JEC COMPOSITES MAGAZINE - Issue #90 - June/July 2014 - 32

process

Possible layer positioning failures or
undulations of each single layer can be
detected and documented with a laser-based analyzing system (OQCU).
This system was also especially developed for the mapretec project.
In addition, a specially designed tooling head can be used to apply a tackifier (SAERfix EP® from Saertex) in an
automated process to prevent slippage
of the individual fabric layers.

Value created
The main advantages of the mapretec
production process are the reduction
of layup time and the possibility for
parallel production of preforms to
reduce the amount of layup work in
the rotor blade mould. Beside the
higher processing speed compared to
the manual process, the mapretec process offers other valuable advantages.
For instance, the use of sensitive and
flexible hybrid textiles minimises
form and position errors. The high
accuracy of the process also results in
increased quality of the final product.
Because of the higher accuracy, there
is an option to reduce the number of
textile layers building the rotor blade
without reducing failure safety. The
resulting weight savings will allow for
a resource-efficient production and
more economic operation of the wind
turbine.

Successful partnership
The mapretec project was initiated by
the Institut für integrierte Produktentwicklung (BIK) of the University
of Bremen. Based on the results of
previous projects such as Preblade, in
which the root section of a rotor blade
was built automatically, or the LAR
(Large Area Robot) project, in which
a mobile and automated manufacturing process was developed for spar
caps, the area between the root and
the aerodynamic section was chosen as a focus area for the mapretec
project. To achieve the project goals,
i.e. the development of an automated

preforming process for large rotor
blade components, experienced
partners from the textile and rotor
blade industry were necessary. Besides
BIK, who contributed mechanical
engineering, handling technology and
automation know-how, the project
consortium consists of Saertex GmbH
& Co. KG and the associated partner
Areva Blades GmbH. Saertex handled
the development, testing and manufacturing of non-crimp fabrics (NCF).
Areva Blades provided technical
input from the wind energy industry
and supplied an offshore rotor blade
mould. The manufacturing concept
from Areva Blades includes the
application of a consolidated preform
in the area between the root end and
the aerodynamic section, which is
placed into the rotor blade mould
directly. Currently, the manufacture
is based on a conventional hand layup process and local fixation using a
powder binder. The common textiles
which were used so far are much too
stiff to drape perfectly into the mould
without forming wrinkles and undulations. Normally, material defects like
wrinkles are incised and covered with
an additional layer of textile. Because
of the highly complex geometry of
the area between the root end and the
aerodynamic section, a great amount
of time is necessary to produce this
component. This is the reason why it
was chosen to develop a fully automated manufacturing process in the
mapretec project. The efficient customization of the textile was a main
requirement to continue the project
successfully. Only draping without
wrinkles and defects can guarantee a
proper part with optimum parameters.

site industry are based on draping
of textiles directly into the 3D-shaped mould. Complex geometries in
general are a problem for automated
lay-up and involve a disproportionate
automation effort. Another considerable advantage is the fact that
the transformation unit can produce
several different geometries in a row
without significant modifications. It is
also imaginable to use this concept in
aviation. Parts like pressure bulkheads
or wing shells of passenger planes are
possible examples. All of these arguments show the high market potential
of the mapretec production process
because of increasingly strict quality
standards and the growing dimensions
of these parts. Only in this manner is
it possible to achieve the economic,
fast and high quality production of
large composite components.

Key benefits
The production of a plane, horizontal
lay-up followed by near-net-shape
transformation is a completely new
approach for preform assembly in
such dimensions. With this fully
automated process, the main advantages of automation such as higher
process speed, higher reproducibility,
improved quality and resource-efficient use of materials can be achieved. The mapretec project delivers
innovative input for the production of
fibre-reinforced parts and contributes
to economic efficiency in composite
manufacturing. It should be mentioned that within this master project,
six individual sub-developments were
branched out as individual projects,
all of which present a novel approach
for composite processing. n

Market potential
Because the production of large
composite parts is still essentially a
manual process today, the solution
achieved under the mapretec project is an innovative manufacturing
technique. Most of the currently
developed solutions in the compo-

32 jec composites magazine / No90 June - July 2014

More information:
www.saertex.com
www.mapretec.de
www.bik.uni-bremen.de

http://www.saertex.com http://www.mapretec.de http://www.bik.uni-bremen.de

JEC COMPOSITES MAGAZINE - Issue #90 - June/July 2014

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