At JEC Europe 2014 [Paris, Porte de Versailles - March 11-13th] Hexcel will be promoting the latest innovations developed for aerospace and industrial markets. In addition to launching a new carbon fiber and aerospace prepreg, Hexcel is showcasing some of the latest customer applications for which Hexcel’s composites are “the strength within”.
HexTow® HM63 carbon fiber
Hexcel is adding to its extensive range of IM and AS fibers by launching a new High Modulus carbon fiber, called HexTow® HM63. This new fiber has the highest tensile strength of any HM fiber and provides outstanding translation of fiber properties in a composite, including superior interlaminar shear and compression shear strength. It is therefore ideal for any high stiffness and strength-critical applications including space, satellites, UAV, commercial aerospace and helicopters. It also meets the special requirements for premium sports and recreation applications including F1, marine craft, bikes and fishing rods.
At JEC Hexcel will be display a ThermoSet Carbon (TSC) cable for yacht rigging manufactured by Future Fibres, using HexTow® HM63 high modulus carbon fiber for low weight, high break strength and resistance to impact.
NEW HexPly® M92 prepreg for aerospace structures
Hexcel is launching HexPly® M92, a prepreg that combines all the major benefits achieved individually with other 125⁰C curing epoxy resins in one new “multi-purpose” system. These benefits include excellent hot wet Tg performance of 115°C, allowing HexPly® M92 to operate at higher service temperatures from a lower cost 125°C cure. The system is self-adhesive to honeycomb, making it suitable for sandwich structures as well as monolithic components. Other benefits include high toughness, fire resistance, low exotherm, a long out/tack life and the ability to cure by vacuum bag. HexPly® M92 is available in a wide range of prepreg forms (woven and UD tape).
At the JEC show, Hexcel will display a Helicopter Rotor Hub Cap Fairing manufactured by Airbus Helicopters. This oven-cured part is a honeycomb sandwich structure in which the prepreg is bonded directly to the non-metallic core, without any additional adhesive. Airbus Helicopters estimates that weight savings of 8 to 15% will be achieved by manufacturing this part from HexPly® M92, depending on the helicopter type.
HexPly® M77 “Snap Cure” prepreg
To further extend the use of thermoset resins in mass produced composite parts Hexcel has developed HexPly® M77, a rapid curing epoxy prepreg that allows automotive components and sports goods to be press-cured in a 2-minute cycle at 150°C (80 bar pressure).
The low tack of HexPly® M77 enables the prepreg to be cut into precise shapes by laser cutter. The individual plies can then be oriented, assembled and consolidated into a flat preform by robot. Once in the mold HexPly® M77 has an optimized gel time that allows the resin to flow into the contours to produce the precise geometries required. The high Tg of 125°C enables the cured parts can be demolded while hot for a faster production cycle.
This rapid-curing product, with a 6-week outlife at room temperature, is available in various forms including unidirectional or woven reinforcements and heavy tow fibers. It is also supplied as HexMC®, Hexcel’s high performance carbon fiber/epoxy compound developed specifically for compression molding processes. HexMC® is ideal for the series production of complex shaped parts with thickness variation, sharp angles or parts that require inserts to be integrated into the molding process such as screw threads.
HexPly® M79 Low Temperature Cure Prepreg for wind blades and marine
HexPly® M79 was developed to meet industry requirements for a faster and lower temperature curing prepreg for thick laminates. It has evolved from HexPly® M10, Hexcel’s long-established and widely used prepreg resin for marine structures and wind blades. A number of cure cycle options are possible for HexPly® M79 including a very low temperature cure of 8-10 hours at 70°C or a more rapid cure cycle of just 4-6 hours at 80°C. With previous systems it could take 10 hours to cure a laminate at 80°C. HexPly® M79 also has a very long out life at room temperature of at least 6 weeks.
When HexPly® M79 carbon fiber UD prepreg is used in conjunction with Hexcel’s patented grid technology a void content in the cured laminate of less than 1% is achievable, regardless of the part thickness.
On Hexcel’s stand at JEC visitors can see what we believe to be the thickest carbon prepreg laminate ever made. The lay-up of 695 plies of HexPly® M79 600 gsm carbon UD tape with Hexcel’s grid technology is 400mm thick – and it cured in just 6 hours at 80°C. The very low exotherm of HexPly® M79 allowed the temperature to be increased more quickly in the mold, resulting in a shorter cure cycle.
HiTape® Aircraft Fuselage Panel Demonstrator
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. Parts produced with HiTape® and Hexcel’s HexFlow® infusion resins can be up to 30mm thick with a 58 to 60% Fiber Volume Content, 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 next generation aircraft primary 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 JEC. Aerolia SAS is a major world player in the design and production of aircraft equipped fuselages. Coriolis Composites is a leader in the development and manufacture of automated fiber placement processes for composites.
The fuselage panel is a self-stiffened skin that was designed by Aerolia to meet the mechanical performance requirements for primary structures. Coriolis Composites developed the dry Automated Fiber Placement process for the full scale fuselage skin demonstrator - and the dry preforms were made at Compositadour’s facilities. The HiTape® preform skin and stiffeners were infused with HexFlow® RTM6 resin at Hexcel’s new Applications Laboratory in Les Avenieres, close to Lyon, using a co-infusion process that was developed in-house.
The resulting fuselage panel demonstrates that parts made with HiTape® and HexFlow® RTM6 meet the high mechanical performance requirements for primary structures, including toughness. HiTape® is a cost-effective, highly automated solution for the manufacture of aircraft primary structures that enables aircraft designers to meet the cost and build rate targets for next generation aircraft, while retaining the weight-saving benefits that are achieved with prepregs.