Abstract
The properties of the lubricant get worse with the usage time due to oxidation reaction and contamination. Incorporation of the fine particles is a main factor of the deterioration of the lubricant. If the particles are removed effectively, the used oil could be reused. Using high voltage, electric charges could flow through the cutting oil. Metal particles and contaminants migrated under high electric field and aggregated on the surface of electrodes. Using the high electric field, fine metal particles were separated from the used cutting oil and then the oil became clear. The core chemical structure of the used oil was hardly degraded by the treatment. The application of the high electric field is the useful method to remove the metal particles effectively.
