Air cleaners with nanofiber coatings for commercial vehicles

Small fibers – big effect

The new nanofiber coated MICROGRADE NF filter medium from MANN+HUMMEL sets a new standard for air cleaners in commercial vehicles. It offers an extremely high separation efficiency of up to 99.97% with simultaneously low flow resistance and long service life.

Ludwigsburg, 18th September, 2012 – A new nanofiber coated high-tech filter medium from MANN+HUMMEL is the first choice for vehicles operating in environments with very high soot and particulate levels. Examples are building sites with high dust levels, mines and rallies. Highly efficient air cleaners are indispensible here to protect engines and components such as the turbocharger and air flow meter from excessive wear and defects caused by dirt particles.

MANN+HUMMEL has been using nanofiber technology for a number of years in series applications in the commercial vehicle sector. The new MICROGRADE NF nanofiber coated air filter medium consists of a carrier medium and an extremely thin coating of ultra-fine polymer fibers. These fibers have a diameter less than a micrometer (µm) and are around 80 to 300 times smaller than the fibers of the carrier material. This leads to a considerably larger surface area which allows the retention of more dust particles.

A comparison of the nanofiber medium to the carrier material shows the high performance of nano technology when used for filtration. In tests with particle sizes of 0.7 µm the carrier material achieves a separation efficiency of only 40%. Different nanofiber coatings are reducing the passage of these particles by more than a factor of four. The separation efficiency of the nanofiber medium MICROGRADE NF is therefore with regard to all particle sizes approximately 99.97%.

Customized filter media
MANN+HUMMEL has the expert knowledge necessary to develop high performance filter media designed individually for demanding customer requirements. The filtration specialist uses simulations, laboratory tests and special software to fine-tune nanofiber coatings for customer applications and combines this technology with other media and materials.

The simulation of filtration processes based on numerical processes enables a quick and flexible testing procedure to examine how dirt particles within the ultra-fine nanofiber net move and become attached to the net. Here MANN+HUMMEL uses a special software with a patent pending which is able to use pictures from a scanning electron microscope to automatically determine the diameter distribution of the nanofibers. This distribution is primarily responsible for the deposition rate, the flow resistance and the fiber stability of the medium.