JEC COMPOSITES MAGAZINE - Issue #140 - May/June 2021 - 15

Fabheads - An lndian start-up building 3D printers for composites
3D printed + Surface Layup +
Resin Infused
3D printed + Resin Infused
3D printed complex part, with resin infused finish
duce high-performance carbon
fibre parts. Our idea was to ease
the fabrication of functional
and long-lasting carbon fibre
parts. The series was specifically
aimed to cater for small- and
medium-scale manufacturers.
In contrast to a traditional manufacturing
process, the printing
machines enable the quick and
cost-effective manufacturing of
production-grade carbon fibre
parts. The strength of the resulting
parts can be further augmented
with an additional processing
step, making their properties
comparable to the resin infusion
process.
The FibrBots are differentiated
from other printers by several
technologies developed by Fabheads
over the years.
Printing head:
The printers feature a dual-nozzle
system, one to deposit plastic material
for infill and supports; and
another to lay continuous carbon
fibre reinforcements. Similar to
other carbon fibre 3D printers,
the designers can choose areas
where carbon fibre is to be laid
and areas in which not. They can
also choose the fibre directions
during the printing process.
Both nozzles are attached to a
proprietary high-performance
water-cooled heat sink to allow
faster printing with an extremely
small hot zone, even for very high
printing speeds. Another feature
is the ability to steer fibres based
on pre-programmed tool paths
around curves, which is very
difficult and highly non-repeatable
in traditional manufacturing
processes.
One of the key features of these
printing heads is that they are
compatible to handle fibre-reinforced
plastic material feeds with
varying fibre fractions between
40 to 90%. This is made possible
by Fabheads's patented process
that allows for auto-switching
between its three material feed
modes to the print head. This
allows very-high-speed printing
even during fibre steering, without
the fibres getting distorted or
buckled during the process, even
for extremely high fibre fractions.
3D Printing Plus:
FibrBots can be operated in two
modes: Direct Part Printing and
Preform Printing.
Similar to several other continuous
fibre 3D printers in the
market, the direct printing mode
provides
significantly
higher
strength than a regular plastic
3D-printed part. But the resulting
parts are not suitable for very
critical high-performance longterm
functional applications as
they still cannot be compared
with a carbon fibre part made by
more traditional processes like
hand layup due to the high void
content present in 3D printed
parts.
To tackle this shortcoming,
FibrBots offer another mode for
high-end applications via our
preform printing mode. The
machines print with an 80-90%
fibre fraction to produce carbon
fibre preforms (additive preforms).
As a post-printing step,
these preforms are infused with
any matrix of choice, which fills
the voids in the part and can also
build the finer features, giving
the final part very high strength
and tighter tolerances. The final
part has an overall fibre fraction
in the 40-55% range and a void
ratio of less than 2%, based on the
chosen parameters, reducing the
chances of crack initialization and
increasing the service life of the
part drastically.
During the resin infusion step,
the 3D-printed preform can also
be laid up with some fabrics in
selective areas to add further
strength in the vertical direction
or add a surface fabric to provide
that aesthetic carbon fibre part
feel and for higher strength on
the surface.
Good resin infusion is achieved
by adjusting several factors during
the printing and post-processing
steps, which change from part to
part depending on the geometry.
What is the key strength
of the team at Fabheads?
D.K.: The product development
culture at Fabheads is greatly
influenced by the founding team's
time at ISRO, where high-end
engineering goes hand in hand
with limited resources.
To account for our limited
resources, we go through several
iterations and foresee/solve as
many issues as possible right on
the drawing board via various
mathematical models and simulations
well before the very first
component is 3D printed. This
in fact has led to some of the best
innovations in our machineries
and processes, which
I doubt would have happened
otherwise.
Also, at Fabheads, we are not just
machine builders.
We have people experienced in
carbon fibre part design who
developed some of the largest
carbon fibre aerostructures ever
developed in India during our
time at ISRO, enabling us to assist
our clients to design parts that
effectively leverage the benefits
of FibrBots into the overall manufacturing
process.
Are there plans to make
Fabheads's footprint global?
D.K.: Yes, there are strong
plans. We had plans to physically
be in Europe by late 2021. But
Outcome of 3D
printing plus
technology of
FABHEAD
N°140 May - June 2021 / jec composites magazine
15
JEC COMPOSITES MAGAZINE - Issue #140 - May/June 2021

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