Whatman Grade 54 hardened low ash quantitative filter paper for Büchner funnel and Hirsch funnel filtration enables fast vacuum suction filtration for recrystallization applications.This hard, smooth, high wet-strength Grade 54 fast filter paper enables collection of coarse and gelatinous precipitates with minimal fiber shredding, even when wet.Fast filters for vacuum filtrationHigher nominal particle retention rating (22 µm) than comparable Buchner funnel filter papersFast filtration speed (Herzberg filtration speed 39 s)High purity (0.015% ash maximum)Acid-treated for high wet-strength and chemical resistanceHardened to minimize fiber shedding