“I want to say just one word to you: Plastics!” That might have been good advice to new college graduates a generation ago, but today that could be replaced with this word: “Biofoam.”
Most conversations about the environmental impact of cars focus on drivetrains—hybrid versus diesel versus electric, etc. But the use of new bio-based materials—used in everything from seats to dashboards—also have a big impact on energy, as well as the environmental safety of passengers. That’s why Ford is expanding its use of bio-based soy foam through nearly all of its vehicle lineup this year as part of an ongoing effort to use more renewable and recyclable materials.
Ford’s use of bio foam has helped the company reduce its petroleum oil usage by more than 3 million pounds annually and carbon dioxide emissions by 11 million pounds. In a press release, Debbie Mielewski, technical director, Plastics Research Group at Ford, said, “One day I hope to see the automotive world go totally compostable, removing the use of petroleum-based parts 100 percent.”
We reached out to Debbie to learn more.
HybridCars.com: What are the most toxic or energy-intensive parts found in cars today?
Mielewski: Our goal is to make sure cars today don’t use anything that can be labeled toxic. The objective of my group is to develop alternative materials to limited, traditional petroleum-based plastics.
These materials can be 20 to 30 percent lighter in weight, improving fuel economy. They can utilize a waste material—such as wheat straw, which is left after the grain is harvested. They can have an improved life cycle—less energy to produce and less CO2 emitted into the environment. Some of the materials are compostable, eliminating the landfill of plastics. Plastics are certainly a huge part of the automotive process—and we are quick to recognize that—so the more sustainable we can make these plastics the better. We are also working hard to make sure all Ford cars are 100% recyclable. The materials we use play a huge part in that process.
What’s the relative environmental impact of using these sustainable materials versus the burning of petroleum-based fuel?
Great question. We are never going to make an impact relative to burning petroleum-based fuel. Our materials are designed to be durable—a 10 to 15 year service life—and of course are only utilized once in the lifetime of the car. But, if we compare using the sustainable materials with use of petroleum-based materials, the contributions start to add up.
For instance, with soy-based versus petroleum based foam, we are currently reducing CO2 emissions by over 6 million pounds per year, and conserving about 1.5 million pounds of petroleum. For the wheat straw/polypropylene bins of the Flex, we are reducing CO2 emissions by 30,000 pounds and conserving about 20,000 pounds of petroleum. While these numbers are not big compared to the burning of fuel, we think that everything we can do, without compromising performance and durability, moves us in the right direction for the long term. If we don’t begin the research and development now, we won’t have the materials in the future.
Does the use of natural ingredients offer greater potential to reduce weight of automotive materials than advanced plastics?
In the automotive arena, you have just about every level of plastic materials requirement—from the low requirements of disposable wraps, paint protective films (for shipping) and non-structural plastic gap fillers all the way up to semi-structural, Class A components, or higher heat applications. Some of the natural material/plastic combinations have demonstrated interesting properties such as enhanced energy absorption. When we see something like that, we are thinking about applications to utilize that unexpected performance. When you are inventing new materials, you never know what you are going to discover. That’s the fun part of the job.
Natural fiber reinforced plastics offer weight savings when compared with glass reinforced materials. The density of the natural fibers is around 1.2 and glass fibers are around 2.6. This provides a 20-30% weight savings. In addition, glass fibers are energy intensive to produce. If we can utilize a fiber that is currently a waste product, such as the wheat straw, it’s a win-win for everyone—farmers, automakers, consumers, and the earth.
What are the safety and durability challenges to using bio/plant-based materials instead of petrol-plastics?
The technical challenges for each material and application we’re developing are different, of course. For the soy foam, our main technical challenges were performance, odor and plant logistics. The performance of the first soy formulations was, shall I say, less than perfect. The foams were stiff, crumbly and did not remotely match the microstructure that was desired for automotive seat cushions or any other application. We had to re-balance the chemistry to accommodate the slow reactivity of the soy polyols we were using. Additionally, the soy polyols had a strong odor, similar to vegetable oil. This would never be acceptable in the vehicle interior. We had to learn how to “strip” the odorous molecules out of the functionalized oil. We even invented a new way to produce functionalized soybean oil. We have several patents on these methods.
The challenges with natural fiber plastics are significantly different. In some plastics, moisture absorption by the fibers reduces mechanical properties over time. The material can become less rigid due to moisture absorption. So we are looking for ways to treat the fiber, so that it is not so hydroscopic. The natural fibers also pose issues with degradation during the processing (during injection molding). Sometimes, odor during processing is unacceptable, color of the part (turning brown) is an issue and sometimes, if the fibers are degraded, the performance of the part suffers. We have run into incidences where the plant workers actually like the smell of the natural fibers during processing—smells a bit reminiscent of a bakery. So we are constantly dealing with the issue of scent, ensuring the end product is odor-neutral.
The compostable plastics like PLA pose a number of durability issues from degradation in hot, humid environments to reduced impact properties. They also require long cycle times to process—something not likely to be adopted by processors who want to maximize their productivity. We have and are continuing to work diligently on each of these issues in our laboratory to make sure we have the highest quality end product.
How will the use of biodegradable plastic affect end-of-life environmental impact of cars?
We think that in the future it can have quite an impact. Right now, most of the vehicle is comprised of metals, which are already recycled. Plastics compose about 300 pounds of the typical vehicle, and although some of that plastic is already recycled—and we are working on technologies to recycle more—there is plastic going into landfills. The compostable plastics, while not currently meeting our requirements for performance or durability, hold promise for the future. If we can “grow” the materials for our cars and then put them back into the soil at the end-of-life as a nutrient to grow more plants, I think that would be a major accomplishment. It relieves us of our dependence on foreign petroleum, partners us with the farming community, improves our CO2 lifecycle and reduces our environmental impact. It’s just going to take some time, and some growing pains, to get there.