DROPPING POINT OF LUBRICATING GREASE

Group # 9 Tamse, Jan Marvin M.

1. Introduction

1.1 This experiment aims at determining the dropping point of given lubricating

grease.

2. Theoretical Background

3. Material/Equipment Used

3.1 Grease Cup –

3.2 Test tube –

3.3 Thermometers –

4. Methodology

4.1 The cork of the test tube was placed on the first thermometer. This was adjusted

until the bulb reaches at the center of the expected position of the grease cup. The

second thermometer was then suspended in the oil bath in such a way that its bulb

will be at the same level as the bulb of the first thermometer.

4.2 The cup was filled with grease by pressing the larger opening into the grease.

4.3 The cup and the thermometer were placed in the test tube. The test tube was then

suspended in the oil bath with the oil level within ¼ of the rim.

4.4 The oil bath was stirred and heated at a rate of 8 to 12°F until the bath reached a

temp of 30°F below the expected dropping point. At this point, the rate of heating

was reduced. The slow heating was continued such that the difference between

the two thermometers is between 2 to 4°F.

4.5 When a drop of grease was observed, the temperatures on the two thermometers

were then noted and their average was then recorded as the dropping point of the

grease.

5. Data and Discussion

Table 5.1 Calculated dropping point of the lubricating grease

TRIAL DROPPING POINT

1 192 °C

2 198 °C

Trial 1:

Grease Temperature: 180 °C

Oil Temperature: 204 °C

Dropping Point: 180+204

2=192 °C

Trial 2:

Grease Temperature: 182 °C

Oil Temperature: 214 °C

Dropping Point: 182+2 1 4

2=198°C

6. Conclusion

The Dropping point of a lubricating grease represents the temperature where it

starts to drip. This is useful in identifying the working temperatures of a given

lubricating grease. Note that the dropping point indicates the temperature limit

where the grease loses its structure, not the point where it becomes non-

functional[1].

7. Recommendation

It is recommended that a different grease sample should also be used for the sake

of comparison.

8. Bibliography