When Toyota Motor Corp.’s Lexus unit set out to create its first dedicated hybrid sedan, it decided to make more than the engine environmentally friendly. Thirty percent of the interior trim and cargo area in the HS 250h sedan will be molded using plant-based resins, pushing the automotive bioresin picture well beyond its current levels.
“We wanted to use as much of eco-plastics as possible,” said Lexus product planning manager Michael Moore in a Jan. 11 interview at the North American International Auto Show. Toyota introduced the 250h Lexus at the Detroit show.
For a comparison, some vehicles have started using a soy-based urethane foam for seating, with 5 percent of the foam from a soy blend. The Lexus car’s seating will use soy-based foam but the car extends the possibilities with structural composites blending resin and kenaf, along with corn-based polylactic acid.
Bioplastics are used in the trunk trim and window trim, for a door scuff plate, a floor finish plate, a toolbox area in the trunk and for the package tray behind the rear seats. “We use it in foam and injection molded parts,” said Mark Templin, Lexus Group vice president and general manager.
And the Lexus hybrid is not the only car pushing the bioplastics message for Toyota. The next Prius hybrid, due out in late spring, also will use plant-based resins in many of the same places as the Lexus car. Toyota did not specify what percentage of bioresins will be used in the Prius.
Some materials, like PLA, are difficult to use in highly visible parts, where greater wear and exposure to ultraviolet rays from the sun will damage them, Moore said. Instead, those materials will be used in substrates where consumers may not see them, but where they still will make an impact. Lexus estimates that the switch to natural sources for plastics will help reduce carbon-dioxide emissions by 20 percent over the life of the car.
The 250h will be sold only as a gasoline and battery hybrid, like Toyota Corp.’s Prius model, and because of that status likely will attract buyers who already are drawn to environmentally friendly materials. That gave Lexus a good platform to bring those materials more heavily into play, Moore said.
“You can use some unique materials that are new to the luxury market, and I think consumers who are looking at this will be looking for new products, especially those with an environmental benefit,” he said. The 250h goes on sale in North America later this year. Toyota is based in Toyota, Japan.
Source: Plastic News, 2009-01-21.