1 Carbon Fibre

8/12/2019 1 Carbon Fibre

1/5

Chemical & Engineering News

Serving the chemical, life sciences and laboratory worlds

Cover Story

Home September 26, 2011 Issue Cover Story Getting The Steel Out

Advertisement

Advertise Here

September 26, 2011

Volume 89, Number 39pp. 10 - 14

Getting The Steel Out

Automakers push ahead on energy-saving carbon fiber composites

despite questions of economic viability

Marc S. Reisch

SGL Group

Fiber FactorySGL Carbon produces industrial and sporting-good grades of carbon fiber. Here, a worker

monitors production at the firms carbon fiber plant in Muir of Ord, Scotland.

The Lamborghini Sesto Elemento sports car, set to go into limited production late next year, will harness a

powerful V10 engine to accelerate from zero to 60 mph in 2.5 seconds. Its cousin, the Gallardo LP 560-4 Spyder, takes

1.5 seconds longer to get up to that speed. The biggest difference between the two is that the Sesto is a carbon fiber car

weighing in at just 2,200 lb. The aluminum-framed Spyder weighs a hefty 3,417 lb.

ng The Steel Out | Cover Story | Chemical & Engineering News http://pubs.acs.org/cen/coverstory/89/8939cover.html?f

10/2/2011


2/5

Buyers of the Sesto will benefit from corrosion-free composites similar to those that also fill out the f rames of big

planes such as the new Boeing787 Dreamlinerand theAirbusA350. Although most drivers cant afford a

Lamborghinimuch less the $3 million Sesto Elementothey may yet have their chance at buying an affordable

carbon-fiber-based vehicle.

Automakers are increasingly looking to combine emis sion-limiting propulsion technologies with stif f, lightweight

carbon composite frames. Their hope is that the new components will replace steel and aluminum in the assembly of

energy-efficient hybrid and all-electric vehicles.

Not everyone thinks automakers will succeed with carbon fiber cars. Anthony J. Roberts, an expert in carbon fiber

technology who heads AJR Consultant, argues that a lot of the talk about automotive use of carbon fiber is hype

meant to make companies look environmentally responsible.

As Roberts points out, carbon fiber is expensive. Its generally made by polymerizing the petrochemical acrylonitrile

into polyacrylonitrile, or PAN. PAN is then extruded into fibers and carbonized in a high-tech oven. The fiber is next

woven into a preformed part and then infused with epoxy or other resins.

Industrial-grade carbon fibers suitable for use in cars cost close to $30 per kg, Roberts says. High-end vehicle builders

can afford expensive carbon fiber parts. But how many people will really spend an extra $5,000 to $6,000 beyond the

usual cost for a small car to own an electric car with a carbon composite body? he asks.

Although Roberts is skeptical, several automakers are pushing ahead with plans to make carbon fiber composites an

integral part of a new generation of electric cars intended mostly for inner-city use. They will be going beyond

fiberglass composite body panels, already found in some cars, to create structural composite components that are nowthe province of metal.

In 2013, BMWplans to launch two mass-produced vehicles with carbon fiber composite passenger cages: the battery-

powered i3, formerly known as the Megacity, and the hybrid i8, which can run on batteries or an internal combustion

engine. Two years ago, the carmaker formed a joint venture with carbon fiber maker SGL Carbonto make carbon fiber

parts for the i3 series.

SOURCE: AJR ConsultantView Enlarged ImageFiber SupplementsDemand for industrial carbon fiber is expected to increase from 40% to 70% of market.

Similarly, automaker Daimlerstarted a joint venture earlier this year with Japanese carbon fiber producer Toray

Industriesto develop mass production techniques for carbon fiber-reinforced components. The partners plan to start

producing parts for Mercedes-Benzpassenger vehicles next year. Daimler has also hooked up with resins maker BASF

to design an all-electric concept vehicle, the Smart Forvision, with a passenger cage and doors made of carbon fiber

composites.

Audi, the high-endVolkswagenbrand, plans to incorporate more carbon fiber into mass-produced cars. Earlier this

year,Audiformed a partnership withVoith, a German machinery parts maker, to develop an automated process chain

to make high-volume carbon fiber car parts.

Resin makersare also eager to get in on the action surrounding carbon fiber composites. Earlier this month,Huntsman Advanced Materialssaid it was launching a multi-million-dollar engineering study to expand its McIntosh,

Ala., epoxy manufacturing facility so it can meet growing demand from composite makers. A few months ago, BASF

invested more than $10 million in a research team to advance development of lightweight composites for the auto

industry.

In June, epoxies producer Dow Chemicalsaid it intends to form a joint venture with Turkish carbon fiber maker Aksa

Akrilik Kimya Sanayii. Although the two firms have been light on details, automotive use of carbon fibers and

derivatives is one of the opportunities behind their cooperative effort.

The U.S. government is also flexing its muscle to push carbon fiber technology. Oak Ridge National Laboratoryhas

spent a decade on developing alternative carbon fiber feedstocks and lower energy fiber production processes. The lab

is building a $35 million pilot carbon fiber facility and recently held the first meeting of a consortiumintended to


10/2/2011


3/5

transfer technology developed at the lab to industry.

BASF

VisionaryBASF and Daimler collaborated on the Smart Forvision concept electric vehicle, which features a

carbon epoxy passenger cell and doors.

Consultant Roberts says automotive applications are now just a tiny portion of the industrial carbon fiber market,

which he sets at roughly 16,000 metric tons per year. Total global f iber demand, including aerospace and sporting

goods, is about 40,000 tons. He projects that overall fiber demand will nearly quadruple by 2020. Industrial fiber

demand is likely to increase almost sevenfold to 105,000 tons.

However, much of the industrial growth, Roberts predicts, wont come from the auto industry. More promising

markets, he says, include turbine blades for offshore wind energy projects, compressed natural gas storage tanks, and

components for deep-sea oil-drilling platforms. Big automakers have been looking at carbon fibers since the

mid-1970s, he says, and have never really gotten serious about them.

But many automakers believe the time for automotive carbon fiber composites has come. Stefan Kienzle, who heads

materials manufacturing at Daimler Research & Advanced Engineering, says that Daimler started to use carbon fiber

composites a decade ago. Today, were prepared for broader use, he says. As Kienzle sees it, the three most

important reasons to use carbon fiber composites are their light weight, their safety potential, and the reduction in

the number of parts needed to assemble a car.

Many automakers believe the time for automotive carbon fiber composites has come.

Less weight means lower vehicle energy consumption. Properly designed carbon fiber parts are so strong they will

easily carry the weight of batteries and electric propulsion systems while also protecting passengers in the event of a

crash. In addition, one composite component often can replace four metal components, reducing assembly time andcost.

Using Torays resin transfer molding process and Daimlers auto production expertise, the partners expect to speed up

composite part making and cut the $125-per-kg cost by more than half. Thats still much higher than the $7.00 per kg

it costs to make a steel part. But add in cost savings from assembly and tooling and Daimler figures it can produce a

competitively priced composite part.

The firm had another important reason to tie up with Toray: It needed a guaranteed source of carbon fiber, Kienzle

says, and Toray is the top global producer. In the past, industrial-grade carbon fiber users have been left in the lurch

as companies rushed to fill large orders for high-priced aerospace-grade fiber.

Although Daimler has produced carbon-fiber-based carsthe high-end Mercedes-Benz SLR McLaren is a notable

examplecarbon fibers use in mass production vehicles so far has been limited to nonstructural components.

Like Daimler,BMW expects to change that. When the German firm introduces the i series cars in 2013, they will

contain carbon fiber drawn from a production line that stretches from PAN synthesis in Otake, Japan, to fiber

production in Moses Lake, Wash., and woven preform manufacturing in Wackersdorf, Germany. SGL Automotive

Carbon Fibers, BMWs joint venture with SGL, has invested about $135 million so far in the facilities, according to

Andreas W uellner, one of two managing directors of the venture.

Both sides will benefit, Wuellner explains. SGL gets to deepen its involvement in the industrial carbon fiber sector,

and BMW gets an ensured supply of fiber and textile preforms for car parts. The carbon fiber composite parts that

BMW will manufacture in Landshut, Germany, will be 50% lighter than steel and 30% lighter than aluminum,

Wuellner says.


10/2/2011


4/5

The supply chain is long and a bit complex, Wuellner admits, but it has certain advantages. SGL joined with

Mitsubishi Rayon, an established maker of PAN and carbon fiber, to build the Otake PAN plant. It will supply

feedstock for the Moses Lake fiber plant, which will run on low-cost, renewable hydroelectric power. Transportation

costs and environmental impact will be kept under control, he says, by shipping materials by boat and rail each step of

the way from Japan to Germany.

Overall, the partners say, the emissions of the all-electric BMW i3, from manufacturing to the end of its life, will be

one-third less than those of a comparable vehicle with a high-efficiency internal combustion engine. If the car were to

consume electricity solely from hydropower or photovoltaic sources, emissions would be 50% less, they assert.

Resin makers such as BASF say they are working on technologies to speed up the curing of epoxy fiber parts. Christian

Fischer, president of polymer research at BASF, says the company has developed specialty epoxies for the resin

transfer molding process. The resins quickly and completely saturate a woven preformed part, preventing dry areas

that might negatively affect mechanical properties, he says. Only then is the curing process initiated with heat.

Although thermoset epoxies are the m ost advanced of the resins used to create carbon fiber composites, BASF is also

working on polyurethane and nylon systems. Fischer says thermoplastic resins are especially promising because they

would facilitate end-of-life recycling of composite parts.

Huntsman, a significant supplier of epoxies for aerospace composites, has developed new epoxies suited for

automotive parts, says Marketing Manager Klaus Ritter. Our main focus is to speed the resin curing process, he

says, from 10 minutes to 60 seconds.

BMWView Enlarged Image

ElectrifyingThe BMW i8 (left), a hybrid electric vehicle, and the i3, a plug-in electric, are set to debut in 2013.

As chemical makerssuch as BASF and Huntsman look to improve the resins used in composites, others have been

working on ways to reduce carbon fiber precursor and processing costs. For example, carbon fiber producer Zoltek hasa project with papermaker Weyerhaeuser to turn low-cost lignin left over from paper production into a carbon fiber

precursor. That project is slated to receive $3.7 million in financial assistance from the Department of Energy.

One of the longer-running efforts to lower the cost of carbon fiber has been going on at DOEs Oak Ridge National

Laborataory since the late 1990s. The lab has explored both the development of alternative fiber precursors and ways

to lower fiber processing and carbonization costs. Achieving those goals would contribute to U.S. energy independence

through such things as lighter-weight vehicles and high-performance windmill blades, says Tom Rogers, the labs

director of commercialization strategy partnerships.

Cliff Eberle, composite materials technology development manager at Oak Ridge, tells C&EN that almost all carbon

fibers today are made from PAN in a high-energy process. After fiber formation, about 50% of the fiber mass is lost

during the carbonization treatment.

Among the projects the lab has worked on is the development of polyethylene-based precursors that contain more

carbon by weight than PAN and are easier to process. The resulting fibers, which have about half the performance of

PAN-based fiber, would be good for auto body panels but not structural components, Eberle suggests. However, the

labs target is to develop higher-performing fibers for use in structural components.

Lignin precursors are plentiful, inexpensive, and not derived from oil, but are particularly challenging, he says,

because the quality varies greatly depending on the plant source, where the plant is grown, and the season of

harvest. PAN lends itself to making a good fiber, but lignin is a complex molecule, and it is hard to get it to build the

ladder structures we want, he says.

Oak Ridge has also worked on technologies to reduce the time and energy needed to make carbon fiber by a factor of

two or three, Eberle says. The use of plasma and microwave heat treatments could both speed up the process and


10/2/2011


5/5

lower overall processing costs, he says.

The Carbon Fiber Composite Consortium, which Oak Ridge lab managers created as a technology exchange and

transfer organization, met with 26 members for the first time this month. Among the major fiber makers, SGL and the

Toho Tenaxdivision of Japans Teijinare members. Also members are U.S.-based carbon electrode maker GrafTech

Internationaland petrochemical maker Saudi Basic Industries Corp., which plans to build a carbon fiber plant in Saudi

Arabia based on technology licensed from Italys Montefibre.

Dow and 3Mare among the resin makers that have joined the consortium. The others are mostly parts

manufacturers such asAdvanced Composites Groupand finished good suppliers such as office furniture maker

Steelcaseand French car seat maker Faurecia.

The consortium has its critics, however. Zsolt Rumy, president of Zoltek, says he is unconvinced of the benefit in

joining. Weve made more progress on lignin precursor research in six months than the Oak Ridge Lab did over the

last few years, he contends.

Dee James (D. J.) DeLong, former general manager of BP Amoco Carbon Fibers, which was bought by Cytec

Industries in 2004, says he is skeptical of efforts to develop alternative fiber feedstocks that require a lot of

processing. He is even more leery of exotic microwave and plasma carbonization techniques, when electric furnaces

suffice. DeLongs company, DeLong & Associates, is now the U.S. carbon fiber distributor for Turkeys Aksa.

Others are on the fence about taking part in the consortium. We dont see much there yet, says Billy Harmon, R&D

director for Cytec Carbon Fibers, which focuses mostly on aerospace-grade fiber. But we are negotiating with them

now and may join them in the future.

If carbon fiber makers hope to gain more than a toehold in the auto market, theyll have to make efforts on their own

or with industry consortia to make composites more affordable. A lignin-based carbon fiber costing 30% less than

PAN-based fiber would be an enormous breakthrough enabling even the most cost-conscious carmakers to use

composites, Daimlers Kienzle argues. I think the chemical industry has to do more homework on the basic material

for carbon fibers to bring costs down, he says.

Chemical & Engineering News

ISSN 0009-2347

Copyright 2011 American Chemical Society

Advertisement


Documents

1 Carbon Fibre