She’s grown used to skepticism when she proposes using natural fibers for various vehicle components. “People said, ‘You can’t put soy oil in and make a good foam.’ Well, you couldn’t just drop it in and make a good foam; it took some work,” she explains. “But the chemistry can be rebalanced, and you can incorporate hydroxylated soy bean oil into the foam. We do it in every single North American-built vehicle now, and many other industries do it, too.”
One problem is that people don’t think of green solutions as technical solutions. “They put biofiber materials in the green box, and they’re only in the green box,” she says. “When you say lightweight, everyone goes directly to carbon fibers.” While there is more weight savings with carbon fiber, natural fibers offer both the environmental benefits and the opportunity to work with other industries to provide a revenue stream for them.
Another benefit to natural fibers is that unlike glass fibers they don’t break during injection molding. “Natural fibers tend to flow and bend and fill all the cracks and crevices where glass fiber does not make its way,” Mielewski says. In addition, glass fibers are less conducive to anisotropy (orientation in all directions) than natural fibers.
“If our engineers got used to designing with natural fibers they would love it, because they wouldn’t have to worry about all the directional shrinkage and directional reinforcement,” Mielewski explains.
Ford is currently developing a console for the Lincoln MKX that will incorporate both pulp and glass fibers into the composite, and Mielewski hopes that designers will use more biofibers as they learn more about them.
Mielewski’s group is currently studying bamboo for composite fibers and algae oil for resins. They’re also working with Mexican tequila producer Jose Cuervo to develop applications for composites made with fibers from agave, which is used in tequila production. Since Ford has three assembly plants in Mexico, this research fits well with the company’s efforts to convert local waste streams into sources of revenue for residents.
The challenge is developing the supply chain to deliver a steady stream of the agave material. Someone must be willing to harvest the fiber, dry it, chop it and compound it into plastics so that it’s commercially available to use for vehicles. The problems involved in setting up such supply chains have been an important part of the learning curve in working with biocomposites, admits Mielewski.