When the BMW i3 city car rolls from the company’s Leipzig plant later this current year, it will represent the very first carbon-fiber car that can be manufactured in any quantity-about 40,000 vehicles per year at full output. The lightweight but sturdy nonmetallic structure in the new commuter car, the consequence of 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 expensive for usage in automotive mass production.
CFRPs are engineered materials that happen to be fabricated by embedding webs of carbon fiber inside molded polymer resins. The fibers bolster the physical properties of your plastic matrix component likewise 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 from the production process during the next three to five years should cut CC composite costs enough to complement those of aluminum chassis, which still command limited over standard steel car frames.
CFRP structures weigh half those of 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 reduce parts counts with a factor of 10, along with the entice automakers is clear. But despite the benefits of using CFRPs, composites cost significantly more than metals, even allowing for their lighter weight. Our prime prices have thus far limited their use to high-performance vehicles including jet fighters, spacecraft, racecars, racing yachts, exotic sports cars, and notably, the most recent Airbus and Boeing airliners.
Whereas steel goes for between $.80 and $1/kg, and aluminum costs between $2.40 and $2.60/kg, polyester and epoxy resins vary from $5 to $15/kg and the reinforcing fiber costs an additional $2 to $30/kg, based on quality. Make it possible for 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 ways to produce affordable carbon-fiber cars on the mass-scale.
But adapting structural composites to low-cost mass production happens to be 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 last year assessed CFRP manufacturing costs and identified potential innovations in each step in the complex process.
“Our methodology is usually to follow, through visits and interviews, the whole value chain from your 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 and also the chances for cost reductions.
Even though sporting goods, military, and aerospace industries have traditionally developed and first applied composite materials, the pre-eminence of the segments when it comes to sales is ending, Kozarsky said. The wind-turbine business will cope with aerospace for your top market as larger, more-efficient offshore wind-power installations are constructed.
“It’s cheaper to utilize bigger turbine blades, that may basically be made using carbon-fiber materials,” he noted.
The Lux report predicted that the global niche for CFRPs will a lot more than double from $14.6 billion in 2012 to $36 billion in 2020, as innovative new production technologies lower carbon-fiber costs-the key cost-driver. Through the same period, demand for carbon fiber is anticipated to go up fourfold from 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 twelve smaller Chinese companies.
“A large amount of everyone is discussing automotive uses now, that is totally at the other end of the spectrum from aerospace applications, since it possesses a better volume and many more cost-sensitivity,” Kozarsky said. Following a slow start, the car industry will delight in another-largest average industry segment improvement during the entire decade, growing at the 17% clip, in accordance with the Lux forecast.
The Lux analysis suggests that CFRP technology remains expensive primarily because of high material costs-in particular the carbon-fiber reinforcements-along with slow manufacturing throughput, he reported.
“The industry has reached an appealing precipice,” he was quoted saying, wherein industrial ingenuity will vie using the traditional technical challenges to attempt to match the new demand while lowering costs and speeding production cycle times.
The best-performing carbon fibers-the greater grades used in defense and aerospace applications-get started as precisely what is called PAN (polyacrylonitrile) precursors. Due to difficulty in the manufacturing process, PAN fibers cost about $21.5/kg, in accordance with Kozarsky, who explained that makers subject the PAN to a series of thermal treatments when the material is polymerized and carbonized since it is stretched. The resulting “conversion” leaves the filaments oriented along the length 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 in the new Carbon Fiber Technology Facility at Oak Ridge National Laboratory (ORNL), which is funded with $35 million in United states Department of Energy money among the more promising efforts to decrease fiber costs. Part 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 out of low-quality plant fibers or renewable natural fibers including wood lignin, and melt-span PAN.
Near term the Lux team expects the job that ORNL has been doing with Portuguese acrylic-fiber maker FISIP (majority properties of SGL) on textile-grade PAN to attain costs on the pilot-line scale of $19.3/kg in 2013. Although significant, it might be just a modest reduction in comparison 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 since they could offer potential conversion efficiencies of 70% to 75%. If mechanical performance targets can be met, pilot-line costs of $13.8/kg may be achieved by 2017, stated the report.
The Oak Ridge group, Kozarsky said, is also concentrating on novel microwave-assisted plasma carbonization techniques that will produce useful, uniform fiber properties. And ORNL’s nonthermal plasma oxidation process is shown to have the potential to stabilize and cross-link the precursor materials rapidly and efficiently.
Polyolefin-precursor carbon fiber, along with these kinds 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 curiosity about enhancing the resin matrix also,” with research concentrating on using thermoplastics rather than existing thermosets and producing higher-toughness, faster-processing polymers.