AF plates are made of fibrous elements that are able to separate and hold back unwanted contaminating components like mold, dust, bacteria, etc. while maintaining the flow of air. Another type is chemical filtration, such AF uses a special type of chemical component instead of physical interaction with contaminating elements. Air filters are presented in variations that differ in the material used in the filter itself, like paper, foam, cotton, steel, oil, and more, but HVAC/R and air purifiers mostly use 2 types of material - fiberglass and polyester. There are 3 stages of air filtering - pre-filter, after-filter, and final filter, and at each stage, different types of AF plates may be used to improve the purification quality.
The construction and layout of a filter plate may differ, depending on the device that utilizes it. There are non-reusable air filters that should be disposed of after exploitation. Such utilities include mostly filters that are used to separate dangerous and poisonous particles. They are commonly utilized in factories and similar facilities. There are washable and reusable filters, they are mostly used in air purifiers and small HVAC/R systems, they may require special chemical reagents to be adequately cleaned.