The quest for “green” vehicles is far more than just fuel consumption or emissions: What goes into a car can be just as important as what comes out of it. That’s the reason why Ford Flex contains a revolutionary new plastic that’s reinforced with wheat straw.
“We can use the chopped straw to replace some of the pure polypropylene, so we’re replacing a petroleum product,” says Dr. Leonardo Simon, associate professor in the department of chemical engineering at the University of Waterloo, where the plastic was developed. “Or we can use it to replace mineral fillers like glass fibre or talc. Those are twice as heavy as wheat straw, so you’re saving weight.”
Ford currently uses the plastic on the 2010 Flex’s third-row storage bin. The company says that with this application alone, it is reducing petroleum use by more than 9,000 kg per year, and is creating a market for wheat straw, the leftover stalks once wheat is harvested.
“We developed this plastic in 2004, through a grant funded by the Ontario Ministry of Agriculture,” Simon says. “A colleague at the University of Guelph invited me to participate in the grant. The challenge was to improve value for farmers.”
The initial work was low-key: They brought a bale of straw into the lab.
“A lot had been done on the agricultural side, but it was mostly on live plants,” Simon says. “Nobody spent a lot of time analyzing wheat straw from a bale.”
The most difficult process was chopping it, since farm machinery cuts it into pieces small enough for animal bedding or compost, but not nearly fine enough to add to plastic.
Once they were able to grind the straw cost-effectively, the next challenge was temperature:
The plastic had to be warm enough to easily mold into shapes, but if it got too hot, the straw would break down.
The wheat-based straw also offers opportunities at the end of the car’s life, and Simon says the plastic has performed well in recycling trials. “If you have part of a car made of polypropylene with wheat straw, at the end of life, you can grind it and use it again.”