Which Kind of Filter Paper is Suitable for You?

Filter paper is frequently used in lab experiments. Filter paper is loose and has a strong absorption ability to liquid. The filter paper commonly seen in the analytical laboratory is used as a filter medium to separate the solution from the solid.

The right filter paper will get twofold results with half the effort. Choosing the right filter paper can be determined by considering the following four factors. At present, the filter papers mainly include quantitative analysis filter paper, qualitative analysis filter paper, and chromatographic qualitative analysis filter paper.

Hawach Scientific Co., LTD. is specializing in the production of Qualitative filter paper, and product quality stability, exported to all parts of the world.

Qualitative filter paper refers to “qualitative analysis filter paper”, which is compared with quantitative analysis filter paper and chromatography qualitative analysis filter paper. The paper is loose and has a strong absorption of liquid.

Qualitative analysis filter paper generally has a large amount of residual ash, which is only used for general qualitative analysis and filtration of precipitation or suspended substances in solution, not for quality analysis.

(1) the general use of natural filtration, the use of filter paper, and the ability to trap solid particles, so that the liquid and solid separation;
(2) as a result of the filter paper mechanical strength and toughness are weak, as far as possible with less filtering method, such as must accelerate the filtering speed, in order to prevent filtering failure, in the air pump filtering, according to the size of the suction in the funnel stack 2 ~ 3 layers of filter paper, in the vacuum filtering, in the leakage. First pad a layer of dense press cloth, and then put filter paper to filter;
(3) filter paper had better not filter hot concentrated sulfuric acid or nitric acid solution.

Hawach Technical Data

GradeParticle RetentionProduct AppearanceFiltration SpeedAsh Content(%)Basis Weight(g/m2)Wet Burst(mm H2O)

Optional diameter

55/70/90/110/125/150/180/185/240/320/400 mm.

Hardness: Filter paper will become wet when filtered. The use of tough filter paper after wet water should be considered for long-term filtration experiments.

Filter paper pore size

Currently, the quantitative analysis filter paper is divided into three categories: fast, medium, and slow speed. The white belt (fast speed), blue belt (medium speed), and red belt (slow speed) are classified on the filter paper box. The shape can be round or square. The type and specification of the qualitative analysis filter paper are basically the same as those of the quantitative analysis filter paper, indicating fast, speed, and slow speed, but printed with fast speed, medium speed, and slow speed.

Filter paper pore size:
Fast speed: 80 to 120 microns
Medium speed: 30 to 50 microns
Slow speed: 1 to 3 microns

Filtration efficiency: The degree and size of the water-permeable pores on the filter paper affect its filtration efficiency. High-efficiency filter paper has not only fast speed but also high resolution.

Capacity: The solid particles accumulated during filtration may block small holes in the filter paper. Therefore, the denser the water seepage pores, the higher the capacity, and the more filtration is allowed.

Applicability: Some filter papers are prepared by special production steps. For example, in the test medicine for measuring the nitrogen content in blood, it is necessary to use a nitrogen-free filter paper or the like.

Note that filter paper cannot filter zinc chloride, otherwise, the filter paper will be corroded and damaged by zinc chloride.