Filter media refers to the porous material that plays a leading role in the filtration process, and its main duty is to allow the working medium (such as liquid, gas or slurry) to pass through its own pore structure, and at the same time, effectively capture and intercept the solid particles, suspended solids, microorganisms, liquid droplets, or other impurities therein, so as to achieve the purpose of separation, clarification, purification or concentration. Filter media is the core component of the filtration device, its performance directly affects the filtration process of separation accuracy, filtration efficiency, equipment stability and operating costs.

There are many kinds of filter media, according to the material, form, production process and application of different areas, can be broadly divided into the following categories:

  1. fabric media: also known as filter cloth or screen, woven from natural fibres (such as cotton, linen, silk, wool) or synthetic fibres (such as polyester, polypropylene, nylon, etc.)
  2. granular media: including coke, gravel, fine sand, sawdust, activated carbon, glass slag, acidic white clay and other solid particles with a certain shape and particle size.
  3. porous solid media: such as porous ceramics, porous glass, porous plastic, stainless steel powder metallurgy products.
  4. membrane media: including organic polymer membrane (such as polysulfone, polypropylene, polyethersulfone, etc.) and inorganic membranes (such as ceramic membranes, metal membranes, etc.).
  5. rigid porous media: such as sintered metal plates, porous ceramic plates, etc.
  6. porous cardboard media: such as decolourised wood cardboard, synthetic fibreboard, etc., this type of media to paper or fibreboard as the basis, through a special process to form a porous structure.