© Evonik/Photographer Uwe Feuerbach

“Promoting innovations in the aviation industry”

In the future, larger PLEXIGLAS® sheets for aircraft glazing will provide passengers with a better view. Additionally, they increase the production efficiency of traditional cabin windows.

Evonik is investing in a new stretching and polishing line in Weiterstadt and, starting in 2018, will be delivering PLEXIGLAS® sheets for the aviation industry that are larger than what is currently on the market. During an interview, Martin Krämer, Head of Acrylic Products division in the Performance Materials segment, explains which opportunities this investment provides.

PLEXIGLAS® takes off

With its PLEXIGLAS® aviation materials, Evonik has been one of the worldwide leading manufacturers of this segment for more than 80 years. Well-known aircraft manufacturers have been using the product of the Essen-based company for a long time. Due to its high optical quality, low weight and good processability, PLEXIGLAS® is traditionally used in cabin windows of commercial aircrafts, cockpit windows in aircrafts and helicopters.

Evonik already ranks among the leading manufacturers of aviation materials. What are your goals with this new plant?

Martin Krämer: We are investing in a growing market with a highly specialized product portfolio. Formerly, we only delivered the primary product for stretched sheets. With the new plant, we will also be able to stretch and polish the sheets ourselves and will thus become a full-service provider of cast and stretched PMMA sheets for the aviation industry. With this step, we are shoring up our position as the leading manufacturer of polymer materials and intermediates. Therefore, this investment is the next logical step for us. It enables us to effectively pursue our strategy in the Acrylic Products business line – after all, the aviation industry is recording attractive growth rates.

However, there are of course already other suppliers for these products. What is the unique benefit customers have from your new plant?

Krämer: For one, we increase delivery assurance. The industry currently has a growing demand for stretched PMMA sheets but is facing limited capacities of the providers on the market. With the new production plant, our long-term experience in this field of application and our particular PLEXIGLAS® expertise we can support our customers’ growth and drive innovation in the aviation industry together with them. After all, the industry has currently reached its limit when it comes to large-scale glazing.

Stretched PLEXIGLAS®

Materials used in aviation must endure extremely high strain. Thus, a special type of PLEXIGLAS® is used in aircrafts and helicopters. In simple terms, this means that certified sheets from cast PLEXIGLAS® are elongated or stretched in a highly elaborate and complex process. The advantage of stretched PMMA sheets is that they have improved impact resistance and increased chemical stability.

Stretched PMMA sheets are currently only available in the industry at a maximum size of 2.5 by 2.5 meters.

Krämer: That is true. For passenger aircrafts, such plates are cut to produce several windows. However, this size is still too small for panoramic windows and challenging cockpit windows made of one piece. As of 2018, we will be able to provide our customers with the largest plates worldwide – at a size of up to 3.7 by 5.4 meters. With this courage for further development, we are creating an important precondition for the construction of panoramic airplanes. That is a significant development and a good example of how we use our passion for our products to bring our vision “Evolution in Acrylics is our Passion” to life.

How do your customers benefit from this?

Krämer: There is a clear trend towards larger cabin windows in commercial aircrafts. With our new formats, we enable extra-large glazing for aircraft windows for the first time. Of course, the new formats also allow larger designs for hoods and windshields. We also help our customers in making their production more efficient.

Easy to process

The stretched PLEXIGLAS® sheets will be particularly even. Experts refer to it as a significantly improved thickness tolerance. This figure shows how far the thickness of the material deviates from a desired nominal value. The smaller the deviation and the more consistent the figure, the more even are the technical properties of the material and the simpler it is to process.

How so?

Manufacturers of conventional aircraft windows can then produce more windows than before from a single stretched plate. This is economical for our customers and thus a true benefit that we can offer in addition to the actual product. Just as we also offer the option of larger designs for hoods and windshields.