well-informed about plastic glazing. Their interest is not (in) weight saving, but adaptability and functionality.

“We want to stay the leader in the segment, like Saint Gobain Sekurit is for mineral glass. And we want to be global. With our mother company, we are a glazing-solution maker.”