Nonwovens in Filtration
Dr.-Ing. Jörg Sievert / Freudenberg Filtration Technologies KG - Germany
What are nonwoven fabrics and why are they so successful in the filtration industry ?
Nonwoven fabrics can be designed in a wide variety, which makes them successful to fulfill the requirements arising from the different areas of filtration. It is common to distinguish between depth-loading and surface-loading filters which require different types of nonwoven fabrics. Both filtration principles will be explained and an extensive range of nonwoven filter media will be introduced, from wet laid to dry laid nonwovens, from nonwovens with very coarse fibres to media with nano fibres . Specifically the fibre diameter has a significant influence on the performance of filter media. Subsequently, different nonwoven manufacturing technologies are available to produce different types of filter media with different characteristics.
The future trends in filtration require higher particle collection efficiencies, in particular for particles < 1 m m, lower pressure drop to minimize the energy consumption and high dust holding capacities to extend the lifetime of the filtration products. These properties require different design features and appear to be contradictory. However, new developments in nonwoven fabrics show interesting solutions and offer improvements. A variety of examples will be shown.
The adsorption of gases or odors becomes more and more important in addition to the removal of particulate matter. Various technologies are available to manufacture nonwoven media which are able to remove gaseous impurities successfully. Examples and an overview will be given.
FILTECH 2011 - March 22-24, 2011 - Wiesbaden - Germany - www.Filtech.de