Retsch MM 400 - Manual (Page 10)

2/8/2012 10 Retsch GmbH
Do not use ceramic or natural stone milling cups for
milling graphite or graphite mixtures.
The high lubricating properties of graphite cause high
milling ball speeds, the energy of which cannot be
absorbed by the material owing to its low density.
For this reason there is a danger that the ceramic
or natural stone inserts of the milling cups will be
destroyed by the ball/s.
For further information our application laboratory will
be pleased to assist you.
Protective equipment
The milling chamber of the laboratory mill MM 400 is
enclosed by a strong covering hood.
Starting the machine is possible only with the hood
closed.
Emissions
Noise characteristic values :
The noise characteristic values are also influenced by
the properties of the material to be milled.
Example 1:
Intensity of sound L
WA
= 71.4 dB(A)
Emission value related to
workplace L
pAeq
= 61 dB(A)
Operating conditions:
Container: 2 steel milling cups of 25 ml
Milling organ: 1 steel ball 20 mm
Material charged: Quartz crushed pebbles approx.
4.0 – 6.0 mm
Charged quantity: 8ml
Example 2:
Intensity of sound L
WA
= 76 dB(A)
Emission value related to
workplace L
pAeq
= 65 dB(A)
Operating conditions:
Container: 2 steel milling cups of 5 ml
Milling organ: 2 tungsten carbide balls 8 mm
Material charged: Quartz crushed pebbles approx.
1.0 – 1.5 mm
Charged quantity: 1.5ml