About the Selection and Use Notes of Qualitative Filter Paper

HAWACH qualitative filter paper is often used in conventional filtration, and different filter papers have different separation capacities and different flow rates. Generally, when the filtration rate is slow, the separation ability is strong, the adsorption effect is obvious, and the particles can be retained to a greater extent. It is suitable for chemical analysis and clarification of suspended solids, which takes a long time. Qualitative filter papers cover most laboratory applications and are often used for the clarification of liquids and for qualitative analytical separation of sediments. In the filtration of industrial production, it is often used to separate solid substances from related liquids or extract liquids. It is not used as an analytical filter paper, but as a paper filter material. , to chemical product filtration, electroplating industry filtration, and so on.

In industrial filtration, filter paper can be selected, which can save time while ensuring filtration performance, medium flow rate, and medium particle retention, and can filter high-viscosity liquids and emulsions (such as sweet fruit juice, wine, syrup, resin solution, oil or Plant extracts, traditional Chinese medicine infusion). The filter paper is slightly thicker and has a higher loading capacity, which is suitable for the passage of coarse particles, culture medium, and colloidal sediment.

lab grade filter paper laboratory filter paper filter paper used in laboratory

How to choose qualitative filter paper?

In the selection of qualitative filter paper, three main points should be considered:
1. Larger effective area is suggested, with a larger dust-holding capacity, and smaller resistance. But the cost would also increase and you can choose it based on your specific requirement.
2. Finer fiber diameter is suggested, with higher filtration efficiency and better interception effect.
3. Higher binder content is suggested, with higher tensile strength, and higher filtration efficiency The background dust accumulation of the filter material is small, and the resistance is good, but the resistance increases accordingly.
4. There are different grades of qualitative filter paper available, for instance, BI0-6, BIO-5, BIO-4, BIO-2, and BIO-1. The BIO-1 filter paper, it’s widely used in laboratory applications to clarify liquids. The BIO-2, it’s suitable for soil nutrient retention in plant growth experiments, and also for the detection of specific contaminants in the air and soil testing. For the BIO-4, it is suitable for rapid filtration of routine biological liquids and organic leachate clarification in analysis and is also suitable for sampling in air pollution monitoring that only requires high flow rates but does not require the strict collection of fine particles. The BIO-5. Can be used in chemical analysis, clarification of suspended solids, and water and soil analysis. The BIO-6, it’s used in boiler water analysis.

Precautions when handling qualitative filter paper

●How to deal with qualitative filter paper
The filter paper may be damaged if handled with pointed tweezers.
Handle the filter paper with tweezers, etc. with a flat tip.

●Setting of qualitative filter paper
The side marked with the product name on the product packaging is the front of the filter paper.
Set the front side of the filter paper to be up (the side that was in contact with the fluid before filtering).
If set in the opposite position (set the reverse side of the filter paper to the top), the filter life may be shortened.

●Size of qualitative filter paper
The filter paper expands and contracts by a maximum of 0.7% according to the change in humidity. In addition, after soaking in water, it can grow up to 4%. Therefore, the size of the filter paper should be selected based on the size of the filter paper setting part of the filter and the size change of the filter paper.