Table 1.

Filter material description.

Property	Wool	Polypropylene	Processed Blend
Blend Composition (%)	60	40	-
Diameter (μm)	21.0	22.9	-
Length (mm)	43	67	-
Short Fiber content (%)	37	1	-
Fiber Type	Carbonized crutchings and locks	3 denier staple fiber with hydrophilic finish	-
Cleaning	6 bowl machine-scouring in 65 °C water, BD40 detergent in bowls 1 and 2		-
Areal Density (g/m2)	-		≈320
Pressure Drop (Pa) at face velocity of 0.15 m/s	-		≈30
Penetration P0.3 (%), unworn (%)	-		≈2