JEC COMPOSITES MAGAZINE - Issue #119 - Supplement lnnovation report - 20

JEC WORLD 2018

Polyurethane-RTM nose cone for jet engines
The innovation enables the production
of composite components based on a
polyurethane matrix using a high-pressure RTM process (HP-RTM). This
combination allows the production of
aeronautic components prone to abrasion and impacts in a very cost-efficient and fast process.
The strength and stiffness properties
of the resulting parts are comparable
to components produced by established technologies and processes.
The combination of a fibre reinforcement, polyurethane resin and
high-pressure RTM is particularly
interesting - the low-viscosity, highly-reactive PU enables a fast processing route; in combination with a cavity
pressure of 30bar or more, a low void
content can be achieved.
Additionally, PU offers outstanding

Complex structural applications of
MAI sandwich technology
Based on the concept design from the early
stage of the project, a cross-industry netshaped 2.5D sandwich demonstration part
was created, including an injection-moulded
surface feature. The project team, with partners along the process chain, responded to
the demand to produce this challenging part
for structural applications based on carbon
fibre-reinforced thermoplastic materials.
The first trials showed that even unidirectional non-woven skin layers loft during the
process when the material is in the molten
state, which is needed to achieve the required
drapeability and bonding with the core layer.
To prevent these unacceptable voids from
occuring in a structural part, the following process was designed. In a first step, the
two outer layers are thermoformed as wellknown monolithic parts. These can be easily
overmoulded to increase the integration of
additional structural and/or functional re-

20

abrasion resistance, as well as excellent
impact toughness in a wide temperature range.
The PUR-RTM process was implemented to manufacture a jet engine
nose cone - a typical aeronautic component exposed to prolonged abrasion
and impacts.
Today's manufacturing technologies
for this type of part, mainly based
on prepreg systems, have significant
shortcomings such as the need for a
complex coating or the use of toughened systems leading to higher injection viscosity.
It was shown that with the newly developed process, high-quality polyurethane composite components are
feasible. Simultaneously, processing
times and efforts are reduced dramatically.

Finalist: University of Applied Sciences
Rapperswil (Switzerland)
Partners: FACC (Austria), Rühl
Puromer GmbH (Germany), Isotherm
AG (Switzerland), WPT, TU Dortmund
(Germany)

Aerospace - Process
quirements within the part.
In the next process step, the core layer (foam,
fold core or injected core) is positioned between the two outer skin layers in a press, after the contact surfaces of the inner and outer
layers are preheated to allow bonding by
thermal diffusion welding.In the final process
step, injection moulding of a long fibre-reinforced thermoplastic material around the
edges allows a net-shape design as well as
local edge reinforcement.For the team, it was
obvious that - driven by the strategic goal of
the MAI Carbon cluster - a breakthrough for
CFRP sandwich technology into large-scale
production must be achieved. This resulted in a dramatic cycle time reduction from
hours to less than 5 minutes (aeronautic
materials) and 2.5 minutes (automotive materials) by using only one mould, which is the
result of a well-designed process composed
of robust and fully-automated process steps.

jec composites magazine / N° 119 supplement - Innovation Report

Finalist: Airbus (Germany)
Partners: BMW Group (Germany),
Technical University of Munich (TUM)
(Germany), Neue Materialien Bayreuth
GmbH (Germany), Werkzeugbau
Siegfried Hofmann GmbH (Germany),
BASF SE (Germany), Foldcore
(Germany), Neenah Filtration
(Germany), SGL Carbon GmbH
(Germany)
Table of Contents for the Digital Edition of JEC COMPOSITES MAGAZINE - Issue #119 - Supplement lnnovation report
