By ALASTAIR SLOANE
Conventional materials may have had their chips - Toyota is developing biodegradable materials for car construction from sweet potatoes.
The Japanese carmaker has a new product it calls Toyota Eco Plastic, derived from crops it has been growing in Indonesia since 2001.
Eco Plastic is being used in floor mats
for the Toyota Raum - on sale in Japan - and more extensively in Toyota's ES3 concept car.
Toyota has so far used the material in cars but it could be used in plastic sheeting for crop propagation and for domestic rubbish bags.
The production process involves breaking down starch from the sweet potato into enzymes to create a sugar.
This is fermented into lactic acid and then polymerised, refined and moulded to create the raw bioplastic material. Toyota says the cost of the process is only marginally greater than for conventional oil-based plastics.
The project is part of a biotechnology business Toyota set up in 1998, after its president Hiroshi Okuda identified water and food as key areas for future research, convinced that they would one day have a critical global impact.
Toyota is also looking at the potential of the sweet potato for producing hydrogen for fuel cell and electric vehicles.
At present, the global bioplastics market is just 20,000 tonnes annually, but Toyota calculates that as much as 30 million tonnes of the total annual plastics demand of 150 million tonnes could be replaced by bioplastics.
It aims to increase production from its Indonesia project to 20 million tonnes annually.
