Successful MIL-P-25690 certification for stretched PLEXIGLAS

Stretched sheets of polymethylmethacrylate (PMMA) from Röhm now satisfy the quality requirements of US standard MIL-P-25690 for the aviation industry. Sheet thicknesses of up to 20mm (0.787") have been certified. In particular, the certification attests to the chemical resistance of the material, its impact strength (for example against bird strikes), and the fulfilment of optical requirements.

PMMA has been used for decades in areas of the aviation industry where the highest requirements are placed on the material. These include passenger cabin windows, windscreens, and cockpit windows as well as cockpits. The stretched material is superior to cast PMMA in, for example, impact resistance and chemical resistance. The sheets are produced and stretched in Weiterstadt, in the German state of Hesse. To meet the demand for materials for the aviation industry, the Acrylic Products Business Unit started up in 2018 the world's most advanced production facility for stretching of PMMA.

The plant produces sheets of sizes up to 5.0m x 3.0m (200" x 120"), which is double the normal current size. The first customers in the aviation industry have been supplied with samples of the new material since the end of 2018. As Falk Majert, head of the business unit, explains: "With this successful certification, we are consolidating our position as a leading supplier of aviation materials and a driver of innovation in the sector. We offer the customer cast as well as stretched PMMA of the highest quality from a single source. With the now certified stretched material we're opening up new design and innovation options, and thus also further growth prospects, for customers."