How to judge whether a high-efficiency filter is qualified

High-efficiency filters are mainly used for collectionIt captures particle dust and various suspended matter below 0.5um, and is the terminal filtering device of various filtration systems. The filter material is made of ultra-fine glass fiber paper, rubber paper, aluminum foil and other materials folded as partitions, and sealed with new polyurethane sealant. The outer frame is made of galvanized sheets, stainless steel sheets, and aluminum alloy profiles. High-efficiency air filters can be widely used in air-conditioning terminal air supply in clean rooms in industries such as optical electronics, biomedicine, precision instruments, beverages and food. Therefore, the filters must be tested one by one before leaving the factory, and they can only be put into use after passing the test.

So, how should we judge whether the high-efficiency filter is qualified?

1. Check raw materials

1. The filter material itself is low in efficiency. If the efficiency of the filter material itself does not meet the requirements(the definition of high-efficiency filter material: tested at a wind speed of 5.3cm/s, the filtration efficiency for 0.3μm dust is ≥99.97%), then Can’t make a good filter.

2. The material is dusty. Traditional high-efficiency filters with partitions. If the partitions are made of paper and the raw materials are not strictly controlled, the paper partitions may generate dust. If the production environment of the filter material is poor, the filter material itself contains a large amount of dust that may fall off, and the manufactured filter may also generate dust. It is worth noting that some inspection methods cannot detect this type of dust.

2. Visual inspection

1. The surface of the filter material is cracked or slightly damaged. Damage to the filter material is easily visible to the naked eye, and it is easier to repair a small amount of damage. This kind of repair should be carried out at the filter manufacturer. Some minor damages are not easily visible to the naked eye and can only be detected through inspection on a test bench.

2. During the production process of the filter, the filter material may be damaged due to excessive weight or some human factors. If the damage is only in some places and is not serious, it may be repaired into a qualified product, but the repair quality should meet the standard requirements.

3. Sealing defect, air leakage occurs at the joint between the filter material and the filter frame. In production inspection, most efficiency failures are caused by this air leakage. Most of this situation can be repaired, but the appearance after repair should not have obvious defects.

4. Air leaks from the seams of the filter sealing strips. Many high-efficiency filters have sealing strips on their frames. Sometimes the interface is not handled well, which can cause air leakage. Some manufacturers use on-site foamed polyurethane sealing strips, which have no seams and therefore no air leakage problems. If jointed strips are used, the joints should be made into a labyrinth.

3. Simple test

In many cases , after the filter is installed, people can use the downstream dust concentration to judge whether the filter is qualified, at this time, if the upstream concentration is too high, even if the filtration efficiency is qualified, it may be misdiagnosed as unqualified due to the high downstream concentration.

That’s all for today’s knowledge. If you want to know more about High Efficiency Filter Glue, you can contact the author.