Home › Blog › Reticulated foam selection
Choosing the Right Reticulated Polyurethane Foam for Your Application
Reticulated polyurethane foam is a lightweight, flexible, and durable open-cell foam whose structure lets air and water pass through while trapping dust and debris. The specification that matters most is porosity — and matching pores-per-inch to your application is most of the selection battle.
What is reticulated polyurethane foam?
The foam is produced through a unique manufacturing process involving controlled combustion, which removes cell windows and leaves an open skeletal structure. Porosity is measured in pores per inch (PPI), typically ranging from 4 PPI to 100 PPI. Lower porosities (4–20 PPI) allow more fluid and air flow; higher porosities (80–100 PPI) restrict flow significantly. Cell count typically varies ±5 PPI, and thickness affects filtration capacity.
- High compressibility
- Low compression set, typically under 5%
- Polyether variants offer better moisture and mildew resistance than polyester variants
Common applications include cushioning, sound absorption, air and fluid filtration, and dust or insect trapping.
Specialized coatings
Acrylic coated
Used where the foam sees UV exposure but not direct weather — commercial windows and outdoor HVAC filters. Costs more than uncoated.
PVC coated
The most durable (and most expensive) option, used in curtainwall weep baffles, outdoor speaker covers, and flame-retardant applications.
Bacteriostatic coated
Anti-microbial properties minimize bacteria and mold growth — suitable for wet environments like aquariums and fish ponds.
Industry standards by application
| Application | Standard porosity | Notes |
|---|---|---|
| Residential window / door weep baffles | 30 PPI | Uncoated for protected areas; coated for UV exposure |
| Curtainwall / commercial windows | 30 PPI (40 PPI high-rise) | PVC coating recommended |
| HVAC filters | 20–30 PPI | 40–45 PPI for higher-airflow equipment |
| Power switches | 45 PPI | Requires UV-resistant, UL-94 HF-1 compliant PVC coating |
H-O Products capabilities
We offer porosities from 4 PPI to 100 PPI in increments of 5–10 PPI, and cut shapes up to 5 inches thick and 60 × 118 inches using CNC water jet and digital cutting equipment.
Ready to spec a reticulated foam?
Send the application, the airflow or filtration requirement, the exposure conditions, and the geometry. Engineering reviews every RFQ and recommends a porosity and coating.
Samples typically ship in 3 to 5 business days for common die-cut configurations; standard production runs about two weeks; special orders are quoted to the job.
Family-owned in Winsted, Connecticut since 1971 · ISO 9001:2015 certified · OEMs worldwide send us a drawing — and get back their part.
Frequently asked questions
What PPI should I choose?
Match porosity to flow: 4–20 PPI for maximum air and fluid flow, 30 PPI as the fenestration weep-baffle standard, 20–45 PPI for HVAC filters depending on airflow, and 80–100 PPI where flow must be restricted.
When does reticulated foam need a coating?
Acrylic coating for UV exposure without direct weather, PVC coating for maximum durability or flame-retardant requirements, and bacteriostatic coating for wet environments where microbial growth is a concern.
Request a quote for your reticulated foam part
Send H-O your material role and geometry—engineering reviews every RFQ, recommends a family per material, and converts samples on your geometry.