MOULD TOOLS & MOULDING LOW VOLUME DEMAND PROMPTS INNOVATION
“Not everything suits
it. So, at present, and I mean at
present because materials are changing
every month, simple products without ne
detail or moving parts in a soft to medium
plastics are possible. But the cost is just a
few hundred pounds for such tools.”
Obviously, because 3D-printed tools do
not disperse heat, with cycle times three to
four times longer than they would be in
metal tools, consideration has to be given
to, for example, material, ‘residence time’ in
the barrel and the ability to remove the parts
High speed machining of mostly aluminium standardised cavity blocks
supports lower volume production on faster-to-make tools at lower cost, but
3D-printing makes lower quantities, into the 10s, a viable proposition.
Inset – High speed machining comes with some limitations, such as corner
radii, but it avoids the added time and cost of EDM, seen here
by hand. For quantities of 100,
ejector pins are likely to be part
of the tool. Steel sprue inserts
are employed to prevent damage
in the moulding machine.
The big challenge in being
able to realise this is how to
keep 3D-printed materials at,
and it is this nut that the company has
cracked – the materials are available to
anybody, with TPE or TPU typically found
best. How the insert is then loaded to the
tool is another part of Plastic Parts Direct’s
magic. The tools are produced with
50-micron layers or, for a super-smooth
mould cavity nish, 25 microns.
Importantly, if the company takes on a
job on the basis of 3D-printing the mould
tool and, for whatever reason, that doesn’t
work, the customer is not left high and dry.
“Part of the service, if we choose to send a
customer down this road, is the
reassurance that, should that not work, we
produce an aluminium tool and the price to
the customer is the same. We do not let
the customer down,” Bowes assures.
The company is still at the beginning of
its journey, but hybrid tools having metal
inserts are a possibility, while 3D-printing
material development is rapid. A larger 3D-
printing machine is on the buy list, which
will boost the current 140 mm cube tool
edge length capability (giving a 100 mm
cube part envelope). The hit rate on winning
low volume work has jumped to around
25% now, with the company having
produced 20-30 tools at the time of
Machinery’s early March visit over a period
of about 18 months. The of cial launch of
the service was last November, with the
3D-printed tooling now a part of the
company’s advertised service.
20 July/August 2020 | www.machinery.co.uk | MachineryMagazine | @MachineryTweets
/www.machinery.co.uk