AMPLIFICATIOn HPC’s recent coverage of lightning strike protection technologies for composite aircraft (“Lightning strike protection strategies for composite aircraft,” HPC May 2013 or visit http://short.compositesworld. com/94qeyhzA) went to press without one of the important suppliers/ contributors, an omission corrected here. Lightning strike protection and static dissipation materials are also available from Technical Fibre Products Inc. (TFP, a James Cropper Co., Schenectady, N.Y.). The company can produce metal-coated carbon fibers in-house, through its subsidiaries Electro Fiber Technologies LLC and Metal Coated Fibers Inc. (MCF), colocated with TFP in Schenectady. Metal plating is done using either an electrodeless plating or electroplating process, depending on the requirements; the metal options include copper, nickel, silver, gold, alloys and more, in variable thicknesses up to 65 percent of the finished product weight. Nickel-free, environmentally friendly alternatives also are available, says David Jhaveri, TFP’s business development manager. The metallized fibers are then converted into veil or mat, trade named Optiveil or Optimat, using polyester, polyurethane or acrylic binders, in continuous or chopped form, from 5 mm/0.2 inch up to 1,650 mm/65 inches in width. Alternatively, the metallic tows can be prepregged, woven or made into customized forms to meet specific application needs. Veil weights from 4 g/m2 up to 200 g/m2 are available and are designed for EMI (electromagnetic interference) shielding, thermal conductivity, static protection and as part of an overall lightning strike protection strategy. “Optiveil also offers multifunctionality such as providing a high-quality surface finish for the composite part in combination with conductivity and EMI shielding,” adds Jhaveri. The veils and mats also are suitable for use in resistive heating applications, such as aircraft deicing.
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weight savings and performance we were looking for and it was process-efficient. The flexibility in the material range also helped us find the optimized reinforcement for each application.” One major component in which TeXtreme was used was the rigid sail mast. The forward parts of the wingsail’s rear element, or flap noses, are sandwich constructions primarily in torsion and are critical to both stiffness and strength.
toughness properties due to the interleaved spread fiber tows. Layup time was saved, because it was possible to lay half the number of plies compared to tape, and the woven TeXtreme could be placed on the bias easily, eliminating the tedious hours of hand-cutting tapes for +45° and -45° placement. TeXtreme also offered a cosmetic surface finish on the laminates, which was important because many surfaces on the boat were unpainted to save weight. One big benefit, explains Smyth, is that some woven materials have only a narrow selvedge to hold them together, which means that when they are cut, they must be handled gently to prevent them from coming apart. Oxeon, however, uses a binder that holds its dry fabric together for infusion layups. “We had a wide range of areal weights and fiber styles to choose from,” adds Smyth. TeXtreme 100 g/m2 cloth was used to fabricate the wing elements and fairings, and TeXtreme 80 g/m2 cloth was used in the lightest of the fairings, typically as the faceskins in a foam-cored sandwich. Says Kramers, “We were pleased with TeXtreme as it turned out to offer both
Their skin laminate angles are optimized to provide the correct torsional stiffness profile along the length of the aerodynamic foil. Because the flaps are exposed, durability also had to be considered. The trailing edge (aft) portion of the sail element was designed to be as light as possible. A very thin sandwich laminate of TeXtreme and lightweight foam core delivered aerodynamic performance, with just enough rigidity to maintain its aerodynamic shape. The skin laminates were precured, then the inside skin was draped over a male former and sealed against moisture ingress. Honeycomb core was prebonded to the outside skin, then mated to the inside skin, thanks to the flexibility of the TeXtreme laminates. The combined layup was cured at ambient temperature under vacuum, saving the time and energy that would have been expended during autoclave cure, while still delivering mold outer finish. The use of TeXtreme, and the smaller amount of adhesive required to bond the core to the faceskins, resulted in a 5 kg/11 lb weight savings over the ~50m2/~538.2 ft2 area of the flap nose, concludes Smyth.
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jEC EUROPE 2013 PRODUCT ShOwCASE
See a much more extensive version of this Showcase online at http://short.compositesworld.com/45abRSEq.
Unidirectional thermoplastic tapes
Programming, simulation for ATL
Barrday Inc. (Millbury, Mass.) reported that it has extended its thermoplastic laminate technology to unidirectional thermoplastic tapes, targeting structural applications in the commercial aerospace, military/defense and industrial markets. These products use carbon fiber and high-performance glass fiber reinforcements in polyetheretherketone (PEEK), polyetherketoneketone (PEKK), polyetherimide (PEI), polyphenylene sulfide (PPS) and polyamide (nylon) matrices. Initial tape widths will run from 160 mm to 305 mm (6.25 inches to 12.0 inches). However, the equipment has been sized to produce prepregs at widths of up to 610 mm/24 inches. www.barrday.com
CGTech (Irvine, Calif.) introduced three new programming and simulation software modules for automated tape laying (ATL) machines. The first is VERICUT Composite Paths for Engineering (VCPe). It allows the user to measure and evaluate the effects of AFP and ATL path trajectory, material steering, surface curvature, course convergence and other process constraints as they would be applied in manufacturing. The software also provides produceability analysis of the fiber angle, based on the curvature of the part, and overlap and gaps needed for structural analysis. The tape course geometry can be written to various CAD formats for further evaluation by users’ existing analysis methods and tools. (See two more modules online.) www.cgtech.com
horizontal tape placement machine Century Design Inc. (CDI, San Diego, Calif.) launched its M777 horizontal tape placement machine. It offers precision tape placement on small- to large-diameter straight and tapered mandrels. The specially designed placement head controls the tension of the tape and its position on the mandrel during production of standardized and high-quality tubular components. CDI says the demand for such a machine has been driven by customers looking to improve manufacturing methods used to make tubular structures, such as golf shafts, fishing rods and bike frames and struts. The M777 also can wrap prepreg and thin-film tapes from the same tension head. That, in turn, enables part completion on one machine. www.centurydesign.com
Infusion molding supplies Airtech International (Huntington Beach, Calif.) showed Thermalimide E, a high-performance bagging film for cure temperatures up to 426°C/799°F. Thermalimide E RBCS is a film treated on both sides with a release coating; it can be used for cure cycles up to 405°C/761°F. Also new: Flashbreaker PS1 is a high-temperature/high-tensile strength polyester film that is coated with a high-tack, pressure-sensitive silicone adhesive for oven or autoclave cures up to 204°C/399°F. (See more offerings online.) www.airtechonline.com
Compression router eliminates splintering Sandvik-Coromant (Amsterdam, The Netherlands, and Fair Lawn, N.J.) introduced at the JEC Europe 2013 show its new CoroMill Plura high-production compression router for carbon fiber composites and other composites for which splintering is a common problem. As a compression end mill, its design combines positive and negative helix angles and six effective cutting edges. The unit’s microgeometry is said to allow for close tolerances, a surface finish accuracy within 4 µm (0.00015748 inch) and high material removal rates. (See more online.) www.sandvik.coromant.com
One testing machine, 100 test standards Zwick GmbH (Ulm, Germany, and Kennesaw, Ga.) introduced its Allround-Line testing machine that reportedly covers 21 types of tests and can conform to 115 standards over a wide temperature range. Said to be ideal for fiberreinforced composites whose properties depend on fiber alignment, the fiber, the matrix and the fiber/matrix interface, the machines are available with a force range starting at 5 kN and, depending on the requirements and force range, is available in either flatbed or column format. The machine’s testControl II control electronics, are said to provide precise, reproducible test results. www.zwick.com
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