Proven in motorsport, fiber-reinforced plastics are now widely used in lightweight construction - and increasingly in safety-critical production components such as crash boxes, B-pillars, and battery housings.

Dynamic Lightweighting

“Lightweight construction is a key strategy for saving materials and energy in component manufacturing,” says Prof. Dr. Markus Milwich of the Competence Center for Polymers and Fiber Composites at the German Institutes of Textile and Fiber Research (DITF), and representative of the Lightweight Construction Alliance Baden-Württemberg. The market is growing rapidly: a study commissioned by the German Federal Ministry for Economic Affairs and Energy shows that patent applications for plastics and plastic composites in lightweight construction rose by nearly 400% between 2001 and 2021[1]. “In 2019, lightweight construction contributed about 4% to Germany’s GDP and accounted for roughly 3.2 million jobs,” says Prof. Milwich.

High Crash Resistance

In mobility industries, carbon fiber reinforced plastics (CFRP) are a focal point - especially for safety. CFRP components can absorb up to 100 kJ/kg of specific impact energy, far more than steel’s 20–30 kJ/kg[2]. Instead of collapsing abruptly, the composite material disperses crash energy in a controlled, stepwise manner. Hybrid sandwich structures - featuring a plastic core and fiber-reinforced skins - provide a clear safety advantage for vehicle occupants.

Lower Impact Forces

CFRP is up to 50% lighter than steel[3]. Less weight means less energy during impact - translating to lower injury risk. The Fraunhofer Institute for Structural Durability and System Reliability (LBF) has developed a 3D sandwich battery housing made from fiber-reinforced plastic that is 40% lighter than aluminum. The design integrates flame protection, complies with ISO 12405-2/-3 safety standards[4], and provides robust protection for electric vehicles - at a fraction of the weight.

More Sustainability

Lower weight also means reduced energy consumption. “Especially for moving masses such as in cars, aircraft, and ships, every gram saved leads to fuel savings over the vehicle’s lifetime,” explains Prof. Milwich. According to the U.S. Department of Energy, reducing a vehicle’s weight by 10% can lower energy consumption by up to 8%[5].

Fiber-reinforced plastics improve efficiency without compromising safety. A further step: thermoplastic matrix systems based on PET, which combine recyclability with the strength of carbon[6]. Plastics are becoming essential materials for high-performance lightweight structures in the mobility systems of the future. Prof. Milwich sums it up: “Thanks to their outstanding energy and resource efficiency, lightweight designs are key to climate protection, sustainability, and conserving raw materials.”

[1] https://www.bundeswirtschaftsministerium.de/Redaktion/DE
[2] Soutis, C. (2005). Fibre reinforced composites in aircraft construction. Progress in Aerospace Sciences, 41(2), 143–151
[3] https://www.ipa.fraunhofer.de/de/presse/presseinformationen
[4] https://www.lbf.fraunhofer.de/de/projekte
[5] https://www.energy.gov/eere/vehicles
[6] https://2018.lbf-jahresbericht.de/leistungen

Image Source: Plastic is Fantastic – AI-generated using DALL·E

Image Caption: Less weight, less crash energy – lower risk of injury. The illustration shows how fiber-reinforced plastics absorb impact forces in a controlled manner, enhancing vehicle safety.