Plastics News Europe - September 2019 - 29

additive manufacturing

automating the next step
In additive manufacturing, printing the parts is just the first step. In most cases, secondary
manufacturing operations of some kind are needed. Successful additive mass production
will require efficient and automated methods to tackle the issue

he importance of post-processing and the need for scaling
these processes should not be
underestimated. Post processing, in
one form or another, is an inevitability when using additive manufacturing (AM) technologies but is particularly critical for serial production
applications of AM - both in terms of
the financial costs and the time it
takes between a part leaving the AM
system and being fit for purpose as
an end-use product, writes Joseph
Crabtree, CEO at Additive Manufacturing Technologies Ltd.
The advantages of AM have all
been well documented over the past
10-20 years - a period in which AM
has emerged as a truly disruptive
technology for prototyping and production - and are invariably seen as
being enabled by the additive hardware that builds the parts. In reality,
however, this is a partial picture, particularly for serial production applications. AM hardware systems are actually just one part - albeit a vital part
- of an extensive ecosystem of technologies that enable AM, both preand post-build.
By focusing just on the AM build
process, a fundamental part of the
production process chain is often
overlooked, namely the post-processing steps once the part is out of
the AM machine. Manufacturers
using (or considering using) AM for
serial production applications need
to first identify the appropriate additive process for their targeted application. From there the post-processing requirements must be
identified and focused on, otherwise the use of AM as a viable alternative to traditional manufacturing
processes may end up being negated completely.

Post-Processing for AM
Post-processing is actually an umbrella term for a number of stages
that AM parts may need to go
through after they come out of the
AM system and before they are fit
for purpose and can include excess
material
removal,
curing/heat
treatment, support removal, machining, surface finish processes
such as bead blasting, colouring
and inspection.
Hence in AM production applications, post-processing is a considera-

september 2019

The PostPro3D BLAST process can achieve consistent surface finish on non-line of sight
organic lattice structures

ble element of the overall cost-perpart and can be anything up to 60%
of total cost, depending on the application. It is therefore often the area
where the technology falls down as a
competitive manufacturing technology. Support removal and other
post-processing activities are often
labour intensive, and therefore costand time-consuming. In addition,
there is often a necessity for post-processing to enhance final part characteristics, in terms of functionality or
aesthetics.
And while a focus on design for
AM (DfAM) can, to some extent, reduce the number of necessary
post-processing steps, this is largely
dependent on the designer. How
well does the designer understand
the intricacies of the AM process and
the specific capabilities of the AM
system being used? Does the designer understand how to orientate the
parts in the machine(s), and how to
generate optimal support structures
for build and removal?
In general, post-processing requirements for a given application
depend on the geometry of the
component and how well it is designed for manufacturability using
AM.
However, regardless of how well a
product is designed for AM, it cannot
eliminate the need for post-processing for all AM processes. The problem
is that for an industry that calls itself
disruptive, manufacturers are still
largely post-processing parts the

same way they did 100 years ago -
manually. And it is this that is slowing
the whole process chain down for
production applications of AM.

Streamlining AM
Post-Processing
There is an evident need for digital
and automated post-processing solutions that increase efficiency and reduce the overall time and costs of
production with AM, specifically with
polymer AM processes and thermoplastic materials. It is in this area that
Additive Manufacturing Technologies
has directed its focus.
There can be no argument about
the increased number and improved
nature of the thermoplastic materials
palette available for AM processes in
recent years. Alongside these material developments, the AM systems
that produce thermoplastic parts
have also significantly improved in
resolution, accuracy, repeatability and
overall quality, and they are therefore
consistently meeting industrial requirements for exacting prototyping,
tooling, and some production applications.
New AM systems and innovative
purpose-developed
thermoplastic
materials notwithstanding, the critical mass of AM production applications remain lower than they otherwise might be due to the limitations
placed on the overall process chain
by the post-processing phase. This is

➡ Continued on page 30

Plastics News Europe - September 2019

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