Heißkanaldüsen Typ SLT/-DLT Customer information

Heißkanaldüsen Customer information Typ SLT/-DLT
Precision and costs under control
Weißer+Grießhaber relies on BlueFlow ® Hot-Runner
Engineering for Micro Parts
Extremely thin-walled products with ultra-fine structures
are a speciality of Weißer + Grießhaber. In a pilot
application of the new BlueFlow ® hot-runner nozzles
from Günther Heisskanaltechnik GmbH, the company
has engineered a more cost-effective production of
precision filters, a safety component for the automobile
industry, with greater process stability.
Already in the year 2009 the plastics processor Weißer +
Grießhaber (www.Weißer-Grießhaber.de) from
Mönchweiler, a town in the Black Forest area, was
awarded “the innovation award for the promotion of
innovative achievements in medium-sized industrial and
skilled trade enterprises” for its directly injected filter. For
the first time, filter screen fabric and threading were
produced in pure injection moulding in one shot for these
precision components for the automobile industry. This
replaced the previous procedure, in which an existing
metal or plastic screen fabric was overmoulded to obtain
a ready-to-install component. The impact on costs was
significant, which, depending on the product, sank by
around 60 to 80 per cent. In the meantime, a large
number of variants are produced, in quantities ranging
from several tens of thousands to double-digit millions,
for other industries too. Such polyamide filters with
weights of about 0.1 grammes are used for example in
ABS and ESP systems to filter out even the finest
particles from the brake fluid and accordingly ensure
reliable functioning.
Fig. A particularly efficient and easily regulated heating technology
allows slim high-performance nozzles.
For any questions, please contact our Application Engineering department at + 49 (0) 6451 5008-31 or -63.
The information is given in accordance with our present-day knowledge and is meant to provide technical background.
www.guenther-hotrunner.com
4/11 Subject to technical changes
iA
Thread thicknesses of 0.10 to 0.15 millimetres and mesh
apertures as tiny as 0.07 millimetres are scarcely visible
to the naked eye. Burring must also be reduced
accordingly to under 5 micrometres.
Weißer+Grießhaber spent about five years developing
the directly injected filters. This concerned mould making
above all and the moulds are still being constantly
improved. The hot runner and control engineering as well
as the adaptation of the process parameters have had a
decisive influence on the qualitty and process stability.
One of the decisions taken by Weißer+Grießhaber as
part of the continuous further development was to use
BlueFlow ® , the new heating technology developed and
produced by Günther Hot-Runner Engineering, in their
own manufacturing before the launch on the market and
to evaluate the experience with it. The first obvious result
of using the new nozzles”, explained Siegfried Kaiser,
Head of Sales and Project Management at Weißer+
Grießhaber, was the much lower temperature and
pressure levels compared to the systems used before –
which had also ranked among the top technologies. The
temperature window used during the process is much
smaller; the average temperature sinks and becomes
more stable.” That not only reduces the strain on the
mould; it sustainably saves energy and substantially
reduces downtime. Another aspect, which is at least just
as important, is that the higher temperatures and
pressure levels before used to cause unacceptable
material damage and consequently rejects. Furthermore,
not all cavities in the 8-cavity mould were filled and
the reject rate reached double-digit percentage levels.
These problems are now over: GÜNTHER's hot runner
fills all cavities and the reject rate is less than 1 per cent.
There is also a great improvement in injection gate
quality.
Fig. A micro filter (outlet valve for an automotive application) made of
non-reinforced PA66 from Bada, injected in one processing step; 0.1
grammes and 1,848 apertures measuring 0.07 x 0.07 mm. The
maximum permissible burring is 4.5 µm.
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