Putoline air filters are based on leading-edge open cell foam technology.
Fully reticulated (open cell) foam, as used in all Putoline filter products, consists of a honeycomb of tiny, interlocking cells of uniform size.
When treated with specially formulated filter oil, each passageway is like hundreds of very small centrifugal/oil bath filters connected one to another.
In this way, the foam traps and holds the particles throughout the entire volume of foam.
