Hexcel is exhibiting at Composites Europe in Stuttgart, Germany (September 22-24) to promote composite materials that offer performance and processing benefits to customers in Automotive, Wind Energy and Recreation markets.
Hexcel has developed a range of composite materials for automotive, meeting requirements for structural performance, high temperature resistance, impact absorption, visual appeal and high production volumes.
Hexcel’s fast curing prepreg HexPly® M77 meets the needs for volume production with a 2-minute press-cure cycle at 150°C (80 bar pressure). The system is optimized for automated processing, with low tack enabling precise shapes to be cut by laser and allowing individual plies to be oriented, assembled and consolidated into a flat preform by robot. While curing in the mold the optimized gel time of HexPly® M77 enables the resin to flow into the contours to achieve the precise geometries required for the finished part. The high Tg of 125°C allows cured parts to be demolded while hot for a quick turnaround and faster production cycles.
Building on this technology Hexcel has developed and installed a fully automated preform manufacturing line at its facility in Neumarkt, Austria capable of achieving production rates of less than 2 minutes per preform. The preform design is precisely tailored to the customer application and the process allows for full design flexibility regarding ply weights, orientation and contours. It also allows additional materials such as adhesive to be integrated into the process. To ensure the highest quality standards, camera based automated quality controls are implemented throughout the whole line.
The benefits of HexPly® M77 epoxy resin are also available in the form of HexMC®-i, a high performance carbon fiber/epoxy compound developed for compression molding which has a very high fiber volume content assuring excellent mechanical performance. HexMC®-i is recommended for the series production of complex shapes with thickness variation, sharp angles or parts that require inserts such as screw threads to be integrated into the molding process. It is an ideal alternative to lightweight metals for structural applications, can be hybridized with metal and has superior mechanical properties to vinyl esters. Hexcel’s technical support team provides advice on HexMC®-i processing and mold design.
On Hexcel’s stand at Composites Europe there will be a number of automotive parts including CFRP reinforced BIW parts manufactured from HexPly® M77 using Hexcel’s fully automated 2D preform production line. There will also be a demonstrator panel manufactured by Plastic Omnium using HexPly® M77 demonstrating the 40% weight reduction achievable in trunk floors using this technology.
HiMax™ carbon fiber multiaxials are non-crimp fabrics, produced by Formax, a 50% joint venture with Hexcel. HiMax™ fabrics combine excellent structural properties, with good drape and handling characteristics and are used extensively within automotive components and in larger structures in the marine and infrastructure markets. The highly flexible format is available in a wide range of fabric styles with weight per ply from 50-1200 gsm, fiber orientations from 22.5° through to 90° in up to 4 layers and a wide range of fiber types from high performance fibers through to heavy tow materials.
HiMax™ fabrics are supplied in widths of 1270mm as standard and up to 1650mm wide on application. The “high drape” formats are suitable for complex curvatures and the ultra-light weight stitching is ideal for applications that require class A surface finish. HiMax™ materials can be supplied with and without powder binder making them ideal for RTM and infusion processes.
Hexcel has added HexPly® M79 to its prepreg range, providing a product that cures more quickly at low temperatures, with a very low exothermic reaction to meet the requirements for thick laminates such as wind blades and yacht masts. Where previous systems for thick laminates required a 10 hour cure at 80°C, HexPly® M79 cures in 8-10 hours at 70°C or just 4-6 hours at 80°C and the system has a long 6 week outlife at room temperature. 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.
Pultruded Carbon Profiles
Hexcel’s Polyspeed® Pultruded Carbon Profiles are a newly launched technology for pre-cured, thick-ply carbon fiber elements that are ideal for structurally reinforcing wind turbine blades and for any other industrial application requiring load-carrying performance.
Carbon fiber tows are impregnated with polyurethane resin and shaped and cured in a continuous pultrusion process resulting in perfect fiber alignment and a smooth surface. This method results in consistently higher structural properties than can be achieved with any other conventional manufacturing process.
The pultruded elements form production-ready components in a wide range of shapes (e.g. L-shaped, rectangular) and are fully compatible with Hexcel’s epoxy thermoset resin matrices. They can be used in combination with Hexcel prepregs including HexPly® M79 and HexPly® M77 and are compatible with many commercial thermoset infusion resins.
Hexcel has decades of experience supplying prepregs, laminates and polyurethane systems for premium sports goods and has developed a range of composite products for this market including the prepregs HexPly® M49, EH04 and M77.
At Composites Europe, visitors will see the Corima UP "S" carbon bike wheel that is used in competition triathlons, time trials and flat stages. The highly aerodynamic 73 mm wheel has excellent stiffness and is very low weight thanks to the use of Hexcel’s HexPly® carbon fiber prepregs and PrimeTex® very lightweight gap-free fabrics.
Also on display will be an ice hockey stick manufactured by Fischer using Hexcel’s HexPly® carbon fiber/epoxy prepreg and Primetex® gap-free reinforcements for a high performance, lightweight hockey stick with great visual appeal.
New Hexcel app
Hexcel is launching its first iPhone and iPad app at Composites Europe, focusing specifically on HexPly® prepregs for aerospace and industrial markets. The app allows users to select the best prepreg resin for their application based on market and application, cure temperature and maximum service temperature (Tg). The app also allows the user to view the full range of Hexcel’s prepreg resin data sheets. The new Hexcel app is available for download free of charge to all users through the Apple iTunes Store (search: ‘Hexcel Prepreg Selector’).