The relatively low density of wood - particularly in the form of veneer - makes it the perfect choice of material for use in lightweight construction. "Many potential practical applications exist for wood (veneer)-plastic composites (known as veneer prepregs), such as in the automotive sector," explains Professor André Wagenführ from the Institute of Natural Materials Technology at TU Dresden, adding: "They are cost-effective and, in addition to their specific material assets, highly recyclable." On the basis of their short processing time, the MERGE scientists are using thermoplastic processes to produce the veneer prepregs in question, sourcing the wood used in this experimental process locally from native European beech and spruce.
The manufacturing process is performed in two parts. First, the veneer is pre-dried at around 80 degrees Celsius, after which it is impregnated using a plasticized thermoplastic matrix. Then, the veneer is cooled under pressure at room temperature until it sets, with the plastic forming a layer on the outer vessels of the veneer. The crucial factor for lightweight construction purposes is the veneer's consistently low interior density from start to finish.
These veneer composite materials are destined for practical use in the MERGE project's own lightweight electric automobile, known as "MERGE Up!" and developed by the "Chemnitz Car Concepts" research project. They are used to make the covers for a functional input system in the car's center console and as exterior components for the side door. "The MERGE project has demonstrated impressively that the renewable natural material veneer still has plenty of innovative potential. As fiber reinforcement in composite with other materials, it offers many new forward-looking potential applications," says Ursula Geismann, a keen proponent of veneer as a useful material and head of Initiative Furnier + Natur (IFN), which was formed in 1996 by Germany's veneer producers and their partners.
Initiative Furnier + Natur e. V. (53604 Bad Honnef, Germany)