ALMOST a decade after it started developing biodegradable plastics from sweet pototoes, Toyota is set to introduce production components made from plants rather than oil-based materials in the forthcoming Prius.
Now known as ecological plastic, the plant-based foam and injection-moulded parts will be found throughout the new-generation Prius, including the scuff plates, deck trim and seat cushions.
Prius will be launched in Japan next month and is scheduled to be released in Australia in July.
Toyota formed a biotech company called PT Toyota Bio Indonesia in 2001, and that year produced a small concept car called the ES3 with bioplastic body, interior and mechanical components of starch extracted from sweet potatoes and sugar cane.
In May 2003 it became the first car-maker in the world to install plant-based plastic interior components with the release of the Japan-market second-generation Raum mini-MPV, while the futuristic 1/X hybrid concept car displayed at the recent Melbourne motor show featured seaweed-based materials.
For the Prius, Toyota will introduce a new range of plant-derived ecological bioplastics made from the cellulose in wood or grass.
The two principal crops are kenaf (a member of the hibiscus family and related to cotton and okra) and ramie, commonly known as China grass and one of the strongest natural fibres, similar to flax in absorbency and density.
Toyota says this is a particularly timely breakthrough for plant-based eco-plastics because 2009 is the United Nations’ International Year of Natural Fibres, which covers kenaf and ramie.
Other interior components in the next-generation Prius are made from the latest Toyota-developed super olefin polymer, which the company says has excellent recoverability and does not deteriorate after repeated recycling.
Toyota claims to have expanded the use of materials free of chlorine and bromine, while the use of PVC resin in the new Prius is a fraction of that used in a conventional car.
Recycled sound-proofing material has also been used in the new Prius.
While the Prius door trims are made entirely from purely plant-derived kenaf fibre and polylactic acid, most of the other components are made in combination with petroleum-derived materials.
However, Toyota says it remains committed to expanding the use of ecoplastic in vehicle parts.