Metzeler Schaum Gmbh

Wolfgang Friedl

Ulrich Heitmann

Andreas Harms

A foam material element for sound-damping cavities, particularly for light metal extruded profiles used in rail car construction. The foam material element has a foam material sandwich with at least two layers, namely a resilient layer and at least one heavy layer disposed on the resilient layer. The resilient layer is formed of soft foam polyurethane and the heavy layer is formed of a flocculated foam polyurethane compound. Prior to being inserted in a cavity to be sound-proofed, the foam material element is compressed and weld-sealed in an air-tight film. The element is inserted through an opening of the cavity in its compressed condition. After insertion and placement of the foam material element, the film is opened and, as a result of its exposure to air, the foam material element expands to such a degree that at least one heavy layer, biassed by the resilient layer, comes into contact with the walls substantially over a broad surface area.

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Memmingen, Germany

Wolfgang Friedl