Connecting with the Future:
Clear Views Ahead
EVONIK WILL MAKE POSSIBLE MUCH BIGGER WINDOWS IN AIRPLANES AND HELICOPTERS—SO THAT PASSENGERS AND PILOTS CAN SEE JUST AS MUCH AS PEOPLE IN A CONVERTIBLE. FOR THAT REASON, IT’S BUILDING THE WORLD’S MOST MODERN STRETCHING AND POLISHING PLANT FOR POLYMETHYL METHACRYLATE IN WEITERSTADT, GERMANY.
Spectacular sunrises over the African savanna, millions of lights illuminating New York City at night, white clouds piled up like luscious towers of cotton candy—today only the passengers who are sitting next to an airplane’s window can enjoy breathtaking sights like these. Their neighbors sitting along the aisles can only do their best to imagine these spectacular views. That’s because normal airplane windows are only 29 centimeters high.
Airplane manufacturers now aim to change that very soon. In their concept studies of the airplane of the future, all the passengers will have an unobstructed view over the clouds. In their technical visions, the designers are already seeing fully glassed-in planes flying through the air. From inside, the passengers and pilots can observe their surroundings unhindered through gigantic panoramic windows. However, it will still take some years for these visions to be realized. “Today there’s already a definite trend toward bigger cabin windows in passenger planes,” says Martin Krämer, who heads the Acrylic Products Business Line at Evonik. For example, Boeing has enlarged the windows of the current model of the Dreamliner by two thirds—to a height of 48 centimeters. And that’s only the beginning.
Outstanding mechanical and optical properties, low weight, and easy processing: The materials used in the aerospace industry must withstand extremely high levels of stress. That’s why a special kind of PLEXIGLAS * sold under the ACRYLITE trademark in the Americas is often used for the windows of airplanes and helicopters—and this has been the case for decades. In simple terms, these windows are made of cast PLEXIGLAS, which is elongated in a time-consuming and very complex process. The technical term for this is “stretching.” Evonik is one of the leading producers of the necessary intermediate product.
In the future, Evonik will also take over the stretching and polishing process, thus making much larger windows possible. That’s yet another example of the smart way the Group is organizing its PLEXIGLAS® business. In Weiterstadt, Germany, Evonik is investing double-digit millions of euros in a new stretching and polishing facility for PLEXIGLAS® materials for aircraft. Production is scheduled to begin in early 2018.
At the moment, the industry has reached its limits regarding the size of large airplane windows. Currently, the biggest available stretched polymethyl methacrylate (PMMA) panels measure only 2.5 by 2.5 meters. Each of these panels is cut into several windows for passenger airplanes. However, this format is too small for producing large panorama windows or heavy-duty cockpit windshields in a single piece.
Evonik will soon become the first and only company in the world to market panels that are double this size—up to 3.7 by 5.4 meters—and deliver them directly to airplane window producers. As a specialty chemicals manufacturer, it will thus create a key prerequisite for the production of panorama windows for aircraft.
What’s more, the larger panel format will enable manufacturers of conventional aircraft windows to produce almost twice as many windows from a single panel. That makes economic sense. “We are rounding out our product portfolio as a full-service supplier of cast and stretched PMMA panels for the aerospace industry and positioning ourselves as a leading producer of polymer materials and intermediate products,” explains Roland Mickal, who heads the Transportation market segment in Evonik’s Acrylic Products Business Line.
The current aerospace-industry growth rates are attractive for Evonik. According to estimates, the four biggest producers of passenger aircraft, taken alone, will deliver approximately 30,000 new airplanes to their customers by 2031. That’s because more and more people all over the world can afford to fly away on vacation or are flying on business trips.
In the stretching process, the blocks of PLEXIGLAS® are first heated up and then stretched out with the help of clamps. This expands one square meter of PLEXIGLAS® into a panel measuring three square meters. Subsequently the cooled-off material is cut and polished. “The new facility will be the most modern one of its kind in the whole world. Thanks to our technology leadership, we will be able to offer our customers optimized products in the future,” says the Evonik expert Roland Mickal.
In addition, the stretched PLEXIGLAS® panels from Evonik will be extremely uniform. According to the experts, their thickness tolerance will be greatly improved. This is a value that indicates the extent to which a material’s thickness deviates from a desired target value. The smaller the deviations and the more constant this value remains, the more uniform are the technical properties of the material. There’s also another factor regarding airplane windows in particular: The lower the thickness tolerance is, the more lightweight are the windows and thus the entire airplane—and the less kerosene is consumed. That makes flying in a panorama jet not only more fun but also more environmentally friendly.
* Two brands, one product: Evonik is a worldwide manufacturer of PMMA products sold under the PLEXIGLAS® trademark on the European, Asian, African and Australian continents and under the ACRYLITE® trademark in the Americas.