Qualitative Filter Papers-Grade 4: 20-25μm

Grade 50: 2.7 μm*
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 Büchner
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).

Grade 93: 10 μm*
This filter paper is intermediate in speed and retention between Grades 1 and 4.

Available in a dispenser pack, which can be attached to the wall or bench, placed on a
shelf either upright or flat, and used as a normal carton or as a convenient dispenser.

The envelopes are released individually for easy one-at-a-time removal.

Package and envelopes are clearly marked for size and content.