Biomaterials From Dandelions, Straw?

Ford Motor Co., which already is rapidly expanding use of soy-based materials for foam seats and headliners, now is looking into more renewable agricultural feedstocks for biomaterials, such as wheat straw and dandelions, Ford's head of plastics research says.

A high-quality natural rubber can be made from the root of the Russian dandelion, and Ford is working with researchers at Ohio State University to develop automotive applications, Deborah Mielewski, Ford technical leader-Plastics Research, tells attendees at the Society of Plastics Engineers Automotive TPO Global Conference.

TPO stands for thermoplastic olefin, a family of plastics used extensively for automotive exterior and interior parts.

While tires and other rubber parts made from dandelions are a ways off, wheat straw, a waste product left over from wheat harvesting, already is in production, Mielewski says. It is used as a natural reinforcement material for a polypropylene plastic storage bin in the third row of the Ford Flex cross/utility vehicle.

This application, alone, reduces annual petroleum usage by some 20,000 lbs. (9,072 kg) and carbon dioxide emissions by 30,000 lbs. (13,607 kg) per year. Plastic parts using natural fibers for reinforcement, instead of glass or other man-made fillers, can be up to 30% lighter, depending on the part, Ford says.

The research that led up to the Ford Flex wheat-straw application was conducted by the University of Waterloo in Waterloo, ON, Canada, and partly funded by the Canadian government's BioCar Initiative. Within 18 months of bringing the project to Ford, a process for reinforcing plastic with 20% wheat straw in high volume was created.

“This is not a glamorous part,” Mielewski says, “but the point is we plan to migrate it, and we are looking at a lot of different new applications for wheat-straw material.”

Interior door trim panels and other plastic-molded components seem suited for the new technology, Mielewski says.

Ford has been touting its use of soy-based materials since it was the first auto maker to launch soy-based seat cushions and backs in the Mustang in 2007. Now, 2 million vehicles are on the road with soy-based cushions, and Ford will have 23 models with soy-based interior materials by the end of the year, she says.

The auto maker also is migrating the use of soy to other components, such as the headliner on the new Escape.

Even though Ford now is using about 300,000 gallons (1.1 million L) of soy oil annually in production, it is not a record for the company. Ironically, driven by the vision of Henry Ford, the auto maker used a similar amount of soy oil for use in car paint in 1937, Mielewski says.

The new vision for plastics at Ford is not only to have materials based on environmentally friendly, renewable feedstocks, but to make them easy to dispose of or recycle when they are scrapped.

Plastic parts, even those made with bio-based materials, remain difficult to recycle, and that has led to Mielewski's interest in a class of biodegradable resins known as polylactic acid or PLAs.

PLAs are made from the sugars in corn, sugarbeets, sugarcane, switch grass and other plants. When it is time to be junked, a plastic part made from PLA can biodegrade in a landfill in 90 to 120 days, compared with up to 1,000 years for a traditional, petroleum-based plastic.

Mielewski says she likes PLAs because they can be used to produce textiles used for carpeting and upholstery, which can be especially difficult to recycle, and they can be easily molded into many different types of plastic parts.

Nevertheless, durability and other issues still need to be resolved for PLA resins. The first applications likely will be protective wrappings used during vehicle manufacturing and transit.