When the BMW i3 city car rolls out from the company’s Leipzig plant later this season, it can represent the first carbon-fiber car that might be made in any quantity-about 40,000 vehicles a year at full output. The lightweight but sturdy nonmetallic structure in the new commuter car, the effect of BMW’s joint venture with SGL Technologies in Wiesbaden, will mark a milestone in the introduction of carbon-fiber-reinforced plastic (CFRP) materials, that have traditionally been very expensive to be used in automotive mass production.
CFRPs are engineered materials which are fabricated by embedding webs of carbon fiber inside molded polymer resins. The fibers bolster the physical properties of your plastic matrix component in the same manner that the skeleton of steel rebar strengthens a poured-concrete structure.
Although 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 match those of aluminum chassis, which still command a premium over standard steel car frames.
CFRP structures weigh half that from steel counterparts along with a third less than 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 interest automakers is obvious. But despite the advantages of using CFRPs, composites cost far more than metals, even allowing for their lighter weight. Our prime prices have thus far limited their use to high-performance vehicles for example jet fighters, spacecraft, racecars, racing yachts, exotic sports cars, and notably, the newest 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 yet another $2 to $30/kg, based on quality. To permit cars to remove the United states government’s fast-approaching 54.5-mpg average fuel-economy bar, automakers along with their suppliers are striving to make approaches to produce affordable carbon-fiber cars in the mass-scale.
But adapting structural composites to low-cost mass production is definitely a technical and manufacturing challenge, said Ross Kozarsky, Senior Analyst at Lux Research, an unbiased research and consulting firm that targets emerging technologies.
Kozarsky follows composite materials and led an investigation team that a year ago assessed CFRP manufacturing costs and identified potential innovations in each step from the complex process.
“Our methodology is usually to follow, through visits and interviews, the full value chain from your tow, yarn, and grade level onwards, examining the supplier structure as well as the general market costs,” he explained. The Lux team then developed a cost model that mixes material, capital expenditure, infrastructure, labor, and utility consideration and the chances for cost reductions.
Even though the sporting goods, military, and aerospace industries have traditionally developed and first applied composite materials, the pre-eminence of those segments in terms of sales is ending, Kozarsky said. The wind-turbine business will contend with aerospace to the top market as larger, more-efficient offshore wind-power installations are constructed.
“It’s more economical to make use of bigger turbine blades, which can basically be made using carbon-fiber materials,” he noted.
The Lux report predicted that this global industry for CFRPs will over double from $14.6 billion in 2012 to $36 billion in 2020, as innovative new production technologies lower carbon-fiber costs-the major cost-driver. Throughout the same period, requirement for carbon fiber is anticipated to rise 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 lots of individuals are talking about automotive uses now, which can be totally at the other end of the spectrum from aerospace applications, since it features a higher volume and much more cost-sensitivity,” Kozarsky said. After having a slow start, the auto industry will like another-largest average industry segment improvement through the entire decade, growing in a 17% clip, according to the Lux forecast.
The Lux analysis suggests that CFRP technology remains expensive primarily because of high material costs-particularly the carbon-fiber reinforcements-in addition to slow manufacturing throughput, he reported.
“The industry has reached a fascinating precipice,” he was quoted saying, wherein industrial ingenuity will vie with all the traditional technical challenges to try and fulfill 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-start out as what is called PAN (polyacrylonitrile) precursors. As a result of difficulty from the manufacturing process, PAN fibers cost about $21.5/kg, according to Kozarsky, who explained that makers subject the PAN to a number of thermal treatments where the material is polymerized and carbonized because it is stretched. The resulting “conversion” leaves the filaments oriented along the size of the fiber allow it the ideal strength and toughness. Various post-processing stages and 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 was funded with $35 million in United states Department of Energy money as among the more promising efforts to lower fiber costs. Portion of the project is to identify cheaper precursor materials that may 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 work that ORNL has been doing with Portuguese acrylic-fiber maker FISIP (majority owned by SGL) on textile-grade PAN to obtain costs on the pilot-line scale of $19.3/kg in 2013. Although significant, it might be merely a modest reduction if compared to the 50% necessary for penetration in high-volume auto applications.
One of the major limitations of PAN, he explained, is that “at best 2 kg of PAN yields 1 kg of carbon fiber, which supplies a conversion efficiency of only 50%.” Dow Chemical is investigating dexnpky63 polyolefins-polyethylene, polypropylene-as being the feedstock mainly because they could offer potential conversion efficiencies of 70% to 75%. If mechanical performance targets could be met, pilot-line costs of $13.8/kg may be achieved by 2017, stated the report.
The Oak Ridge group, Kozarsky said, can also be taking care of novel microwave-assisted plasma carbonization techniques that could produce useful, uniform fiber properties. And ORNL’s nonthermal plasma oxidation process can have the potential to stabilize and cross-link the precursor materials rapidly and efficiently.
Polyolefin-precursor carbon fiber, along with these types 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 fascination with increasing the resin matrix at the same time,” with research focusing on using thermoplastics rather than existing thermosets and producing higher-toughness, faster-processing polymers.