Nanofiber Filter TechnologyDerek L. Balchuck

MEEN 3344

Spring 2009

Likely Filter Materials

• Cellulose for the base material • Alumina powder with glass fibers bonded at 100°C• Polyvinyl-alcohol • Polyvinylidene Chloride• Polyvinylidene Fluoride• Polyvinylidene Halide• Melamine-formaldehyde as resin

• The base material is made from a web of cellulose

• The cellulose web has the ability to retain a rigid shape

• The nanofibers are then applied by electrospinning the desired material to the cellulose layers.

• Resin is applied, most likely immediately before the nanofiber material leaves the pipette.

• Forming various layers of nanofibers, cellulose and other materials result in a stepped filtration device

• Note 1: the nanofibers are less than 200 nanometers in diameter

• Note 2: Even though the gap between the nanofibers is greater than the particle’s size, the filter can still filter out that particle

Fabrication of Filters

Benefits • High volume filtration

efficiency in air or fluids• The filter is not made of

paper so when moisture is present, the filter does not absorb the condensation.

• Holds-up to sand and salt• In a relatively dry

atmosphere, the maximum operating temperature is 250ºF.

Applications• Military – sand, salt, water, high temperatures and radioactive

materials (pre-filter for the HEPA filters)• Marine and liquids – condensation in the air flow and ultra fine dust

particles (for engines), filter out particulates in the water or other various liquids

• Industrial, Agricultural and Off-road vehicles – high volumes of sand, dirt, salt and high temperatures

• After treatment compatible – particulate filters found on post January 1, 2007 will plug-up when using a wet gauze filter, charged with oil (K&N)

Disadvantages

• The nanofiber material will tear easily. • The nanofiber filters cost more than the typical paper

filter, due to the additional manufacturing processes. • Maximum temperature sustained with the humidity above

90% is only 100ºF.

Sources

• http://www.donaldson.com/en/filtermedia/support/datalibrary/052023.pdf

• http://www.donaldson.com/en/filtermedia/support/datalibrary/052025.pdf

• http://www.google.com/patents?id=D0ESAAAAEBAJ&pg=PA6&dq=donaldson+nano+air+filter&source=gbs_selected_pages&cad=1_1#PPA1,M1