Atlanta, Georgia – A wind-resistant polyurethane car hood based on the hydro-dynamism of shark skin underwater was recognised for innovation at JEC Americas, the composites trade show which took place in May.
Unlike the smooth surface of most car hoods, Frimo’s Street Shark has a textured finish, which say the company, not only cuts it weight but reduces the drag from wind that can slow a vehicle down.
Prototypes are being used on modified versions of two sports cars, the Porsche 911 and BMW Z4, according to Frimo.
The company’s marketing manager, Sven Garcia Alba said the surface was developed from the skin of a German zoo shark. The company used shark's skin as a model from which it designed the aluminium mould for the part.
The company set about designing an RTM (resin transfer moulding) part that would imitate a shark’s ability to “knife” through the water.
Alba said: “Shark skin feels like fine sandpaper. The hood texture had to be enlarged to get the same effect in the air - which has lower density than water but, other than the larger size, it’s exactly the same structure of the shark on which it was modelled.
“The extruder which the Shark has, builds a very small turbulence on top of the surface, which builds a kind of a layer on this top,” Alba said. “Flowing air is not touching the part itself anymore - like going over wheels,” he added.
The reduced drag is like the puck on an air hockey game — air floats over the surface without touching the hood. Even better, the “skin” helps the air actually flow faster over the surface.
A version of this story appeared in Plastics News - sister publication to Urethanes Technology International magazine on 4 June.
