Special Coverage


DETROIT – Japanese automotive supplier Yazaki Corp. is looking to develop its vehicle interior business with new environmentally friendly materials.

One of the most promising is the natural fiber kenaf, Leonid Grigorian, supervisor-research products for Yazaki Technical Center America, says at the Convergence Transportation Electronics Conference here.

Kenaf is an annual hibiscus belonging to the mallow family, which includes cotton and okra. Kenaf Industries of South Texas, which makes decking from the fiber, says on its website that kenaf is a “traditional backyard-fiber crop in Africa and Asia.”

Grigorian says kenaf is more cost-effective than better-known natural fibers derived from bamboo and hemp and also provides a more reliable supply.

Yazaki is using kenaf as a bioplastic in combination with petroleum-derived polypropylene commonly used in interior applications.

Grigorian says he is surprised at the findings of this marriage in Yazaki’s research trials. While durability of natural materials, especially in the automotive environment, has been a common concern, kenaf actually strengthens polypropylene in environmental durability testing, although he can’t yet explain the phenomenon.

Components made with this combination also deflect heat quite well, with kenaf “significantly improving” the heat-deflection temperature of polypropylene, which Grigorian says could expand polypropylene’s use to under-hood applications.

Yazaki has found a good mixture level of the two materials, with kenaf comprising 60% of the total weight of a particular part.

“We do hope that it will find its way into a conventional product,” Grigorian says of kenaf, adding it’s not much more expensive than polypropylene both as a material and to process.

Yazaki displays Texas-grown kenaf in pellet form and also combined with polypropylene in a finished plastic piece at its booth here. While kenaf is naturally dark brown in color, John Currie, production manager-high voltage products, says it can be dyed.

However, he suspects there is less color variation available in a part containing kenaf than with one made with pure polypropylene.