As early as 2014, scientists from the Fraunhofer Institute of Wood Research in Germany have developed a wood-based foam that can be used as an environmentally friendly insulation material. Now they go one step further and combine this wood-based foam with metallic materials to create a composite material with a wider range of potential applications.
The original wood-based foam first ground wood particles into a sticky substance, and then introduced gas into the substance to make it appear foamy, and finally made it dry naturally. Most of the wood was from forestry waste. .
Wood-based foams are often processed into the form of rigid boards or flexible mats. The finished product is reportedly very suitable for building insulation, it is more environmentally friendly than traditional petroleum-based foams, and it will not over time like some loose alternatives. And it settled down.
To create the new wood-based metal hybrid foam, the research team led by Dr. Frauke Bunzel first created an open-cell metal "sponge" using a casting process. Then add wood fiber foam into it-the sponge is repeatedly mechanically struck, and the vibration causes the viscous foam to drip from the sponge, filling all the holes. Finally, it is air-dried.
This composite material is called "HoMe foam" (short for wood and metal in German) and is a lightweight composite material that not only retains the heat and sound insulation properties of wood-based foam, but also Metal sponges have much higher flexural strength. This feature enables it to provide structural support. It is also worth mentioning that this material is also conductive.
Now, it is hoped that HoMe foam can be added to the interior of traditional materials or used as a separate panel, such as a sound pad in a car engine compartment, or a step pad on a car floor. Scientists are currently improving the manufacturing process of wood-based foam and using the optimized manufacturing process on metal sponges to enter commercial-scale production as soon as possible.