Does lubricant conduct electricity?
Pure lubricants are basically non-conductive. Then the problem comes - static electricity. Because of the poor conductivity of insulators, static electricity is easily produced when friction occurs. Oil products in transportation and flow will produce static electricity by friction with containers and components. If these static electricity is not released in time, it may generate static sparks and cause combustion explosion.
For the generation of static electricity, the better the insulation of the material, the easier it is to generate static electricity. The conductivity of insulators is much lower than that of conductors.
Normally, the conductivity of lubricating oil is very low, so it can be used as insulation oil or transformer oil, although the role of transformer oil is not lubrication. Nevertheless, in some cases, the lubricant may also conduct electricity, mainly related to the composition of the lubricant and the impurities contained in the lubricant.
What factors affect the conductivity of lubricating oil
1) Conductivity of base oil and lubricating oil:
Lubricating oil is made of base oil and additives. The lower the refining degree of base oil, the stronger the polarity, and the stronger the electric conductivity of the oil. According to the refining method and degree of base oil, API classifies base oil into five categories: API oil, API II oil, API III oil, API IV oil and API V oil.
2) The effect of additives on the conductivity of lubricating oil:
In addition to the type of base oil, additives also affect the conductivity of lubricants. Organic metal additives can improve the conductivity of lubricating oil. Common organic metal additives, such as ZnDTP antiwear agent, are widely used in engine oil and hydraulic oil. It is a multi-functional additive, which can resist wear, oxidation and metal corrosion.
3) The influence of temperature on the conductivity of lubricating oil:
In addition to base oils and additives, temperature also affects the conductivity of lubricants. For the same kind of lubricating oil, the conductivity of lubricating oil increases with the increase of temperature. However, the relationship between the conductivity and temperature of lubricating oil is not simply proportional. The increasing trend of conductivity is different for different lubricating oils when the temperature rises.