If the BMW i3 city car rolls out from the company’s Leipzig plant later this coming year, it is going to represent the 1st carbon-fiber car that will be created in any quantity-about 40,000 vehicles per year 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 development of carbon-fiber-reinforced plastic (CFRP) materials, that have traditionally been too costly for usage in automotive mass production.
CFRPs are engineered materials which can be 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 that a 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 throughout the next 3 to 5 years should cut CC composite costs enough to suit those of aluminum chassis, which still command limited over standard steel car frames.
CFRP structures weigh half that relating to steel counterparts plus a third below aluminum ones. Add the inherent corrosion resistance of composites as well as the ability of purpose-designed, molded components to slice parts counts from a factor of 10, and the attract automakers is obvious. But despite the key benefits of using CFRPs, composites cost significantly more than metals, even making it possible for their lighter weight. Our prime prices have thus far 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 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 also the reinforcing fiber costs one more $2 to $30/kg, dependant upon quality. To enable cars to remove the U.S. government’s fast-approaching 54.5-mpg average fuel-economy bar, automakers and their suppliers are striving to create approaches to produce affordable carbon-fiber cars about 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, a completely independent research and consulting firm that targets emerging technologies.
Kozarsky follows composite materials and led research team that this past year assessed CFRP manufacturing costs and identified potential innovations in each step of the complex process.
“Our methodology is to follow, through visits and interviews, the entire 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 designed a cost model that combines material, capital expenditure, infrastructure, labor, and utility consideration and also 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 the segments when it comes to 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 built.
“It’s less expensive to use bigger turbine blades, that may only be made using carbon-fiber materials,” he noted.
The Lux report predicted that the global niche 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 major cost-driver. During the same period, need for carbon fiber is anticipated to go up fourfold in 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 more than twelve smaller Chinese companies.
“A great deal of folks are speaking about automotive uses now, which can be totally with the opposite end of the spectrum from aerospace applications, since it possesses a much higher volume and more cost-sensitivity,” Kozarsky said. Right after a slow start, the car industry will enjoy the second-largest average industry segment improvement through the entire decade, growing in a 17% clip, in accordance with the Lux forecast.
The Lux analysis suggests that CFRP technology remains expensive mainly because of high material costs-especially the carbon-fiber reinforcements-along with slow manufacturing throughput, he reported.
“The industry has reached an interesting precipice,” he was quoted saying, wherein industrial ingenuity will vie with all the traditional technical challenges to try to meet the new demand while lowering costs and speeding production cycle times.
The very best-performing carbon fibers-the higher grades used in defense and aerospace applications-start off as precisely what is called PAN (polyacrylonitrile) precursors. Due to the difficulty of the manufacturing process, PAN fibers cost about $21.5/kg, based on Kozarsky, who explained that makers subject the PAN to a series of thermal treatments when the material is polymerized and carbonized because it is stretched. The resulting “conversion” leaves the filaments oriented along the length of the fiber allow it the perfect 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), which has been funded with $35 million in Usa Department of Energy money as among the more promising efforts to reduce fiber costs. Area 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 blueprint is always to test various 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 such as 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 owned by SGL) on textile-grade PAN to achieve costs at the pilot-line scale of $19.3/kg in 2013. Although significant, it could be merely a modest reduction in comparison to the 50% required for penetration in high-volume auto applications.
One of the leading limitations of PAN, he explained, is the fact “at best 2 kg of PAN yields 1 kg of carbon fiber, which supplies that you simply conversion efficiency of only 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 could be met, pilot-line costs of $13.8/kg could possibly be achieved by 2017, stated the report.
The Oak Ridge group, Kozarsky said, is also taking care of novel microwave-assisted plasma carbonization techniques that can produce useful, uniform fiber properties. And ORNL’s nonthermal plasma oxidation process is shown to have the possibility to stabilize and cross-link the precursor materials rapidly and efficiently.
Polyolefin-precursor carbon fiber, put together 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 lot of curiosity about improving the resin matrix at the same time,” with research working on using thermoplastics instead of the existing thermosets and producing higher-toughness, faster-processing polymers.