482
M
MILLS
Planetary Ball Mill
PBM-4
●
Quick and easy cleaning
●
Rapid fine crushing
●
Easy exchange of
grinding jars and balls
●
Grinding jars and balls are made from a wide range
of materials
●
Grinding jar volume up to 500ml
●
Progr. control
●
End fineness
< 1
µ
m.
PBM-4, Planetary Ball Mill
MRC Planetary Ball Mills for fine grinding of soft, hard to brittle or
fibrous materials
The MRC Planetary Ball Mills are used for fine grinding of soft, hard to brittle
or fibrous materials. Dry and wet grinding are possible. They support the daily
sample preparation for laboratory- and development usage.
Working principle:
MRC Planetary Ball Mills consist of several cylindrical grinding jars (positioned
on the sun wheel as shown in the figure) which are filled with loose grinding
balls. Two superimposed rotational moves the grinding jars:
Like a planetary system the grinding jar rotates on an orbit around the
centre. This rotational movement is the self-rotation of the grinding container
Grinding
jar
superimposed. The resulting centrifugal and acting
acceleration forces lead to strong grinding effects.
As well as coriolis acceleration. The result is an
intensive grinding effect between the grinding balls
and the sample.
There are different rotational ratios. With a rotation
ratio of 1 :-2 the grinding jar rotates twice during a
sun wheel turn. The minus of this case indicate the
opposite rotation direction.
Sun
wheel
The movement patters of the sample/grinding
balls/can be modified according to the speed
ratio between the sun wheel and the jars. One
option is for sample to be slammed against the
jar watts and stressed.
Another option will allow for the grinding balls to
roll over the sample.
Operation:
MRC Planetary Ball Mills enable the convenient
programming of the following grinding parameters:
●
Grinding duration in hours and minutes
●
Speed
●
Speed ratio (speed sun wheel: grinding jar).
Benefits:
●
High efficient fine grinding up to end
fineness < 1
µ
m
●
Different speed ratios available
●
Grinding jars from 12ml to 500ml made
from different materials
●
Suitable for long-term trials and
continuous use
●
Automatic direction reversal to avoid
agglomerations
●
Reproducible results thanks to progr.
grinding parameters.
Grinding jars:
The selection of the right
grinding jar and the correct filling level
has a big impact on the grinding result.
According to the application you have
to select the correct material and
amount/volume for the grinding jar and
the grinding balls. The jar filling should
consist of about 1/3 sample and 1/3 ball
charge. The remaining third is the free jar
volume that is necessary for the
movement of the balls. The following
table provides recommendations.
Selection guide for grinding jars and balls:
We recommend always to select grinding jars and balls built from the same material.
Nominal volume
Sample amount
Recommended ball Charge
Max.feed size
10mm 20mm 30mm 40mm
12ml
5ml
<1mm
5pcs.
-
-
-
25ml
10ml
<1mm
8pcs.
-
-
-
50ml
5-20ml
<3mm
10pcs.
3pcs.
-
-
80ml
10-35ml
<4mm
25pcs.
5pcs.
-
-
125ml
15-50ml
<4mm
30pcs.
7pcs.
-
-
250ml
25-120ml
<6mm
50pcs.
15pcs.
6pcs.
-
500ml
75-225ml
<10mm 100pcs.
25pcs.
8pcs.
4pcs.
