Lightweight and Fire-Retardant

The renovation of European railway operator Duetsche Bahn’s fleet of 66 ICE-3 fast trains is one example of composite materials’ ability to meet customers’ specific needs. The installation of air conditioning systems, passenger entertainment systems and new seating added unwanted weight to the ICE-3 rail cars. In addition, the original plywood floors didn’t meet the new European fire standards. The company needed a flooring solution that could help it shed the added weight and comply with the fire standards. Lightweight composite flooring was the answer.

Composite fabrics producer Saertex, based in Germany, provided its LEO® material system for the floor. LEO is a layered, non-crimp fabric that offers higher mechanical properties and greater lightweighting potential than woven fabrics, according to Daniel Stumpp, head of global marketing at the Saertex Group. The four-component composite system includes a special fire protection coating, a glass fiber reinforcement, SAERfoam® (a core material with integrated 3D-glass fiber bridges) and the LEO vinyl ester resin.

Composites manufacturer SMT, also located in Germany, manufactured the flooring in a vacuum infusion process, using reusable silicon vacuum bags made by the English company Alan Harper.

“We save about 50 percent in weight [from] the former plywood panels,” Stumpp says. “The LEO system, being based on a continuous-fiber laminate with a non-filled resin system, has an excellent mechanical performance … . Furthermore, the composites don’t rot, which is a big advantage, especially in regions where it snows in winter time and the floors get very wet.” Both the floor panels and the carpet and rubber materials on top meet the new fire retardancy standards.

SMT produced more than 32,000 square feet of panels, which have so far been installed on about a third of the eight-wagon ICE-3 trains. Each panel size is being optimized during the refurbishment process to fit a particular car.

The OEM for the ICE-3 cars, which was not involved in the floor refurbishment process, was so impressed by the new composite flooring that it has ordered composite roof segments to replace the old metal roof structures in the rail cars.

Going the Distance

California-based Proterra, a designer and manufacturer of zero-emission electric buses, has been using composite materials for all of its bus bodies since 2009. In 2017, the company’s Catalyst® E2 bus set a world record by traveling 1,100 miles on a single battery charge. That bus featured a lightweight body built by composites manufacturer TPI.