Hello and welcome to this week’s Insight.
This week I’m going to turn my attention
to one of the most popular materials used
in manufacturing – polypropylene – and
a recent breakthrough which means the material
can now be 3D printed using selective laser
sintering. I’m going to explore what this
means for design, and how it could substantially
reduce your product development times.
Polypropylene is a thermoplastic addition
polymer made by combining propylene monomers.
Today it is one of the most commonly produced
plastics in the world and its use is increasing
rapidly.
But there’s good reason for its popularity.
It’s tough, semi rigid and has excellent
heat, chemical and fatigue resistance. And
it’s also easy to use in injection moulding.
Did you know for example that 32% of the plastic
used in a typical car is polypropylene?
All of this was too good to be true, because
until recently you could not 3D print in the
material due to its high crystallinity – it
tends to shrink and warp.
So, let’s step back. Previously, if you
wanted a part in polypropylene you faced limitations
in getting a cost-effective rapid prototype
and you could forget about designing complex
geometries.
Of course, you had options – you could still
protype using CNC machining or injection moulding,
but this limits you in what you could achieve,
both cost-wise and in design.
Another possible solution was to use a polypropylene-like
thermoset resin that was UV cured, but it’s
not the same material and it does not have
the same properties; so, while you could test
the design, it would not always perform the
same way the actual material would.
Far from ideal really.
But you can take the brakes off as far as
this fantastic material is concerned because
3D printing is now possible.
Let’s just stop a minute and think about
that.
It means that a whole new world of complex
geometries opens up. Your engineering design
world for polypropylene has just got so much
bigger.
Perhaps even better, you can now prototype
and perfect your design using this material
more cost-effectively and faster than ever.
There are no compromises, you can now test
your design for function in its actual operating
conditions, as well as testing its form.
And let’s not forget its never been more
important to get new concepts and designs
to market quickly. But against this has always
been the fear that if the product or component
is not spot on, then the complaints will quickly
pile up. And in the era of social media that
can really damage your brand.
In this race to market where being first really
counts and you don’t want to be left in
the wake, where else can you shave days, weeks
or even months from that development cycle?
Well for polypropylene the development cycle
would probably take you from a 3D printed
prototype to injection moulding. As we have
already covered in a previous video hopefully
your prototype was developed with mass manufacture
in mind because this will save you time in
the long run.
Regardless of that, your injection moulding
supplier should be able to do a design for
manufacturability analysis and if needed suggest
some areas that could be improved.
Why not simply find a supplier that can take
you through the whole process – from 3D
printing so you can test the prototype – through
to injection moulding. You can have the benefit
of their knowledge for the entire process.
Also, why not see if you can get bridge tooling
developed in aluminium moulds so that you
can start production even while you are waiting
for your permanent steel moulds?
All this means you can get that polypropylene
part or component, designed, tested and produced
far more quickly than ever before.
So that’s a big tick for mass production
parts, but what about something bespoke or
a little bit special?
While injection moulding and CNC machining
are great for mass production, they do have
their limitations.
If you really want to let your imagination
go, then you can design anything that you
want using 3D printing. From organic shapes
to honeycomb structures to save weight, there
are no limitations.
To conclude, polypropylene is a fantastic
material with numerous applications. Now that
the technology allows it to be 3D printed,
a whole new world has opened up for you, both
to get product to market faster than ever
before and to design components or parts that
were previously impossible.
That’s it from me this week. I look forward
to seeing you again next Friday.
