Industry Market Trends

Do Bioplastics Have a Place in Automotive Manufacturing?

Dec 17, 2012

(c) Ford Motor Company

Bioplastics are finding diverse applications in automobile manufacturing as replacements for petroleum-based plastics. They're already appearing in automobile interiors and undercarriages -- and even under the hood.

According to "The Bio-Based Materials Automotive Value Chain," a report from the Center for Automotive Research (CAR) of Ann Arbor, Mich., "the U.S. automotive industry is estimated to be a $370 billion industry for 2011, and the majority of this value is in the automotive parts sector." This suggests that "penetrating even a small portion of this industry could provide significant returns to investment in new materials and technologies, such as bio-based automotive parts and components, if these technologies are successfully adopted by the industry."

Bio-materials in a general sense can include natural fibers used as fillers and reinforcements for automotive applications, but here we're primarily discussing bioplastics -- polymers from plant sources such as soybeans, castor beans, corn or sugarcane that can replace petroleum-based polymers and provide equal or sufficient performance characteristics. Such materials, while not necessarily biodegradable, can offer reduced life-cycle environmental impacts and greenhouse gas (GHG) emissions. They can help companies fulfill increasingly restrictive environmental regulations and can provide a possible hedge against the volatility of the price of the petroleum feedstocks used for conventional plastic resins.

In its report "Bridging the Divide between Demands and Bio-Based Materials," Lux Research Inc. points to automotive as a large potential market for bioplastics. The firm says that about 12 percent of the mass of a vehicle is made up of polymers. The most important plastics in automotive are polypropylene (PP), nylon, polyurethanes and acrylonitrile butadiene styrene (ABS), all of which have bio-based substitutes either currently on the market or on the way. Ford, Toyota and Mazda are working on bio-based materials for low-performance applications such as doormats, seat foams and tire covers.

Plant-Based Polymer Substitutes

Soy-based foam seat. (c) Ford Motor Company

Polyurethane foam as used in car seats and upholstery represents one important target for replacement with bio-materials. Polyols, a key ingredient of polyurethane foam, can be derived from plants instead of petroleum. The CAR report says that Ford is now using soy-based polyurethane in various vehicles for foam seating, headrests and headliner.

Cargill makes a brand of soy-based polyols it calls BiOH, introduced in 2005, and claims that "for every million pounds of petroleum-based polyols replaced with BiOH polyols, nearly 2,200 barrels of crude oil can be saved." Those savings can add up, says Cargill; industry uses more than a billion pounds of polyols yearly. BiOH is mostly used in flexible foams today, but Cargill believes it also has a market opportunity in rigid foams, coatings, adhesives, sealants and even in shoe soles. The company says BiOH can constitute up to 20 percent of the volume of flexible foam depending on the application.

BioAmber, based in Minneapolis, Minn., a green-chemistry firm backed by Japanese industrial firm Mitsui, has developed bio-based succinic acid, which can be used as a direct substitute for petroleum-based succinic acid in polyurethane. The company also manufactures a bio-based 1,4 butanediol (BDO), used in the manufacture of plastics, fibers and polyurethanes. The company says it manufactures its succinic acid using a fermentation process that "improves the carbon footprint by consuming carbon dioxide rather than emitting it as a byproduct." BioAmber makes its product at a large-scale facility in Pomacle, France, owned by ARD but plans to move manufacturing to Sarnia, Ontario, Canada, in 2013. At full capacity, the Canadian facility will be able to produce 34,000 metric tons of bio-succinic acid and 23,000 tons of bio-based 1,4 BDO yearly. Further factories are planned for Thailand, North America, Europe and Brazil.

BioAmber announced recently that it was chosen as supplier of bio-based succinic acid for automotive plastics for a joint effort by Japan's Mitsubishi Chemical and Faurecia, a French automotive supplier operating in 33 countries. The announcement says European regulations require the automobile industry to increase its volume of recyclable materials to 85 percent by 2015, constituting an important driver behind adoption of bio-materials. The objective of the Mitsubishi-Faurecia effort is "to develop a polymer that can be used in mass-production for automotive interior parts," including "door panel trim strip, structural instrument panel and console inserts, air ducts, door panel inserts, etc." Nicolas Pechnyk, vice president for engineering at Faurecia Interior Systems, says that the strategic partnership will ultimately make Faurecia "the first automotive equipment supplier to mass-produce a 100 percent bio-based plastic."

The Lux Research report identifies polyvinyl chloride (PVC) as a possible automotive target for bio-plastics. Because of its durability and water resistance, PVC is used in automotive manufacturing for such applications as window seals, gaskets and underbody protection. The material is used for car interiors in seats, upholstery, trim, door panels and dashboards. It is favored as insulation for electrical cables. Market research firm ICIS says Belgian chemical company Solvay Plastics is developing a facility that will produce 60,000 tons per year of bio-based ethylene for PVC.

Lux points to polybutylene succinate (PBS) as a substitute in automotive applications for polypropylene (PP), polyethylene terephthalate (PET) and polyethylene (PE), in part because of PBS's high tensile strength and heat resistance. PBS is a biodegradable plant-based polymer synthesized from succinic acid and BDO. PBS, however, has not yet been produced at sufficient commercial scale for use in automotive manufacturing.

The interior of the Lexus HS 250h incorporates bioplastic. Credit: Toyota.

The CAR report says that GM is using polypropylene (PP) made from wood for seatbacks in the Cadillac DeVille and PP made from flax for trim and shelving in the Chevrolet Impala. Ford is using PP from wheat straw for interior storage bins in the Ford Flex and PP from coconut for the loadfloor in the Focus BEV. The Lexus CT200h contains polyethylene (PE) made from bamboo and corn in its luggage compartment, speakers and floor mats, and multiple Mercedes-Benz models have PE from flax in the engine and transmission cover and in underbody panels. The report mentions numerous other applications of bio-based materials in BMW, Fiat, Volkswagen, Ford, GM, Lincoln, Mazda, Chrysler, Toyota, Honda and other vehicles.

Bioplastics Go Under the Hood

Bio-based nylon is now being produced at commercial scale, according to Lux, and has applications in the automotive industry. The CAR report says that American chemical company DuPont teamed up with Japanese auto parts manufacturer Denso to develop a bio-based nylon resin from the castor bean plant. Called Zytel 610, the material contains 40 percent renewable content by weight. It was first used commercially in a radiator end tank for the Toyota Camry. CAR calls this application "impressive," as it means the material "meets the requirements of the hot, chemically aggressive underhood operating environment." Impressive also is the fact that, unlike many other bioplastics, Zytel 610 is less expensive than the petroleum-based resin previously used. Fiat plans to use the material for fuel lines, says the report.

This Toyota example highlights the value of the "toehold" strategy for market penetration of bioplastics, as I mentioned in my previous article about bioplastics in packaging. As CAR puts it, this shows how a company can gain market share by "debuting new bio-based materials in low volume applications and then expanding the use of the materials." CAR believes further commercialization of bio-based materials in the automotive supply chain will benefit from collaboration among automakers, suppliers, research institutions and other stakeholders.

EDITOR'S NOTE: This article is the second in a series on how bioplastics are being used throughout the manufacturing industry. You can read the rest of the series here: