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4 Pressed preforms are cut to near-net shape, stapled together to maintain proper orientation during injection, and then layed up in a mold for resin transfer molding (RTM). Here, a technician loads a Life Module side-frame preform into its mold (this task is now automated) prior to resin impregnation, via Krauss-Maffei injection unit, and cure in a Schuler press. 9 As fnal assembly of the i3 begins, the carbon fber roof is lowered into position for attachment to the Life Module. 10 An i3 Life Module, with doors and glass installed, is lowered onto a Drive Module, the aluminum-framed lower section of the car that incorporates the batteries, motor and wheels. 5 In the Leipzig Body Shop, RTM'd parts for the Life Module are brought together. Before assembly begins, each side frame has hinge and crash reinforcements attached robotically. preforming, resin transfer molding (RTM) and preparation for assembly as part of the Life Module. Te most important person in the CFRP Building is a youth- ful, energetic and busy engineer named Rene Koschkar, head of production planning, carbon fber parts at BMW. Standing on a mezzanine that overlooks the composites manufacturing foor, Koschkar explained the materials, tools and equipment used to fabricate the Life Module. When kitted stacks arrive from Wackersdorf, he explained, the plies in the stacks are frst stapled together to prevent slippage and then delivered to one of three Fill Gesellschaf mbH (Gurten, Aus- tria) Preformliners in use in Leipzig. Tere, the stack is placed in a heated preforming mold where a thermoplastic binder is applied to the carbon fber. Te Fill Preformliner press then preforms the stack to conform it to the shape of the mold. Next, the preformed stack is transferred to a cutting station, where an ultrasonic knife is used to trim the preform to near-net shape. Koschkar noted, here, that BMW has worked hard to mini- mize touch labor in composites manufacturing, relying on robotics wherever possible to staple, move, place, remove and cut stacks and preforms. Tis is particularly important, he pointed out, as the i3 approaches rate production, to ensure efciency and repeatability in its manufacturing processes. Following ultrasonic cutting is the most important step in the fabrication process: high-pressure resin transfer molding (HP- RTM). Te Leipzig plant is equipped with seven 3,000-ton hy- draulic presses supplied by Schuler Pressen GmbH (Waghäusel, Germany). Each is serviced by two Krauss-Mafei (Munich, C T J U N E 2 0 1 4 2 7 0614CT IM-OK.indd 27 5/20/2014 8:35:38 AM