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Glass technology which helps keep offices and houses cool in summer and warm in winter has gone mobile by being adapted for use in automotive applications. 

Saint-Gobain Sekurit International, a 350-year-old company, is one of the top 100 industrial groups in the world, providing flat glass, high-performance materials, construction products, building distribution and packaging. It has been manufacturing car glazing products for over 80 years, and is a global Tier 1 supplier to all major OEMs. 
Automotive Industries (AI) asked Dr. Volkmar Offermann, marketing director of Saint-Gobain Sekurit International why the company decided to develop SGS ComfortSky® Automotive glazing. 

Offermann: The regulatory constraints, as well as the constant performance improvements required from their suppliers by the OEMs are a permanent challenge for glass makers. This is because the passenger’s comfort is a big concern, and the glazing has a big influence on the heat perception inside the cabin. In this context, Saint-Gobain Sekurit took advantage of the building material experience of the Saint-Gobain group to apply products already being used in the construction sector and to adapt the use of this material for automotive use. The idea was that, if you feel comfortable at home, you have the right to feel comfortable in your car as well. By extension, when the temperature is controlled by the glass, there is less load on the air conditioner, and that helps OEMs meet the European Union and United States 
regulations on fuel consumption. 
AI: How does it work? 

Offermann: The SGS ComfortSky® is a low emissive product, which has been in use in buildings for a number of years. It is a special coating applied on the glass when it is still flat. This coating acts as a thermal wall under both in summer and in winter conditions by keeping the car interior cool in summer and warm in winter. As a result, you have similar thermal properties to well-insulated glass in your house. The challenge for automotive application was to make this coated glass bendable, and able to provide the mechanical, optical, and aspect required by the regulation and the specific OEM requirements. In the automotive the situation is a little bit different than in building: the cars offering a glass roof are combined with a shutter that protects the passengers from heat, cold and light. Extensive driving tests have shown that this comfort brought by the shutter can be totally replaced by a SGS ComfortSky alone. That allows the OEM to remove the shutter, save weight, as well as gain in terms of habitability, and aerodynamics performance and CO2 emissions. 
AI: Is SGS ComfortSky ready for the market (series production)? 

Offermann: The SGS ComfortSky is ready for the market, and has been in serial production for several months since it was successfully launched. 
AI: What car models are benefiting from the new technology? 

Offermann: The two first cars equipped with a SGS ComfortSky roof are the Ferrari FF and in a totally different segment the new C4-Cactus from Citroën. This confirms that this product is not only for luxury segments, but really a product for all. It provides a high quality saving solution for the OEM. 
AI: What are the benefits to the carmaker and the end customer? 

Offermann: For the carmaker, the shutter offers a saving of three to seven kilograms. There is also a significant space saving in the mounting. They also save on costs by removing the whole shutter system (motor, fabric, structure). For the passengers, the SGS ComfortSky roof offers an equivalent of category four sunglasses, and gives the feeling of very high-tech glazing. They can enjoy the visibility given by a big panoramic roof letting light into in the cabin and at the same time not be made uncomfortable by too high luminosity, heat or cold temperatures. 
AI: How do you compare SGS ComfortSky performance in summer and winter? 

Offermann: In summer conditions, 80% of the energy is re-emitted outside the glazing, providing a real shield against heat. When a car is parked in a sunny place for hours, the passengers will enter into a vehicle which is at least 10 degrees Celsius less than in a similar car parked in the same conditions. In terms of use, this lower temperature makes a real difference and allows the driver to start the engine and go, while the driver next to him has to wait a few minutes before to be able to touch the steering wheel. Above all, the passengers will enjoy the sunglass effect looking through the glazing without discomfort or danger. Let me stress the fact that today a SGS ComfortSky roof is the best glazing solution in the automotive market in terms of heat protection. It provides a nearly 100% UV filter and rejects 80% heat coming from outside through the glass. In winter, the glass keeps the warm temperature inside and avoids heat loss. You can compare the performance to double glazing in houses. In winter, a car parked for a few hours in the cold will be warmer on entry than one which does not have SGS ComfortSky. Of course, the SGS ComfortSky still performs when the car is running as it is a passive solution – but the parking situation illustrates perfectly the performance in extreme conditions. A final advantage for tall people is that they will not have the cold or hot wall effect above their heads. This is the final argument for removing the shutter and replacing it with a glass roof in all situations. 
AI: What can we expect form SGS in the future? 

Offermann: Saint-Gobain Sekurit is working on four axes: environmentally friendly products; safety and security; creating emotional glazing; and perceived quality. All these products must be developed taking into account the major automotive constraint – at an affordable cost. Guided by these criteria over the next few months we will launch new products answering to new safety and security requirements like lead-free glazing or glazing bringing emotion and creating new atmosphere. These will be high-quality products adapted to new mobility modes and will always be focused on integration simplification. Last, but not least, we will introduce dedicated products for CO2 reduction like ultra-light glazing.Â