Fiber and resins supplier Hexcel (Stamford, Conn., USA) is featuring in its booth HexTow HM63 carbon fiber, HexTool composite tooling, PrimeTex spread-tow carbon fiber fabric, HiTape dry carbon fiber reinforcements, HexPly M77 snap-cure prepreg and HexPly M79 prepreg.
HexTow HM63 carbon fiber offers what Hexcel says is the highest tensile strength of any high-modulus fiber, providing good translation of fiber properties in a composite, including what is said to be superior interlaminar shear and compression strength. HexTow HM63 is suitable for any high-stiffness and strength-critical applications including space, satellites, unmanned aerial vehicles (UAV), commercial aerospace and helicopters. It also meets the requirements for premium sports and recreation applications including F1, marine craft, bikes and fishing rods.
HexTOOL composite tooling material is said to provide the ability to meet strict requirements for stability and repeatability of tolerances previously accomplished by machined Invar tools, in addition to improved thermal performance and reduced weight of carbon tools over metal tools. At CAMX Hexcel will display tooling manufactured by Sawyer Composites using HexTOOL M61. This tooling is used by CFAN to make the fan blades for the GE90 and GEnx engines.
PrimeTex carbon fiber fabrics feature fibers spread in the warp and weft direction to provide a uniform weave and gap-free finish. The PrimeTex spreading process is said to increase the closure factor by 5 to 8 percent compared to conventional weaving processes (depending on the carbon tow and FAW). PrimeTex fabrics are designed for Aerospace laminates as the gap-free structure reduces porosity and requires less part finishing. PrimeTex reportedly offers good water tightness when used in honeycomb sandwich structures such as aircraft belly fairings or helicopter structures.
HiTape advanced dry carbon fiber reinforcements combine the benefits of automated processing with the cost-effectiveness of out-of-autoclave infusion technologies. HiTape allows preforms to be manufactured in a fully automated lay-up process, with high deposition rates. When infused with HexFlow resins, HiTape parts can be up to 30 mm thick with a 58 to 60 percent fiber volume fraction, resulting in mechanical properties that are as high as those achieved with primary structure prepregs. To demonstrate the potential of HiTape for cost and cycle efficient primary aircraft structures, Hexcel has worked with Aerolia SAS and Coriolis Composites to design and manufacture an aircraft fuselage panel demonstrator that will be on display at CAMX.
For automotive, HexPly M77 snap cure prepreg has a 2-minute cycle at 150°C/302°F (80 bar pressure). The low tack of HexPly M77 enables the prepreg to be cut into precise shapes by laser cutter, then oriented, assembled and consolidated into flat preforms by robot. The high Tg of 125°C/257°F enables the cured parts can be demolded while hot for a faster production cycle.
HexPly M79 prepreg was developed to meet industry requirements for a faster and lower temperature curing prepreg for thick laminates in the wind energy and marine industries. It will cure in 8 to 10 hours at 70°C/158°F or in just 4 to 6 hours at 80°C/176°F. On Hexcel’s stand at CAMX, visitors can see a carbon fiber laminate consisting of 695 plies of HexPly M79 600-gsm carbon unidirectional tape that cured in just 6 hours at 80°C. The very low exotherm of HexPly M79 allows the temperature to be increased more quickly in the mold, resulting in a shorter cure cycle.
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