PRODUCT NEWS
EMERGENCE OF SIMULATION
SUMITOMO
WHERE DOES 3D PRINTING FIT INTO THE
PLASTICS MANUFACTURING MIX?
As disruptive trends go, 3D printing - also
called additive manufacturing - is often touted
as a technique to rival injection moulding.
But rather than viewing them as competing
technologies, used for the right application
they actually complement each other very
well, emphasises Nigel Flowers UK managing
director of Sumitomo (SHI) Demag.
In the last six years the global 3D printing
market has more than doubled. By 2020,
analysts estimate the sector will be worth
US$3.1bn. In comparison, the global plastics
moulding market is forecast to reach US$690.
bn by 2023.i “While we cannot knock the level
of innovation happening in the 3D printing
space, in reality additive manufacturing
is not the universal panacea it’s made out
to be. Right now it continues to perform
strongest for prototyping rather than mass
manufacturing,” says Nigel.
Looking to the future, there are exciting
developments in both markets. Whether
the current global trade wars and currency
fluctuations will accelerate demand for onsite
production remains to be seen. Yet the idea
that 3D printers are about to overthrow
traditional manufacturing techniques -
including moulding, forging, casting, and
even subtractive CNC manufacturing - is
simply scaremongering. There is space for
all of these technologies, notes Nigel. The
key for any manufacturer is to make a well-
informed decision based on a number of
criteria.
Examining production volumes, cost, barriers
to entry and the future of part customisation,
Nigel offers some counterarguments to help
bust the myths that one technology is going
to win over the other.
MYTH ONE: ECONOMIES OF SCALE
Cost is obviously a big factor when
considering which technology to opt for,
especially in the production of plastic parts.
For manufacturing components in high
volumes, 3D printing today is currently not
fast or cost effective enough to produce
precision parts in large quantities. Where 3D
printing is beneficial is for prototyping and for
generating customised parts in low volumes.
Functionality also plays a big part. Just
because you can print anything you want,
it doesn’t mean that the design or materials
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will perform any better than the current
methodology of injection moulding.
For several years now the medical sector has
successfully used 3D printing to produce
very bespoke components. Among them
prosthetics, implants, hip replacements,
hearing aids and even dentures. For these
individual parts, injection moulding would not
be a financially viable option due to the cost
of creating a mould tool.
Similarly, aerospace manufacturers
are embracing 3D printing to upgrade
components and create replacement parts
for maintenance, repair and overhaul (MRO)
which is big business. In a report issued by
Airbus, MRO spend will double to over US$120
billion per year in the next two decades,
which involves upgrading the existing fleet of
passenger aircraftii. For those parts which may
have a long lead time, a complicated supply
chain or no longer be in production, 3D
printing offers a viable and agile alternative to
the aerospace sector.
When designing a prototype using injection
moulding, the process can again be quite
lengthy. Whereas a 3D printer will let you
create the part using the end material,
injection moulders will typically use foam
and adapt the design until it’s approved and
the tool can be designed and tested. Here, an
industrial 3D printer is often used to scope
out and fine-tune the part, which can then be
used as a blueprint to design the mould tool.
The tipping point for injection moulding
will come relatively quickly once mass-
production ramps up. Calculating the payback
would involve comparing the unit costs and
production time for 3D printing and offsetting
this against the cost for tooling development,
making, testing and shipping the tool, plus
the new unit costs and any assembly. Typically,
a contract mass moulder producing electronic
casings estimates a ROI of 10,000 parts.
MYTH TWO: ENVIRONMENTAL
FOOTPRINT
The sustainability credentials of 3D printing
are often inconclusive. While some advocates
say printing locally saves on transportation
costs, gauging the true environmental impact
is inherently more complex.
Take for example energy consumption. While
injection moulding machines, particularly
all-electric systems, continue to cut energy use
- the latest Sumitomo (SHI) Demag IntElect
range for example uses the same amount of
energy as switching on a household kettle
- some 3D printing processes used 50-100
times more electricity than injection moulding
machines. Several years ago, a study by
Loughborough academics, dubbed the Atkins
Project, did find that the in-use phase through
lightweighting, particularly components used
by the aerospace industry, saved on fuel costs.
These savings more than compensated for the
energy used during production, discovered
researchers.