Hexcel to display carbon fiber reinforcements at air show

Another technology innovation that benefits aircraft engines is Hexcel’s HexPly M91 prepreg that is used by CTAL – a Rolls-Royce/GKN Aerospace joint venture – to manufacture DOVE demonstrator fan blades for new generation lightweight turbofan engines. Hexcel supplies HexPly M91 as slit tape which CTAL uses to lay-up the blade in an automated process that produces a complex aerodynamic shape, with a constantly changing thickness across the blade length.

The result is as thin as a titanium fan blade - and lighter.   HexPly M91 provides outstanding performance, including very high toughness and high residual compression after impact (CAI). It gives improved tensile performance in combination with both Intermediate Modulus (IM) and High Strength (AS) carbon fibers.

Good hot-wet properties up to 120°C (250°F) are also obtained.  Good tack life and out-life provide flexibility during processing on the shop floor and low exothermic behaviour allows for simple cure cycles of thick monolithic structures.

Hexcel also innovates in jet engine noise reduction.  A new treatment for Hexcel’s honeycomb core called Acousti-Cap has been proven to quieten jet engine noise more effectively than any competing system.

Acousti-Cap is Hexcel’s broadband sound reducing honeycomb that enables engine designers to achieve superior acoustical performance without a structural weight penalty. Acousti-Cap consists of a permeable cap material embedded into honeycomb cells to create an acoustic septum.

Customers specify the flow resistance characteristics, overall core thickness, number of caps in a cell and insertion depth. The result is a product tuned to their acoustic requirements. Quieter engines bring a number of advantages including recurring cost-savings from lower landing fees at airports, increased fleet flexibility and improved cabin comfort.

Weaving Technology Innovations

Hexcel is a world leader in weaving technologies and PrimeTex is a unique carbon fiber fabric in which the fibers are spread in both the warp and weft direction to provide a uniform weave and gap-free finish.

The PrimeTex spreading process increases the closure factor by 5-8% compared to conventional weaving processes (depending on the carbon tow and Fiber Areal Weight).  PrimeTex also allows high K tow fibers to be used without increasing the areal weight of the fabric or the closure factor between the warp and the weft, unlike traditional woven carbon fabrics. 

PrimeTex carbon fiber reinforcements are ideal for Aerospace laminates as the gap-free structure reduces porosity and requires less part finishing thereby reducing man hours.  Very Low Weight PrimeTex (available at 98 gsm with HS3K carbon fiber or 160 gsm with IM12K fiber) can lower the mass of a composite structure, resulting in even greater weight savings than with standard composite reinforcements.

Thanks to the combination of HexFlow out of autoclave resin systems and PrimeTex fabrics, porosity is significantly reduced.  In addition PrimeTex gives excellent water tightness when used in honeycomb sandwich structures such as aircraft belly fairings or helicopter structures.

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