23 April 2002
23 April 2002
At this year’s JEC, Hexcel Composites promoted its latest developments for the composites industry, including new fibre-reinforced matrix products, adhesives, honeycombs and carbon fibres that are extending the range of applications for composites. “New Horizon” was the theme of the Hexcel stand.
Hexcel’s next generation phenolic matrix, HexPly® M41, has been developed to meet the latest Fire, Smoke and Toxicity (FST) and OSU heat release requirements for aircraft interior parts, such as side wall panels, flooring panels, ceiling panels, galleys and toilet modules. HexPly M41 is a very fast curing matrix, with cure schedules of 4 minutes at 160°C or 7 minutes at 140°C for crushed core pressing. Crushed core pressing is a commonly used technique for manufacturing aircraft interior parts. Honeycomb is sandwiched between prepreg layers in a mould and the core is crushed in local areas during processing to achieve contoured shapes, without the need for honeycomb profiling. The fast low temperature cure cycle enables Tedlar films to be co-cured with HexPly M41 prepreg.
HexPly M41 is highly versatile system that, in addition to crushed core pressing, can be processed using a multi-daylight press, autoclave or vacuum bagging. Three levels of tack are available, to suit the preferred manufacturing process. When HexPly M41 is used to manufacture flat panels, a cure cycle of 30 minutes at 135 C is recommended.
Hexcel Composites launched HexFIT, its film infusion technology, at JEC 2001. This year Hexcel introduces carbon HexFIT to the product range. HexFIT is supplied as a stack of resin films that are interleaved between layers of dry fibre reinforcements. A special finishing film layer can also be included. HexFIT can be cured using low cost vacuum bag moulding and it enables quality components to be manufactured quickly and cost-effectively. HexFIT is particularly useful for manufacturing thicker composite components, such as wind turbine rotors, as the material is easy to form and produces void free laminates.
The new carbon HexFIT variants have unidirectional carbon fibre reinforcement layers. The smaller diameter filaments of carbon fibre can make it difficult to fully infuse the reinforcement when using wet laminating resins. However, with HexFIT the resin only has to flow a few millimetres to fully wet out the laminate, so there is no risk of dry fibres remaining in the cured component. HexFIT produces carbon fibre laminates with a much lower low void content. It also provides improved mechanical properties due to the perfect unidirectional fibre alignment.
Until now, Hexcel has not been well known as a manufacturer of gel coats, but two new HexCoat products are being launched at JEC by Hexcel. HexCoat 01 is a new epoxy gel coat developed to meet the requirements of the rail industry. This unique product provides the rail industry required flame-retardency, plus excellent surface finish and a fast low temperature gelation. HexCoat 01 was developed to co-cure with Hexcel’s HexPly M34 prepreg at temperatures between 75 and 130°C.
HexCoat 02 was developed for wind energy applications. It is a two-part epoxy system, in which both parts are thixotropic. This makes the gel coat much easier to mix than existing products. HexCoat 02 is highly durable in harsh environments, abrasion resistant and suitable for in-mould use.
Hexcel’s Redux® film adhesives have been structurally bonding aerospace components since the 1950’s. Hexcel Composites is now introducing a range of Redux pastes to the established film adhesives, foaming films and primers.
The Redux 800 series is a range of one and two-part epoxy pastes that cure at room temperature or at elevated temperature for higher levels of mechanical performance. The range includes Redux 810, a high shear, high peel structural paste for honeycomb bonding, metal-to-metal bonding, composite bonding and structural repair. Redux 820 is a two-part cell edge bonding adhesive, ideal for the manufacture of honeycomb sandwich structures. Redux 830 is a low density syntactic filler that has excellent compression characteristics of up to 50 MPa from a room temperature cure. Redux 840 is a one-part, foaming, thixotropic, epoxy paste adhesive that provides a shear-carrying connection across any discontinuities in bonded sandwich panels. Redux 850 is a high temperature resistant, composite bonding, two-part epoxy paste adhesive, providing excellent lap shear strength.
Since Hexcel launched its HexMC carbon fibre/epoxy sheet moulding compound at JEC last year, the award-winning product has attracted the interest of leading sports goods manufacturers, automotive designers and aircraft interior manufacturers worldwide. HexMC enables manufacturers of small to medium sized components to achieve fibre-reinforced thermoset matrix performance from a rapid volume manufacturing process. The visual aspect of HexMC has ensured that product is in demand as much for its aesthetic value as for its low weight and performance enhancing capabilities. HexMC is being used by Trek to manufacture the rear links for the cross country full suspension Trek Fuel 100, enabling a saving of more than 50 grams per bike and providing a link that is twice as strong as its aluminium predecessor.
Hexcel began manufacturing honeycomb over 50 years ago, and the HexWeb product range continues to evolve. New products include HexWeb HRP-C fibreglass core for aircraft nacelle applications; HexWeb
HDC-F heavy density fibreglass honeycomb for potting replacement in sandwich panels; HexWeb Mil-PAA improved corrosion resistance metallic core for flight control structures and aircraft nacelles; HexWeb HRH-86 low cost non-metallic core for marine and rail interiors, and aircraft secondary structures; and HexWeb HRH-36 high performance aramid honeycomb for lightweight, high performance non-metallic aerospace applications (including aircraft flooring, interiors and secondary structures).
Hexcel Composites has augmented its carbon fibre product offering by adding some new products to the existing range. The Magnamite® PV series was developed to improve the translation of carbon fibre tensile strength properties in pressure vessel applications. The new products are marketed under the references PV36/700, PV42/800 and PV42/850. Some customers have already reported a 15-20% improvement in burst pressure performance versus other carbon fibres of the same tow tensile strength.
Hexcel has also introduced two new Intermediate Modulus (IM) fibres to complement its well established IM6 and IM7 fibres. The new Magnamite products have the references IMC-12K and IM7C-12K. Both fibres exhibit typical properties of 800 ksi tensile strength and 42msi tensile modulus. Magnamite IMC is targeted at non-aerospace applications and Magnamite IM7C was developed for the aerospace industry.
Brazilian company Dilutec has developed a complete gelcoat portfolio for shipyards, for applications ranging from the manufacture of the boat mould to small repairs of the hulls and decks.
Sharp & Tappin has installed and commissioned a Compcut 200 composite plate saw at Renault Sport Racing in Enstone, Oxfordshire, UK.
The Massachusetts Department of Transportation (MassDOT) selected a lightweight FiberSPAN fibre reinforced polymer (FRP) bridge deck, manufactured by Composite Advantage, for the Rugg Bridge on Route 57.