0.22 0.45 Micron Hydrophobic PTFE Membrane Filters Disc - Hawach No additives in the whole process; stable physical and chemical properties and good compatibility. As a PTFE membrane filter manufacturer, Hawach provide a series of pore sizes(0.1μm, 0.22μm, 0.45μm, 1.0μm, 3.0μm, 5.0μm, 10μm), high porosity, large dirt holding capacity, recoil and high-temperature disinfection; good pressure resistance.