1. What is a filter media?
Any porous material that can pass a fluid and retain the solid particles contained in the fluid to achieve the purpose of solid-liquid separation is collectively referred to as a filter medium.
It is a key component of the filtration device, which determines the accuracy and efficiency of filtration.
2. Filter media classification
There are many types of filter media, which are divided into three categories according to their structure: flexible media, rigid media, and loose filter media.
(1) Flexible filter media:
Metal filter media
Non-metallic filter media: Polypropylene, polyester, synthetic fiber, glass fiber, non-woven filter cloth, filter paper, filter mat, filter liner
Metal, non-metal mixed media
(2) Rigid filter media:
Sintered metal mesh, metal fiber sintered felt, powder sintered material, porous ceramic, sintered porous plastic, sintered aluminum oxide, glass filter media
Loose filter media:
Diatomaceous earth, expanded perlite powder, cellulose, sand, charcoal powder
3. Common filter media and applications
(1) Polypropylene fiber (PP)
Polypropylene has good abrasion resistance and high elastic recovery rate. It is an excellent thermoplastic fiber. Polypropylene felt is commonly used in low-temperature pulse filter bags in smelting plants and pulse filter bags in chemical and pharmaceutical plants.
(2) Polyester fiber (polyester)
Polyester fiber has good performance at room temperature and is the main filter material in bag filter. Can be subjected to 130 °C operating temperature under dry conditions; continuous work above 130 °C will become hard; fade; crisp, the temperature will weaken its strength.
(3) P84 fiber (polyimide)
P84 filter material and P84/glass fiber composite filter material have good temperature resistance, flame retardancy and other properties, and have been widely used in steel blast furnace gas purification, calcium carbide furnace dust collection, power station coal-fired boilers, municipal waste incinerators and other industries High-temperature flue gas filtration and achieved good results.
(4) PTFE (polytetrafluoroethylene)
PTFE is a neutral polymer compound with a unique molecular structure that is completely symmetrical in structure. The special structure makes it have good thermal stability, chemical stability, insulation, lubricity, water resistance and so on.
High temperature resistance, wide use temperature range, can be used at 260°C (long-term continuous use at high temperature, instantaneous temperature up to 280°C; chemical stability, corrosion resistance; good self-lubricating, low coefficient of friction, very small filter wear; PTFE The surface tension of the film is very low, and it has good tackiness and water repellency.
PTFE coated membrane filter can achieve surface filtration, because PTFE membrane filter is a microporous structure, the surface without through-holes, so that dust can not enter the membrane through the surface of the membrane or the substrate, so that only the gas through Dust or material is trapped on the surface of the membrane. At present, the coated filter has been widely used in industrial dust removal, precision filtration and many other fields.
(5) Glass fiber
Deep filtration, the filter material consists of multiple layers of glass fiber, suitable for filtering hydraulic oil, lubricating oil, refractory liquid, fuel and synthetic liquid.
(6) stainless steel mesh
Surface filtration with very low flow resistance. Filtering methods used are: weaving, twill and linen.
Metal mesh filters are suitable for use in suction filters for hydraulic and lubrication systems, or for coarse filtration of high-speed fluids, or for the safe filtration of coolants.