Once the BMW i3 city car rolls from the company’s Leipzig plant later this year, it will represent the 1st carbon-fiber car which will be made in any quantity-about 40,000 vehicles annually at full output. The lightweight but sturdy nonmetallic structure of the new commuter car, the effect of BMW’s joint venture with SGL Technologies in Wiesbaden, will mark a milestone in the creation of carbon-fiber-reinforced plastic (CFRP) materials, which may have traditionally been very costly to use 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 in the same manner that a skeleton of steel rebar strengthens a poured-concrete structure.
Even though 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 through the next three to five years should cut CC composite costs enough to match the ones from aluminum chassis, which still command reasonably limited over standard steel car frames.
CFRP structures weigh half that relating to 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 slice parts counts with a factor of 10, as well as the attract automakers is obvious. But despite the advantages of using CFRPs, composites cost significantly more than metals, even allowing for their lighter weight. The top 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 up-to-date 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 range between $5 to $15/kg and also the reinforcing fiber costs one more $2 to $30/kg, according to quality. To enable cars to clear the U.S. government’s fast-approaching 54.5-mpg average fuel-economy bar, automakers as well as their suppliers are striving to make methods to produce affordable carbon-fiber cars around the mass-scale.
But adapting structural composites to low-cost mass production has long been a technical and manufacturing challenge, said Ross Kozarsky, Senior Analyst at Lux Research, an unbiased research and consulting firm that is focused on emerging technologies.
Kozarsky follows composite materials and led an investigation team that just last year assessed CFRP manufacturing costs and identified potential innovations in each step of your complex process.
“Our methodology is usually to follow, through visits and interviews, the whole value chain from the tow, yarn, and grade level onwards, examining the supplier structure and the general market costs,” he explained. The Lux team then designed 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 those segments in terms of sales is ending, Kozarsky said. The wind-turbine business will contend with aerospace for your top market as larger, more-efficient offshore wind-power installations are constructed.
“It’s more economical to use bigger turbine blades, which may only be made using carbon-fiber materials,” he noted.
The Lux report predicted that this global industry for CFRPs will more 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. In the same period, requirement for carbon fiber is expected to increase fourfold from your 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 a dozen smaller Chinese companies.
“A lot of folks are talking about automotive uses now, which is totally with the other end of the spectrum from aerospace applications, since it comes with a much higher volume and many 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 with a 17% clip, according to the Lux forecast.
The Lux analysis suggests that CFRP technology remains expensive due to the fact of high material costs-particularly the carbon-fiber reinforcements-as well as slow manufacturing throughput, he reported.
“The industry has reached an intriguing precipice,” he said, wherein industrial ingenuity will vie together with the traditional technical challenges in order to meet the new demand while lowering costs and speeding production cycle times.
The best-performing carbon fibers-the higher grades utilized in defense and aerospace applications-get started as what exactly is called PAN (polyacrylonitrile) precursors. As a result of difficulty in the manufacturing process, PAN fibers cost about $21.5/kg, in accordance with Kozarsky, who explained that makers subject the PAN to several thermal treatments where the material is polymerized and carbonized as it is stretched. The resulting “conversion” leaves the filaments oriented along the size of the fiber to give it the optimal strength and toughness. Various post-processing stages and also 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), which has been funded with $35 million in Usa Department of Energy money as among the more promising efforts to lessen fiber costs. Section of the project would be to identify cheaper precursor materials that can be processed into good-quality fibers (see “Oak Ridge collaborates for cheaper carbon fiber,”. The blueprint would be to test many types of potential low-cost fiber precursors for example the cheaper polymers, inexpensive textiles, some produced from low-quality plant fibers or renewable natural fibers for example wood lignin, and melt-span PAN.
Near term the Lux team expects the project that ORNL has been doing with Portuguese acrylic-fiber maker FISIP (majority properties of SGL) on textile-grade PAN to accomplish costs in the pilot-line scale of $19.3/kg in 2013. Although significant, it might be only a modest reduction when compared to the 50% needed for penetration in high-volume auto applications.
One of the main limitations of PAN, he stated, is that “at best 2 kg of PAN yields 1 kg of carbon fiber, that gives you with a conversion efficiency of only 50%.” Dow Chemical is investigating dexnpky63 polyolefins-polyethylene, polypropylene-as the feedstock since they could offer potential conversion efficiencies of 70% to 75%. If mechanical performance targets could be met, pilot-line costs of $13.8/kg might be achieved by 2017, stated the report.
The Oak Ridge group, Kozarsky said, can also be 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, 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 lot of fascination with increasing the resin matrix as well,” with research concentrating on using thermoplastics rather than existing thermosets and producing higher-toughness, faster-processing polymers.