Heißkanaldüsen Typ SLT/-DLT Customer information

Heißkanaldüsen Customer information
Typ SLT/-DLT
Stable and Material Saving Processing of Flame Retardant Polyamides with
GÜNTHER Hot Runner Technology
Material
tube
Heater
Air
Gap
solidified
plastic
Melt
Shaft made of
titanium alloy
Open nozzle tip
Fig. 5 Detail
Nozzle with shaft and open nozzle tip (DHT nozzle)
The optimal thermal insulation minimizes the heat loss of
the nozzle through heat conduction. This assures
consistent temperature control in the nozzle and prevents
an excessive rise in temperature at which the temperature
measured in the nozzle is much higher than the
target temperature. This prevents any possible damage
of the plastic melt or additives (flame retardant) caused
by an excessive rise in temperature.
To keep the shear stress on the melt as low as possible,
the nozzle was provided with an open nozzle tip (Fig. 5)
instead of a torpedo tip. This allows an unobstructed melt
flow through the nozzle and intermediate gating into the
cavity. As the parts are filled through a sub-runner, the gate
vestige at the injection point is of little importance.
Compared to a nozzle with torpedo tip the residual sprue
is slightly bigger.
Fig. 6 Vertical construction of the hot runner system for
“pushbutton insertion guide“, Component 1 (PA66-
GF25): 4-drop, 2x 5DHT50 nozzle on sub-runner
The opening characteristics of the nozzle are critical for a
reliable process. Tests have shown that both nozzles
with an open nozzle tip give an even filling pattern at the
same temperature. These filling patterns carried out to
different filling degrees can be reproduced over a large
number of cycles. Figures 6 and 7 show the result of the
filling analysis at 25% and 50% filling.
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
7/12 Subject to technical changes
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