When the BMW i3 city car rolls out of the company’s Leipzig plant later this year, it can represent the initial carbon-fiber car which will be produced in any quantity-about 40,000 vehicles each year at full output. The lightweight but sturdy nonmetallic structure of your new commuter car, caused by BMW’s joint venture with SGL Technologies in Wiesbaden, will mark a milestone in the growth of carbon-fiber-reinforced plastic (CFRP) materials, that have traditionally been very costly to use in automotive mass production.
CFRPs are engineered materials that are fabricated by embedding webs of carbon fiber inside molded polymer resins. The fibers bolster the physical properties in the plastic matrix component in the same manner which a skeleton of steel rebar strengthens a poured-concrete structure.
Even though the i3 electric vehicle (EV) won’t exactly come cheap-estimates run from $40,000 to $50,000-BMW reportedly claims that forthcoming improvements within the production process throughout the next three to five years should cut carbon composite costs enough to match those of aluminum chassis, which still command a premium over standard steel car frames.
CFRP structures weigh half that relating to steel counterparts along with a third below aluminum ones. Add the inherent corrosion resistance of composites along with the ability of purpose-designed, molded components to cut parts counts by a factor of 10, along with the appeal to automakers is clear. But despite the advantages of using CFRPs, composites cost far more than metals, even making it possible for their lighter in weight. Our prime prices have up to now limited their use to high-performance vehicles like jet fighters, spacecraft, racecars, racing yachts, exotic sports cars, and notably, the most recent Airbus and Boeing airliners.
Whereas steel is true of between $.80 and $1/kg, and aluminum costs between $2.40 and $2.60/kg, polyester and epoxy resins cover anything from $5 to $15/kg along with the reinforcing fiber costs one more $2 to $30/kg, based on quality. To allow cars to get rid of the Usa government’s fast-approaching 54.5-mpg average fuel-economy bar, automakers in addition to their suppliers are striving to make strategies to produce affordable carbon-fiber cars about the mass-scale.
But adapting structural composites to low-cost mass production has always been a technical and manufacturing challenge, said Ross Kozarsky, Senior Analyst at Lux Research, an independent research and consulting firm that targets emerging technologies.
Kozarsky follows composite materials and led research team that just last year assessed CFRP manufacturing costs and identified potential innovations in each step from the complex process.
“Our methodology is always to follow, through visits and interviews, the entire value chain from the tow, yarn, and grade level onwards, examining the supplier structure and also the general market costs,” he explained. The Lux team then created a cost model that mixes material, capital expenditure, infrastructure, labor, and utility consideration as well as the chances for cost reductions.
While the sporting goods, military, and aerospace industries have traditionally developed and first applied composite materials, the pre-eminence of these segments in terms of sales is ending, Kozarsky said. The wind-turbine business will cope with aerospace to the top market as larger, more-efficient offshore wind-power installations are made.
“It’s more economical to utilize bigger turbine blades, which could only be made using carbon-fiber materials,” he noted.
The Lux report predicted that the global industry for CFRPs will greater than double from $14.6 billion in 2012 to $36 billion in 2020, as innovative new production technologies lower carbon-fiber costs-the most important cost-driver. Throughout the same period, interest in carbon fiber is anticipated to rise fourfold through the current 27,000 million ton (24,500 million t) to 110,000 million ton (99,800 million t).
Major suppliers of carbon fiber include Toray, Zoltek, Toho, Mitsubishi, Hexcel, Formosa Plastics, SGL Carbon, Cytec, AKSA, Hyosung, SABIC, and over 12 smaller Chinese companies.
“A lots of everyone is talking about automotive uses now, that is totally with the other end of the spectrum from aerospace applications, since it features a better volume and much more cost-sensitivity,” Kozarsky said. Following a slow start, the auto industry will like another-largest average industry segment improvement throughout the decade, growing at the 17% clip, in line with the Lux forecast.
The Lux analysis suggests that CFRP technology remains expensive mainly because of high material costs-particularly the carbon-fiber reinforcements-and also slow manufacturing throughput, he reported.
“The industry has reached an intriguing precipice,” he was quoted saying, wherein industrial ingenuity will vie with all the traditional technical challenges to attempt to satisfy the new demand while lowering costs and speeding production cycle times.
The very best-performing carbon fibers-the larger grades employed in defense and aerospace applications-begin as what exactly is called PAN (polyacrylonitrile) precursors. Due to difficulty of the manufacturing process, PAN fibers cost about $21.5/kg, in accordance with Kozarsky, who explained that makers subject the PAN to a number of thermal treatments in which the material is polymerized and carbonized since it is stretched. The resulting “conversion” leaves the filaments oriented along the duration of the fiber to give it the ideal strength and toughness. Various post-processing stages along with the surface-acting additives help ensure durability and “handleability.
Kozarsky singled out a commercial/government R&D collaboration at the new Carbon Fiber Technology Facility at Oak Ridge National Laboratory (ORNL), that has been funded with $35 million in United states Department of Energy money as one of the more promising efforts to reduce fiber costs. Area of the project is usually to identify cheaper precursor materials which can be processed into good-quality fibers (see “Oak Ridge collaborates for cheaper carbon fiber,”. The program is always to test many types of potential low-cost fiber precursors like the cheaper polymers, inexpensive textiles, some made from low-quality plant fibers or renewable natural fibers including wood lignin, and melt-span PAN.
Near term the Lux team expects the task that ORNL has been doing with Portuguese acrylic-fiber maker FISIP (majority owned by SGL) on textile-grade PAN to accomplish costs with the pilot-line scale of $19.3/kg in 2013. Although significant, it might be only a modest reduction if compared to the 50% needed for penetration in high-volume auto applications.
One of the leading limitations of PAN, he said, is “at best 2 kg of PAN yields 1 kg of carbon fiber, which supplies you with a conversion efficiency of just 50%.” Dow Chemical is investigating dexnpky63 polyolefins-polyethylene, polypropylene-since the feedstock simply because they could offer potential conversion efficiencies of 70% to 75%. If mechanical performance targets might be met, pilot-line costs of $13.8/kg could be achieved by 2017, stated the report.
The Oak Ridge group, Kozarsky said, is likewise working on novel microwave-assisted plasma carbonization techniques that will produce useful, uniform fiber properties. And ORNL’s nonthermal plasma oxidation process has been shown to have the potential to stabilize and cross-link the precursor materials rapidly and efficiently.
Polyolefin-precursor carbon fiber, put together with these sorts of alternative thermal-treatment mechanisms, should reduce costs to sub $11/kg at pilot-line scale in 2017, he noted. Kozarsky added that “there’s a great deal of interest in improving the resin matrix at the same time,” with research centering on using thermoplastics rather than existing thermosets and producing higher-toughness, faster-processing polymers.