Filter Papers Qualitative Grade 642 Ahlstrom-Munksjö

This Ahlstrom-Munksjö qualitative laboratory filter paper is a 2 µm, Medium Speed grade with finer particle retention than Grade 601, but a slightly lower filtration speed. Grade 642 also has higher absorption than Grade 601. It is used in general laboratory applications to retain particles above 2 µm in size.

Grade 642 is also found in agricultural and environmental laboratories for plant growth trials, soil testing, and air analysis for monitoring specific contaminants, and in the filtration of organic and sulfide precipitates. Ahlstrom-Munksjö manufactures a full range of laboratory filter paper for use in the beer industry. Grade 642 is recommended for the wort colour test.

Ahlstrom-Munksjö 642: 2 µm, Medium Speed. Equivalent to Whatman Grade 2, 2 CHR, 20 CHR.

Ahlstrom-Munksjo Cross Reference

How to Choose the Right Filter Paper Size?

The filter paper should be about 1.5 to 1.8 times the funnel diameter.

Please note the below grid is a recommendation of what diameter filter paper is compatible with glass or plastic filter funnels.

When folded into a cone (typically in quarters), it should fit inside the funnel with about 5 to 10mm extending above the rim for easy handling.

What Is Filter Paper Used For?

Filter paper is used to separate solids from liquids or gases, acting as a semi-permeable barrier that allows certain substances to pass through while retaining others. It's commonly used in laboratories for various applications, including filtration, sample preparation, and analysis.

What Do the Grades of Filter Paper Mean?

Filter paper grades indicate the level of particle retention, though the numbering doesn't run simply from coarse to fine. Ahlstrom-Munksjö Grade 642, for example, has a finer 2 µm retention than Grade 601 (2.5 µm), while Grade 631 is considerably coarser at 10 µm. Consider the thickness of the filter paper too: thicker papers can hold more material, but they may also reduce flow rate.