... ppi ,20ppi,30ppi,40ppi,50ppi,60ppi,70ppi,80ppi polyurethane filter foam1.10 ppi ,20ppi,30ppi,40ppi,50ppi,60ppi,70ppi, ... high mechanical strength.5) It be as the filter material can effectively filter particles with the diameter of 15um due to ... materials, like foam ceramic filter,foam metal filter,foam with activated carbon filter,foam with photo catalyst filter,antimicrobial foam filter etc.7) It ...