DEARBORN, MI – Materials made from rice hulls, walnut shells, flax fibers and coconuts are finding their way into vehicle interiors.

They’re not in prime real-estate sections or high-touch points. But they’re showing up in places such as glovebox bins. Other applications are armrest inserts and visor linings, says Jim Preston, vice president-business development for materials producer Rhe Tech.

His firm uses the natural materials to reinforce polyolefin and polypropylene polymers. Although clients are not limited to the auto industry, he foresees a greater use of those compounds in vehicle interiors.

Why?

“Because they are inexpensive, available in large quantities and work well when we compound them with polymer products,” Preston says at the 2014 WardsAuto Interiors Conference.

The cost savings is because it is more expensive to use polypropylene alone to acheive certain engineering characteristics than to strenthen it with added reinforcing materials.  

A big draw is they’re renewable resources. “The green aspect absolutely is the sex appeal of it,” Preston says. “That’s appealing to OEMs. The lightweight part is a given.”

A conference attendee likens the use of nutshells and such as turning discards into feedstock for thermoplastic polymers. Rhe Tech began producing bio-reinforced materials during the recession, seeing an opportunity to drum up new business during a tough time.

No additional tooling is needed, but temperatures in mold-in-color product processes must go no higher than 400 º F (204 ºC) “or they’ll burn up,” Preston says.

“Flax fibers are incredibly strong, and there is no shortage of rice hulls,” he says in listing various attributes.

Ironically, using rice hulls in bio-reinforced polymers is not a selling point to automakers in Asia, where rice is a major staple.

“Asian OEMs want nothing to do with rice (polymer compounds),” Preston says. “It is seen as a food product, not a material.”

Other organic additives include paper powder derived from ground-up recycled magazines and wood fiber converted into the consistency of sawdust.

Currently, Rhe Tech has one commercial automotive application for its bio-reinforced materials: an electrical bracket on a Ford F-150. Rice hulls are used for that.

Such materials are found elsewhere in vehicles, such as gloveboxes. Suppliers of those are Rhe Tech competitors, “but we’ve got several things in the works,” Preston tells WardsAuto.

sfinlay@wardsauto.com