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BMW's i3 car leads pack in SPE awards

By: By David Vink
EUROPEAN PLASTICS NEWS

November 15, 2013

NEUSS, GERMANY — BMW AG's new all-electric i3 car can be seen in German car showrooms beginning Nov. 16, and the automaker has begun a TV advertising campaign in Germany for the vehicle.

The commercial starts by showing the i8 model, due for launch in early 2014, and the i3 model driving parallel through deserted city streets. The camera then follows the i3 as it separates from the i8, with BMW praising the lightweight and strength of its carbon structure, before the camera zooms in to a view of the interior.

Weeks ahead of the official Nov. 16 launch in the show rooms, the i3 — with a 35,000 euro ($47,000) price tag — has already picked up three awards at the Society of Plastics Engineers' Central Europe "automotive awards night" on Oct. 14 in Neuss, near Düsseldorf, Germany. The awards were for both interior and exterior applications.

The car picked up first prize in the exterior category for the painted thermoplastics body panels (door, wing/fender, tailgate panels and bumper fascias), which are injection molded on KraussMaffei and Engel injection presses at BMW's plant in Leipzig, Germany. Mold tools have been supplied by ILMA Plastica srl in Varese, Italy (for door panels), Hofmann Innovation Group GmbH and BMW's plant in Landshut, Germany.

While an Engel Duo 4000 two-platen machine is used for some of the thermoplastic body panels, KraussMaffei Technologies vice president of sales, Frank Peters, told Plastics News several days after the SPE awards at the K 2013 fair that its two MX WL4000-17200/12000/750 rotary ("swiveling") platen injection molding machines are the only rotary-platen machines producing i3 body panels at BMW in Leipzig.

The i3 is the first BMW car to have an exterior skin made entirely in thermoplastic. The car's roof, however, is produced with recycled carbon-fiber-reinforced plastic (CFRP). BMW points out that it uses three different thermoplastic injection molding processes: a standard molding process; a "twin" two-component injection molding process, molding and bonding the outer skin and its substructure in separate, successive stages; and parallel injection molding of the outer skin and substructure with bonding in one automated process.

As the skins are in polar polypropylene EPDM (ethylene propylene diene monomer) elastomer modified copolymer, the material requires flame treatment to ensure good paint adhesion, prior to hand cleaning and then the application of filler, base and top-coat paint layers by robots. According to BMW, "dispensing with conventional cataphoretic dip priming [as conventionally used with metal body panels] reduces vehicle weight by [22 pounds]."

SPE's jury awarded the panels for their sustainability, the complexity of the entire exterior body panel system and the precise tolerances involved.

EPDM-modified PP talc-filled plastic used for the door panels comes from LyondellBasell Industries and Total SA, the thermoplastic elastomers used to seal door-panel skins together and the associated two-component adhesive are supplied by respectively Kraiburg TPE GmbH & Co. KG and Sika AG. Other material suppliers cited by SPE CE are Bayer MaterialScience AG, BASF AG and PPG Industries.

The i3 car also picked up two SPE CE prizes in the interior category. Use of recycled carbon-fiber composites from SGL Carbon AG to make the carbon fiber fleece reinforced polyurethane rear seat shells brought the application third place in the interior category for carbon fiber producer SGL and polyurethane supplier BASF Elastogran. The product was touted for its combination of lightweight construction and sustainability. The seat shells are produced for BMW by seating specialist F. S. Fehrer Automotive GmbH's composite components division.

In an Oct. 28 statement on the award, F. S. Fehrer pointed to the integration of a weather strip channel, an omega-shaped clamp, Isofox fastenings, cup-holder and storage receptacle functions in the thin 1.4mm single self-supporting part, saving 550 grams of weight over conventional serial parts' design. The company claims the i3 application is the first serial production use of a carbon-fiber-based material in a PU matrix. Wolfgang Ehnert, technical manger of Fehrer's composites components division, said "the technology opens up an entire range of new design and functional possibilities. Our development staff are already working on new promising applications."

Fourth place in the SPE CE automotive awards night's interior category went to the i3 for the "visible nature" interior trim parts made by Polvlies Frank Berger GmbH & Co. KG and AFP B.V., the parts being molded by in Vilsbiburg, Germany-based Dräxlmeier Interieursysteme GmbH, in molds and machinery from R & S Technik GmbH. This natural surfaced trim material is used on the door panels and on the dashboard — this being clearly seen on the dashboard in the TV commercial, and the development was praised by the SPE jury as "the first door cladding with visible natural fibers as a design element."

Isabella Schmiedel of Dräxlmaier said at the AVK Federation of Reinforced Plastics conference in Stuttgart in September that the door panels are compression molded in 50 percent kenaf-fiber-reinforced PP with 1,800 g/m² weight and covered in a 200-micrometer thick 180 g/m² PP matt transparent PP sealing layer.

The visible nature trim over air-conditioning areas on the dashboard involves an additional sealing layer on the underside, in either 100-400 micrometers PP film or a PES/PP non-woven material, Schiedel said. Dräxlmaier had earlier won a 2013 BMW innovation award for the visible nature application's reduction of petroleum-based content. Dräxlmaier also has a wood lamination decor process, but Schmiedel did not specifically link this to partial dashboard cladding in open-pored eucalyptus wood that can also be seen in the TV advertisement film.

Aside from the SPE CE awards for the mentioned exterior and interior applications, BMW has won JEC Composites and AVK Federation of Reinforced Plastics innovation awards in respectively April and September 2013 for the development and use of CFRP for the "Life Module" passenger cell structure of the i3 car.

With the larger i8 plug-in hybrid model due for launch in early 2014 with a 126,000 euro ($170,000) price tag, TV viewers will no doubt soon be seen another commercial, with the camera following the i8 as it splits off from the i3.