HEPA and ULPA filters are both high-efficiency air filters that are similar in many ways, but there are some key differences that set them apart in terms of capturing airborne particles.

High-efficiency filters are widely used in various industries and applications that require clean air, such as pharmaceutical, electronics, food, and medical fields. However, different types and grades of high-efficiency filters have different initial resistances, which affect their performance and

Filter material: The selection and application of filter bag material is the core technology of bag-type dust collectors, which affects the performance and lifespan of HEPA filters. Different filter materials should be chosen according to the environment, nature, temperature, and technical requireme

Efficiency is an key indicator of air filters, it reflects the air filter's ability to filter contaminants.
MPPS efficiency, counting efficiency, gravimetric efficiency, fractional efficiency, particulate matter efficiency, initial efficiency, minimum efficiency, integral efficiency, local efficiency etc. Add up to a dozen efficiencies, which efficiency should we really be concerned about? What is the significance of each efficiency?

Filters for compressed air are used in a wide range of applications and testing is an important step in ensuring filter performance and effectiveness. Through airflow measurements, particulate capture efficiency tests, oil mist removal efficiency measurements and life assessment, we can fully evaluate the quality and capability of a filter. Through the correct selection and use of compressed air filters, the quality of the process can be improved, the life of the equipment can be extended, maintenance costs can be reduced and more efficient production can be achieved.

As one of the items of clean room inspection, leakage testing of high-efficiency filters has received more and more attention since the implementation of the 2010 version of GMP.

Clean room testing status can be divided into three categories

1, empty state facilities of the clean room all pipelines connected and running but no production equipment, materials and production personnel.

2, static has been built in all the facilities of the clean room installed in the production equipment and suppliers agreed by the owner of the way to test far turn, but no production personnel in the field.

3, dynamic facilities in accordance with the provisions of the way to run the state and the provisions of the personnel present in the prescribed manner of work.

Testing items: air velocity and air volume, air exchange, temperature and humidity, differential pressure, suspended particles, planktonic bacteria, settled bacteria, noise, illumination and so on. Specifically, you can refer to the clean room testing standards.

A series of experiments triggered by a phenomenon that doesn't comply with the theory
Theoretically, for the same filter, the higher the airflow, the lower the filtration efficiency.
However, our engineers found in the testing process, when the velocity of the wind is high to a certain value, the filtration efficiency no longer follows the rule of decreasing with the increase in air volume, but increases with the increase in air volume.
Later on, after we checked the related information from many sources, as well as communicated with the professionals in the industry and analyzed them, we considered the following possible reasons:
1) When tested in higher air volume, the filter element strength is not enough, the structure is damaged.
2) Filter materials with high filtration efficiency under high air volume do exist.

As we all know, the highest filtration efficiency level of high-efficiency filters can reach 99.999995 or more for different particle sizes of pollution. In the past, there are always people who correspond the level of clean room with the efficiency level of high efficiency filter, and always think that the more 9 high efficiency filters are used, the cleaner the clean room can reach the cleanliness of 100 or even 10 levels.
In fact, this concept is wrong, although the high efficiency filter is the core component of the clean room, but the clean room want to achieve 100 or even 10 levels of cleanliness, high efficiency filter is not the only condition.
There are many factors affecting the cleanliness level of clean room, such as the number of air changes, door and window sealing, and personnel entering and leaving the air shower room.