4# Polyether Polyurethane Foam
H-O Products 4# Polyether Polyurethane Foam is an open cell, medium density polyether polyurethane foam with a density of 4 lb/ft³ ±10% and an indentation force deflection of 65 lb/50 in² average at 25% deflection per ASTM D3574 — the highest in the polyether polyurethane series. The material passes FMVSS-302, REACH, and RoHS. It is very conformable and suited to sound, light and dust sealing, noise and air infiltration prevention, foam wrap window installation, and insulating, cushioning, and vibration damping applications.
Key Properties
- Indentation Force Deflection Average (25% Deflection): 65 lb/50 in² (ASTM D3574)
- Tensile Strength (Average): 23 psi (ASTM D3574)
- Elongation (Average): 230% (ASTM D3574)
- Density: 4 lb/ft³ ±10% (ASTM D3574)
- FMVSS-302: Pass
- RoHS: Pass
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- Specifications
- Applications
- General Info
- FAQs
Physical Properties
| Property | Value | Test Method |
| Thickness | 1/8″, 3/16″, 1/4″, 3/8″, 1/2″, 3/4″, 1″ | — |
| Color | Gray | — |
| Material/Substrate | Polyether Polyurethane Foam | — |
| Cell Structure | Open Cell | — |
| Density | 4 lb/ft³ ±10% | ASTM D3574 |
Mechanical Properties
| Property | Value | Test Method |
| Indentation Force Deflection Average (25% Deflection) | 65 lb/50 in² | ASTM D3574 |
| Indentation Force Deflection Average (65% Deflection) | 150 lb/50 in² | ASTM D3574 |
| Indentation Force Deflection Minimum (25% Deflection) | 55 lb/50 in² | ASTM D3574 |
| Indentation Force Deflection Minimum (65% Deflection) | 110 lb/50 in² | ASTM D3574 |
| Tensile Strength (Minimum) | 16 psi | ASTM D3574 |
| Tensile Strength (Average) | 23 psi | ASTM D3574 |
| Elongation (Minimum) | 150% | ASTM D3574 |
| Elongation (Average) | 230% | ASTM D3574 |
| Tear Strength (Average) | 2.30 lb/in | ASTM D3574 |
| Tear Strength (Minimum) | 1.50 lb/in | ASTM D3574 |
Flame & Fire Performance
| Property | Value | Test Method |
| Flame Retardant | Flame retardant by special request | — |
| FMVSS-302 | Pass | — |
Regulatory / Compliance Data
| Property | Value | Test Method |
| REACH | Pass | — |
| RoHS | Pass | — |
Aging Performance
Dry Heat Aging
| Property | Value | Test Method |
| Retention of Tensile Strength After 22 Hours, 140°C, Dry Heat Aging | Min. 70% | ASTM D3574 |
Steam Autoclave
| Property | Value | Test Method |
| Retention of Tensile Strength After 5 Hours @ 120°C, Steam Autoclave | Min. 70% | ASTM D3574 |
Compliance
- FMVSS-302 — Compliant
- REACH — Compliant
- RoHS — Compliant
- Sound, light, and dust seals in doors, windows, and enclosures requiring the highest firmness in the polyether polyurethane foam series
- Noise and air infiltration prevention around doors and windows where a firmer foam is required to maintain seal under higher clamping loads
- Foam wrap window installation where the foam sets the window snugly into the house frame while providing insulation and cushioning
- Insulation, cushioning, and vibration damping in construction, HVAC, and consumer product assemblies requiring firmer compression resistance
- Automotive applications requiring FMVSS-302 compliance and a medium-density open cell polyether foam substrate
Common industries: construction, fenestration, automotive, HVAC, consumer goods, electronics.
The 4# Polyether Polyurethane Foam is the highest-density grade in H-O Products’ polyether polyurethane foam series, at 4 lb/ft³ ±10%. It is an open cell foam designed for sound, light, and dust sealing; prevention of noise and air infiltration through and around doors and windows; foam wrap window installation; and general insulating, cushioning, and vibration damping applications. The material is very conformable and delivers the highest indentation force deflection and tensile strength in the series.
Tensile strength is 16 psi minimum and 23 psi average per ASTM D3574 — the highest average in the series. Elongation is 150% minimum and 230% average — also the highest average in the series. IFD averages are 65 lb/50 in² at 25% deflection and 150 lb/50 in² at 65% deflection, both the highest in the polyether series. Tear strength is 1.50 lb/in minimum and 2.30 lb/in average.
Retention of tensile strength is a minimum of 70% after 22 hours at 140°C dry heat aging and after 5 hours at 120°C steam autoclave, both per ASTM D3574. The material passes FMVSS-302, REACH, and RoHS. A flame retardant formulation is available by special request.
Compliant with FMVSS-302, REACH, and RoHS.
What differentiates the 4# Polyether Polyurethane Foam from the lower-density 2# and 1.2# grades?
The 4# is the highest-density grade in the polyether polyurethane series at 4 lb/ft³, with the highest IFD at 25% (65 lb/50 in² average), the highest tensile strength average (23 psi), and the highest elongation average (230%) in the series. It is appropriate when the firmest compression resistance available from this foam family is required. Note that UL 94 HF-1 and California TB 117 are not listed on the 4# TDS — the 2# grade should be selected when those specific compliance ratings are required.
Why does indentation force deflection matter for open cell polyurethane foam selection?
Indentation force deflection (IFD) measures the load required to indent a foam sample by a defined percentage of its thickness, providing a practical measure of firmness. For sealing, cushioning, and insulation applications, selecting the appropriate IFD ensures the foam compresses adequately under service loads while maintaining sufficient structure to hold its position. The 4# grade's average IFD of 65 lb/50 in² at 25% — nearly double the 2# grade's 35 lb/50 in² — makes it the appropriate selection for applications requiring a substantially firmer foam response.
What is the service temperature range for the 4# Polyether Polyurethane Foam?
A specific service temperature range is not stated on the manufacturer's TDS for this material. Aging performance data includes retention of tensile strength after 22 hours at 140°C dry heat aging and after 5 hours at 120°C steam autoclave, both with a minimum retention of 70%.
Is the 4# Polyether Polyurethane Foam suitable for regulated environments?
Yes. The material passes FMVSS-302, REACH, and RoHS, as stated on the TDS. UL 94 HF-1 and California Technical Bulletin 117 are not listed on this TDS. A flame retardant formulation is available by special request.
How should the 4# Polyether Polyurethane Foam be specified?
Specify grade (4# Polyether Polyurethane Foam), thickness, compliance requirements (FMVSS-302, REACH, RoHS as applicable), dimensional tolerances, and finished format.
