Author: Vanessa 28 Mar. 2025     Category: Understanding Filtration

In the air treatment system of modern buildings, bag filters have become the core components of central air conditioning and centralized air supply systems due to their high efficiency, stability and economy. Whether it is a commercial complex, hospital, or electronic factory, bag filters can effectively intercept particulate matter in the air to ensure that the indoor air quality (IAQ) meets international standards.

Ⅰ. Classification and characteristics of bag filters

Based on the dual standard system of European EN 1822 and American ASHRAE 52.2, modern bag filters have formed a complete performance grading system suitable for different air purification needs:

Primary bag filters (G3-G4):

Mainly used for pre-filtration, while maintaining an ultra-low initial wind resistance of ≤50Pa, achieving a weight efficiency of ≥85%. Intercept large particles (such as dust and pollen) and protect the rear-end high-efficiency filter. It is characterized by low wind resistance and high dust holding capacity, and is suitable for places with general air quality requirements such as shopping malls and hotels.

Medium and high-efficiency bag filters (F7-F9):

Using gradient density fiber arrangement technology, the interception efficiency of 0.4-1μm particles is as high as 95-99%. The filtration efficiency is higher and can capture particles ≥1μm (such as bacteria and smoke). Commonly used in hospitals, laboratories and electronic factories to ensure that the air cleanliness meets the ISO 14644 standard.

Ultra-high efficiency bag filter (H10-H13):

Using multi-layer composite filter material, integrated nanofiber coating technology, MPPS (most penetrating particle size) filtration efficiency of 99.97%, suitable for ultra-clean environments such as pharmaceuticals and chip manufacturing, especially excellent in semiconductor manufacturing environments, and can stably maintain ISO Class 5 cleanliness.

Ⅱ. Advanced filter material technology and performance optimization of bag filters

Filter material is a key factor in determining the performance of bag filters. The current mainstream filter materials include:

Polyester fiber (PET):

Economical and practical, suitable for primary filtration, temperature range -40℃~120℃, washable and reusable.

Glass fiber (GF):

High temperature resistant (up to 250℃), stable efficiency, commonly used for medium and high efficiency filtration, but high humidity environment should be avoided.

Composite melt-blown material (PP+PE):

Combined with electrostatic electret technology, it can improve the adsorption capacity of tiny particles and is suitable for F7-F9 level filtration.

Breakthrough innovative materials for bag filters:

Intelligent electret material:

Through the patented corona treatment process, a persistent electrostatic potential field is formed on the surface of the filter material, which increases the capture efficiency of submicron particles by 35-50%, while maintaining an annual efficiency decay rate of ≤1%.

Composite nanofiber structure:

The unique “sandwich” structure sandwiches the 0.3μm ultrafine fiber layer between the supporting substrates to achieve the corresponding filtration performance while ensuring wind resistance.

Key performance parameters:

1. Efficiency change during the service life cycle

  • Initial efficiency: 95-105% of the standard value
  • 1000-hour efficiency: maintain 90%+ of the initial value
  • Scrap critical point: efficiency drops to 80% of the initial value

2. Dust holding capacity（DHC）: measuring the service life, high-quality bag filters can reach 500-800g/m².

  • Dust holding capacity under standard working conditions: ≥600g/m² (ASHRAE 52.2 test)
  • Actual service life: 8000 hours for G4 level/5000 hours for F8 level (RH≤60% working conditions)

3. Structural integrity:

  • Burst strength: ≥2000Pa (EN 1886 test)
  • Moisture resistance: No deformation for 72 hours under RH95% environment
  • Temperature range: -30℃ to 80℃ continuous working capacity

4. Energy efficiency and environmental parameters

Energy-saving characteristics:

Environmental certification:

  • Carbon footprint: ≤3.2kg CO₂eq/㎡ (ISO 14067 certification)
  • Recyclability: ≥92% (in line with EU circular economy standards)

Ⅲ. Production requirements and advantages of Trenntech bag filters

Trenntech, as an international leading filtration solution provider, strictly follows European and American standards for its bag filters and has significant advantages in the following aspects:

Strict production standards

  • Material selection: Only filter materials certified by ISO 9001 are selected to ensure no fiber shedding and chemical volatilization.
  • Performance testing: Each batch of products is tested by MPPS (most penetrating particle size) to ensure efficiency meets the standard.

Core advantages

  • Long-life design: By optimizing the pleat depth and number of bags, the dust holding capacity is 20% higher than that of ordinary products.
  • Energy saving and low resistance: The wind resistance is reduced by 15%, helping the central air conditioning system to save electricity.
  • Customized service: Support non-standard sizes and special treatments such as oil and mildew resistance to meet the needs of different industries.

At Trenntech, we not only provide filters, but also provide a complete air quality management ecosystem. From material research and development to intelligent manufacturing, from performance verification to intelligent operation and maintenance, we use the German precision engineering concept to protect every critical environment. Contact Trenntech and get professional technical support immediately.

Vanessa

My name is Vanessa, and I am a content writer specializing in corporate content creation. With more than 10 years of writing experience, I am committed to providing companies with high-quality, impactful content to help them stand out in a competitive market. My background covers multiple industries, including technology, finance, marketing, etc. In the process, I have accumulated rich knowledge and skills, and can deeply understand the needs of audiences in different fields, so as to create more targeted articles and content. I am good at writing blog posts, white papers, case studies, product descriptions, etc., and I am familiar with SEO optimization strategies to ensure that the content gets good exposure in search engines. At the same time, I also have good project management skills and can complete high-quality works within a tight time frame. I believe that high-quality content can not only convey information, but also build customer trust and brand image.