During the operation of the engine, the oil will be oxidized and decomposed by high temperature, resulting in impurities such as colloid and carbon accumulation. Impurities such as gum, carbon accumulation and grinding chips, carbon slag, gray sand, and gum, if they enter the friction surface with the oil, they will accelerate the wear of the engine parts and block the oil passage, so that the engine can not get good lubrication. Therefore, the modern automobile engine is equipped with a collector, a coarse filter and a fine filter to remove impurities in the oil, reduce the wear of the parts, and extend the service life of the oil.

The filter element is composed of two parts: one part is a full-flow filter element, which has small flow resistance but low filtration accuracy; The other part is the shunt filter element, which is characterized by high filtration accuracy and large ash capacity, but the flow resistance is also large. The continuous supply of lubricating oil is ensured by the full-flow filter element with small flow resistance, and the impurities are filtered by the shunt filter element with high filtration accuracy. At the same time, the filter element uses a new material, the ash content is higher than the traditional material, can fully meet the requirements of modern engines, but because of its high technical content, the current domestic production manufacturers are not many.