JEC COMPOSITES MAGAZINE - Issue #111 - March 2017 - Special JEC World - o - 61

JEC WORLD 2017

MANUFACTURING

Voith roving applicator
This innovation is a fully-automated direct fibre placement machine, called Voith Roving
Applicator (VRA).
The VRA uses untreated roving and binder
powder to generate a net-shaped dry stack.
The stack is produced in five consecutive
steps: roving is first spread, assembled in a
50mm-wide tape, a binder is applied on these
tapes on-line, then the tape width is checked
by on-line quality control and finally, the
bindered tapes are placed on a rotatable/
movable table by several pairs of grippers.
This results in the assembly of a near netshape preform stack step by step, with local
reinforcements or layers that can be placed at
any angle in any area.
The main advantage of this manufacturing
process is that the resulting preform is fully
adapted to the mechanical requirements and
loads of the final part, with great flexibility
and fast adaptation. Moreover, even though

the individual grippers are quite standard,
the VRA is scalable: the lay-up rate can be
increased by a factor two by doubling the
amount of grippers.
In addition to this increased production rate,
this innovation has a strong goal of reducing production costs. Untreated roving and
binder are used for their cost effectiveness,
but also because, thanks to the VRA, these
raw materials can be processed into a useable

Company: Voith Composites GmbH &
Co KG (Germany)
preform directly from the fibre in one step
- without having to use costly intermediate
steps or semi-finished products, and with almost no waste.
Several VRAs are already linked with an automated production line used for a future
automotive high volume series CFRP part.

3D PRINTING

Smart manufacturing
of continuous-fibre composites: Atropos
Atropos is the name of the first 6-axis
robotic arm able to 3D print continuous-fibre composites using thermosetting resins. In the process supporting
Atropos, the fibres are impregnated and
drawn to the head of a numerically-controlled machine that can place them in
a precise and repeatable manner. Once
extruded by the printing head, the material is irradiated by a dedicated UV
lamp to quickly cure the resin.
The choice of focusing on thermosetting resins with curing times shorter
than one second makes it possible to
place continuous fibres at speeds of
about 50 mm/s for now, thereby rapidly generating products characterised
by significantly higher working temperatures compared to conventional thermoplastic resins.

To optimise the internal and external
shape of the object, +LAB developed a
slicing algorithm that can predictively
plan the machine movements to place
reinforcing material where the maximum stresses appear in the final object.
Furthermore, the algorithm can also
vary the fibre/matrix ratio up to 60%
in volume. With both these characteristics, it is possible to obtain a lightweight
and customisable part with optimised
performance according to its use.

Company: +LAB - Politecnico di
Milano university (Italy)
Partners: Owens Corning (France),
KUKA Robotics (Germany)

The main strength of this project is to
be able to control the fibre direction as
the part is produced to get the best of
the fibres' anisotropic nature, thanks
to the algorithm developed by +LAB.
Thus, different parts with the same
shapes can be produced and customised
according to their in-service loads.

No111 March 2017

/ jec composites magazine

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