Is it feasible to judge the maximum operating temperature of the grease only by the drip point?

The commonly used basis for judging the maximum service temperature of lubricating grease mainly includes: dropping point, thickener type, base oil type, additive type and dosage, etc. The most scientific method is to make a comprehensive judgment.

Although the maximum service temperature of lubricating grease cannot be determined solely by the dropping point, the dropping point is still one of the convenient methods for judging the maximum service temperature of lubricating grease. It is generally believed that the maximum operating temperature of the grease should be 30~50°C lower than the dropping point of the grease, and necessary corrections can be made according to the oil separation, oxidation stability, thermal stability and other indicators of the grease.

All base oil types will directly affect the maximum service temperature of the grease. At this time, it is necessary to comprehensively consider the flash point, evaporation loss and thermal decomposition temperature of the base oil and the specific performance index requirements of the grease. If the dropping point of the grease is low, even if perfluorocarbon oil is used as the base oil, the maximum operating temperature of the grease cannot be higher than its dropping point; similarly, if a bentonite grease with a high dropping point is used, and the base oil is Mineral oil, the maximum temperature of the grease should not be higher than the maximum temperature of mineral oil.

The dropping point of lubricating grease with different types of thickeners and the maximum service temperature of base oil are as follows:

In addition, because additives, especially extreme pressure additives generally have certain chemical activity, they will have irreversible effects on the structure of grease at high temperatures, and will also aggravate corrosion. Therefore, when additives with strong activity are added, appropriate Reduce the maximum service temperature of the grease.