How to Judge the Quality of Filter Paper?

Hawach provides our customers with high quality qualitative and quantitative cellulose filter papers. In the section of qualitative filter paper, standard filter papers and wet-strengthened filter papers are available. Known as one of top quality filtration, HAWACH will help you find the right type for your industrial or research need, and match the needs of your applications in different levels of purity, hardness, flow rate, loading capacity, and chemical resistance all the time.

How to judge the quality of the filter paper of filter is a problem that most people will encounter. Here are some methods.
Wet Strengthened Filter Paper
Method 1: Water detection method
Place the filter flat on the ground or on the table, and sprinkle some water on the filter paper. If the filter paper penetrates after half a day, it is a better filter paper, or if the filter paper penetrates into the water within 5 minutes, it is not recommended, as it is inferior, made of cotton pulp. If the filter paper that penetrates into water within 3 to 4 hours, it is made of low-grade wood pulp paper. Although it can be used at a lower price, it will reduce the air production efficiency of the air compressor and consumes more electricity.

Method 2: Fluorescence method
It measures the fluorescence brightness of the aqueous solution containing sodium fluorescein under specific conditions, and the brightness reflects the weight of dust, thereby calculating the filtration efficiency of the filter paper. Fluorescence detection technology is currently only used in France. The test dust source of the fluorescence method is sodium fluorescein dust generated by sprayers. The test method is to first get sampling before and after the filter and then dissolve sodium fluorescein on the sampling filter paper with water as a basis for judgment.

Method 3: Sodium flame method
This detection technology originates from the United Kingdom and is one of China’s current national standard methods. Its test dust source is a polydisperse phase sodium chloride salt spray. It is a technique to determine the speed of saltwater splashing under the agitation of compressed air. As a result of drying, small salt crystal particles are formed and enter the air duct. Samples are taken before and after the filter paper, and the salt mist sample will make the color of the hydrogen flame blue and brighter. This technique is to judge the salt mist concentration of the air by the brightness of the flame, by which to determine the effect of the filter on the salt mist.

Method 4: Oil mist method
Originated in Germany, it is a technology that uses the difference in turbidity of the gas sample before and after the filter paper to determine the filter’s efficiency in filtering oil mist particles. The oil mist method is easy to cause damage to the filter when detecting the filter paper, and cannot directly read the value, resulting in a waste of time.

Hawach provides different types of filter paper. If you have any questions about that. Don’t hesitate to contact us.