CompositesWorld

NOV 2017

CompositesWorld

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NEWS 31 CompositesWorld.com Reconfigurable Tooling & Fixtures Molding a new paradigm In one sense, reconfigurable mold tools have always been with us. ose who mold flat panels, both solid and sandwich-style configu- rations, learned early on that flat tables fitted with repositionable x and y borders made relatively inexpensive adjustable, reusable tooling systems. But for parts with dimensional and geometric complexity, not to mention a potential order of magnitude greater expecta- tion in terms of dimensional accuracy, things haven't been so simple. Nevertheless, adapt- able tooling has taken form on two distinct application fronts. One is molds for preheating, consolidation and/or cure that can be reshaped and reused. is type is especially of interest for low- volume/one-off production of curved struc- tures (e.g., yacht hulls, architectural facades). e second front of the reconfigurable/ adaptable push continues a long tradition: Reconfigurable/flexible assembly tooling has been researched for composite aerostructures production since the late 1980s. e large, permanent steel frames used to manufacture complex composite aircraft structures today are being transformed into automated fixtures made from reusable and reconfigurable modules. ese recent technology advances have been driven by the commercial aircraft industry's need to meet high production rates (e.g., 50-60 aircraft/month). Reshapable, reuseable molds e hot topic on the reshapable/reusable mold tool front is multipoint forming (MPF). MPF has been used to shape sheet metal for decades. Featuring reconfigurable dies comprising numerous pins, MPF realizes the desired tooling surface geometry by adjusting individual pin height. is technology is now used by BMW AG (Munich, Germany) to shape preheated carbon fiber/epoxy prepreg patches before they are simultaneously bonded and cured onto steel B-pillars in its Carbon Core hybrid composite/metal body-in-white for its 7 Series cars (see Learn More). Although a variety of companies and research organizations have pursued adaptation of MPF to composites, MPF recently has been commercialized by ADAPA (Aalborg, Denmark) and is now used by Curve Works (Zoetermeer, e Netherlands) to eliminate recurring tooling costs and, as a result, make production of one-off, 3D curved panels affordable. Retrospectively, Surface Generation (Lyndon, UK) applied MPF to composites moldmaking in 2005 via its Subtractive Pin Tooling (SPT) technology (see Learn More). Instead of milling a tool from solid metal billets, SPT delivered precision molds, and did so in days rather than months. Delft University of Technology (TU Delft, Delft, e Netherlands) and the University of Birmingham (Birmingham, UK) also pursed MPF for composites, the latter via the 2014-2017 Automated Manufac- turing Process Integrated with Intelligent Tooling Systems (AUTOMAN) project. e goal of AUTOMAN, however, was not to deliver molds but, instead, to build large 3D panels from metals and composites for use in trains, ships, aircraft and buildings. AUTOMAN aimed to develop the world's first fully reconfigurable pin- based tooling system with in-process sensing and computer control. Projected benefits were a 50-100% increase in panel manufacturing efficiency, cost savings of 80%, and 30-50% material and energy savings over the product lifecycle. By project end, AUTOMAN did build and demonstrate a multi-pin tool as well as a numerical model for simulating forming of sheet metal, including predictions of forming limits and springbacks. However, additional development is needed, including further software and sensing integration, transfer to industry-specific applications and scale-up to large panels. Years before AUTOMAN, architect and civil engineer Christian Raun Jepsen founded ADAPA Adaptive Moulds in Denmark to develop dynamic mold technolo- gies and manufacturing of freeform architecture. Although its business has been built mostly in architectural and concrete applications, the company has spent the past two years learning about composites and thermoplastics. Curve Works is ADAPA's first customer in the composites industry. e idea for Curve Works came while director François Geuskens worked at TU Delft: A shipyard wanted to build boats from composite panels. "is is standard with FIG. 1 Fast forming of foam and composites Curve Works uses a 3.6m by 1.56m ADAPA adaptive mold to form thermoplastics, composites and foam core, the latter shown here preheated at 150°C and molded into a doubly curved shape, which decreases resin uptake vs. scored foam to produce lighter composite panels. Source | Curve Works/ADAPA

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