20 PPI Uncoated Reticulated Foam UL94 HF-1 Rated
H-O Products 20 PPI Uncoated Reticulated Foam UL94 HF-1 Rated is a compressible open cell polyether polyurethane foam with a nominal cell count of 20 ppi ±5 (CREST), a density of 1.4 lb/ft³ ±0.10, and a volumetric air flow rate of 22 cfm ±3.5 per ASTM D3574-91. The material is UL94 HF-1 rated, is available in charcoal gray, and is used inside extrusions and cavities where it is not exposed to UV or sunlight. It is a mid-pore grade in the uncoated UL94 HF-1 reticulated foam series.
Key Properties
- Compression Force Deflection @ 25%: 0.50 psi ±0.10 (ASTM D3574-91)
- Compression Set @ 50% Deflection: 15% loss maximum (ASTM D3574-91)
- Tensile Strength: 18 lb/in minimum (ASTM D3574-91)
- Elongation @ Break: 180% minimum (ASTM D3574-91)
- Density: 1.4 lb/ft³ ±0.10 (ASTM D3574-91)
- UL94 HF-1: Rated
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- Specifications
- Applications
- General Info
- FAQs
Physical Properties
| Property | Value | Test Method |
| Thickness | 1/4″, 3/8″, 5/8″, 1/2″, 3/4″, 7/8″, 1″, 1-1/8″, 1-1/4″, 1-3/8″, 1-1/2″, 1-3/4″, 2″ | — |
| Material/Substrate | Polyether Polyurethane Foam | — |
| Color | Charcoal Gray | — |
| Cell Structure | Open Cell | — |
| Cell Count | 20 ppi ±5 | CREST |
| Foam Grade | T-20 | CREST |
| Density | 1.4 lb/ft³ ±0.10 | ASTM D3574-91 |
Mechanical Properties
| Property | Value | Test Method |
| Compression Force Deflection @ 25% | 0.50 psi ±0.10 | ASTM D3574-91 |
| Compression Set @ 50% Deflection | 15% loss maximum | ASTM D3574-91 |
| Tensile Strength | 18 lb/in minimum | ASTM D3574-91 |
| Elongation @ Break | 180% minimum | ASTM D3574-91 |
| Tear Strength | 5 lb/in minimum | ASTM D3574-91 |
Acoustic / Air Flow
| Property | Value | Test Method |
| Volumetric Air Flow Rate | 22 cfm ±3.5 | ASTM D3574-91 |
| Air Pressure Drop | 0.15 ±0.05 | ASTM D3574-91 |
Flame & Fire Performance
| Property | Value | Test Method |
| UL94 HF-1 | Rated | — |
Aging Performance
Dry Heat Aging
| Property | Value | Test Method |
| Tensile Strength Dry Heat Loss | 15% maximum | ASTM D3574-91 |
Autoclave Aging
| Property | Value | Test Method |
| Compression Set @ 50% Deflection Autoclave Loss | 10% maximum | ASTM 3574-91 |
| 25% Compression Load Deflection Autoclave Loss | 15% maximum | ASTM D3574-91 |
Compliance
- UL94 HF-1 — Rated
- Weep baffling in commercial and residential construction where UL94 HF-1 flame rating and mid-pore filtration are required for use inside extrusions and cavities not exposed to UV
- General filtering applications requiring 20 PPI open-pore filtration with UL94 HF-1 compliance and the full available thickness range to 2″
- NEMA enclosure and generator or compressor housing ventilation where moderate air flow, UL94 HF-1 flame rating, and an uncoated foam are all specified
- Moisture infiltration barriers in building envelope assemblies requiring UL94 HF-1 compliance and mid-pore filtration performance
- Draft and air infiltration seals in doors, windows, and access panels where UL94 HF-1 rated uncoated 20 PPI reticulated foam is specified
Common industries: construction, HVAC, fenestration, electrical enclosures, industrial equipment, automotive.
The 20 PPI Uncoated Reticulated Foam UL94 HF-1 Rated is a mid-pore grade in H-O Products’ uncoated UL94 HF-1 rated reticulated foam series, with a nominal cell count of 20 ppi and a volumetric air flow rate of 22 cfm ±3.5. It is a UL94 HF-1 rated uncoated polyether polyurethane foam designed for general filtering applications and weep baffling in commercial and residential construction, used inside extrusions and cavities not exposed to UV or sunlight.
Per the TDS note, the Crest visual PPI standard is the industry accepted nomenclature for defining reticulated foam pore size; however, the air flow is the only quantifiable value for determining PPI for published specifications, and the only exception allowed is if visual PPI is agreed as a standard in advance prior to order submission.
Compression force deflection at 25% is 0.50 psi ±0.10. Compression set at 50% deflection is 15% loss maximum, with the tightest autoclave compression set loss in the series at 10% maximum. Tensile strength is 18 lb/in minimum with a dry heat loss maximum of 15%. Elongation at break is 180% minimum. Tear strength is 5 lb/in minimum. Air pressure drop is 0.15 ±0.05 per ASTM D3574-91. The 25% compression load deflection autoclave loss is 15% maximum.
Compliant with UL94 HF-1.
What differentiates the 20 PPI Uncoated UL94 HF-1 grade from the standard 20 PPI Uncoated grade and from adjacent UL94 HF-1 grades?
The UL94 HF-1 rating is the primary differentiator from the standard 20 PPI Uncoated grade. Within the UL94 HF-1 uncoated series, the 20 PPI grade is the mid-pore grade with a volumetric air flow of 22 cfm ±3.5 and carries the tightest autoclave compression set loss at 10% maximum. It shares the full thickness range to 2" with the 10 PPI and 30 PPI UL94 HF-1 grades.
Why is compression force deflection important for a UL94 HF-1 uncoated reticulated foam?
Compression force deflection determines how readily the foam compresses to fill a cavity under installation force. The 20 PPI UL94 HF-1 grade has a CFD of 0.50 psi ±0.10 at 25%, providing moderate resistance that allows the foam to seat reliably in its cavity while maintaining consistent contact with cavity walls for reliable filtration performance.
What is the service temperature range for the 20 PPI Uncoated Reticulated Foam UL94 HF-1?
A specific service temperature range is not stated on the manufacturer's TDS for this material. Aging performance data includes tensile strength dry heat loss of 15% maximum per ASTM D3574-91 and autoclave aging performance per ASTM 3574-91 and ASTM D3574-91.
Is the 20 PPI Uncoated Reticulated Foam UL94 HF-1 suitable for regulated environments?
Yes. The material is UL94 HF-1 Rated, as stated on the TDS. The standard uncoated grade is for use in applications not exposed to UV or sunlight, as stated on the TDS. No additional compliance standards are specified.
How should the 20 PPI Uncoated Reticulated Foam UL94 HF-1 be specified?
Specify grade (20 PPI Uncoated Reticulated Foam UL94 HF-1, Foam Grade T-20), thickness, color (Charcoal Gray), compliance requirements (UL94 HF-1), dimensional tolerances, and finished format. Per the TDS, air flow is the only quantifiable value for determining PPI for published specifications.
