|
Summit, NJ, Dec. 7, 2000 – In the first large-scale use of thermoplastic
composites in a commercial airplane wing, Fokker Special Products has adopted
a Fortron® polyphenylene sulfide (PPS)-glass fabric composite for the inboard
leading-edge nose on the wings of the new Airbus A340-500 and -600 series.
The company, based in Hoogeveen, The Netherlands, has a range of
responsibilities for this component, including production engineering and
manufacturing.
The composite, made with Fortron 0214C1 PPS, replaces aluminum in this
application to reduce weight by 20 percent. It also speeds fabrication,
improves impact resistance, holds tight tolerances from -55 to 80°C (-65 to
175°F), and has excellent resistance to hydraulic fluids, deicing agents,
fuel and other chemically aggressive fluids. The composite, which is trade
named Cetex® continuous fiber reinforced thermoplastic, is supplied by Ten
Cate of Nijverdal, Netherlands.
Until now, the inboard leading-edge nose in Airbus A340 aircraft, which sits
forward of the front spar in the main wing box, has been a five-section,
aluminum “D-nose.” The redesigned thermoplastic component forms a “J-nose”
containing two sections having lengths of 2.5 and 3.2 meters (8.2 and 10.5
feet).
The J-nose forms the leading edge of the wing between the fuselage and
inboard engine. Reinforced by arch-shaped ribs and stiffeners, it is rigid in
cross section but flexes along the length of the wing along with the main
wing box. The J-nose is aerodynamically shaped as part of the wing’s fixed
leading edge and encloses electrical, de-icing and other systems.
Ten Cate supplied Fokker Specialty Products with glass fabric combined with a
film of PPS “semi-preg” for manufacturing the aircraft skin. Preconsolidated
sheets having five of these prepreg plies are used to compression mold ribs
and stiffeners. These laminates measure about 1.2 by 3.6 meters (4 by 12
feet). A specially developed sizing compound applied to the glass helps bond
the PPS to it. The PPS-glass combination is consolidated in an autoclave at
over 300°C (570°F) and elevated pressure.
Fokker Special Products cut the multilayer sheets into blanks for ribs,
stiffeners and other parts. These components are press-formed, machined to
net shape and resistance welded together to create a strong, cohesive unit.
Welding eliminates the need for rivets, reducing stress concentrations,
assembly time and cost.
“The PPS matrix gives us the advanced processing and performance
characteristics we need to create a revolutionary leading-edge nose,” says
Arnt Offringa, engineering and R&D manager for Fokker Special Products.
“It also allows the elements to be welded. This is a significant factor in
the success of the J-nose, since we can create a strong, homogeneous unit
without the added effort and expense of riveting.”
Willem Van Dreumel, research director at Ten Cate, says the benefits of Fortron
PPS extend beyond the wings of the new Airbus models. “Cetex composites made
with Fortron PPS also form the ailerons and the keel beam, which are
fabricated by the French firm Aerospatiale. We teamed PPS with a carbon fiber
fabric in these components to build exceptional strength and stiffness at low
weight.
“Fortron PPS has been invaluable in our work on the new Airbus series. It is
the only PPS qualified for the aircraft, because it offers optimum viscosity,
chemical, mechanical and thermal properties.”
The new 500 and 600 series are being developed by Airbus UK and will expand
the capabilities of the Airbus A340 aircraft, which came into service in
1993. The 600 series, which has a stretched-fuselage so it can carry more
passengers, is scheduled for delivery in 2003. The 500 series, with the
longest range of any commercial aircraft at over 15,700 km (9,800 miles),
will be delivered after the 600 series. Weight savings and improved
fabrication are crucial for both models.
Fortron 0214C1 PPS is a special film grade that offers many benefits compared
to injection molding grades. In particular, this grade has higher elongation
and excellent strength and toughness.
For further information on Ticona and
Celanese AG, please visit our websites: www.ticona.com and www.celanese.com
# # #
NA Contacts:
Paul Reichenbacher 507-457-4069
|