The primary filters are mounted on all vacuum cleaners and trap all forms of common dust, even the finest particles; There are different types of primary filters:
These filters can be in L and M class for the collection of hazardous dust and they can be in different media for the different applications such as for example in PTFE (thanks to the PTFE membrane, dust falls down easier during the filter cleaning and doesn't penetrate the filter material) or Nomex® (to be used in case of hot material).
When the potential hazardous dust has to be collected further absolute H class filters are needed, Nilfisk provides both upstream (located before the blower) and downstream (as last filtration stage) absolute filters. In terms of filtration efficiency the filters can be HEPA 14 and ULPA 15.
Activated carbons filters
Activated carbon filters are mainly used for the following applications: