Ahlstrom-Munksjö’s qualitative grades of filter paper are recommended for use in analytical methods that determine or identify particulate constituents of a mixture, irrespective of the amount present. Qualitative filter papers are often used in routine separation work that still requires high purity and consistent performance. These filter papers cover a wide range of laboratory applications, such as liquid clarification, qualitative analytical separations for precipitates, and buffer filtration. They are also used for soil analysis and food and beverage testing.
Standard Grades (Non Wet-Strengthened)
Standard qualitative filter papers are suitable for quadrant folded or gravity flow applications. These grades contain a high level of alpha-cellulose that provides high purity (ash content below 0.06%). The inherent strength of standard grades is suitable for routine quadrant folded applications but does not allow use in vacuum work due to low wet resistance. Grade 3 hw is recommended only for general purpose filtration due to a higher ash content (<0.1%) and lower filtration properties.
Ahlstrom 3 hw
This is a strong filter paper with a medium flow rate and retention. Grade 3 hw is commonly used in student laboratories. This strong general-purpose filter is also in Buchner funnels carbonate, lead chromate and beryllium hydroxides.
Typical Grade Properties