Ford continues its pursuit of sustainable materials to use in its vehicles with the ’14 F-150 pickup, which will feature a wiring harness containing plastic reinforced with rice hulls, a byproduct of rice grain.

The hulls, sourced from farms in Arkansas, will replace a talc-based reinforcement in a polypropylene composite developed by Ford and Whitmore Lake, MI-based supplier RheTech.

Debbie Mielewski, Ford technical leader-plastics research, says rice hulls were chosen to reinforce the plastic used on the wiring harness because there was an abundance of them that the rice farmers didn’t know what to do with.

“This is the first automotive application of the rice-hull material,” she tells WardsAuto. “It’s replacing talc, which is a silicate material mined from the earth. It’s not particularly high-end, a kind of filler, but we’re using something that is in excess and a waste product.”

Mielewski says research revealed the hulls are very similar in performance to talc and meet every one of Ford’s performance and durability requirements. “That’s one of our mantras here, (the sustainable material) must perform and be as durable as the material it replaces.”

Other materials currently used by Ford include recycled cotton, carpeting, tires, plastic bottles, post-industrial plastics and soybeans.

In a volume vehicle such as the F-150, the amount of sustainable material adds up. For example, Ford estimates it uses about 10 million lbs. (4.5 million kg) of recycled cotton in its F-Series trucks annually.

Although the rice hulls are slated for use in the wiring harness, they likely will migrate to other areas of the F-150, as well as other Ford vehicles, in the future.

Mielewski says that has happened with previous sustainable materials such as soy-based foam, which first was used in the seats of the ’08 Mustang. Today, it’s found in nearly every Ford product, and has exhibited the same durability of the oil-based foam it replaced.

No real costs savings are realized by using sustainable materials in small quantities, but the savings improve when materials are spread across Ford’s vehicle lineup in larger volumes, as is the case with the soy-based foam, Mielewski says.

Sustainable materials also weigh less than the materials they replace, making them a vital element in Ford’s desire to drive weight out of its vehicles to meet looming government fuel-economy mandates.

“The natural fibers are lighter than glass, so you can get anywhere from 15% up to 30% weight reduction,” Mielewski says. “That’s been a big motivator, along with doing the right thing (for the environment). Eventually, we’ll be limited on materials that are not sustainable, so why not make progress now where it makes sense?”

Mielewski, who has been conducting sustainable-material research at Ford for 12 years, says finding the next material for automotive use is a painstaking task. Through a trial-and-error process, her team tests anything that could serve as a suitable replacement for existing materials. However, those efforts sometimes are met with failure.

“We are looking for materials that are byproducts of agriculture or waste products, things that are in excess,” she says. “We start mixing (the materials) into various polymers and giving them a shot to see if they have the right properties. Sometimes they perform differently, and sometimes they have an advantage.”

bpope@wardsauto.com