the mechanical-physical operation which is used for the separation
of solids from fluids (liquids or gases) by interposing a porous
media through which only the fluid can pass. Oversize solids
in the fluid are retained on the surface as well as within the
matrix of the filter media.
Filter papers retain the impurities or particles of the liquid
fluids on the surface as well as within the matrix of the
The particles or impurities are settled into
the filter, modifying its filtration properties. Within the
filter fibers arranged in an anarchic way into the filter
paper, it creates a secondary filtration layer.
This is the reason why it is no possible
to determine a nominal porosity for the filter papers. As
guidance it is possible to find the retention ranges into
our technical specifications tables.
Often the filter papers are named as depth filters; they
have a high capacity to retain particles and allow process
big quantities of sample.