Plastics News Europe - September 2019 - 26

additive manufacturing

Amid the general euphoria about the opportunities presented by additive
manufacturing, there are those who take a more level-headed view of the
disruptiveness of the technology. According to Nigel Flowers UK managing
director of Sumitomo (SHI) Demag, for example, injection moulding and additive
manufacturing are more complementary to one another than competitors

additive manufacturing
won't make other
technologies obsolete
W
"

hile 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," said Nigel Flowers emphatically.
The idea that 3D printers are
about to overthrow traditional manufacturing techniques - including
moulding, forging, casting, and even
subtractive CNC manufacturing - is
simply scaremongering, he said.
"There is space for all of these technologies. The key for any manufacturer is to make a well-informed decision based on a number of criteria."
In that context, there are several
prevailing myths that need debunking, summed up in the below - a few
counterarguments to the perception
that 'one technology is going to win
over the other', as Flowers said.

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 will perform any better than the current methodology of
injection moulding," he pointed out.
For several years now, the medical
sector has successfully used 3D printing to produce bespoke components.
Among them prosthetics, implants,
hip replacements, hearing aids and
even dentures. For these individual

Mould tools can create special surface textures and blend materials
and colours for numerous consumer products

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 aircraft. 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," Flowers noted. 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
september 2019

Plastics News Europe - September 2019

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