MUNICH – To many, “i” was just a letter of the alphabet – until it was used by a then unknown computer company to skyrocket to the global position Apple holds today. And now BMW is hoping to go far on “i” too, investing billions in the i3 electric car due to come onto the market by the end of the year.
The four-door compact with an aluminum chassis and carbon fiber body will be a first in environmentally friendly mobility. “This is a bigger step than going from horse-drawn carriages to motor vehicles,” says BMW CEO and Chairman of the Board of Management Norbert Reithofer.
So far BMW is the only mass producer of carbon-fiber-reinforced plastic, or CFRP, bodywork. Makers of racing cars like McLaren and Lamborghini use the material, but that’s auto-industry haute couture as opposed to assembly line production – and at BMW’s Leipzig factory, the i3 is going to roll off the lines at the same speed as conventional car bodies.
It’s a big difference, and if the Bavarian car company succeeds in its bid to enter the carbon-fiber age it would be light years ahead of competition like Audi, Volkswagen and Daimler. Its “i” project could even usher in a new industrial era.
But there’s a long way to go before that happens. The global carbon-fiber market is very small. By way of comparison: Per year, 1.3 billion tons of steel are processed, and 40 million tons of aluminum – but only 40,000 tons of carbon fiber. And BMW needs more than 30,000 tons.
Supplying that quantity in tailor-made quality is quite simply too much for providers. And since purchasing poses a problem, says BMW’s Dennis Baumann, head of business development, the car manufacturer decided to make its own CFRP together with specialists SGL Carbon.
Hanging by a thread
Producing carbon fiber is energy-intensive, but because from the beginning of its “i” project BMW has been playing the sustainability card, only a climate-neutral production process is possible. After all, the environmentally friendly marketing pitch for i-models has to be credible. So the completely new factory that BMW and SGL are operating some two hours out of Seattle in Moses Lake, in the U.S. state of Washington, was built and will be operated in accordance with state-of-the-art sustainability principles, with a hydroelectric facility supplying SGL Automotive Carbon Fibers with “green” power.
The raw material, or precursors, used – petroleum-based carbonaceous acrylic fiber — comes from Japan. In Moses Lake, all that is not carbon is burned out of these fibers from dozens of rolls in four oxidation ovens each of which is 15 meters (49 feet) long, nine meters (29.5 feet) high, weighs 80 tons and is operating at 300° C. After going through two more high-temperature ovens (800°C and 1,300°C) the carbon fibers are 40 times stronger than steel — a car could be suspended from a strand no wider than a shoe lace.
The black fibers are then wound around huge spools for the trip to Germany, specifically to a kind of textile factory located in Oberpfalz. Here BMW has undertaken another pioneering project in automobile production, with a vast sewing machine that joins the strands together to make mats weighing anywhere from 150 to 600 grams (5 to 21 ounces) per square meter. The mats are then soaked in synthetic resin and molded. BMW i-models will weigh some 300 kilograms (660 pounds) less than if the bodies were made with conventional materials. In addition to race cars, CFRP has for years also been used in the manufacture of planes and boats.
BMW’s competition is of course also using some carbon fiber in its models, for example for trunk lids, roofs and spoilers. But because they’ve gotten no further than that, BMW is not admitting anyone to the production facility where the carbon fiber is formed into car bodies at costs that still make the cars viable for mass distribution.
Indeed, plenty of automobile engineering experts are skeptical that it can actually be done. The race is on.
