Filter bags made of PP needle felt (polypropylene) can have several special finishes.
In some market segments these rare characteristics are required:
- Asymmetry - the fiber support is not located centrally, but on the side. In this rare case, the dust side of the bag is on the non-smoothed side of the surface. This finish has an influence on the filtration efficiency.
- PTFE membrane – it can also be used with polypropylene needle felts. In order to achieve a very high filtration efficiency, the microporous membrane is the right solution.
- Spark blocking - thanks to special manufacturing technology such material can be used in applications where sparks can occur.