Shanghai high efficiency air filter detector
First, visual inspection and simple tests can detect the cause
1) The surface of the filter material is broken or slightly damaged. Filter material damage is easy to observe with the naked eye, a small amount of damage repair is easier, the best repair in the filter factory. Some minor damage is not easy to see the naked eye, only through the test bench detection can be detected.
2) In the production process of the filter, the filter material is too heavy or some human factors will damage the filter material. If it is only damaged in a few places and not serious, it is possible to repair qualified products, but the repair quality should meet the standard requirements.
3) Sealing defects, air leakage in the combination of filter material andair filterframe. In production inspection, most efficiency disqualification is caused by such air leakage. Most of these cases can be repaired, but the repaired appearance should not have obvious defects.
4) There is air leakage at the joint of the filter sealing rubber strip. Many HEPA filters have sealing strips on the border. Sometimes the interface is not handled well, which will cause air leakage. Some manufacturers use on-site foaming polyurethane seals, no seams, there is no air leakage problem. If a joint is used, the joint is best made into a maze. (Shanghai high efficiency air filter manufacturer)
Two, the raw material itself
1) Low efficiency of filter material itself. If the efficiency of the filter material itself does not meet the requirements (the definition of high efficiency filter material: detection at 5.3cm/s wind speed, for 0.3μm dust filtration efficiency ≥99.97%), it will not be able to produce a qualified filter. This truth who all understand, but the market does indicate that some is efficient, the actual can not reach the efficient filter material.
2) material dust. Traditional partition high efficiency filter, if the paper partition, and the raw material control is not strict, the paper partition has the risk of dust. Filter material production environment is poor, filter material itself with a large number of dust may fall off, the filter may also dust. It is important to note that some tests cannot detect such dust. (Shanghaihigh efficiency air filter manufacturer)
High efficiency air filter detection
Three, the problem of detection itself
1) During factory inspection, if the scanning detection method is used, there may be eddy current on the outlet surface of the filter, and the surrounding dust will enter the scanning area with the eddy current. (Shanghai high efficiency air filter manufacturer)
If eddies exist, dust will certainly exceed the standard during the scan. At this point, you cannot determine whether the dust is from the filter leak or vortex, and inexperienced operators may judge a good filter as a waste. Some foreign manufacturers, in order to eliminate the misjudgment caused by eddy current, put the filter test table in the clean room. Domestic manufacturers don’t have that luxury, so we have to find ways to eliminate turbulence. (Shanghai high efficiency air filter manufacturer)
2) In many cases, after the filter is installed, people use the downstream dust concentration to judge whether the filter is qualified. At this time, even if the filter efficiency is qualified, it may be misjudged as unqualified due to the high downstream concentration.
Due to the strict requirements of the use place, the filter must be tested one by one before leaving the factory, and can be put into use after qualified. The filter testing includes factory testing and field testing. In these two testing processes, the filter may be unqualified for the following reasons.
Visual inspection and simple testing can detect the cause of the filter surface cracked or slightly damaged. Filter material damage is easy to observe with the naked eye, a small amount of damage repair is easier, the best repair in the filter factory. (Shanghai high efficiency air filter manufacturer)
Some minor damage is not easy to see the naked eye, only through the test bench detection can be detected. Excessive pressure or some human factors may damage the filter material in the process of filter manufacturing.
The high efficiency filters are respectively partition free high efficiency filter, partition high efficiency filter, high temperature resistant high efficiency filter, combined sub-high efficiency filter, super high efficiency filter, DOP with liquid trough type high efficiency filter, knife rack type high efficiency filter (dense pleated high efficiency filter/combined high air volume high efficiency filter) ULPA ultra-high efficiency filter.