This is the clearing technology that an object such as parts or components having oil substances thereon is cleaned efficiently with water. This technology can effectively prevent the removed oil substances from re-sticking to the surface of the object after the oil substances is once removed from the surface of the object. This effective prevention is provided by overflowing water with detached oil from the cleaning tank. And the removed oil substances is separated from the water by inexpensive recovery device with a surface of polyethylene terephthalate etc to which the removed oil is more easily stuck than the water (has high oleophilic). Water separated from oil substances can be reused as the cleaning water. The first feature about this technology is to be able to clean an object having oil substances thereon without using an organic solvent and the second feature is no using of a large amount of water. Therefore this technology is environmental technologies. This technology can be used widely when an object having oil substances thereon is need to be cleaned at pretreatment processes such as rough cutting or grinding etc in manufacturing.
This technology can save cleaning water because the cleaning water is separated from oil substances and is easily reused.; This technology is at useable level and is implemented in our factories.