4.2# EPE Foam
4.2# EPE Foam is a high-density closed-cell expanded polyethylene foam with a nominal density of 4.2 pcf (67 g/l) and a compressive strength of 35.7 psi at 25% deflection. The foam delivers 98 psi tensile strength, 22% tensile elongation, and a maximum service temperature of 176°F, with water absorption below 5.0% by volume. Flammability passes FMVSS-302 at less than 4.0 in/min. Fuel immersion data is not available for this grade.
Key Properties
- Compressive Strength @ 25%: 35.7 psi (ASTM D3575)
- Tensile Strength: 98 psi (ASTM D3575)
- Tensile Elongation: 22% (ASTM D3575)
- Compression Set @ 50%: 15% (ASTM D3575)
- Density: 4.2 pcf (67 g/l) (ASTM D3575)
- Service Temperature (Max.): 176°F (ASTM D3575)
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- Specifications
- Applications
- General Info
- FAQs
Physical Properties
| Property | Value | Test Method |
| Density (Grade) | 4.2 pcf (67 g/l) | ASTM D3575 |
| Color | Black | — |
| Material / Substrate | Expanded Polyethylene Foam | — |
| Buoyancy | 57.5 lbs/ft³ | ASTM D3575 |
| Water Absorption | < 5.0% (vol) / < 0.02 lb/ft² | ASTM D3575 / C272 |
Mechanical Properties
| Property | Value | Test Method |
| Compressive Strength @ 10% | 29.4 psi | ASTM D3575 |
| Compressive Strength @ 25% | 35.7 psi | ASTM D3575 |
| Compressive Strength @ 50% | 56.0 psi | ASTM D3575 |
| Compressive Strength @ 75% | 113.0 psi | ASTM D3575 |
| Compression Set @ 25% | 7% | ASTM D3575 |
| Compression Set @ 50% | 15% | ASTM D3575 |
| Tensile Strength | 98 psi | ASTM D3575 |
| Tensile Elongation | 22% | ASTM D3575 |
| Tear Strength | 28 lbs/in | ASTM D3575 |
| Compressive Creep (1,000 hr) | 5.5% @ 10 psi | ASTM D3575 |
Thermal Properties
| Property | Value | Test Method |
| Thermal Conductivity | 0.28 BTU·in/ft²·hr·°F | ASTM C177 |
| Thermal Resistance @ 70°F | 3.6 | ASTM C177 |
| Coefficient of Linear Thermal Expansion | 4.2 × 10⁻⁵ in/in/°F | ASTM D696 |
| Service Temperature (Max.) | 176°F | ASTM D3575 |
Flame & Fire Performance
| Property | Value | Test Method |
| Flammability | Pass (< 4.0 in/min) | FMVSS-302 |
Chemical Resistance
| Property | Value | Test Method |
| Chemical Resistance (1 hr exposure) | Pass | Various |
Compliance
- FMVSS-302 — Compliant (Pass, < 4.0 in/min)
- High-load packaging cushioning and protective inserts
- Shipping pads for heavier product protection
- Flooring underlayment
- Protective foam tape constructions
- Moisture barrier applications in construction
Common industries: packaging, shipping, construction, and converted-foam components.
4.2# EPE Foam is a high-density closed-cell expanded polyethylene foam, positioned within the EPE family as a load-bearing grade for packaging, cushioning, and construction applications where the foam also serves as a moisture barrier. At 4.2 pcf nominal density, it provides substantially higher compressive strength and tear resistance than the mid-density EPE grades, with elongation and elasticity reduced compared to the lighter grades — characteristic of a higher-density closed-cell construction.
Mechanical performance includes 29.4, 35.7, 56.0, and 113.0 psi compressive strength at 10%, 25%, 50%, and 75% deflection respectively; 98 psi tensile strength; 22% tensile elongation; 28 lbs/in tear strength; and compression set of 7% at 25% and 15% at 50%.
Thermally, the material has 0.28 BTU·in/ft²·hr·°F thermal conductivity, 3.6 thermal resistance at 70°F, a coefficient of linear thermal expansion of 4.2 × 10⁻⁵ in/in/°F, and a maximum service temperature of 176°F.
Environmental and chemical performance includes water absorption below 5.0% by volume / 0.02 lb/ft², compressive creep of 5.5% at 10 psi after 1,000 hours, buoyancy of 57.5 lbs/ft³, and qualified pass results for chemical resistance (1 hr exposure). Flammability passes FMVSS-302 at less than 4.0 in/min. Fuel immersion data is not available for this grade.
Compliant with FMVSS-302 (flammability) and the listed ASTM test methods: ASTM D3575, C272, C177, and D696.
What differentiates 4.2# EPE Foam from lower-density EPE grades?
4.2# EPE Foam is a high-density grade in the H-O EPE line at 4.2 pcf (67 g/l), delivering 35.7 psi compressive strength at 25% and 98 psi tensile strength — substantially higher than the mid-density grades (1.3# through 2.8#). It is positioned for packaging and cushioning service that requires high load-bearing capability and tear resistance. The trade-off versus the lighter grades is lower elongation (22%) and higher compression set (15% at 50%), and unlike the lower-density grades, fuel immersion data is not specified for this grade.
Why is compression set critical for this material?
Compression set measures the foam's ability to recover its original thickness after sustained compression. For cushioning, shipping pad, and gasketing applications, a low compression set means the foam retains its protective and sealing performance over the life of the package or assembly. 4.2# EPE Foam delivers 7% compression set at 25% and 15% at 50% per ASTM D3575.
What is the service temperature range for 4.2# EPE Foam?
The maximum service temperature is 176°F per ASTM D3575. The TDS does not specify a minimum service temperature.
Is 4.2# EPE Foam suitable for flame-rated environments?
Yes. The material passes FMVSS-302 flammability at less than 4.0 in/min, and chemical resistance to 1 hr exposure is documented as pass. Fuel immersion data is not available for this grade on the manufacturer's TDS; for marine fuel immersion applications, the lighter EPE grades (1.3# through 2.8#) carry documented Fuel B / 33 CFR §183.114 pass results and should be evaluated instead.
How should 4.2# EPE Foam be specified?
Specify grade (4.2# EPE Foam, 4.2 pcf / 67 g/l density), thickness, sheet or roll dimensions, compliance requirements (FMVSS-302), dimensional tolerances, and finished format (sheet, die-cut, kiss-cut, or laminated construction).
