Page 109 - 20250602 EEA QM Edition 6.0

Quality Requirements Edition 6.0 European Enamel Association

Required reagents:
8.5.1 Testing of setting agents and other accessory materials
Methylene blue solution (I)

Dissolve 3.2 mg methylene blue in 500 ml distilled water of about 70 C. Put Purpose and scope
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this solution in a 1000 ml measuring flask and fill up at 20 C with distilled
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Testing of setting agents and other accessory materials can mostly be done in the
water.
laboratory of the enamelling shop. The various analytical processes presuppose

training and experience.
Methylene blue solution (II)
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Dissolve 1.6 g methylene blue in 500 ml distilled water of about 70 C. Put this Normally, setting agents are genuine or chemically pure chemicals supplied by the
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solution in a 1000 ml measuring flask and fill up at 20 C with distilled water. chemical industry with their final quality control.

6n sulphuric acid It is substantial for the processing plant to store the setting agents according to their
storage specifications. Some of them, e.g. sodium aluminate, are hygroscopic. That is
Mix 167 ml concentrated H2SO4 (Density 1.84) with 700 ml distilled water and
fill up to 1000 ml with distilled water. to say, they adsorb water, so that the agent cannot be used for enamelling if not stored
properly.

In case of doubt about the correct storage of accessory materials, suppliers or
manufacturers should be contacted for the corresponding specifications.

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