Continuing its effort to develop sustainably sourced materials, Ford Motor Co. is evaluating bamboo fiber-reinforced plastics for use in injection molded interior parts like storage bins or side panels on seats.
Fast-growing bamboo offers a renewable alternative to traditional reinforcement materials like glass fiber. Flexible and strong, it compared favorably to other fibers in a range of materials tests.
"One of the things we've been trying to do is develop materials that are valuable waste products, side products, in various parts of the globe," said Deborah Mielewski, who leads the sustainable materials team of Ford's research department. "Instead of shipping materials, as we currently do, all over the place ... we're trying to look at what's readily available and plentiful in various parts of the globe and then develop the materials around that."
Mielewski expects the bamboo composite to be ready for production within five years for applications with low impact requirements.
Ford already uses wheat straw, rice hulls and cellulose fibers to reinforce plastics in production parts. The bamboo material would targeted for Asian markets first, Mielewski said, as the feedstock is readily available there. The team is working with potential North American suppliers of bamboo to evaluate the properties and potential applications of species grown in that region.
Natural fibers like bamboo offer a potential weight savings of 15 to 20 percent over glass fiber composites, along with reduced tool wear. Ford is currently working with the polypropylene-based resins for its bamboo project, with polymer choice limited by the heat stability of the natural fibers. The team is also looking at looking at technologies that would enable the use of higher processing temperatures, with one option being to pre-treat the fibers to remove volatile materials, Mielewski said.
"I still think there's a huge desire for weight reduction in vehicles and a lot of the weight reduction technologies are very expensive, like carbon fiber," Mielewski said. "So even if you have a pre-treatment on a natural fiber, I think you are still at a price advantage as compared to some of the other lightweighting technologies."
Ford reports the bamboo fibers performed better in tests than other reinforcement materials, with less change in properties from the beginning of fill to the end of fill. Mielewski said this could be because natural fibers bend where glass fibers would break when flowing around corners in a tool. And the natural fibers delaminate more from the polymer matrix under impact, absorbing more energy.
The team is working to improve impact characteristics of bamboo-reinforced materials so the technology could be used in more interior applications, including, perhaps, as a design feature with the natural fibers exposed instead of obscured with pigments or coatings. Though there is not today a strong consumer demand for visible natural fiber details, Mielewski hopes that will change. She sees a logical connection between highlighting sustainably sourced materials and environmentally minded markets like electric vehicles or carsharing fleets.
"My hope is someday in the near future we'll be more interested in being able to see these green materials, because they really are beautiful in the plastic," she said. "I think there are some advantages to natural fibers that we have not exploited yet."
