FRITSCH PULVERISETTE 7 premium line - Manual (Page 36)

The large surface of many small balls results in high thermal stress due to
the friction effect. It can already be measured after 5 minutes of grinding
above 100 °C by a surface sensor on the surface of the lid. Inside the
grinding bowl, the temperature is then much higher.
The adhesive used is permanently resistant to temperatures
of up to 140 °C. If the external temperature does not exceed
100 °C, the adhesive will hold.
5.4 Filling quantities of grinding bowls
Grinding bowl Min. sample quantity Max. sample quantity
20 ml 1 ml 9 ml
45 ml 3 ml 20 ml
80 ml 10 ml 30 ml
CAUTION!
For wet grinding with large balls with a diameter of >
10mm, at least half the maximum sample quantity must be
inserted. If the suspension is highly fluid, the balls will not
have any resistance and the balls and the grinding bowl
could be damaged. The result is the same as if no material
to be ground were filled. The same applies to dry grinding
with less than the minimum sample quantity.
NOTICE!
If the minimum filling quantity is fallen short of, increased
wear due to abrasion is to be expected. This can cause
irreparable damage to the mill components.
5.5 Filling the grinding bowl
Do not fail to comply with the following sequence:
1.
Place the grinding balls in the empty bowl.
2. Fill material to be ground over the balls.
Using the device
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