How to choose between fiberglass HEPA and PTFE HEPA?

These two filter materials are often compared in projects, but if the comparison is only focused on 'which one is more efficient', the direction will be biased.

The selection of filter material should go back to the conditions of use. Temperature and humidity, media in contact, requirements for outgassing, cleaning and replacement methods, these factors determine which material is more suitable. The performance of the same filter material under different working conditions may vary greatly, and we cannot draw conclusions just by looking at the material name.

Judging materials from the use environment

Let’s first look at the actual usage conditions of the project.

Temperature : Glass fiber filter materials usually have good temperature resistance and are suitable for occasions with certain temperature requirements. PTFE filter materials have different temperature resistance ranges, and the specific values ​​need to be confirmed with the supplier. When selecting materials for high-temperature working conditions, in addition to the filter material itself, you must also look at the temperature resistance boundaries of the edge sealing glue and the outer frame material, whichever is the lowest.

Humidity : PTFE has low hygroscopicity, and performance stability may be more advantageous in environments with high humidity or where there is a risk of condensation. The performance of fiberglass filter media may change after absorbing moisture, and actual humidity conditions need to be evaluated.

Contact media : If the air flow contains corrosive gases or chemical reagent volatiles, the resistance of the filter material needs to be confirmed. The chemical inertness of PTFE is generally good, but the specific applicability depends on the type and concentration of the medium.

Outgassing requirements : Semiconductor and other processes that are sensitive to gaseous pollutants may have additional requirements for the outgassing of filter materials and adhesive materials. When selecting materials for such occasions, it is necessary to confirm the suitability of the materials with the supplier.

Compare machine data under the same operating conditions

Different filter materials may have different performance after being made into a complete machine.

When comparing, don't just look at the filter material report, but ask for the efficiency and resistance data of the entire product under the same air volume. Under the same dimensions, the pleated structures and effective filtration areas of the two filter materials may be different, and the resistance performance will also be different.

If the goal is to reduce energy consumption, the actual operating point of the fan should be calculated together with the operating time, instead of just looking at the nominal low resistance. For specific comparison methods, please refer to the relevant ideas on low-resistance HEPA long-term energy consumption accounting. For matching For the FFU fan filter unit system, changes in the resistance of the filter material will affect the working point of the unit, and this needs to be checked when selecting materials.

Structure and ongoing maintenance

After the filter material is selected, the compatibility with the structure must be confirmed.

Edge sealing method : Different filter materials and adhesive materials have different bonding properties, and the edge sealing process needs to be matched. This item affects the sealing reliability in long-term use.

Support structure : The mechanical strength of fiberglass and PTFE is different, and the support method after folding may be different.

Replacement method : Device-side application such as For the fan filter unit at the EFU equipment end , the filter material selection should also consider the requirements for replacement operations. Some filter media are more sensitive to the operating environment, and protective measures may need to be adjusted when replacing them.

Testing requirements : The testing items and methods for different filter materials may be the same, but the judgment standards must be confirmed according to the project requirements. involving For HEPA/ULPA air filter products of different grades, the test data should be checked according to the corresponding standards.

Compare according to the same working conditions

When comparing two filter materials, first unify the filtration grade, outer frame size and design air volume.

If one of these products enlarges the filter material area, the decrease in resistance cannot be entirely attributed to the material itself. The frame adhesive material, operating temperature and humidity, and subsequent replacement methods must also be included in the overall machine evaluation.

The conclusion of the comparison may be: both materials meet the requirements, and the cost is more appropriate; or a certain working condition determines that only one of them can be selected. Regardless of the result, the judgment is based on the working condition data, not the material name itself.

About Aili Industrial’s filter material selection and cooperation

Aili Industrial can discuss the configuration of filter materials such as glass fiber and PTFE based on the filtration level, air volume, resistance and equipment operating conditions. filter with FFU fan filter unit、The fan filter unit at the EFU equipment end is matched in the same manufacturing system, and the filter material selection and complete machine structure can be confirmed together during the planning stage.

Material selection and specific performance should be subject to confirmed product technical data. It is recommended to provide the temperature and humidity of the use environment, contact media and testing requirements to facilitate the determination of appropriate filter material solutions.