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Composite-body BMW i3 starts production

By: Rhoda Miel

September 18, 2013

More than a dozen years after BMW AG first introduced a concept car made in carbon fiber composites, it has launched full assembly of its i3 electric vehicle, calling it the first time that carbon fiber has been used in “volume production.”

“Today represents a milestone in our company’s development,” said BMW production chief Harald Krüger during a Sept. 18 ceremony in Leipzig, Germany.

BMW has invested more than 400 million euros ($533 million) in Leipzig alone to support the i3 assembly line. The car not only uses carbon fiber for its body panels, but also is built on a carbon fiber frame.

BMW, based in Munich, Germany, has also invested in key production at both BMW and BMW joint venture operations in Wackersdorf, Landshut and Dingolfing in Germany and Moses Lake, Wash.

Using carbon fiber rather than traditional steel for structures allowed BMW to reduce enough weight to cancel out the weight of the battery packs that power the electric engine in the i3, while still maintaining safety standards.

In a news release, the company also noted that composites will allow the company to produce cars while using 50 percent less energy and 70 percent less water, with the bulk of the environmental savings thanks to eliminating the traditional paint process used for steel or aluminum-bodied cars. The company is also using energy from wind turbines to power its production lines, so buyers will be able to not only point to reduced fossil fuel use in their driving, but also in their car’s manufacturing.

“We are completely redefining sustainability with regard to personal mobility,” Krüger said.

Delivery of the i3 to customers in Europe begins in November while North America and China will begin receiving the cars in early 2014.

To make the cars a reality, BMW had to collaborate with other firms. Its Moses Lake joint venture, SGL Automotive Carbon Fibers, is a joint venture with SGL Carbon SE, with SGL owning 51 percent of the firm which produces the textile used in the carbon fiber.

BMW also has an agreement with Boeing Co. to work together on developments for carbon fiber manufacturing simulations and automated production. Boeing, based in Seattle, uses carbon fiber throughout its manufacturing, most extensively on the 787 Dreamliner.

The same collaboration is happening throughout the auto industry as it looks for ways to use more advanced composites, said Jai Venkatesan, director of material science and engineering for Dow Chemical Co. of Midland, Mich., during the Society of Plastics Engineers’ Automotive Composites Conference & Exhibition in Novi, Mich., Sept. 11-13.

The auto industry has been using more composites to reduce weight, but while there have been some breakthroughs like BMW and General Motor Co.’s use of carbon fiber for the 2014 Corvette, the bulk of the work has been for lower volume cars or smaller parts.

Carbon fiber and other composites are a major change to the standard way of doing things in an auto industry that was built on steel, he said.

The key to major adaption will rely on improvements that will allow molders to bring cycle time from the current rate of about five minutes to less than two, Venkatesan said.

To do that, suppliers must work together to share best practices, which will allow improvements to quickly spread throughout the auto supply base. Dow itself has a collaborative research project with Dearborn, Mich.-based Ford Motor Co. to develop ways to bring faster carbon fiber manufacturing to the market.

“The only way to get through the market with what is seen as a disruptive process is to collaborate, collaborate, collaborate,” he said.