Evonik is investing several million euros — in the double digits, in fact — in a new production facility to make high-performance polymethacrylimide (PMI) foam for fiber composite cores manufactured in Darmstadt, Germany. At the same time, parts of the original production plant, which went into operation in 1972, will be shut down or extensively modernized. These measures will enable Evonik to continue to meet growing demand for its structural foams from the aerospace industry, among other sectors.

Evonik’s original production plant in Darmstadt has been manufacturing Rohacell PMI structural foam, which is used as a core material for sandwich composite materials, for a half-century. Sales have risen steadily in recent years because of increasing demand for lightweight components in a range of industries, including medical technology, electronics, and automotive and aircraft construction.

Rohacell plays a role in emerging technology developments, such as high-frequency equipment for 5G networks as well as the design of air taxis. In addition, the product range of high-performance foams soon will be expanded with new developments beyond Rohacell structural foam.

Production will continue at the existing plant in Darmstadt during the construction and modernization phase. The first new plant will begin operation in April 2022, and further plants will follow over the course of the year. Additional plants and regional teams are located in Mobile, AL, and Shanghai to support customers in the Americas and Asia.

Rohacell foams provide mechanical strength, even at very low densities; heat-distortion temperature and creep compression strength are superior to any other rigid foam, according to Evonik.

Rohacell IG-F is the industrial-grade product in the rigid foam range and is suitable for a variety of applications, including automotive and watercraft. In the medical technology market, Rohacell IG-F is a common core material for x-ray and CT table tops. Featuring a fine cell structure, the foam takes up minimal resin at the surface, where the cells have been cut open during core shaping. Less resin take-up during part processing means lower final part weight and reduced overall cost. Rohacell IG-F is suitable for prepreg processing, but can also be used in resin infusion and RTM processes up to temperatures of 130°C and pressures of 0.3 MPa.

Evonik also has developed Rohacell RIST-HT for use as a structural core in connection with vacuum infusion processes. Its cell size represents an optimal compromise between low resin uptake and satisfactory bonding of the facings to the foam core. It is used for infusion components in aerospace applications and in sports equipment and automotive structures. Its optimized cell structure makes Rohacell RIST-HT suitable for vacuum infusion and RTM processes, where it allows safe and stable processing at 180°C with pressures up to 0.7 MPa.