Sustainable vehicle design and manufacture

Materials World magazine
,
1 Oct 2006

Researchers at Loughborough University’s Centre for Sustainable Manufacturing and Re-use/Recycling Technologies (SMART) in the UK have completed a two-year study to address the cost and design implications of recovering and recycling vehicle materials and components.

The UK’s Environment Agency estimates that two million vehicles reach the end of their lifecycle per annum. With the advent of the EU’s End of Life Vehicle (ELV) Directive in 2000, which deals with cars, vans and certain three-wheeled vehicles, responsibility rests with manufacturers to meet specified targets – by 1 January 2006, 85% of ELVs had to be recovered, 80% of these had to be recycled and five percent could be incinerated. By 2015, these targets will rise to 95% for recovery and 85% for recycling, although these figures are currently under review.

Dr Shahnin Rahimifard, Centre Director of SMART, argues that manufacturers should be aware of the difference between recyclable and recoverable materials.

'When a manufacturer says 90% of a car is recyclable, that does not always mean it is economically recyclable.’ In order to close this gap between what is economically recoverable and recyclable, ‘we have to improve the quality of the recycled materials from ELVs, do this in an environmentally friendly way and make these activities financially viable’, says Rahimifard.

PhD students at SMART, Chris Edwards and Gareth Coates, have been working to achieve these aims in a project supported by partners such as Jaguar. Edwards has developed a PC-operable system that simulates the shredding process undergone by ELVs. At present, valuable materials such as ferrous and non-ferrous metals are extracted, post-shredding, and sold as scrap metal. The shredder residue, comprising plastics, rubber and glass, is either sent to landfill or incinerated – it constitutes about 25% of the car.

Edwards conceptualised ‘design for shredding’ to ensure that a higher percentage of the vehicle is recovered. He looked at how the disposed materials could either be removed entirely from the designs of vehicles, or how they could be manually dismantled before shredding to be of value for recycling. Automotive polymers are useful for their additives and resilient properties. ‘Design for shredding’ would also raise the value of scrap steel in the market as the material is less likely to contain impurities such as plastics and glass.

Moving on to the delicate area of cost, Coates’ aim was to establish how to get ‘the most amount of value with the least amount of effort’. His software calculates the economic feasibility of recovering, dismantling, shredding and recycling any type of vehicle to meet the targets of 2015.

Coates says, ‘The vehicle recovery industry is consistently changing, oil prices are increasing, which affects virgin and recycled plastics prices, and scrap steel prices are fluctuating. We are trying to capture the effects of these so that the right decision can be made at the correct time.’

For example, part of the model is a database that identifies attributes that hinder the dismantling process, such as accessibility, fixture type and component size, and selects materials that have the best mass removal rates – producing a mass-versus-effort return. By predicting dismantling times, labour costs can also be estimated. On average, it was found to take one hour and 45 minutes per vehicle to remove 27 components and recover 50kg of material.

Coates and Edwards now hope to transfer their research to industry, particularly in light of what they call ‘zero-cost contracts’. Under these agreements, manufacturers have shifted the expense of meeting recycling targets onto vehicle recovery operators, who retrieve and recycle ELVs at their own expense – keeping any profits made from selling the materials.

The team at Loughborough suspect, however, that such dependence on recovery operators could cause long-term problems for manufacturers – for instance, when the market for scrap steel fluctuates and operators can no longer deliver on the agreement. It is argued that the ELV Directive is targetted at manufacturers and that ultimately they need to invest in treatment facilities to safeguard their own ability to meet the targets for 2015 and beyond.

 

Further information:

Loughborough University’s Centre for Sustainable Manufacturing and Re-use/Recycling Technologies (SMART) UK. Email: S. Rahimifard@lboro.ac.uk.