Ahlstrom’s qualitative grades of filter paper are, by definition, recommended for use in analytical methods, which 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.
Ahlstrom offers a complete range of low ash filter papers for general laboratory work that provides you with the correct combination of particle retention, filtration speed, loading capacity and wet-strength. All our qualitative grades consist of > 95% super refined a-cellulose and linter fibers.
- Qualitative analysis
- Low ash content 0.06%/li>
- Untreated/li>
- Consistent performance/li>
- Wet-strengthened grades available/li>
- Custom cut/li>
- Bulk packaging/li>
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 but will weaken when wet. The inherent strength of standard (untreated) grades does not pose a problem when they are used in routine quadrant folded applications. We do not recommend these grades for use in vacuum work or when wet handling is required.
Ahlstrom 609: 4µm – Medium Speed
This grade is an evolution of Ahlstrom 613 for use in the beer industry. This is a filter paper with an extremely low iron and nitrogen content for the analysis of protein in beer.