Membrane filter cartridges – technical overview
Membrane filter cartridges are used for applications where controlled and reproducible retention of fine particles and microorganisms is required. They are typically applied as final filtration or critical process filtration steps where product quality and process stability depend on consistent performance.
Filtration principle
Unlike depth filters, membrane cartridges rely on a defined pore structure to retain contaminants primarily on the surface of the membrane. This enables predictable retention performance and makes membrane filtration suitable for applications requiring absolute or clearly specified micron ratings.
Common membrane materials
- PES (polyethersulfone) – hydrophilic membrane with low protein binding and broad chemical compatibility
- PVDF – mechanically robust membrane suitable for aggressive chemical environments
- PTFE (hydrophobic) – used for gas filtration and non-aqueous solvent applications
- PTFE (hydrophilic) – suitable for aqueous filtration where chemical resistance is required
- Nylon 6.6 – hydrophilic membrane with high mechanical strength
Typical applications
- Final filtration of process liquids
- Biotechnology and pharmaceutical processes
- Food and beverage filtration
- Chemical and specialty fluid filtration
- Gas filtration and venting applications
Key selection criteria
- Required pore size and retention definition (nominal or absolute)
- Membrane material and surface properties (hydrophilic or hydrophobic)
- Chemical compatibility with the process fluid
- Operating temperature and differential pressure
- Cartridge construction, end caps and sealing method
- Cleaning or sterilisation requirements (CIP/SIP)
Membrane filter cartridges are sometimes also referred to as absolute filter cartridges or surface filtration cartridges, depending on the industry and application context.
Membrane filter cartridges are commonly combined with pleated filter cartridges or depth filter cartridges as part of a multi-stage filtration process.