Filter Sponge PPI & Pore Size Chart - Is Higher PPI Always Better? (GaoLeshi)
How to Read Filter Foam PPI & Pore Size: The Complete Comparison Chart
GaoLeshi Technical Note | Reticulated Filter Foam | Updated 2026
PPI is the core metric describing the cell density of filter foam. Understanding it is the key to selecting the right material scientifically.
What Is PPI?
PPI (Pores Per Inch) — the number of pores distributed along one inch (≈ 25.4 mm) of length. It is the single most important specification of reticulated filter foam.
A higher PPI value means smaller pores → higher filtration accuracy, but higher pressure drop. A lower PPI value means larger pores → better flow, but weaker particle capture.
Example: PPI 30 = 30 pores per inch, pore size ≈ 1.2 mm. PPI 60 = 60 pores per inch, pore size ≈ 0.4 mm.
▲ High PPI 60–120
High filtration accuracy, capable of capturing micron-scale particles. Used in medical devices, precision instrument protection and ultrapure water preparation.
▼ Low PPI 10–30
High flow with low pressure drop, captures coarse particles. Used in pre-filtration, pond filtration and agricultural irrigation where throughput matters most.
PPI vs. Filtration Performance
Each PPI range corresponds to a different filtration grade and application
| Grade | PPI Range | Filtration Level | Particles Captured | Typical Applications |
|---|---|---|---|---|
| Coarse | 10–30 | Coarse filtration | Large particles, hair, debris | Pond filtration, agricultural pre-filtration |
| Medium | 40–80 | Medium filtration | Dust, suspended solids | Air purifiers, automotive cabin filters |
| High | 90–120 | High-efficiency filtration | Micron-scale particles | Medical devices, precision instrument protection |
Need Help Selecting?
With 15+ years of polymer foam R&D experience, GaoLeshi provides free technical consultation and custom samples. Send us your target particle size, flow rate and allowable pressure drop, and our engineers will recommend the PPI/density combination.