Hot runner nozzle - Günther Heisskanaltechnik ...

1.4. 7
iT
40°
55°
Fig.Tip geometry for polypropylene
2,5...3,5
ØD1
ØD2
Fig. Gate design A and hot-runner nozzle with
nozzle piece version C
ØD2
ØD1
Fig. Gate design version C and hot-runner nozzle with
nozzle piece version A
Materials
Polyacetal (POM) and Thermo Plastic Elastomers (TPE)
Gate design A
When processing polyacetal (POM) and thermoplastic
elastomers (TPE) with a hot runner nozzle with nozzle
piece, version C and the gate design A, a good injection
gate quality should be attained. Hot runner nozzles with
nozzle piece, version C can be used for injection onto an
intermediate gate and also for direct gating. In direct
gating a higher residual sprue must be expected than
when a nozzle with tip is used. The gate design A must
be used for nozzles with tip and for open nozzles. It must
be taken into account here that the injection gate
diameter in gate bushing "D1" must be smaller than the
diameter in the nozzle piece "D2”
(D1 < D2). When a nozzle piece, version C is used, the
shear in the melt in the area of the injection gate is lower
than when a nozzle with tip is used.
Shear-sensitive materials
Gate design C
Single nozzles are mostly used when processing shearsensitive
materials through an intermediate gate. The
gate design C is exclusively used for open nozzles with a
nozzle piece, version A.
It must be taken into account here that the injection gate
diameter in the "D1" gate bushing must be larger than
the diameter of the nozzle piece "D2" (D1 > D2).
Parts made of Polypropylene (PP)
Hot runner nozzles with modified tip geometry should be
used to process polypropylene. At a height of 2.5 to 3.5
mm (depending on the nozzle type) the tip angle is
reduced from 55° to 40°.
This modified geometry must be ordered separately.
www.guenther-hotrunner.com
Subject to technical changes 4/11