JEC COMPOSITES MAGAZINE - Issue #111 - March 2017 - Special JEC World - o - 32

MANUFACTURING simulation

Simulation boosts the use of thermoplastic
composites in mass production

MATHILDE CHABIN, Composites Product
Marketing Manager, ESI Group,
DR PIERRE GERARD, Expert in Acrylics,
Composites and Nanomaterials Arkema,
PATRICE CLERC, Director, Mecanium

his article highlights the advantage of
fibre-reinforced thermoplastic components versus thermoset when using
composite materials. Given a choice, manufacturers of high-performance composites
might prefer to make parts for a variety of
applications from reinforced thermoplastics rather than reinforced thermosets.
Recyclability, higher ductility and impact
resistance, ease of repair or assembly by
welding and, especially, short mould cycle
times make thermoplastic composites very
attractive.
We now understand the value of fibre-reinforced thermoplastic components, but there
are still three major challenges to overcome.
First, the ability to simulate the manufacturing process, particularly for mass production.
Second, the capability to characterize these
materials in order to understand their exact
behaviour to feed the numerical models.
Third, the ability of the material supplier to
provide new resins to overcome the high
melt viscosity of thermoplastics.
Simulating the manufacturing process
In the past, new tools were made, different
material compositions tested and the manu-

Thermoplastic composite materials promise many advantages for the
mass production of high-performance composite components. These
materials made of melt-processable resins are light, stiff, have an
infinite shelf life, the potential for rapid process speeds, and excellent
recyclability. They are also more lightweight than metallic materials,
and offer more adaptable designs.

facturing process parameters were optimized
in the real world until the desired product
was achieved. Manually reworking the tool
geometry, playing with material composition
and tuning process parameters (such as the
temperature cycle, holding system and tool
velocity) to improve the quality of the manufactured part does not only take a long time,
it is also a very expensive process with high
levels of waste.
During the manufacturing process known
as thermoforming, a sheet of thermoplastic
composite material is heated until it is malleable and then pressed against a tool to give
the composite the desired shape. A range of
defects may be introduced during the manufacturing process, such as fibre path deviation
or wrinkling, for example. These defects can
be investigated and resolved using simulation.
Let's look at one example where the com-

posite did not make contact with the tool at
every point. Thermoplastic resin pooling occurred in the resulting gaps, which is a highly
undesirable defect.
This is where simulation software can step in.
A new capability called die spotting, which
was introduced in Pam-Composites 2016,
allows simulation software to modify the
geometry of the tools to effectively morph it
to the formed part. The result is a new tool in
which the thermoplastic resin will not pool.
The die spotting capability makes it possible to iterate and improve the tooling design
within the software to ensure perfect contact
between the tool and the final product. This
results in homogeneous compaction at the
end of the thermoforming process.
This die spotting capability removes one
of the biggest headaches for composite engineers. The geometry of the tools can be
automatically morphed to ensure proper

Fig. 1: Traction test, picture frame test and bending test (cantilever) used to characterize composite materials
www.mecanium.fr

jec composites magazine / N°111 March 2017

http://www.mecanium.fr

Table of Contents for the Digital Edition of JEC COMPOSITES MAGAZINE - Issue #111 - March 2017 - Special JEC World - o