Lightening the burden of high pressure for hydrogen vehicles

And it’s one that was taken into the focus of Cevotec engineers who designed a solution to save 20% of time, material and cost to build composites-based high pressure vessels.

“The automotive industry has invested billions in fuel cell electric vehicles, but only very few cars are on our streets yet. One of the larger challenges is to efficiently and safely store hydrogen in the vehicle”, said Thorsten Groene, CEO of Munich-based Fibre Patch Placement specialist Cevotec. “There is working pressure of up to 700 bar in the tanks, which translate into approx. 10kg of carbon fibre for 1kg hydrogen storage - a very high ratio.”

Obviously, manufacturers are interested in using less of the expensive fibres to reduce the vessel’s weight and cost.

“Wrapping endless fibres around the liner is best for the cylindrical part,” said Dr. Neven Majic, Executive VP of Cevotec. “But filament winding at the domes means redundant material on the cylindrical part - which translates into excess weight and cost of the final product.” Cevotec’s solution is to apply carbon fibre patches in the dome areas, using the same material, just in patch form.

“The patches are designed to exactly cover the areas causing problems in filament winding,” explained Majic. With patch reinforcements on the liner domes in a first step, the patched liners are passed over to the filament winding process, which subsequently needs less material and production time for the dome areas.

Patching of the domes is done by Cevotec’s SAMBA Series production systems. “The Fibre Patch Placement technology cuts patches from fibre material and places them individually on positions calculated by CAE software ARTIST STUDIO,” continued Majic. “The investment in patch technology pays off from the first day of production,” added Groene. One FPP system can reinforce vessels for several winding machines. Manufacturers can realise at least 20% material and cycle time savings.

“When manufacturers combine winding and patch placement in series production, the FPP capital investment amortises within the first year already. It’s a fairly simple calculation that we present to our interested customers.”

By consequently applying Fibre Patch Placement technology to today’s composite manufacturing challenges, Cevotec supports the advancement of composites for a green mobility revolution. Applications areas for FPP also include many components in aerospace and new urban air mobility, all of which are currently produced manually.

The Munich-based FPP specialist has conceptualised a range of production cell configurations to match the manufacturing process to the different applications. Material efficiency and cost savings of 20-60% are typical benefits for manufacturers switching from manual lay-up to Fibre Patch Placement technology.