The factors that affect the air release rate of lubricating oil include:
The size of bubbles: Larger bubbles are prone to escape, while smaller bubbles trapped inside the lubricating oil are more difficult to release and pose a significant risk.
● Viscosity of lubricating oil: Lubricating oil with higher viscosity has a lower air release rate than low viscosity oil.
Temperature: Low temperature will increase the viscosity of lubricating oil and reduce the rate of bubble release.
Lubricating oil oxidation: Oil oxidation deterioration includes base oil deterioration and additive depletion, all of which can affect the anti foaming performance of lubricating oil.
Lubricating oil is contaminated: Common examples include water ingress into the oil, which can reduce the surface tension of the oil and prevent the formation of large bubbles that float to the liquid surface. Instead, small bubbles are fragmented and suspended inside the oil. In addition to water, the mixture of other oils and solvents in lubricating oil can affect air release.