45 PPI Uncoated Reticulated Foam UL94 HF-1 Rated
45 PPI Uncoated Reticulated Foam UL94 HF-1 Rated is a compressible open cell polyether polyurethane foam with a nominal cell count of 45 ppi ±5 (CREST), a density of 1.4 lb/ft³ ±0.10, and a volumetric air flow rate of 12.5 cfm ±2 per ASTM D3574-91. The material is UL94 HF-1 rated and is used inside extrusions and cavities where it is not exposed to UV or sunlight. It is the finest-pore fully specified grade in the uncoated UL94 HF-1 reticulated foam series.
Key Properties
- Compression Force Deflection @ 25%: 0.65 psi ±0.10 (ASTM D3574-91)
- Compression Set @ 50% Deflection: 25% loss maximum (ASTM D3574-91)
- Tensile Strength: 22 lb/in minimum (ASTM D3574-91)
- Elongation @ Break: 200% 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″ | — |
| Material/Substrate | Polyether Polyurethane Foam | — |
| Color | Black | — |
| Cell Structure | Open Cell | — |
| Cell Count | 45 ppi ±5 | CREST |
| Foam Grade | S-45 | CREST |
| Density | 1.4 lb/ft³ ±0.10 | ASTM D3574-91 |
Mechanical Properties
| Property | Value | Test Method |
| Compression Force Deflection @ 25% | 0.65 psi ±0.10 | ASTM D3574-91 |
| Compression Set @ 50% Deflection | 25% loss maximum | ASTM D3574-91 |
| Tensile Strength | 22 lb/in minimum | ASTM D3574-91 |
| Elongation @ Break | 200% minimum | ASTM D3574-91 |
| Tear Strength | 4.5 lb/in minimum | ASTM D3574-91 |
Acoustic / Air Flow
| Property | Value | Test Method |
| Volumetric Air Flow Rate | 12.5 cfm ±2 | 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 | 20% maximum | ASTM D3574-91 |
Autoclave Aging
| Property | Value | Test Method |
| Compression Set @ 50% Deflection Autoclave Loss | 25% 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 fine 45 PPI filtration are required, for use inside extrusions and cavities not exposed to UV
- General filtering applications requiring fine 45 PPI open-pore filtration with UL94 HF-1 compliance within the 1/4″ to 1″ thickness range
- NEMA enclosure and generator or compressor housing ventilation where fine 45 PPI filtration, 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 fine 45 PPI pore filtration in non-UV-exposed installations
- Draft and air infiltration seals in doors, windows, and access panels where UL94 HF-1 rated uncoated 45 PPI reticulated foam with foam grade S-45 is specified
Common industries: construction, HVAC, fenestration, electrical enclosures, industrial equipment, automotive.
The 45 PPI Uncoated Reticulated Foam UL94 HF-1 Rated is the finest-pore fully specified grade in H-O Products’ uncoated UL94 HF-1 rated reticulated foam series, with a nominal cell count of 45 ppi and a volumetric air flow rate of 12.5 cfm ±2. Foam Grade S-45 per CREST.
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. The TDS features section states the material is available in charcoal gray; however, the Color row in the technical data table lists Black — both are reproduced here as written on the TDS.
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 0.65 psi ±0.10 — the highest in the uncoated UL94 HF-1 series tested to ASTM D3574-91. Compression set at 50% deflection is 25% loss maximum. Tensile strength is 22 lb/in minimum with a dry heat loss maximum of 20%. Elongation at break is 200% minimum — the highest in the series. Tear strength is 4.5 lb/in minimum. Air pressure drop is 0.15 ±0.05 per ASTM D3574-91. Autoclave compression set loss is 25% maximum and 25% compression load deflection autoclave loss is 15% maximum.
Compliant with UL94 HF-1.
What differentiates the 45 PPI Uncoated UL94 HF-1 grade from the standard 45 PPI Uncoated grade and from adjacent UL94 HF-1 grades?
The UL94 HF-1 rating is the primary differentiator from the standard 45 PPI Uncoated grade. Both the 45PPIRETICF and 45PPIRETICFU carry foam grade S-45 and identical mechanical data, but only this UL94 HF-1 grade carries the rated flame classification. Within the UL94 HF-1 uncoated series, the 45 PPI grade has the finest pore structure with a full ASTM D3574-91 property set, the highest CFD (0.65 psi ±0.10), and the highest elongation (200% minimum). Its available thickness range is 1/4" to 1", narrower than the 10, 20, 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 45 PPI UL94 HF-1 grade has a CFD of 0.65 psi ±0.10 at 25% — the highest in the fully specified uncoated UL94 HF-1 series — reflecting its fine, dense skeletal structure. This supports consistent seating and firm filtration contact with cavity walls for reliable fine filtration performance.
What is the service temperature range for the 45 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 20% maximum per ASTM D3574-91 and autoclave aging performance per ASTM 3574-91 and ASTM D3574-91.
Is the 45 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 45 PPI Uncoated Reticulated Foam UL94 HF-1 be specified?
Specify grade (45 PPI Uncoated Reticulated Foam UL94 HF-1, Foam Grade S-45), thickness, color (confirm Black or Charcoal Gray with H-O Products, as the TDS data table and features section differ), 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.
