Japanese automakers try to grow auto parts

TOKYO -- Most Japanese look at a bamboo grove and see a safe haven in case of earthquakes. Bamboo's intertwining roots help stabilize the earth. Mitsubishi Motors Corp. looks at a bamboo grove and sees a safe haven from rising oil prices and worrisome greenhouse gases. It sees raw material for car parts."Bamboo fiber has a high strength compared with other natural fibers," says Mitsutaka Tanase, a researcher in Mitsubishi's advanced vehicle engineering department. In addition, he says, "bamboo grows to its full height in just a few years, compared with the tens of years required for traditional timber," making bamboo a potentially sustainable resource.Mitsubishi and other Japanese carmakers are hoping to grow their car parts in the future. By using parts made of bioplastics, in most cases resins derived entirely or in part from plants rather than petroleum, the automakers aim to make their parts more environmentally friendly. Such parts would help them reach self-imposed and government targets to reduce carbon dioxide and other greenhouse gases.Most bioplastics for autos are still in the research stage. Some earlier versions already are used for casings and other electrical-appliance parts. But for use in auto parts, they are too expensive, are available in volumes that are too small and offer inferior performance compared with petroleum-based alternatives.A global effortIn the effort to bring bioplastics to market, Japanese companies are not alone. The quest for effective bioplastics is a global affair. For example, Ford Motor Co. has a number of efforts under way in the field. It is working with researchers at the University of Toronto on natural fiber composite materials such as hemp. And it has come up with a way to use a soy-derived material to replace 40 percent of the petroleum-based polyols used to make the foam for seat cushions and armrests. Until now, most carmakers have been able to replace only 5 percent of the oil-based materials with soy-based ones. DaimlerChrysler AG makes seat cushions in Brazil from discarded coconut fiber. In the Philippines, it has produced natural abaca fibers to replace fiberglass and plastic in certain parts for the Mercedes-Benz A-class minicar since 2004. Traditional plastics suppliers such as DuPont Co. and nontraditional auto suppliers such as agribusiness giant Cargill Inc. also are researching the use of bioplastics for automotive parts. Indeed, a recent environmental award shows that no one continent can claim leadership in bioplastics. Toyota, Ford and Honda were cited by the U.S.-based Ecology Center in its second annual "Automotive Plastics Report," released Nov. 15, as "leaders in the movement toward using sustainable plastics in indoor auto parts."There is a subtle difference, however, in carmakers' research objectives.In the United States, the industry is keen to use ethanol, derived largely from corn, as a means of reducing America's dependence on imported oil. In Japan, in contrast, parts made with bioplastics using corn-derived sugars are seen as a way to fight CO2 and global warming.That may be because Japanese companies are under more pressure from the government and public opinion to reduce greenhouse gases than are their American rivals. Bioplastics come in several varieties, including polymers derived from renewable resources, petroleum-bio mixed sources and microbial synthesized sources. Those derived at least in part from plants fall into one of the first two categories. Carbon neutral?Several companies claim that their bioplastic parts are "carbon neutral." That means the CO2 absorbed by the plants during their growing phase would offset the CO2 released during their production and eventual recycling. But not all companies have provided detailed studies to back up that claim.Whether carbon neutral or not, bioplastics can reduce significantly the use of petroleum and CO2 emissions. Consider a bioplastic developed by Mazda Motor Corp. and a consortium of two universities, two research institutions and six other companies. The fermentation process used to make it, which involves starches and sugars, takes 30 percent less energy than the process to make a similar amount of polypropylene, Mazda says. The bioplastic is made of 88 percent corn and 12 percent petroleum. Compared with earlier bioplastics, it has improved exterior surface quality, making it suitable for use in interior parts. It has three times the shock impact resistance of and 25 percent higher heat resistance than earlier versions of bioplastics that are currently used in electrical appliances. It also has comparatively higher rigidity, resulting in thinner molds. That implies better productivity in mass production using injection molding.Not yetBut Mazda's bioplastic is not in use yet. Mazda expects to devote several more years to r&d before it can bring the new bioplastic to market.The delay is typical. Most bioplastics are not yet ready for prime time. Few are available in the high volumes the car industry needs. Most are still more expensive but not as strong as their petroleum-based rivals. So far, then, automotive applications of these home-grown plastics are mostly confined to garden-variety parts such as floor mats and interior trim. Few if any are suitable for load- or shock-bearing applications. But as the number and variety of bioplastic parts grow, that could change.For instance, Toyota Motor Corp. already is making limited use of bioplastics. Its Japan-market Raum has floor mats and a spare tire cover made in part from sugar cane and sweet potatoes. Toyota also uses kenaf-based bioplastics for the door trim of the U.S.-built Avalon and package-tray trims in the Japan-built Camry, Premio and Allion sedans. Fast-growing kenaf is a member of the hibiscus family related to jute. The outer fibers in its stalk are similar to the softwood fibers used to make paper; its inner fibers are comparable to hardwood tree fibers.In May 2005, Toyota began operating a pilot plant at its Hirose plant in Toyota City, Japan, to test the feasibility of producing bioplastics. But the carmaker's use of bioplastic auto parts falls short of even that pilot plant's limited output of around 1,000 tons a year. So Toyota plans to market the bioplastic for use in such products as food trays and pencil cases. Honda Motor Co. has developed a corn-based bioplastic material that has the durability and texture appropriate for use as a seat fabric. It plans to use the material in an extremely limited-volume production of fuel cell vehicles it will begin marketing in three years.Bamboo bioplastic Mitsubishi plans to substitute plant-based resin and quick-growing plant fibers for materials such as petroleum-based resins and wood hardboards in car interiors. Its showcase product so far uses bamboo fiber. Mitsubishi combines the bamboo fiber and a plant-based resin, part of which is made by fermenting sugar cane or corn, to make a material suitable for automotive interiors. The bamboo fiber increases the material's rigidity.Mitsubishi says its tests show that prototype parts made of the new bamboo-laced resin cut emissions by 50 percent compared with prototype parts made of a more common resin, polypropylene, over the material's life cycle, including production, use and recycling. Emissions of volatile organic compounds also were reduced by about 85 percent when the material replaced processed wood hardboards. Tanase, the Mitsubishi researcher, also argues that bamboo is superior to kenaf, which is favored by Toyota.Only 40 percent of kenaf, by weight, can be used for its fibers, compared with 50 percent for bamboo, he says. And, Tanase says, "kenaf threatens to disturb the Japanese native ecosystems" if the fast-growing nonnative plant is introduced to Japan. Mitsubishi plans to introduce parts made from the bamboo-laced resin in a Japan-market minicar around 2008. In addition, floor mats made of a plant-based resin and nylon, a material that Mitsubishi developed jointly with textile company Toray Industries Inc., will debut in a new Japan-market special-edition model later this year. So far Japanese carmakers' efforts at using bioplastics are quite limited. But as gardeners know, bamboo can spread rapidly and widely, displacing other plants if the conditions are right. Mitsubishi and other Japanese carmakers hope that their bioplastics also spread rapidly.You may e-mail James B. Treece at jtreece@crain.com

Japanese automakers try to grow auto parts

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