Where it fits
PES pleated cartridges handle sterilising and fine filtration in biopharma and beverage production, normally with a PP or glass fibre pre-filter upstream. This is the final stage — there is no second barrier after it — so integrity testing and biological safety validation are part of the specification rather than optional extras.
Key characteristics
The membrane is highly asymmetric polyethersulfone, its pores narrowing from the outer face inward in a funnel structure. Coarse material is retained in the open outer layers and only the finest fraction reaches the tight layer, which is why initial flux is very high and life markedly longer than a symmetric membrane — throughput and retention stop being a trade-off.
- Naturally hydrophilic — no alcohol pre-wetting required
- Core available in PP, thickened PP, reinforced PP or 316L stainless to suit system pressure
- Membrane passes USP XXII <87> and <88> biological reactivity tests; plastic components comply with FDA 21 CFR and RoHS
Choosing between options
Among the three hydrophilic sulfone-membrane cartridges, the choice is about depth of validation:
| Cartridge | Rating range | Sterilisation | Choose it when |
|---|---|---|---|
| PES pleated (this) | 0.05 – 5 µm | — | Widest rating choice, fine filtration through to sterilising |
| Sterilising-grade PES pleated | 0.1 / 0.2 / 0.45 µm | Repeated 121 °C autoclave and steam-in-place | A sterile barrier that must be validated by bacterial challenge |
| PS pleated | 0.05 – 1 µm | 121 °C autoclave and steam-in-place | Low protein binding, minimising adsorptive loss of biologics |
Operation & change-out
Flush forward with process liquid or purified water and vent trapped air before use. Rated to 5.2 bar at 25 °C, falling to 1.9 bar at 80 °C. Change out when ΔP reaches 3–5 times the clean initial value or 0.24 MPa (35 psi).