FRITSCH PULVERISETTE 7 premium line - Manual (Page 48)

The PULVERISETTE 7 premium line is not suitable for grinding with steel
or tungsten carbide grinding bowls in water suspensions. The application
of extremely high energy results in abrasion wear in the nano range.
That can result in chemical reactions that cannot be controlled.
To what extent the heating up of the material to be ground
needs to be observed naturally depends on the corre‐
sponding sample in each individual case. Noteà a longer
duration may also require a long pause time for cooling
down.
If bowls are removed during a grinding pause, check that
the bowl is seated correctly before the device is switched
back on.
5.12 Conducting a grinding operation
DANGER!
– Explosion hazard!
– Ignition hazard!
– Burn hazard!
– Wear safety goggles.
– Wear safety gloves.
The following needs to be observed when grinding material
for which there is no experience with premium line:
Initially, a grinding duration of 5 minutes should be set and the tempera-
ture measured on the actuating pin using a surface thermometer. If it is
below 80 °C, grinding can be continued until a temperature of 90 °C is
reached. At this temperature, it is advisable to apply a cooling pause of
about 15-30 minutes. At the end of the cooling pause, open the knurled
screw to check if pressure has built up in the bowl. If there is no high
pressure, the grinding and pause times can be programmed in such a
way that the temperature does not exceed 90 °C.
During the pause, the mill continues to run at low speed for
better cooling. (From firmware V1.08 and higher)
Using the device
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