Wheat straw and soy provide alternatives to passe plastic: Green materials are re-shaping how vehicles are made

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Edmonton Journal
Clare Dear

The focus today in the automotive world is on green technology, specifically environmentally friendly, fuel-efficient powertrains. The hype spins around the hybrids, plug-ins and all-electric vehicles some say will be the future of the industry.

There’s more to the green shift than what’s going on under the hood, however. They may not generate big headlines, but researchers and engineers are making major breakthroughs in more efficient and Earth-friendly ways to build cars and some of the parts that comprise those vehicles.

Not only are manufacturers striving to make their products more recyclable, researchers are discovering ways to use natural, organic materials to replace the petroleum-based products used so extensively in today’s vehicles. These new green materials will play an even greater role as automakers aim to meet new fuel efficiency standards by making lighter-weight vehicles, replacing metal components with lighter plastic alternatives.

Typically, the plastics being used by manufacturers have been reinforced with materials such as glass, carbon or polyethylene fibres combined with petroleum-based resins. Now, however, researchers are finding those materials can be replaced with bioplastics and fibres derived from plants without sacrificing critical requirements such as strength and durability. And, with oil prices continuing to rise, these green alternatives are cost effective, too.

A European study predicts that by 2020, bio-based plastics could replace up to 90 per cent of the total amount of petroleum-derived plastics consumed globally in 2007. The auto industry consumes an average of about 135 kilograms of plastic in every car it builds, so it’s no surprise automakers are looking down this road with enthusiasm, especially with the current push to make components either recyclable or biodegradable.

Deborah Mielewski, technical leader of plastics research in Ford Motor Co.’s materials research and advanced engineering department, says the dream is to see those 135 kg of petroleum-based plastics “replaced by what we can grow. It just makes sense.”

In fact, Mielewski notes Ford is already using natural fibre-based plastic in its Flex crossover. This industry-first production-line application uses plastic reinforced with environmentally friendly wheat straw to create the Flex’s third-row interior storage bins. Using the wheat straw as a bio-filler, this application alone is reducing petroleum usage by more than 9,000 kg per year and cutting carbon dioxide emissions by more than 13,600 kg annually. It also has better dimensional integrity than non-reinforced plastic and weighs up to 10 per cent less than plastic reinforced with talc or glass.

Mielewski says that, although this initial application, which was launched on the production line at Ford’s Oakville, Ont., assembly plant last November, is a small step, the potential for green plastics is huge. Wheat straw has good mechanical properties and meets performance and durability specifications, while further reducing the company’s carbon footprint. Potentially, she says, there may be opportunities to use these biodegradable composites in the interior and exterior, as well as under the hood.

Applications already under consideration by the Ford team include centre console bins and trays, interior air register and door trim panel components and armrest liners.

Better still, there are no supply issues with wheat straw. It’s a waste material, the byproduct of growing and processing wheat. In Ontario alone, where more than 28,000 farmers grow wheat, there is about 30 million metric tons of wheat straw waste available at any given time.

“Wheat is everywhere and the straw is in excess,” says Ellen Lee, a technical expert in Ford’s plastics research department. “We have found a practical automotive usage for a renewable resource that helps reduce our dependence on petroleum, uses less energy to manufacture and reduces our carbon footprint. More importantly, it doesn’t jeopardize an essential food source.”

The development of the wheat straw-based plastic was initiated at the University of Waterloo as part of the Ontario BioCar Initiative, which also involves universities in Guelph, Toronto and Windsor.

The goal of the program, which also involves the automotive industry and the public sector, is to accelerate the use of biomass in automotive materials. Ford and its suppliers are currently working with four southern Ontario farmers to supply the wheat straw needed to make the Flex’s storage bins.

Mielewski says her company is working on the use of other natural fibres for use in automotive applications. Dyed coconut hair, for example, is being evaluated for use as an enhancement for the interior plastic used in radio bezels and other trim pieces. It creates a unique texture in the plastic, although internal reviews so far are mixed. “About 50 per cent of our people like it — and 50 per cent don’t,” she says.

Still, she believes there’s a market for such a material. She notes hybrid buyers, for example, might embrace such a look, adding to the environmentally significant statement their choice of vehicle makes.

Another area of interest is the resins used in plastics. Mielewski says researchers are looking at ways to develop resins that will be compostable when the vehicle’s life cycle is complete. Such a breakthrough would be huge “and we’re very serious about it,” she says.

Other eco-friendly advances are finding their way into production vehicles. For example, Ford researchers developed a soy-based polyurethane foam in 2001 that showed potential for use in seatbacks and cushions. Petroleum prices at the time, however, were low so the project moved ahead slowly. Initial issues such as quality and odour were resolved and, as oil prices soared, this technology became more cost competitive. Soy foam is now used in about 10 different models in the Ford family. To date, more than 1.5 million vehicles have seats with the soy foam, which equates to a reduction in petroleum usage by about 680,400 kg, Mielewski says. Ford is also now using a soy foam headliner in its Escape, creating a 25 per cent weight savings over the traditional glass-mat headliner.

Recycled, reclaimed and bio-based materials are also being used in a range of applications. For example, underbody components such as aerodynamic shields, splash shields and radiator air deflector shields are being made using resins obtained from recycled detergent bottles, tires and battery casings. The latest application is the 2010 Escape’s 3.0-litre V-6 engine cam cover. The use of these recycled materials is diverting 11.3 to 13.6 million kg of plastic from landfills.

Discarded nylon carpeting is finding new life as nylon resin that is moulded into cylinder head covers for the 3.0L V-6.

Demands on the auto industry to become even more eco-friendly continue to increase. Legislators are pushing automakers to develop vehicles that are totally recyclable, while the industry is looking for ways to reduce vehicle weight and keep a lid on material costs. It’s an environment that will drive further development of bioplastics, plant-based fibres and more use of recycled materials — and that’s a good thing for all of us.

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