The Role of Qualitative Filter Paper in the Experiment

Qualitative filter paper has a wide range of applications. Today we will introduce its main use. HAWACH filter paper is well-known for its high quality, trustworthiness, and everything for the purpose of customers. To ensure consistent high quality and uniformity, HAWACH selects high-quality natural materials for filter paper production. Before leaving the factory, each filter paper undergoes rigorous testing in terms of packaging weight, thickness, gas flow rate, and mechanical strength. In addition, individual parameters such as particle retention, capillary action rate, filtration characteristics, and apparent characteristics can also be measured as required. The use in the experiment, the following are details:

The role of qualitative filter paper in university experiments, the qualitative filter paper is an indispensable experimental article in university laboratories, so what role does qualitative filter paper play in the experiment? I remind everyone here that qualitative filter paper contains ash It has little effect on the experimental effect. It is also used on the tray to prevent corrosion when weighing corrosive solids with a tray balance. The main filtering function is to filter out the mixed solid and liquid substances, so as to better achieve the solid effect of liquid separation.

In the process of use, because the qualitative filter paper has better moisture absorption performance, it is also used to wipe some concentration-related instruments. It has a good moisture absorption effect on the liquid on the instrument. Qualitative filter paper is suitable for filtering industrial organic suspension turbidities such as petroleum, chemical products, and industrial oil to separate solid and semi-solid impurities. For example, the supporting filter press filters various organic liquids such as transformer oil, turbine oil, melted paraffin grease synthetic resin, and dioctyl sebacate.

The difference between quantitative filter paper and qualitative filter paper is: that qualitative filter paper is used for qualitative chemical analysis and corresponding filtration separation; quantitative filter paper is used for gravimetric analysis test and corresponding analysis test in quantitative chemical analysis. The role of quantitative filter paper is mainly used for washing and weighing analysis experiments after filtration. The ash weight of each filter paper after ashing is a fixed value, and qualitative filter paper is used for general filtration.

Qualitative filter paper

The right choice of filter paper is the key to the success of laboratory filtration. Among the range of filter papers to meet all the needs, qualitative filter paper is the popular choice for general-purpose separations that need high purity and consistent performance.

Made of 100 % high-quality cotton linters, qualitative filter papers are qualified to have alpha-cellulose content of > 98 %. With the highest degree of polymerization, alpha-cellulose is proved to be the most stable cellulose form. Furthermore, the process of acid-washing makes the qualitative filter papers ashless and high purity.

fast flow filter paper filter paper sheets chemistry filter paper

During the qualitative cellulose filtering separations, particulates will be entrapped within the cellulose fibers deep in the media. First, qualitative filter papers are widely used not only in qualitative analytical separations for precipitates and buffers filtration which require the determination and identification of particulates in both liquids and gas, but for soil analysis, and food, and beverage testing. The filter paper made of natural fiber is also a common tool for liquid clarification.

With a higher percentage of alpha-cellulose than other filter papers, qualitative filter papers will weaken when they are handled with water. So, if you are doing the filtration under wet or vacuum conditions, qualitative filter papers are not recommended.

Qualitative filter paper generally adopts gravity filtration, which uses filter paper to trap solid-phase particles to separate the solid liquid. The filter paper has natural mechanical strength and a certain toughness. If you need to speed up the filtering speed, you can fold the filter paper several times (such as stacking two layers of filter paper into a fan shape or a zigzag pattern) to increase the filtering speed.

There are standard and wet-strength qualitative filter papers. The standard one is the most widely used and oldest chemical analysis filter paper, with medium retention capacity and flow rate. The speed and retention capacity of wet-strength qualitative filter paper is medium and can be humidified by a ventilator or other applications requiring high strength. It adopts portable packaging, which can be directly hung on the wall or placed on a workbench and can also be placed vertically or flat on a shelf for easy removal by one. Both large and small packages are clearly marked with the size and quantity.

The specifications of HAWACH qualitative filter paper cover round filter paper with a diameter of 47mm-185mm(70,90, 10,125,150,180, 55,47 and185), and square filter paper with a diameter of 60×60, 41x45mm, which cover most of the laboratory application range and are often used for liquid clarification. For the qualitative analysis and separation of traditional sediments, such as calcium oxalate, lead sulfate, and calcium carbonate, it is often used.

It is a standard filter paper for the determination of cellulase activity, drilling fluid active clay, protective cloth resistance, penicillin, and solid waste chlorinated herbicides. In the food industry, filter paper is often used to separate solid food or extract liquids from related liquids and is also widely used in simple qualitative analysis and separation in teaching. For air pollutant monitoring, there are discs and rolls of filter paper available to collect atmospheric dust from the atmosphere and then use a photometer to measure the degree of pollution.

Some questions frequently asked by customers

1. In vacuum filtration and natural filtration, should I choose qualitative medium-speed filter paper or qualitative fast filter paper?
How to choose qualitative filter paper correctly?
The fast filter paper is selected for the suction filtration, because the suction is mainly filtered by the filter cake, and the resistance is relatively large. In order to filter quickly, choose the fast filter paper.
Use medium speed for natural filtration, which is slow, and easy to form a filter cake, and the filtration effect is better.
2. What is the difference between qualitative filter paper and quantitative filter paper when filtering?
There is no difference in the filtration process. The difference is that the quantitative filter paper has a stable ash value, which can be used for the ignition residue indicator or precipitation analysis in the analysis. Qualitative filter paper does not work.
3. How to improve the filtration speed of ordinary qualitative filter paper?
The fast filter paper is selected for suction filtration, because the suction is mainly filtered by the filter cake, and the resistance is relatively large. In order to filter quickly, choose fast filter paper.
Use medium speed for natural filtration. The speed is slow, it is easy to form filter cake, and the filtration effect is better.