The new hybrid material was developed as part of a joint research project undertaken by several Fraunhofer institutes and led by Dr. Frauke Bunzel from the Fraunhofer Institute for Wood Research , Wilhelm-Klauditz-Institut WKI, which specializes in wood research. For the ‘ HoMe Foam ’ (HoMe is a German acronym for wood-metal), the researchers combined cast metal sponges with wood foam; the latter is characterized by its high level of sustainability and, thanks to its adhesive properties, requires no additional adhesives. Combining the wood foam with a metal sponge affords the new composite material significantly greater bending strength and makes it an ideal core material for sandwich panels or as a self-supporting lightweight semi-finished material. The metal components make the hybrid material electrically conductive, while the wood foam lends it a high level of sound absorption, which makes it suitable for use as an acoustic insulation material, for example in the automotive industry. Production of the hybrid was possible thanks to a new procedure: Using a tapping technique, the fibrous wood foam was inserted into the plates making up the metal sponge until the entire metal sponge was filled. An earlier attempt to insert the foam using pressure failed due to the wood fibers: The wood foam remained on the margins of the sponge and so failed to infiltrate fully.
‘Sustainability’ is currently gaining in importance in the lightweight construction sector. Just recently, 20 institutions and associations from science and industry called for a more intensive debate on the topic.