Characteristics of physical and tribological properties of used lubricants from filtering process of a car engine.

Used lubricant becomes an issue for environment due to disposal techniques and reuse of it through filtering process is the best technique. This paper tried to determine the characteristics of physical and tribological properties of used lubricant from a filtering process. The used lubricant was collected in service from a car engine after running about 6000 km. A Whatman filter paper was used to reduce impurities in used lubricant. The used lubricants were characterized physically to determine kinematic viscosity, density, pour point, and flash point and tribologically to measure wear rate, CoF, surface texture, scar width of disc, and scar diameter of pin using pin on disc apparatus. The results were compared with virgin oil and they show that the physical and tribological properties of used lubricant were decreased compared to virgin oil. The tribological properties of used oil were good lubrication at a speed of 1400 rpm than 500 rpm. [ABSTRACT FROM AUTHOR]