The pore diameter in the film is rather large on the inlet side but decreases gradually towards the outlet side (see "PSE membranes structure" below).
Coarse particles are first trapped near the inlet side, while finer particles are trapped by finer pores situated at greater depths.
Unlike in conventional films with the filtration system localized on the inlet side, the new filter fully functions throughout its entire thickness, leading to a longer service life (see "Trapping of latex mixure" below).
The larger pores on the inlet side ensure a low initial pressure loss. The pore size, after decreasing in the bulk of the film, becomes larger again on the outlet side, providing a high flow rate.
The pore diameter can be as small as 0.05 μm, depending on the product grade. Sharp pore size distribution curves (see charts below) assure reliable removal of fine particles and microorganisms.