Hot runner nozzle - Günther Heisskanaltechnik ...

Valve gate technology
Fig. Valve gate system
Commissioning the valve gate system
Before heating the nozzles and the manifold, switch on
the mould temperature control.
Heating the hot-runner system:
- Heat the manifold with the controller unit's soft start
function. With the softstart function the manifold is
heated to about 100°C and held at this temperature
for approximately 10 minutes.
- The nozzles and manifold must be heated evenly.
Heating the manifold to the target temperature can
take up to 20 minutes.
The needle mechanism may be put into operation when
the hot-runner system reaches production temperature.
The idle system must be held at production temperature
for at least 10 minutes to ensure thermal stability.
When putting into operation for the first time, several
injections may be necessary in order to fill the hot runner
completely with plastic. Until the parts are filled
completely, the cavities must be checked after every
cycle for parts that have not been filled completely.
If the process is interrupted, the hot-runner temperature
must be lowered (depending on the material and
downtime by 100…150°C). The needles must be in the
"closed" position. To prevent damage being caused to
the gate bores / valve needles by cold material, the valve
needles may not be actuated when the injection
moulding machine is being set up or during injection out
through the unit. If the melt is to be injected out through
the open mould / hot runner, the needles must be opened
during the injecting-through process and closed during
the dosing phase.
www.guenther-hotrunner.com
4/11 Subject to technical changes
When the hot-runner system is being turned off, all
control circuits can be turned off at the same time. To
prevent the hot-runner system being damaged by the
build-up of heat, let the mould cooling run on at about
30°C for another 30 minutes approximately. The valve
gate needles should be in the “closed” position here.
Before doing any disassembly, make sure the hot runner
is switched off. To prevent damage to the needle guide /
needle, the needles must be in the opened position.
Before putting the system into operation again, make
sure the needles are in the “closed” position again.
Connection values
Electric
Voltage 230 V~
System *
max. permissible operating
pressure in the hot-runner system 2000 bar
*
Hydraulic
Single valve- gate nozzle
Lifting plate mechanism
Sliding cam mechanism
Pneumatic
max. permissible operating
pressure in the hot-runner system
Single valve gate nozzle
Single needle valve
Lifting plate mechanism
Sliding cam mechanism
iT
If special nozzles or other components with a pressure limit (less
than 2000 bar) are fitted to systems or individual tools, this situation
is documented in the height adjustment and on the type plate.
To attain the right needle speed (needle closing time 20-
40 ms / 7-10 mm travel), the valve must be designed to be
large enough for the actuation (hydraulic/pneumatic).
The connection hoses too must be dimensioned to suit
the flow volume.
The distance between the pressure generation and the
pressure consumption (mould) should be as small as
possible.
Note!
The first filling of the hydraulic cylinders should be done
at a low speed or the cylinders should be deaerated.
40
40-60
40-60
8
mind. 8-10
8
8-10
8-10
bar
bar
bar
bar
bar
bar
bar
bar
1.4. 40