Core points
- Pleated cartridges pack a large membrane area into a standard 10-40 inch format - high flow at low pressure drop compared with depth media of the same rating.
- Media options cover PP, nylon, hydrophilic and hydrophobic PTFE, and PES, with ratings from 0.1 to 50 um in the BROLERN line.
- Thermal welding, no adhesives: nothing can migrate into the product - the construction meets food, beverage, brewing and pharmaceutical requirements.
- Membrane ratings are not affected by feed-pressure fluctuation - a key difference from depth media.
- Public industry references place hydrophobic PTFE membranes at 0.1-0.2 um absolute for solvent and vent duty, and PES at 0.04-1.2 um for aqueous and pharmaceutical streams [source: Scientific Edge cartridge selection guide].
Choosing the membrane
| Polypropylene (PP) | Economical clarification and prefiltration; broad chemical compatibility |
|---|---|
| PTFE (hydrophobic) | Solvents, gases, tank vents - 0.1-0.2 um absolute grades common in industry |
| PES (hydrophilic) | Aqueous and pharmaceutical streams; low protein binding |
| Nylon membrane | General aqueous/organic duty, good solvent resistance |
| Stainless steel mesh | Reusable coarse prefiltration, hot gases |
Match the membrane to the stream first (compatibility), then the rating to the purpose (clarification vs sterilising-grade), then the length to the dirt load. For dirty feeds, protect the membrane with a staged depth prefilter - a coarse-to-fine train typically lowers total cartridge cost per year [source: Scientific Edge cartridge selection guide].
Construction that survives validation
The BROLERN pleated line uses high-performance sub-micron fibre membrane formed by thermal welding: no adhesives, no media migration, and an even pore distribution that is not affected by feed-pressure fluctuation. Retention above 90% across the rating range, low pressure drop and high flow are the reasons plants standardise on pleated membranes for final filtration.
FAQ
PTFE, PES or PP?
PTFE for solvents/gases/vents, PES for aqueous and pharmaceutical streams, PP for economical clarification.
What does absolute 0.22 um mean?
Tested minimum retention (typically 99.9% at 0.22 um) - the sterilising-grade standard, unlike a nominal average.
Why thermal welding?
No adhesive means no extractables - required for food, beverage and pharmaceutical production.
Conclusion
Pleated membranes are the finishing stage of a filtration train: pick the membrane by chemistry, the rating by purpose, and the prefiltration by feed dirtiness. BROLERN pleats and welds in-house across PP, PTFE, PES and nylon with ratings from 0.1 um - send the stream specification and we will propose the construction.