HP-Nozzle, Installation & Service Instructions
herzog systems ag
Tel. +41 71 394 19 69
Fax. +41 71 394 19 60
Seite 6 von 10
Version 06/2022
When machine is powered off or idle for a long period:
Purge processed material from nozzle
Open nozzle
Reduce nozzle temperature
Initial operation
Leakage release area
approx. 1cm
3
per day
Read safety instructions!
1. Bring nozzle to operating temperature
2.
Only for first operation
: tighten 8 body screws and heater band screws to maximum
recommended torques
3. Make sure that polymer is completely melted
4. Purge heated melt. This follows after extrusion at low speed (time ca. 25 - 30s) or
through injecting out at three to five times injection time
Actuator:
Operational data according to engraving on cylinder.
Leakage:
Between needle and guide there is a melt film which prevents the needle from
blocking. The melt film will be continuously renewed and will eventually leak out of the
nozzle in the area indicated beside.
This melt release is completely normal, especially when low viscosity material is
combined with high back pressure. The material will not affect the function of the
nozzle as the actuator piston stroke and lever movement respectively keeps the area
clear. If required any gathered residual material can be manually cleaned away.
While injecting no leakage should emit in this area and the nozzle is completely sealed.
Machine downtime
Actuating nozzle at stages indicated in the graph helps increase longevity of wear parts.
Melt pressure / time graph:
Nozzle actuation stages
Nozzle open
Nozzle closed
Time
Back pressure
Injection
pressure
Actuate nozzle open
Actuate nozzle close
Melt pressure
Dosing start
Injection start
Holding pressure
Ideally at 10 to 50bar
melt pressure
Ideally when pressure
is lowest
