Heißkanaldüsen Typ SLT/-DLT Customer information

Heißkanaldüsen Customer information
Typ SLT/-DLT
Smallest cavity pitches with the new micro flat nozzle type SFT/NFT
A high number of cavities in a small space for micro
articles made from technical thermoplastics is
increasingly becoming one of the demands to be met
today by modern injection molders. In order to enhance
the economical efficiency in the production of such small
articles, the trend today is going towards direct injection
by means of a hot runner, in order to cut down on high
sprue masses in comparsion to the part weight and to
reduce cycle times determined by the sprue.
GÜNTHER hot runner systems have always been
especially well suited for these applications, on account
of their excellent temperature control, outstanding
thermal separation between the hot runner system and
the mold, as well as technical innovations. The
introduction of the SFT/NFT nozzle series has resulted in
an additional wide range of possible applications.
On account of their slightly different design as compared
to conventional hot runner nozzles, cavity pitches from
7 mm can be realized for open hot runner systems, and
from 9 mm for hot runner systems with valve gate
technology.
The flat nozzles of the series SFT/NFT consist essentially
of a metal tube with a tip, open passage or needle
guide, a thermocouple and a nozzle body with integrated
heating elements. The constant excellent temperature
control of these nozzles with simultaneous high heating
output in the area of the tip is achieved by the use of
nickel-plated brass (CuZn) as basic material of the
nozzle body and the two heating cartridges, which are
operated via one control circuit.
www.guenther-hotrunner.com
7/12 Subject to technical changes
Thermal separation from the mold is achieved by an air
gap and by means of a special titanium ring in the contact
area of the tip.
The standard diameters of the material channel of these
nozzles range from 2.8 mm to 6.0 mm, and they are available
in the lengths L of 60 mm, 90 mm or 110 mm. It goes
without saying that custom/made solutions to meet
special application requirements are also possible. In
this case, we recommend contacting our engineering
department.
The advantages of this line of nozzles are shown in the
following example of an interesting application.
The task was to realize direct gating of a part made of
PPS GF30 with a weight of 0.1 g. The part is a housig of
an electronic component and must be molded onto a
punch-out strip for further processing. The customer also
wanted to have separate thermal control of each gate.
Thus, due to the specified size of the injection molding
machine and the required number of 64 cavities, the job
of the hot runner system was clearly defined.
The processing of this glass-fiber filled high temperature
plastic requires the use of a nozzle tip made of a special
hard metal alloy to reduce tip wear and the use of a
thermocouple suitable for high temperature applications.
In addition, the high temperature application also
requires full insulation with a material able to withstand
manifold temperatures up to 600°C, minimizing the heat
dissipation from the manifold.
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.
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