Hawach Filter Paper Summary

Most filter papers are made of cotton fibers and are produced in different ways for different applications. Because the material is made of fibers, it has many holes in the surface through which liquid particles can pass, while larger solid particles cannot. This property allows the separation of mixed liquid and solid materials.

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 Grade 1, 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’s determination.

Wet-strength qualitative Grade 91 filter paper: 10μm plain crepe paper. It is widely used in sugarcane sucrose (content) analysis and pharmaceutical laboratory routine sample filtration.

Wet-strength qualitative 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.

Do you know how to make nanocellulose/polyvinyl alcohol packaging composites from waste filter paper? Objective To study the feasibility of using mechanical methods to treat waste filter pulp to prepare functional packaging composites. Two different sizes of cellulose nanofibrils (CNFs) were separated from the untreated and acetic acid-pretreated waste filter pulp by grinding and high-pressure homogenization. The suspension was filtered into a membrane and prepared by impregnation. Two kinds of CNFs/PVA composite membranes were tested for their mechanical properties and light transmittance. Results The field emission scanning electron microscopy (SEM) showed that the diameter of cellulose fibrils of untreated filter pulp was between 300 and 500 nm.

The diameter of filaments after acetic acid pretreatment was significantly reduced, mainly between 60 and 100 nm. The acetic acid pretreatment filter paper CNFs/PVA composite membrane has good mechanical properties and transparency. The tensile strength is up to 90.45 MPa, which is 201% higher than PVA, the light transmittance is 81.3%, and the PVA is 10.3% lower. The performance comparison of CNFs/PVA composites prepared by the two methods shows that the performance of CNF membranes after pretreatment with acetic acid is obviously improved, and the enhancement effect on PVA is better. It can be used as high-strength and high-transparent packaging materials. Preparation of nanocellulose / polyvinyl alcohol packaging composites from waste filter paper.

The above chemical knowledge is provided by Hawach Scientific Co., Ltd. If you want to consult more information about filter paper, please contact Hawach Scientific Co., Ltd’s official website.