Autore: Vanessa 27 aprile 2025    Categoria: Applicazioni

1. Classification and working principle of bag filter

1.1 Classification by filtration accuracy

Bag filters can be divided into different accuracy levels according to the size of retained particles, and are suitable for a variety of industrial scenarios:

(1) Primary filtration (50-200μm)

  • Application scenario: pre-filtration, removal of large particle impurities, and protection of downstream equipment.
  • The German BASF (Ludwigshafen) chemical plant uses PP needle felt filter bags for primary filtration of raw material liquid to reduce the risk of pipeline blockage.
  • The Dutch DSM (Heerlen) food additive production line uses 50μm filter bags to intercept fiber impurities in raw materials.
  • Material characteristics: Polypropylene (PP) fiber structure is loose, air permeability is good, and can be washed and reused 3-5 times.

(2) Medium efficiency filtration (10-50μm)

  • Application scenarios: fine particle interception, such as coating and electronics industries.
  • The electronics workshop of Schneider Electric (Grenoble) in France uses 25μm PET coated filter bags to ensure a dust-free environment (ISO 14644 Class 7).
  • The automobile spray painting line in Spain (Barcelona) uses 30μm filter bags to prevent paint mist pollution.
  • Material characteristics: The polyester (PET) fiber is dense, and the PTFE membrane is coated to enhance the surface smoothness and reduce particle adhesion.

(3) High efficiency filtration (1-10μm)

  • Application scenarios: high cleanliness industries such as medicine and semiconductors.
  • Roche (Basel) Biopharmaceutical Plant in Switzerland uses 5μm PTFE filter bags to ensure that the injection solution is free of particle contamination.
  • The antibody purification system of UCB Pharma (Brussels) in Belgium relies on 1μm PES composite filter bags, which meet EU GMP standards.
  • Material characteristics: multi-layer composite structure, some of which use electrostatic charging technology to enhance adsorption capacity.

1.2 Classification by structural design

(1) Single bag filter

  • Features: Simple structure, suitable for small flow (<10m³/h) or laboratory scenarios.
  • The test line of Alfa Laval (Lund) in Sweden adopts a single bag system, which is convenient for quick replacement of filter media.
  • The R&D center of Novo Nordisk (Copenhagen) in Denmark uses small stainless steel bag filters for culture medium sterilization.

(2) Multi-bag filter

  • Features: Multiple filter bags in parallel, large processing capacity (up to 500m³/h), suitable for industrial continuous production.
  • The lubricant production line of Shell (Rotterdam) Refinery in the Netherlands is equipped with a 20-bag parallel system, with a single set processing capacity of 200m³/h.
  • The petrochemical plant of ENI Group (Milan) in Italy adopts a multi-bag design to ensure long-term operation.

  • Core filter materials and European technological breakthroughs
MaterialTemperature resistanceChemical resistanceTypical applications Representative European manufacturers
Polypropylene (PP)≤80℃Acid and alkali resistance (pH1-14)Electroplating wastewater (Bilbao, Spain) Freudenberg, Germany
Polyester (PET)≤120℃ Weak acid and alkali resistanceAutomotive painting (Munich, Germany)Porvair, France 
PPS fiber≤190℃Strong acid/solvent resistance Geothermal power generation (Tuscany, Italy) UFI Filter, Italy 
PTFE coating ≤260℃Fully inertSemiconductor gas (Dublin, Ireland) Bekaert, Belgium

3. European standards and test methods

3.1 Key certification standards

  • ISO 16890: Air filter efficiency classification (led by MANN+HUMMEL, Germany).
  • EN 1822: HEPA/ULPA standard, affecting pharmaceutical clean rooms (STFI test of the Swiss Clean Technology Association).
  • EU REACH: Restriction of plasticizer migration (Italian Environmental Protection Agency has the strictest enforcement).
  • DIN 24550: German industrial filter bag size and interface specifications.

3.2 European laboratory test methods

From German fine chemicals to Nordic clean energy, bag filters continue to evolve with modular design and material innovation. With the implementation of the EU Circular Economy Act (2025), recyclable filter bags and digital management will become the focus of competition. Trenntech is conducting strategic cooperation with European industry pioneers. Through the cross-industry collaboration model of “chemical material innovation + AI predictive maintenance”, it promotes the development of filtration technology towards zero waste and full life cycle traceability, and continues to maintain Europe’s technological leadership in the global filtration market.

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.