Typically vacuum filter systems require filter media with improved tensile strength and good flow porosity. This is generally spun-bonded polypropylene (SBPP), polyester and polyester needlefelt. As the demand for finer filtration continues these range of non-woven products are increasing their share of the filter fabric market. Non-wovens represent 90% of all filter media used in dry and liquid filtration.
Spunbonded Polypropylene (SBPP)
SBPP is a less expensive product than polyester. It can be limited in some applications depending on the nature of the fluid and the mechanical performance required. It is often found on gravity feed systems when standard viscose is unsuitable.
Spunbonded Polyester
With greater tensile strength and flow porosity than SBPP at similar weights, polyester is an ideal media for vacuum / pressure systems. It is totally inert and its stability and good chemical resistance ensures complete fluid integrity. Fibre migration is eliminated and there are no ravelling edges. The fibres are extremely fine, typically 16 - 25μm diameters which combined into a complex media create an excellent cake building matrix. An ideal media for both soluble and neat oils.
Polyester Needlefelt
This media is ideally used in fine contamination applications where high dirt loading is expected. The depth of the media provides better levels of filtration, typically 10 - 15 micron nominal in addition to longer filter life compared to SBPP.