Vehicles that come apart for recycling could be possible with a technology developed at Brunel University.
Fixings such as clips and bolts made from so-called ‘shape memory’ plastics and alloys will disengage automatically when they reach a certain temperature, making the recycling of car components more efficient.
The technology, first developed for the electronics industry, could help the UK cope with the expected mountain of cars which must be recycled under the European End of Life Vehicle directive.
Researcher Nick Jones’s work on shape memory technology is funded by Nokia, Motorola and Sony. Components made of shape memory plastics or alloys are designed to return to their original form when a certain amount of heat is applied.
The plastic can be polyurethane and the metal alloys nickel and titanium. Jones said the materials could be formed into nuts, bolts, screws and clips that will lose their threads and heads and allow the product to come apart. The temperature rise can be achieved by the application of an electrical current allowing assembled products, such as a complete car, to fall apart in a controlled way.
Jones’s original aim was to create self-disassembly for consumer electronics to help companies comply with the European Union’s Waste from Electrical and Electronic Equipment directive, which forces manufactures to dispose of their products.
Jones recognises that his work is also important in the car industry, especially when the European End of Life Vehicles directive comes into force. The directive requires all car manufacturers to take responsibility for the disposal of their products. Industry expects as many as 500,000 tonnes of old vehicles will have to be disposed of in the UK each year.
‘You could have one fixture that triggers at 100 degrees C then another at 105 degrees C, so as the vehicle heats up you have controlled disassembly. We don’t have any automotive sponsors at the moment but we’d be happy to talk to them,’ he said.
The technology could be used to make clips for easy windscreen removal and bolts for wheel hubs.
Jones said the issue of self-disassembly being triggered by hot climates was being worked on.
He said prototype clockwork radios and CD players that he had built showed that climatic issues were not an impossible problem to solve.
Even if the surfaces of products reach temperatures of 200 degrees C it does mean that components inside are even half as hot. Work on mobile phones for Nokia and Motorola had confirmed this, he said.
Sidebar: Mountain concern
Hundreds of thousands of tonnes of recycled non-ferrous metal and electrical waste is set to build up in the UK after 2007, because there is no market for it.
Two European directives set to come into force in the UK within the next five years will compel car and electronics manufacturers to dispose of their products once they have fallen out of use.
Although methods of recycling the non-ferrous and plastic parts of cars and electrical gadgets are being developed, the lack of a market for the material is holding back investment in the technology, said Derek Wilkins, purchasing manager of Coventry-based European Metals Recycling.
‘The recycling companies might be able to expand, but when there is no market how can they be confident enough to invest? These directives are still not UK law and the investment window for the machines that can meet the recycling challenge is being missed now,’ he said.
The waste mountain is expected to grow at 280,000 tonnes a year – generated by the EU’s Waste from Electrical and Electronic Equipment directive and the End of Life Vehicle directive which come into force in 2006 and 2007 respectively.
Of the 280,000 tonnes, up to 160,000 is expected to consist of metal waste from car disposal. The iron, steel and aluminium from the UK’s two million cars that are annually scrapped is already recycled or exported.
But under the directive the rest of the car, the plastics, fabrics and non-ferrous metals, representing up to 25 per cent of its mass, cannot be disposed of in landfill. The remaining 120,000 tonnes comes from electrical waste. The consumer electronics industry estimates that every household in the UK will generate 6kg of electrical waste every year. Again, there is no established market for this material either.