Water separation properties (Demulsibility characteristic of oil)
Anton Paar Rheometer Physica MCR 301
OELCHECK
Test equipment:		 Measuring cylinder in the heating bath
Sample quantity
needed:		 50 ml
Unit: The result is normally numerical.
Furthermore the appearance of the three layers and there boundary surface is expressed as letters.
Operating time: About 60 minutes
Analysis of: Mineral oils and synthetic liquids.
Test result: Determination of the water separation capacity for mineral oils and synthetic liquids.
Brief description: For the test 40 ml of distillate water and 40 ml of the oil is heated up to 50°C. The filled measuring cylinder is dunked into a heating bath with constant temperature.
The two liquids are intensively mixed for 5 minutes by a large agitator which is turning with 1500 rpm in the 1:1 Oil-water-mixture. The result is a hazy and non-transparent, instable emulsion. After mixing the agitator is removed from the milky emulsion. In the unmoved sample a separation from water and oil takes place because of gravity. Water goes down to the bottom and oil is swimming on the upper phase. Each 5 minutes the volume of water, oil and the emulsion between these two liquids is measured.
The appearance of these three single phases is described.
The measuring of the volumes is continued, till the thickness of the emulsion between oil and water becomes less than 3 ml. The test will be stopped after one hour if the thickness of the emulsion doesn`t reach 3 ml.
Statement:   Usually water with a density of about 1.000 Kg/m3 separates quite fast from oil with much lower density of about 880 to 940 Kg/m3. The separation can be affected by additives and contamination.
In most cases a fast separation from water is requested. The oil behaviour should be demulsifying. But also the opposite effect can be useful. Some lubricants, like e.g. hydraulic oil out of the HLP-D category, should not work demulsifying, they should furthermore act disperse or detergent. They have to disperse infiltrated liquid into very small particles and keep them as a suspension.

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Last modified: September 2010, © OELCHECK GmbH Disclaimer Imprint