Glass fiber used to be the fiber of choice for reinforcing plastics. Just think of boats or of innovative cars in the 1950s like the Lotus Elite and Chevrolet Corvette. These days, carbon fibers are more and more used, especially in the aircraft and automotive industry. It makes you wonder which new fibers might be popular in composites in the future. Reinforced Plastics investigates a few possibilities.

Carbon fiber is an extremely strong, stiff and successful material. But it does have an Achilles heel. “Yes, we have to go beyond carbon fibers,” says Professor Nicola Pugno from the Laboratory of Bio-Inspired & Graphene Nanomechanics in the University of Trento, Italy. “I recently fractured my right shoulder due to the failure of a carbon fiber reinforced material.”

His accident was caused by the carbon fiber reinforced frame of his bicycle suddenly breaking due to the poor toughness of carbon fiber. In principle you can negate that poor toughness with hybrid composites like carbon/Kevlar. But as Pugno points out: “Kevlar is not as strong as carbon fiber. So if you use it to increase the toughness of the material, you are decreasing its strength. It is the kind of compromise we engineers are used to. But in nature you can find other solutions that are better. Spider silk for example.”

This article appeared in the Jan/Feb issue of Reinforced Plastics.

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