A Guide to Common Air Filter Materials

1. Fiber Media

Synthetic-Fiber Filter Cotton

Material and characteristics: The main raw material is polyester fiber (PET). It offers low resistance, low weight, high dust-holding capacity, moderate cost, and environmentally responsible disposal by incineration. It can replace nonwoven and fiberglass materials across complete ranges of coarse-, medium-, and high-efficiency filtration products and is a major direction for future filter-media development.

Applications: Widely used for general air filtration, including ventilation and air-conditioning systems.

Nonwoven Filter Cotton

Material and characteristics: Its scientific name is polyester fiber. It is manufactured through multiple processes such as melt blowing, needle punching, hydroentangling, and spun bonding. Compared with media of the same grade, it provides consistent quality, high dust-holding capacity, strong moisture resistance, long service life, and good economy and durability. Its disadvantages are relatively high resistance and poor environmental performance because it cannot be incinerated or decomposed.

Applications: A typical medium for coarse- and medium-efficiency panel and bag filters in China. It is commonly used for coarse-dust filtration, including residential air-conditioner screens and primary filters in air purifiers.

Fiberglass Filter Cotton

Material and characteristics: Made from glass fibers of different diameters and lengths through special processing. It delivers stable performance, heat resistance, high efficiency, high dust-holding capacity, and long service life. In some special environments, only fiberglass can meet the requirements.

Applications: Widely used in primary filters for general ventilation systems, high-temperature filters, and high-efficiency filters, including industrial-plant ventilation and air filtration for high-temperature kilns.

HEPA Filter Paper

Material and characteristics: Usually made from fiberglass paper or synthetic textiles. It captures fine particles 0.3 μm and larger, including bacteria, pollen, and dust mites. It offers high efficiency, high air resistance, high dust-holding capacity, and high precision.

Applications: Commonly used in air purifiers, fresh-air systems, and locations with stringent air-purification requirements, including hospitals, laboratories, and semiconductor-chip manufacturing workshops.

2. Activated-Carbon Media

Activated-Carbon Filter Cotton

Material and characteristics: Made by impregnating synthetic fiber with carbon and adhesive. Its main advantage is effective removal of odors and harmful gases such as formaldehyde, benzene, and total volatile organic compounds (TVOCs). It is not primarily intended to provide particle-filtration efficiency and generally must be used with separate coarse- and medium-efficiency filters.

Applications: Commonly used in assembly workshops, spray-painting and paint-curing workshops, surface-finishing areas, and paint booths. It is also used in residential air purifiers to remove odors and harmful gases.

Activated-Carbon Filter

Material and characteristics: Primarily made from activated-carbon granules or activated-carbon fiber. Its strong adsorption capacity effectively removes harmful gases and odors from air. Activated-carbon filters typically contain about 50% activated carbon, and adsorption performance generally increases with carbon content.

Applications: Widely used in air purifiers, fresh-air systems, and air-conditioning systems to remove harmful gases and odors and improve air quality.

3. Metal Media

Aluminum-Foil Mesh Element

Material and characteristics: Made from aluminum foil, it is lightweight, corrosion-resistant, and heat-resistant. Filtration precision can vary widely and can be customized as needed.

Applications: Commonly used for primary filtration in air-conditioning and ventilation systems, as well as industrial environments requiring strong corrosion resistance.

Stainless-Steel Mesh Element

Material and characteristics: Woven or welded from stainless-steel wire. It is resistant to heat, pressure, wear, and corrosion. Uniform pores provide stable filtration, and it can operate at both low and high temperatures. It can also be washed and reused, making it economical and practical.

Applications: Widely used in industrial ventilation, air-conditioning systems, air purifiers, and other air-filtration systems. It is especially suitable for demanding environments that require high filtration precision.

4. Other Materials

Foam Filter

Material and characteristics: Usually made from polyurethane or a similar material. Its soft, porous structure offers strong adsorption, but its mechanical strength is low and it deforms easily.

Applications: Often used for air filtration in small engines and for low-cost applications with modest filtration requirements, including compact residential air purifiers and computer-case fan filters.

PP Filter Element

Material and characteristics: Made by melt-entangling ultrafine polypropylene fibers. It provides filtration across multiple layers, with high precision and strong resistance to acids, alkalis, and corrosion.

Applications: Commonly used for drinking-water and air filtration. It can effectively remove impurities and bacteria from water and particles from air.