Date:4 July 2014
Brakes that are high-tech, more powerful, lighter – yet cheaper: this is just one of the benefits predicted to flow from a project that, it is hoped, will revolutionise production of carbon fibre and make it more accessible to the mass market. Thirteen leading global companies with top carbon fibre expertise – among them supercar maker Lamborghini – are behind the project. They call it Newspec (new cost-effective and sustainable polyethylene-based carbon fibres for volume market applications).
Essentially, it’s about developing sustainable carbon fibre technology. The process could be on stream as early as 2017.
Currently, carbon fibre is created using Polyacrylonitrile (PAN). That’s a process that is expensive and has massive environmental impact. Could new materials retain existing carbon fibre’s combination of strength and lightness while being more planet-friendly and cheaper? If so, it could have huge implications for mass-market products that use materials such as steel.
According to the consortium, they are looking into promising, low-cost, sustainable precursors. An example is polyethylene (PE), which could be derived from bioethanol or recycled.
Lamborghini will build and test carbon composite prototypes for the project. The role of these prototypes will be to ensure the functionality of the PE-based (both virgin and recycled) fibres.
The company has two CFRP development centres (the Advanced Composite Research Centre at its headquarters and the Advanced Composite Structures Laboratory in Seattle in the US). It brings more than three decades of experience in carbon fibre and has specific expertise in developing alternatives to PAN.
A new, cost-cutting recipe Newspec’s main aim is to develop carbon fibre using through promising low-cost polymers, such as polyethylene (PE). In PE’s favour are a high carbon yield of around 70 per cent, high processability and chemical flexibility. Significantly, it’s relatively cheap, at about R30 per kg.
Compared with the PAN precursor currently used, it could save up to 70 per cent in raw material costs. Production cost of converting PE to carbon fibre is R150 per kg versus about R225 per kg of PAN fibres. That’s a 30 per cent cost saving on similar production scales, says Newspec. Polyethylene (PE) precursors for carbon fibre look like a promising avenue.
There are three main sources for PE:
● synthetic oil
● recycled plastics.
A pilot facility for continuous carbon fibre processing is the starting point. If it proves workable this will be scaled up to an industrial-size operation. For those interested in the technicalities of it all, here’s the inside story on the PE-to-carbon process. Newspec says that, for PE stabilisation, an original dry oxidation method is proposed. This is assisted by Electron Beam Curing (EBC), which introduces heteroatoms at the precursor stage. They say this has technical, economic and ecologic advantages.
In addition to this, it can facilitate innovative and flexible development of new CFs. To reduce the graphitisation temperature, they are looking at the use of nucleation agents such as cellulose nanowhiskers, CNTs and fine graphite powders.
Where we will use it
Brake rotors and pads
Carbon ceramics materials will revolutionise braking, says Newspec. Carbon brake discs weigh about half as much as grey cast iron brake discs. To start with, that’s a huge saving in unsprung mass. But even better, the higher-tech material has significant mechanical and thermal properties. Cheaper carbon fibre will open up the mass market to ceramic brakes, especially where light weight is crucial, such as with electric cars.
Automotive structure, body and interiors
Carbon fibre reinforced composites and plastics (CFRP) are become more and more widely used in body and chassis components. Forged CFRP is stiffer than glass fibres; carbon fibres made from PE can help save up to a quarter of costs, with potential uses foreseen in high-end cars.
Aerospace low loaded, secondary aircraft structures
The aerospace industry’s heavy hitters Boeing and Airbus have recognised the significant advantage of composites in its superjumbos such as the B787 and A380. The proportion of composites in these aircraft, which weigh over 250 tons, is almost 50 per cent by weight and 80 per cent by volume.
Wind turbine blades of more than 50 m length
Carbon fibre’s strength/rigidity combination will come in useful as wind turbine blades stretch 50 metres and beyond, massively increasing the enormous tensile loads on rotors. The material can also be used on smaller blades as a retrofit.
Oil and gas pipelines, pressure vessels for oil/gas components
Harsh environments are common in the fossil fuel industry. Think high pressures and maritime zones with their corrosive climates, for instance. Pressure vessels, oil and gas pipelines can benefit from using low-cost CFRC instead of glass fibres to strengthen and retrofit corrosion-damaged and distressed structures.
Source: Newspec, Lamborghini