Composites Europe sheds light on emerging automotive composites

Carbon fiber used in automotive hoods and other parts took center stage at the 2013 Composites Europe trade show in Stuttgart, Germany.

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Composites Europe (Sept. 17-19, Stuttgart, Germany) has grown substantially over the past few years, maturing into a full-fledged trade show that attracts many of the composites industry’s biggest players. The flavor remains German, but given the large amount of composites R&D done in that country, the location is a favorable one.

Activity on the show floor emphasized the industry’s interest in automotive applications. Several car hoods were on display, each designed to demonstrate a different material and process combination. A notable example was a carbon fiber/epoxy hood design developed by the Institut für Kunststoffverarbeitung (Aachen, Germany) and machinery maker Breyer Composites (Singen, Germany) in cooperation with Dearborn, Mich.-based Ford Motor Co. The hood’s molding process employs a gap impregnation technique. A preform is loaded into a horizontal press from Breyer. The press is closed, but not fully, and the preform is supported 3 mm/0.12 inch above the mold surface by a series of pins located on each side of the mold. Epoxy is injected into the mold cavity at the bottom of the tool until the resin fills about a third of the space in the mold. The pins then retract and the mold closes completely. The resin is forced up into the rest of the cavity and infuses the entire preform. Heat is provided via circulating hot water. The total cycle time is 15 minutes, and the demolded hood is ready for paint. There is no word on whether Ford will put this part into production.

Taking a different tack, engineering and manufacturing firm Magna Steyr (Oberwaltersdorf, Austria) and partners Rühl Puromer (Friedrichsdorf, Germany), which contributed polyurethane resin knowledge, and Hennecke (Sankt Augustin, Germany), the molding equipment supplier, developed a demo hood based on glass fiber/polyurethane cored with paper honeycomb. Hennecke officials say their goal is not to save weight, but rather to accelerate production and meet European pedestrian-impact requirements. The core and fiber are inserted into the mold and surrounded by a gap of 0.8 to 1 mm (0.032 to 0.039 inch). Polyurethane is injected into the gap, then it is pressed and cured. The process results in a finished part with a Class A surface every five minutes.

Moldmaker Frimo (Lotte, Germany) split the difference, showing its own demo hood that comprises carbon fiber faceskins and a foam core from 3D Core (Herford, Germany) infused with foaming polyurethane in a low-pressure process. Paint is applied in-mold, so the parts emerge finished with a highly textured surface. The process, say Frimo officials, has a five-minute cycle time.

A fully assembled, functional BMW i3 electric-powered commuter car was on exhibit and SGL Group (Wiesbaden, Germany) introduced a line of nonwoven carbon fiber fabrics manufactured from scrap generated during i3 production.  A stitched variation is used in the i3 roof.

Continuing the automotive theme, TenCate Advanced Composites (Nijverdal, The Netherlands) and Kringlan Composites AG (Otelfingen, Switzerland) reported that they had signed a memorandum of understanding to develop solutions for manufacturing parts based on thermoplastic composites. Kringlan, with TenCate’s help, designed and manufactured a fully carbon fiber-reinforced composite wheel. It includes a single-shot rim and a spoke module that is assembled and bonded separately before integration with the rim. The process is based on press molding and produces a wheel every 10 minutes, offering a 30 to 40 percent weight savings compared to aluminum wheels. Series production is expected in 2014 for a high-end sports car. The fiber is T700 from Toray Industries (Tokyo, Japan). The resin is supplied by SABIC (Sittard, The Netherlands).

A new trade group was announced at the show. Composites Germany, formed by AVK-Industrievereinigung Verstärkte Kunststoffe eV, Carbon Composites eV, CFK-Valley Stade eV and Forum Composite Technology in the VDMA, will focus on public relations, technology innovation and promotion, trade fairs and training. Organization officials also pledged to work with government officials in Berlin, Germany, and Brussels, Belgium, to raise the profile of composites among political leaders.