Choosing the right membrane for air and gas filtration: what you need to know

Imagine standing in a cleanroom where every breath depends on the invisible guardians - filters that keep contaminants at bay. Selecting the right membrane for air and gas filtration isn’t just a technical decision; it’s a safeguard for performance, safety, and compliance.

Removing particles from gas streams is generally easier than from liquids, thanks to multiple interaction mechanisms between particulates and the membrane’s pore surfaces. Larger particles are captured through direct interception (sieve retention), where they simply cannot pass through pores smaller than their size. But the story doesn’t end there -adsorptive forces like inertial impaction, diffusional impaction (electrostatic forces) and electrostatic attraction also play a role in trapping contaminants.

What about particles too small for inertial impaction? Here’s where diffusional movement becomes the hero. These tiny particles, carried by low-viscosity gas streams, collide with filter surfaces through random motion, resulting in exceptional filtration efficiency. In fact, the rate of capture is inversely proportional to the square root of particle diameter- a principle that underscores why air filters excel at removing fine particulates.

With so many filtration media available, understanding what drives efficiency is key to making the right choice. When evaluating membranes for air and gas filtration, consider these critical properties:

• Water Intrusion Pressure – Ensures resistance to liquid penetration.
• Differential Pressure – Impacts energy consumption and system performance.
• Air Flow Rate – Determines throughput and operational efficiency.
• Bacterial and Particle Retention – Protects against contamination.
• Hydrophobicity and Oleophobicity – Maintains integrity in challenging environments.
• Thermal Stability – Supports performance under extreme temperatures.
• Chemical Compatibility – Prevents degradation during exposure to process chemicals.
• Sterilization Compatibility – Aligns with your preferred sterilization method.

Choosing wisely means balancing these factors to meet your application’s unique demands. The right membrane doesn’t just filter—it protects your process, your product, and ultimately, your reputation. 

Explore our OEM membrane filtration solutions.

FAQs

1. Why is membrane selection critical for air and gas filtration?

   It impacts contamination control, system performance, and compliance with sterilization and safety standards. 

2. What mechanisms capture particles in air filtration?

   Particles are retained through direct interception, inertial impaction and diffusional impaction. 

3. Which properties should be considered when choosing a membrane?

   Evaluate water intrusion pressure, differential pressure, air flow rate, bacterial retention, hydrophobicity, thermal stability, and chemical compatibility. 

4. Why is hydrophobicity important for air and gas filters?

   It prevents liquid penetration, maintaining filter integrity in humid or challenging environments. 

5. How does diffusional movement or impaction improve filtration efficiency?

   It enhances capture of ultrafine particles, as the rate of capture is inversely proportional to the square root of particle diameter. 

Authors’ bio

Jacques Hestres, Manager for Media and Membrane
Focusing primarily in Medical OEM applications. Throughout his over 25-year career, Jacques has held various positions in Customer and Technical Service, Operations Planning, and Product Management. This experience has given him the knowledge of the products, the manufacturing processes used to produce these materials, and an understanding of applications where these are used. Jacques holds a Bachelor of Science in Biology from the University of Puerto Rico.

Joseph Vickers, Former Product  Manager — Membrane and Media
A former Product Manager, responsible for the Membranes and Media portfolio. He has previous experience in global marketing and operations, holding an MEng in Chemical Engineering from the University of Surrey.

Antoine Pozniak, Former Product  - Manager Media and Membrane
A former Product Manager,  responsible for Media and Membrane portfolio. He worked with key opinion leaders and developed commercial and technical knowledge. Antoine holds an MBA from Rice University and Bachelor of Arts/Sciences in Interdisciplinary Social Sciences from the University of South Florida.