What should I do if the ULPA filter material is wrinkled, deformed or indented?

Wrinkle deformation and indentation are often ignored as 'minor problems' during filter appearance inspection. The surface of the filter material seems to be just a little uneven, or there are traces of pressure on a certain corner, but it doesn't seem to affect use.

However, the filter material structure of ULPA is different from ordinary filters. The pleats are its filter channels, and the glue lines are its structural support. After the pleats are deformed, the shape of the channel changes, and the local passing wind speed may deviate from the design value; if the indentation affects the glue line or the inside of the filter material, the integrity may already be at risk. These changes are not necessarily apparent in appearance, but may be reflected in leak detection or operating data.

Let me start with a rule: Do not use your hands to smooth out deformed wrinkles, and do not use tools to disturb the indentation locations. The pleats of the filter material have been shaped during manufacturing, and manual intervention at a later stage may cause greater damage. The surface appears to be smooth again, but the internal fiber structure or glue lines may have been damaged. For specific structural features, please refer to the relevant instructions for the structure without partitions.

Once deformation or indentation is discovered, the first step is to record it. Record content includes: location of damage (center of filter surface, edge, close to glue line or corner), size, shape (dent, warp or crease), source (caused during transportation, installation, operation or disassembly). Take photos and keep them, label the product number and the time of discovery. This information is the basis for subsequent judgments on processing methods. If the damage comes from transportation, you need to check the packaging and arrival inspection records; if it comes from installation, you need to check the installation process and operating methods; if it comes from operation, you need to look at it together with the pressure difference and leak detection data.

The second step is to inspect surrounding structures. Fold deformation is often not isolated. Check whether the outer frame is twisted, whether the glue line is cracked or detached, and whether the protective net is deformed or loose. Deformation of the outer frame may cause uneven stress on the entire fold, and cracking of the glue line may cause the deformed position to become an air leakage channel. These correlation checks can better determine the actual impact than just looking at the surface of the filter media. For specific troubleshooting methods, please refer to the relevant instructions for inspection after reverse installation.

The third step is to evaluate whether it affects usage. Mild deformation - such as slight warping of the edge of the filter surface, which does not affect the fit of the glue line and the outer frame - may have a limited impact on performance, but it needs to be confirmed by leak detection. Moderate deformations—those that affect the shape of the channel and significant changes in local passing wind speeds—may require an evaluation of treatment options within the scope of the project, or outright replacement. Severe deformation - accompanied by cracked glue lines, damaged filter material or deformed outer frame - usually needs to be replaced and continued use is not recommended.

Integrity testing is the key basis for judging whether it can continue to be used. You can't judge based on appearance, and you can't let it go just because it 'looks okay'. Conduct on-site leak detection according to project requirements, focusing on scanning the deformation location and its surroundings. If the leak test passes and the resistance data is normal, the damage and test results can be noted in the record and continued use. If a problem is found during leak detection, deal with it according to the location of the leak. involving ULPA ultra high efficiency filter or HEPA high-efficiency filters is the same. The method for judging damage to

If the filter material is found to be deformed or indented during operation, it is necessary to look back and find out the reason. Is it because the pressing force is too large, causing the deformation of the frame to be transmitted to the filter material? Is there a foreign body entering upstream causing local pressure injury? Is it a trace left by improper operation during installation? Find the cause to avoid recurrence during the next replacement. Supporting For the FFU fan filter unit system, check whether there are any structural parts inside the unit that will come into contact with the filter material; equipment-side applications such as The EFU equipment-end fan filter unit has a compact internal space, a smaller distance between the filter material and surrounding structures, and a higher risk of interference during installation and operation.

If you decide to replace, check the condition of the mounting frame and seals before replacing. Deformation of the mounting frame or aging of the seals may also be an indirect cause of wrinkle deformation. After the new filter element is installed, re-measure the pressure difference and air volume under the same working conditions to complete the leak detection and establish a new baseline. involving For HEPA/ULPA air filter replacement, the record content is consistent with routine replacement.

Selection and Acceptance Checklist

About Aili Industrial’s damage assessment package

When dealing with wrinkles, deformations and indentations, it is difficult to determine the extent of the damage and whether it is safe to proceed. This requires the filter material structure, installation status and testing data to be compared together.

Aili Industry has independent manufacturing capabilities in filters, fans, control systems and sheet metal processing, and can provide ULPA ultra high efficiency filter、HEPA high-efficiency filter and supporting air supply equipment. For projects where filter material damage is found, product structure information and on-site photos can be combined to help determine the type of damage and inspection points. When the filter is matched with equipment such as FFU and EFU, the installation spacing and disassembly path can also be checked together during the planning stage to reduce damage to the filter material caused by structural interference during operation.

Provide damage photos, installation records and operating data during inquiry or inspection to help confirm the direction of treatment. The specific handling method shall be subject to on-site testing results and project acceptance conditions.