An air filter element is a type of filter, also known as an air filter cartridge, air filter, or style. It is mainly used for air filtration in engineering locomotives, automobiles, agricultural locomotives, laboratories, aseptic operation rooms, and various precision operation rooms.

During operation, the engine needs to draw in a large amount of air. If the air is not filtered, the suspended dust in the air will be sucked into the cylinder, which will accelerate the wear of the piston group and the cylinder. Larger particles entering between the piston and the cylinder can cause a severe "cylinder pulling" phenomenon. The air filter is installed in front of the carburetor or intake pipe, serving to filter out dust and sand particles to ensure clean air enters the cylinder.

The filter paper in high-quality equipment adopts ultra-fine fiber paper filled with synthetic resin, providing effective filtration and high dirt-holding capacity. For example, a bus with 180kW power can filter out 1.5kg of impurities over 30,000km. High strength is required to withstand strong air flow and extend service life.

The service life of the filter element varies depending on raw materials:

• PP Filter Elements: Replace every 3 months.
• Activated Carbon Elements: Replace every 6 months.
• Fiber Filter Elements: Placed at the rear, less likely to clog.
• Ceramic Filter Elements: Can usually be used for 9 to 12 months.