Following an investment of approximately six million Euros, Evonik Industries AG's new production facility for Rohacell structural foam came on stream at the company's Darmstadt site at the end of 2013. The new facility increases the polymerization capacity at the site by 50 percent. Moreover, the extensive automation of the polymerization process has cut cycle times almost in half.
Rohacell is a structural foam that is used in fiber-reinforced composite parts for lightweight applications and lightweight sandwich constructions. The foam is produced by thermal expansion of a co-polymer sheet of methacrylic acid and methacrylonitrile. During the foaming process, the copolymer sheet is converted to PMI (polymethacrylimide). Rohacell is halogen free, has a very homogeneous cell structure and isotropic properties. The cell sizes can be tailored to all processing methods. The 100 percent-closed-cell foam takes up resin only in the exposed cut cells at the surface. This prevents excess resin from infiltrating further into the foam, which would add unnecessary weight.