Large and heavy components of land vehicles are to be made lighter and more sustainable in the future. This is the aim of the "ECO2-LInE" research project, which is funded by the Federal Ministry for Economic Affairs and Climate Protection (BMWK) as part of the Lightweight Construction Technology Transfer Program (TTP LB). The aim is to partially replace metal constructions with lightweight, natural fiber-reinforced plastic components. Experts from the Fraunhofer Institute for Structural Durability and System Reliability LBF in Darmstadt have developed their own manufacturing process for the compounds in order to be able to produce them with long-term stability and weather resistance. The research team will be showing more about this at HANNOVER MESSE 2024 at the joint Fraunhofer stand B24 in Hall 2.

The clearly defined project goals lead to climate protection

The "ECO2-LInE" project is primarily about saving weight with innovative natural fiber-reinforced lightweight components. At the same time, the production process is to be optimized with regard to the ecological balance and improved recyclability is to be achieved after at least the equivalent service life of the original component - which would make an important contribution to climate protection. The focus is on seat structures for electromobility, tractor crossovers and pick-up attachments. Stowage elements, which form part of a pick-up attachment, are manufactured using printed materials.

New process hydrophobizes fibres and ensures temperature resistance

In order to partially replace metal constructions with lightweight, natural fiber-reinforced plastic components, the Fraunhofer researchers are using the high-speed additive process SEAM (Screw Extrusion Additive Manufacturing), which was established at the Fraunhofer Institute for Machine Tools and Forming Technology IWU. This new 3D printing process is said to be eight times faster than conventional 3D printing. Fraunhofer LBF has developed its own process to ensure that the new components made from natural fiber-reinforced plastic have comparable properties in terms of long-term stability and weather resistance. It hydrophobizes the fibres and thus creates the basis for their temperature resistance. The focus of the developments is on the combined modification of wood fibers by acetylation and subsequent epoxy resin coating.

Natural fibers as a component of polyamides

The actual temperature resistance is achieved by subsequent coating with epoxy resin. This is the prerequisite for being able to incorporate the fibers into polyamides, which, according to the Fraunhofer researchers, has not yet been possible. The benefits of this process for the customer can be easily calculated using the example of a high-speed train: For a train with fourteen gangways and a mileage of 12.5 million kilometers, 160 kilograms can be saved with each sustainable gangway system used. Calculated for the entire train, this corresponds to a saving of almost 115 tons of CO2 equivalent.

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