CompositesWorld
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FEBRUARY 2016 8 CompositesWorld Boeing Aerostructures Australia leads large- scale development of resin infusion as an industrial process. Resin Infusion: Taking off? » Resin infusion is not yet widely used in aerospace applications, but where it is, it provides great economic advantage on highly loaded, critical components. Premium Aerotec (Augsburg, Germany) is producing the rear pressure bulkheads for Te Boeing Co.'s (Chicago, IL., US) 787 Dreamliner and the Airbus (Toulouse, France) A350 XWB, and is using the Airbus-patented Vacuum Assisted Process (VAP) to build the Airbus A400M cargo door. A similar process has been demonstrated by FACC (Ried im Innkreis, Austria) in the DAEDALUS program for an integrated A350 spoiler, and one is being certifed by Aerocom- posit (Moscow, Russia) for the wing and wingbox of the Irkut (Moscow, Russia) MS-21 single-aisle jet (for more on all, see "Learn More," p. 9). Te Mitsubishi Regional Jet (MRJ) program also has developed the advanced vacuum-assisted resin transfer molding (A-VaRTM) process for the aircraft's vertical tail, citing not only productivity improvements but also weight reduction in primary structures. Specifcally, dry fabrics are said to be easier to ft into 3D geometries with ply drop- ofs, reducing the risk of wrinkles commonly seen with prepreg. Proponents of A-VaRTM and several other liquid molding processes are developing a hot compaction process step to densify the preform while shaping it and melting any thermoplastic binder in the dry fabrics to achieve fber volume fractions on par with conventional prepreg processing. Boeing Aerostructures Australia (BAA, previously Hawker de Havilland, Melbourne, Victoria) produces the only other resin-infused structure currently fying on a commercial aircraft, the movable trailing edge (MTE) on the Boeing 787. Te MTE is actually an assortment of separately molded parts that includes the aileron, faperon, inboard and outboard faps, seven spoilers and all of the fairings. Te largest of these parts is the 10m-long by 4m-wide outboard fap. A Boeing subsidiary since 2000, BAA began collabo- rating with the Australian government-funded Coop- erative Research Centre for Advanced Composite Structures (CRC-ACS, Melbourne) in the 1990s to modify the marine industry's VARTM process for aerospace use. Central to its 2003 win of the US$5 billion, 20-year, sole-supplier contract for the B787 MTE, the public/private research efort demonstrated full-scale, resin-infused structures that meet aero- space-quality requirements while integrating multiple components into single, unitized parts, thus reducing assembly labor, time and cost. Computer modeling and process simulation enabled designers to address production issues early and reduce testing, resulting in signifcant cost savings. In 2008, Boeing invested further in infusion by establishing its largest R&D; facility outside the US in Port Melbourne, Victoria. Boeing Research and Technology – Australia (BR&T-A;) now focuses on resin infusion and advanced robotics and automation. "Resin infusion technology enables use of lower cost materials ... without the need for expensive auto- claves," said David Pook, Melbourne Tech Centre manager for BR&T-Australia.; Using Hexcel's (Stamford, CT, US) HexRTM6 epoxy resin and a specially developed HexForce 12K spread- tow carbon fber fabric, BAA uses a modifed form of VARTM, Boeing's patented Controlled Atmospheric Pressure Resin Infusion (CAPRI). Tis reportedly By Ginger Gardiner / Senior Editor OUT OF AUTOCLAVE SUPPLEMENT