Why is the grade of filter material different from the grade of the entire filter?

The purchasing document says 'H14 high efficiency filter', but the test report received says 'filter material efficiency complies with H14'. These two sentences look close, but they actually don't mean the same thing.

Filter material testing and complete machine testing have different test objects. The filter material report tests material samples, and the complete machine report tests the assembled product. There are several processes such as folding, edge sealing, outer frame and sealing structure, each of which may affect the final performance.

Processing changes the filtration path

Just because the filter material has qualified performance when it leaves the factory does not mean that it will perform the same after it is made into a filter.

If the filter material is squeezed or scratched during the pleating process, the local filtration path may change. When pouring glue, the colloid distribution is discontinuous and there are gaps between the filter material and the frame. Air may bypass the filter material from these positions. The assembly accuracy of the outer frame and the fitting state of the sealing gasket will also affect the sealing performance of the complete machine under actual installation conditions.

The purpose of complete machine testing is to incorporate these processing and assembly factors into the evaluation. Filter material testing cannot cover these links because it tests the unprocessed material itself.

The contents of the two reports are different.

When you get the filter material report, you look at the sample information, test conditions and efficiency data. The focus is on whether the material itself meets the requirements.

When getting the complete machine report, in addition to efficiency, you must also compare the product model, dimensions, rated air volume, sealing method and unit number. The conclusions of the whole machine report apply to the product of this model and specification and do not automatically cover other size or construction variants.

The two types of reports also have different uses in projects. The filter material report can be used for preliminary judgment of material selection, and the complete machine report is the basis for product acceptance. If the purchase requires testing data for the entire filter, it is not enough to provide only the filter material report. involving For products of different grades of HEPA/ULPA air filters , the testing requirements and reporting forms may be different. The verification shall be carried out according to the corresponding standards.

Common file errors

The project required a complete H14 filter, but only the filter material grade report was received - this is a common problem in the procurement process.

In this case, it may be due to the supplier's misunderstanding, or it may be that the product itself only has filter material testing data. No matter what the reason is, the purchasing personnel should ask for clear inspection objects and product numbers, and check the inspection results of the finished machine after the outer frame, glue filling and folding.

There is another situation: the report contains complete machine data, but does not have a single unit number, and can only be traced by batch. If batch projects require unit-by-unit traceability, this type of report cannot meet the requirements, and the supplier needs to supplement the numbering information.

Even if the performance of the filter material is qualified, confirmation of finished product quality and sealing cannot be omitted. These are the respective boundaries of the two types of detection and cannot replace each other.

Non-standard products must have a clear acceptance scope

For small-sized filter elements and filters with special structures used on the equipment side, the detection method should be agreed in advance when customizing.

There are often no ready-made standard models for this type of product to compare with. The testing plan needs to be determined together with the supplier: whether to test the entire unit or the filter material, what air volume to use, what the report format is, and whether unit-by-unit numbering is required.

Write these clearly in the technical agreement so that design, procurement and on-site acceptance can use a consistent basis for judgment. For matching FFU fan filter unit or For the filter element used in the fan filter unit at the EFU equipment end , the testing requirements and the acceptance of the complete machine can be agreed together to avoid discovering that the data does not match after arrival.

Checking actions during acceptance

When the goods arrive, compare the test report with the actual product: can the model, size, grade, and serial number on the report match the actual product?

Confirm whether the report tests the entire unit or the filter media. If it is a filter material report, check whether the project has other complete machine testing requirements.

File the report by product number and associate it with the installation location and on-site leak detection results. In this way, when problems arise later, they can be traced back to the testing data corresponding to the specific product.

About Aili Industrial’s testing data cooperation

Aili Industry can discuss the matching relationship between efficiency level and air volume resistance based on the filter element, fan and equipment structure. filter with FFU fan filter unit、The fan filter unit at the EFU equipment end is matched in the same manufacturing system, and the test data of the filter material, complete machine and supporting products can be uniformly checked during the delivery stage.

When ordering, please specify the test standards, air volume, report form and serial number requirements to facilitate subsequent installation and acceptance traceability. Specific information shall be subject to the project agreement and contract documents.