JEC COMPOSITES MAGAZINE - Issue #121 - May 2018 - 32

MANUFACTURING Prototyping

Injection moulding:
running tests earlier with 3D printing

eva söhnLein,
CEO
Hans Geiger Spritzgiesstechnik GmbH

The production of prototype tools for injection moulding is extremely
complicated and costly, especially when steel or aluminium are used.
The tools must therefore be milled and hardened, which means that
their production is not only relatively expensive, but it may well take
a week. But the time pressure on companies is increasing. In order to
provide tools in a significantly more time and cost-effective manner,
Hans Geiger Spritzgießtechnik GmbH recently tested the additive
manufacturing process for production.

resulting in significant advantages for both
the manufacturer and the customers.

W

ith additive manufacturing,
the first tools can be made
available for viewing in just
under six hours. The printing process
uses a special synthetic resin that is much
cheaper than the materials used so far,
thus reducing production costs by up to
70%. By eliminating milling and hardening, the prototype can be tested in just a
few hours instead of several days - saving
up to 90% time.
Injection moulding tools have to
withstand enormous loads. For this
reason, resistant metals are preferred in
production, which requires an expensive
and time-consuming manufacture. This
is not a problem for mass production -
thousands of operations mean investment
costs pay off shortly. But the fixed costs
are out of proportion, in particular for
small batch sizes or individual parts needed to produce prototypes - especially if
the prototype does not result in an order.
In addition, time plays an increasingly important role. An alternative is 3D printing.
Initial tests have already been carried out
at Hans Geiger Spritzgießtechnik GmbH,

32

Acceleration of the development
and test phases
Manufacture at Geiger previously took
several days.
With the help of additive manufacturing,
it was possible to shorten the duration
to just 6 hours. This significant time
reduction has made it much easier to test
whether an object can actually be injection-moulded as planned. Consequently,
tool manufacturers can quickly test
whether a prototype is fully functional
or if any improvements are necessary.
3D printing even makes a functional test,
an early test run with series-like moulds,
possible quite quickly. This means that
not only can prototypes be tested for
their functionality, but it is also possible
to choose the design and materials early
on. With the accelerated process comes a

jec composites magazine / N°121 May - June 2018

cost reduction of up to 70%, which greatly
minimises the financial risk involved in
prototype manufacture and makes it possible to offer more attractive prices. It can
be demonstrated easily and quickly how
certain requirements can be met without
any great time and money expenditure.
This is a significant advantage in the tendering phase, for instance.
PolyJet: a fast and efficient process
using synthetic resin
There are several ways to make tools using
3D printing. A liquid starting material can
be hardened layer by layer, or a powder
can be melted selectively. With the PolyJet
process used by Geiger, the workpiece
is built up in layers. First, tiny droplets
are sprayed onto a building platform and
crosslinked via UV light. Synthetic resin
is used for printing. The best results were
achieved with Digital ABS, especially
for complex geometries. Following the

Hans Geiger
Spritzgießtechnik GmbH recently tested 3D printing for
manufacturing prototypes
(source: Ippicture / pixabay.
com)
Table of Contents for the Digital Edition of JEC COMPOSITES MAGAZINE - Issue #121 - May 2018
