Two composite products are taking advantage of the material’s strength and lightness to offer previously unseen levels of protection from head to toe – a motorcycle helmet and an advanced orthotics system.
A Racing Helmet
While some motorcycle racers might be leery of a helmet that’s thinner and lighter, helmet manufacturer Bell Powersports recognizes that using composites can better protect racers. The company’s new Pro Star helmet combines its Flex Impact Liner technology with a CFRP shell reinforced with TeXtreme® spread tow carbon fiber fabric. Integrating the ultra-thin carbon fiber fabric into the shell has reduced its weight by 21 percent.
Weight reduction is critical, says Dave Kolosek, North American sales manager for Oxeon, which manufactures TeXtreme. “First, races last approximately 45 minutes, and average speeds are in excess of 150 miles per hour so it is very demanding on the athlete’s body. Therefore, every gram that can be saved has a cumulative effect on reducing the neck fatigue of the rider over a race,” he says. “Secondly, reducing the weight of a helmet has very positive effects from a safety viewpoint. Should an accident occur, the reduced mass of the helmet can help in offsetting rotational forces.”
Spread tow carbon fiber fabrics weave a high-count carbon fiber tow – in this case 12,000 filaments (12K) – into a lightweight fabric. This allows for thinner laminates and straighter fibers with reduced crimp, according to Oxeon. Fewer crimps, in turn, help to reduce weight as there are fewer places which need to be filled with resin.
Oxeon tested many layup sequences to see which would provide the desired weight savings yet still pass the testing protocol. “The unexpected part was how thin we could make the shell and still have it perform,” says Kolosek. “This was due to having multiple thin plies of TeXtreme working together to deflect upon impact while not delaminating.”
The helmet shell, which is bladder molded, is not only lighter and thinner than previous versions, but it also is stiff and strong enough to pass Bell Powersports’ in-house cold and hot impact tests as well as all required third-party testing. “You would think a thinner helmet would not be durable enough, but that’s one of the big benefits of TeXtreme and thin ply construction,” says Kolosek. “Multiple thinner plies are able to work better together under deflection than fewer thicker plies over the same total thickness, thereby significantly reducing interlaminar shear.”