Grinding While Cooling; Maintenance And Cleaning - IKA M 20 Universal mill Betriebsanleitung

Grinding while cooling

Plastic, soft or smeary materials have to be cooled if they are to
be ground.
There are two hose couplings located at the rear of the grinder
in order to connect the cooling brine. Cooling with tap water is
usually sufficient for substances which become hot as a result of
the grinding operation and are thus given to smearing or those
that produce oil.
The grinding chamber may only be filled halfway especially when
drugs containing oils and similar materials are ground.
If more refrigeration is required then the ground matter should be
cooled prior to being put into the grinding chamber.
The following procedure shall apply if liquid nitrogen is used in
order to embrittle the material to be ground:
Safety information:
Suitable protective gloves must be worn when filling
and transferring liquid nitrogen!
Protective glasses must be worn!
• The sample to be ground is put into a suitable vessel (e.g. evapo-
rating dish) and covered with enough liquid nitrogen until it is
completely covered.
When using liquid nitrogen make certain that the sample is not
capable of reacting with oxygen.
• Cool grinding chamber using liquid nitrogen.
• Put the deep-cooled sample into the grinder and grind approxi-
mately 15 seconds.
• Then open the grinder and add liquid nitrogen for only as long as it
takes for the sample to become deep-cooled again (embrittled).
Safety information:
Make certain that the liquid nitrogen has evaporated be-
fore beginning the grinding operation.
NOTE: Danger of overpressure!
• Repeat the grinding operation for approximately 15 seconds.
• Repeat the sequence of cooling and grinding until desired fine-
ness has been achieved.
• If the required fineness has not been achieved after 5 minutes,
then a further reduction in grain size is unlikely.
The respective grinding chambers are sealed by means of laby-
rinth sealings. Though they are dust-proof, they are not leak-
proof. This should be taken into account for substances where
liquids may escape.
Replacing the grinding tools
The grinding tool is fixed by means of the retaining tube and the cap
nut is unscrewed by using the SW 10 spanner. The grinding tool,
which rests on a double-edge track, may then be pulled out.

Maintenance and cleaning

The device is maintenance-free. It is only subject to the natural wear
and tear of components and their statistical failure rate.
Cleaning:
For cleaning disconnect the mains plug.
Only use cleansing agents which have been recommended by IKA:
Water (containing surfactant) and isopropyl alcohol.
- Wear protective gloves during cleaning the instruments.
- Electrical instruments may not be placed in the cleansing agent for
the purpose of cleaning.
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