JEC COMPOSITES MAGAZINE - Issue #111 - March 2017 - Special JEC World - o - 41

Hybridisation - A toolbox for efficient lightweight production

tow-preg placement, are used. To
achieve the bonding, micro-form-fit
and surface activation mechanisms are
generated by local exposure of the fibres at the substrate surface. The fibre
exposure is realised by a robot-guided
laser scanner. To achieve a repeatable
and defined sublimation of the resin,
the laser parameters are controlled by
on-axis low-coherence interferometry.
As the bonding after overmoulding is
determined by the thermal management within the joining zone, the laser
source is also used for pre-heating the
substrate. After the injection moulding
step, laser-induced lock-in thermography is used for non-destructive characterisation of the bonding quality.

Fig. 2: Integrated manufacturing cell (AZL)

This production technology for hybridisation uses an injection moulding
machine with a turning plate. All the
systems are integrated into the manufacturing cell (Fig. 2).

Fig. 3: Individualised mass production of a hybrid continuous/long glass fibre-reinforced bicycle saddle (IKV)

hybrid part consisting of continuous
and short fibre-reinforced part sections.
Hybrid functionalised thermoset/
thermoplastic composite parts
An evolution of this integrated thermoplastic process is the OPTOlight
process, which opens the potential
for hybridisation of thermoset parts
by thermoplastic injection moulding.
Compared to thermoplastic sheets,
thermoset parts can be better tailored
to the load requirements of parts due
to the applicability of textile preforming processes and offer superior

performance in terms of temperaturedependently mechanical properties
(e.g. creep, stiffness and strength).
Using laser processes as enabling
technology, a consortium around
the Aachen Centre for integrative
Lightweight Production (AZL) of
RWTH Aachen is currently in the last
phase of installing an integrated process chain for intrinsic joining of thermoset and thermoplastic composites
(Fig. 1).
A standard high-pressure RTM process, as well as the forming of a loadand scrap-optimised sheet made by

On the 0° position of the turning plate,
the base substrate is moulded by RTM
resin injection or alternatively by compressing the tow-preg laminate. The laser ablation step takes place on the 90°
position and the overmoulding step on
the 180° position. With this technology, a bonding strength of 10-12 MPa
can be achieved on shear-lap specimens. The transfer to a new functionalised part is in process.
Hybridisation as an enabler
for individualisation
Beyond the functionalisation of parts
with ribs and fastening elements, hybridisation can act as an enabler for
individualisation. This addresses the
users' demand to use products exactly
tailored to their needs, as well as the
management of variants in production.
The approaches gathered within the
Industry 4.0 concept are of the highest relevance to manage the complexity of individualised production of
mass products. At the last K-show, the
Institute of Plastics Processing (IKV)
at RWTH demonstrated such a concept

No111 March 2017

/ jec composites magazine

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