|Until a few years ago, carbon fibre reinforced plastic (CFRP) composites found application in aerospace, auto racing and high-end sporting goods. However, CFRPs are increasingly being used in several new manufacturing applications where material cost is secondary to performance, high strength and reduced weight considerations, as per Reinforced plastics.com. Carbon fibres are classified by tensile modulus � the amount of pulling force a fibre can sustain without breaking. Low modulus fibres have a tensile modulus below 34.8 mln psi (240 mln kPa). At the opposite end, ultrahigh modulus carbon fibres have a tensile modulus of up to 145.0 mln psi (1.0 bln kPa), making them 10 times stronger and 5 times lighter than steel (with a tensile modulus of 29 mln psi -200 mln kPa). CFRP have a tremendous potential for growth with the adoption of innovative processing techniques and production advances that make use of these high-performance reinforcements practical for applications in industries, previously considered unaffordable. In 2009, demand slipped noticeably as the global economy worsened, while supply increased leaving ample inventories with manufacturers of carbon fibre along with relatively low lead times to consumers. The carbon fibre market is expected to rebound in 2010 and beyond, as the market recovers from the credit crunch and economic recession. Recent capacity additions in the industry have increased supply, while delays in the major aerospace programs and the global economic crisis have softened demand. Prices of commodities have also declined, notably in acrylonitrile and energy, which are two of the biggest cost inputs in the carbon fibre manufacturing process. The global carbon fibre market has grown at double digits over the last five years and is expected to continue growing but at a slower pace, increasing from levels of 2008 of US$1.5 bln to US$2.5 bln in 2014, according to Lucintel. Positive growth of 1.8% is expected this year, primarily due to increased demand in commercial aerospace and wind energy.
Carbon fibre composites have long been used in aerospace applications due to it�s significant strength, stiffness and weight advantages over aluminium alloys, making aircrafts stronger, lighter, more fuel efficient and cheaper to fly. Aerospace is the largest segment of the market for carbon fibre at 21%, according to AeroStrategy LLC. In 2008, CFRP constituted 37% of aerospace composite demand, compared to 35% for glass fibre reinforced plastics (GRP). Boeing and Airbus aircraft account for nearly 60% of today�s demand. Other major consumers of CFRP are the industrial (15%), sporting goods (14%), wind energy (11%) and automotive (10%) sectors. The automotive industry has been slower to adopt carbon fibre composites, reserving them for high-end vehicles and race cars. Japanese carbon fibre products supplier Toray Industries has developed a carbon fibre processing method that it says paves the way for mass production of lightweight, fuel-efficient automobiles. The process, which integrates proprietary resin transfer moulding (RTM) techniques with improved resin infiltration and hardening technologies, is said to shorten the moulding cycle to produce CFRP parts down from 160 minutes to 10 minutes. The CFRP parts are 50% lighter than steel and 1.5 times safer in a collision. The global wind energy industry is growing by leaps and bounds and consuming an increasing amount of composites. Wind turbines come in a variety of sizes. Utility-scale turbines often have blades over 40 m long. And the trend is toward longer and longer blades to increase the energy-producing efficiency of the turbine. Manufacturers are finding that as wind turbine blades grow longer, the stiffness advantage of carbon fibre composites outweighs the cost differential compared with glass fibres. Near-term growth of these composites will be driven by increased business from the wind turbine market, as well as CNG tanks and aerospace. Wind energy sector remains strong with clear potential of continuing 20-25% annual growth.
Emerging commercial processes for extracting the carbon fibre from a composite leave two issues unsolved: how to process the recycled fibre to produce new products that can give the very best structural properties and how to improve on the existing recycling process to recover useful products from the polymer matrix, explain researchers from the University of Nottinghamin. Until now, carbon fibre recycling has used thermal processing to break down the resin, leaving clean carbon filaments. But this process leads to a degraded product. The new research will investigate a cleaner and more efficient way to extract the fibre by dissolving the composite material in supercritical fluids. This method will also extract the chemicals out of the polymer, resulting in less waste. In addition, the research involves new techniques to process the recycled carbon fibres into forms that can achieve much greater proportions of recyclate in a composite to provide better structural properties. The recycled materials would be used in non-critical applications such as seats, overhead lockers and other interior features on aircraft as well as for automotive body panels.
Engineers at the Massachusetts Institute of Technology (MIT) are using carbon nanotubes to stitch together plies of carbon fibre materials which could make aircraft skins and other products perhaps 10 times stronger at a nominal increase in cost. �Nanostitching� aligns billions of carbon nanotubes perpendicular to each carbon fibre layer and uses a thermal process to melt a polymer �glue� between the layers. The nanotubes are sucked up into the polymer as it melts, filling the spaces around the carbon fibres and �stitching� the layers together. Since the nanotubes are 1000 times smaller than carbon fibres, they cause no damage to them. Dramatic improvements can be achieved with nanotubes comprising less than 1% of the mass of the overall composites, while adding only a few percent to the cost of the composite.