Description

Quantitative filter papers – hardened low ash grades
The maximum ash content of these grades is intermediate between ashless and qualitative grades. They are particularly suitable for Buchner filtrations where it is desirable to recover the precipitate from the filter surface after filtration. Other characteristics include high wet strength and chemical resistance, which are similar to the acid hardened ashless filter papers.

Grade 50 (2.7 um*)
Retention of very fine crystalline precipitates. The thinnest of all Whatman filter papers with a slow flow rate, these filters have a hardened and highly glazed surface, which also keeps the paper free from loose surface fibers. Highly suitable for qualitative or quantitative filtrations requiring vacuum assistance on Buchner or 3-piece filter funnels. Very strong when wet and will withstand wet handling and precipitate removal by scraping. In the electronics industry, the virtual absence of fiber shedding is utilized in carriers for integrated circuits. This grade is also available in Smear Tab format for wipe testing (e.g. testing of surfaces for radionuclide contamination).