Polyester non-woven fabric​, also known as geotextile, is a water-permeable geosynthetic material made of synthetic fibers by needle punching or weaving. The finished product is cloth, generally 4-6 meters wide and 50-100 meters long.

Since most air purifiers in passive adsorption purification mode use a fan + filter mode to purify air, dead corners will inevitably exist when the wind uses the flow of air. Therefore, most passive air purification can only produce a certain amount of purification around the air purifier.