Hawach Filter Paper Summary

Qualitative filter paper – standard grades
The qualitative filter paper is used to identify the properties of a substance in a qualitative analysis technique. The folded qualitative filter paper speeds up the flow rate and increases the load force compared to the same type of flat filter paper.
Grade 1: 11μm Most frequently used in daily filtration, medium retention and flow rate. Very widely used in laboratory applications to clarify liquids. Typically used for quantitative analytical separation of precipitates such as lead sulfate, calcium oxalate, and calcium carbonate.
In agriculture, it is used for soil analysis and seed testing; in food, Grade 1 filter paper is commonly used in conventional methods for separating liquids and separating liquids from solid foods. And widely used in teaching simple qualitative analysis separation.
In the case of air pollution monitoring, wafers and coils are available, and atmospheric dust is collected from the air stream and then measured with a photometer; in gas detection, the filter paper is wetted with a coloring agent and quantified by light reflection.
Grade 2: 8μm is slightly stronger than Grade1, but the filtration time is relatively long (ie, the filtration speed is relatively slow), the adsorption is stronger than Grade 1, and it is folded into Grade 2V. In addition to the normal filtration of 8μm particles, its additional adsorption properties come in handy, for example, to retain soil nutrients in plant growth experiments and to monitor specific contaminants in air and soil testing.
Grade 4: 20μm is ideal for rapid filtration of conventional biological fluids and organic leach clarification in the analysis. Air pollution monitoring requires only high flow rates but less stringent sampling requirements for fine particle collection.
Grade 5: 2.5μm The most efficient qualitative filter paper for collecting small particles at a high flow rate. Suitable for chemical analysis, clarification of suspended solids and cement soil analysis.
Grade 6: 3 μm The flow rate is twice that of Grade 5, but the particle retention is equal. Often designated for boiler water analysis

Qualitative filter paper – wet strengthened grades
Wet-strength qualitative filter paper contains a small amount of chemically stable resin, thus enhancing wet strength. This does not therefore introduce any significant impurities into the filtrate. However, due to the nitrogen content of the resin, these grades of filter paper cannot be used for Kjeldahl determination.
Grade 91: 10μm plain crepe paper. It is widely used in sugarcane sucrose (content) analysis and pharmaceutical laboratory routine sample filtration.
Grade 113: 30 μm high load capacity. Wrinkle paper with the highest thickness and the highest flow rate compared to other filter papers. It is an ideal product for filtering crude or gelatinous precipitates.