The aircraft and motor industries could become much greener thanks to new research into carbon fibre recycling by engineers at The University of Nottingham.
Aircraft manufacturers are increasingly using carbon fibre instead of metal to build their aircraft because it is lighter and stronger, but at the moment there is no commercial use of ‘recycled’ carbon fibre in the industry. That could be about to change thanks to a unique research project led by the University’s Faculty of Engineering.
The AFRECAR (Affordable Recycled Carbon Fibres) project will develop low-cost, high-strength manufacturing materials based on recycled carbon fibre. These can be used as lightweight structural reinforcement in the aerospace and motor industries in non-critical applications such as seats, overhead lockers and other interior features on aircraft and body panels in cars.
Half of the weight of Boeing’s new 787 passenger airliner is made up of carbon fibre composites. This makes it stronger, lighter, more fuel efficient and therefore cheaper to fly. Older aircraft which are now out of service are ending up in aircraft ‘graveyards’ located in deserts across the world. The idea is to recycle and reuse the valuable carbon fibre which up to now has only been disposed of in landfill.
New carbon fibre costs upwards of £10,000 a tonne which is why the industry considers it worth recycling. Lead researcher on the project in the Division of Mechanics, Materials and Structures in the University’s Faculty of Engineering, Dr Steve Pickering, said: “The UK is taking a lead globally in developing recycling technology for carbon fibre and this research will ensure that we continue to be at the forefront of new developments.” The project team also includes Professor Nick Warrior and Dr Ed Lester.
Billy Glover, Managing Director, Environmental Strategy for Boeing Commercial Airplanes, said: “The Boeing commitment to the environment is reflected in our proactive involvement in composites recycling. We continue to work with industry leading technology developers and recyclers towards environmentally progressive recycling for aircraft production and end-of-life. This project will provide key technology contributions for carbon fibre composite recycling solutions."
There are emerging commercial processes for extracting the carbon fibre from a composite but there are two problems that need solving; how to process the recycled carbon fibre to produce new products that can give the very best structural properties and how to improve on the existing recycling processes to recover useful products from the polymer resin used to bond the carbon fibres together in the composite?
Up to now, work on recycling carbon fibre has used thermal (heat) processing to decompose the polymer resin leaving clean carbon filaments which can be bundled or pressed into sheets for re-use. But this process leads to a slightly degraded product. This new research will investigate a cleaner and more efficient way of extracting the fibre by dissolving the composite in supercritical fluids. This method will also extract the chemicals out of the polymer resin so there will be less waste.
Supercritical fluids are substances at a temperature and pressure above their thermodynamic critical point. They can diffuse through solids like a gas and dissolve materials like a liquid and are suitable as a substitute for organic chemical solvents in a range of industrial and laboratory processes.
New techniques are also being developed to process the recycled carbon fibre into forms that can achieve much greater proportions of recycled carbon fibre in a composite and so give better structural properties.
The £900,000 project is funded by the Technology Strategy Board. The other partners are the aircraft makers Boeing, the Ford Motor Company, composite materials supplier Advanced Composites Group, fibre processing company Technical Fibre Products, carbon fibre manufacturer Toho Tenax and Milled Carbon, a company leading the way in carbon fibre recycling.
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Notes to editors: The University of Nottingham is ranked in the UK's Top 10 and the World's Top 100 universities by the Shanghai Jiao Tong (SJTU) and Times Higher (THE) World University Rankings.
More than 90 per cent of research at The University of Nottingham is of international quality, according to RAE 2008, with almost 60 per cent of all research defined as ‘world-leading’ or ‘internationally excellent’. Research Fortnight analysis of RAE 2008 ranks the University 7th in the UK by research power. In 27 subject areas, the University features in the UK Top Ten, with 14 of those in the Top Five.
The University provides innovative and top quality teaching, undertakes world-changing research, and attracts talented staff and students from 150 nations. Described by The Times as Britain's "only truly global university", it has invested continuously in award-winning campuses in the United Kingdom, China and Malaysia. Twice since 2003 its research and teaching academics have won Nobel Prizes. The University has won the Queen's Award for Enterprise in both 2006 (International Trade) and 2007 (Innovation — School of Pharmacy), and was named ‘Entrepreneurial University of the Year’ at the Times Higher Education Awards 2008.
The Technology Strategy Board is a business-led executive non-departmental public body, established by the government. Its role is to promote and support research into, and development and exploitation of, technology and innovation for the benefit of UK business, in order to increase economic growth and improve the quality of life. It is sponsored by the Department for Innovation, Universities and Skills (DIUS). For further information please visit www.innovateuk.org.