There are many types of surface filtration membranes, which we usually divide into hydrophilic and hydrophobic (there are also some hydrophilic and hydrophobic dual-purpose membranes). In short, hydrophilicity is more suitable for filtering aqueous solutions, but not for filtering organic solvents, acid-base solutions, and air; hydrophobicity is suitable for filtering organic solvents, acid-base solutions, and air. But in fact, according to the different filter materials, they have different characteristics.

Fiberglass material filter membrane belongs to depth filtration, and its main use is as a filter layer, which is directly added to the filter membrane.

Filters of different sizes have detailed requirements on the pore size of the pre-filtration membrane. If the aperture is too large, the rim will extend below the seal ring, causing fluid to leak. Multilayer filtration is often used when filtering thick and difficult-to-filter solutions, such as serum. Stack two or three layers of membranes with different pore sizes. A polyester separation layer is added between the filter membranes to facilitate the filtration of the solution. A glass fiber material prefilter is added on top.