PORON® 4701-41 Soft Enhanced Sealability (Unsupported)
PORON 4701-41 is a soft, unsupported cellular polyurethane foam with enhanced sealability versus the standard 4701-40, available in three density grades: 240 kg/m³ (15 lb/ft³), 320 kg/m³ (20 lb/ft³), and 480 kg/m³ (30 lb/ft³). The grades deliver CFD of 57, 97, and 247 kPa (8, 14, 36 psi) respectively at 25% deflection, with compression set maximums of 1.7–2.5% at 70°C (158°F). Compliant with UL 94 HBF (File E20305) and UL JMST2 (File MH15464).
Key Properties
- Compression Force Deflection @ 25%: 57 kPa / 8 psi (240); 97 kPa / 14 psi (320); 247 kPa / 36 psi (480) (ISO 6916-1)
- Compression Set, % max @ 70°C: 1.7 (240) / 1.5 (320) / 2.5 (480) (ISO 1856 Test A)
- Density: 240 / 320 / 480 kg/m³ (15 / 20 / 30 lb/ft³)
- Dielectric Strength: 2.3 / 2.4 / 3.4 kV/mm (IEC 243-1)
- Recommended Constant Use Temperature (Max.): 90°C (194°F)
- Available Thicknesses: 0.79–12.7 mm (0.031–0.500″)
We want to help!
Enter your information and we'll get you in touch with our knowledgable staff. We know how important to the right product for your project.
Request a Consultation
- Specifications
- Applications
- General Info
- FAQs
Physical Properties
| Property | Test Method | 240 kg/m³ (15 lb/ft³) | 320 kg/m³ (20 lb/ft³) | 480 kg/m³ (30 lb/ft³) |
| Color (Code) | — | Black (04) | Black (04) | Black (04) |
| Density Tolerance | ASTM D3574-95, Test A | ± 10% | ± 10% | ± 20% |
| Available Thicknesses, mm (in) | — | 0.79 (0.031), 1.14 (0.045), 1.57 (0.062), 2.36 (0.093), 3.18 (0.125), 4.78 (0.188), 6.35 (0.250), 9.53 (0.375), 12.7 (0.500) | ← same | ← same |
| Thickness Tolerance | — | ± 10% | ± 10% | ± 10% |
| Compression Force Deflection, kPa (psi) | ISO 6916-1; 30 mm/min, 25% deflection | 57 (8) | 97 (14) | 247 (36) |
| Compression Set, % max @ 70°C (158°F) | ISO 1856 Test A | 1.7 | 1.5 | 2.5 |
| Dimensional Stability, % max change — 22 hrs @ 80°C | — | ± 2 | ± 2 | ± 2 |
Electrical Properties
| Property | Test Method | 240 kg/m³ (15 lb/ft³) | 320 kg/m³ (20 lb/ft³) | 480 kg/m³ (30 lb/ft³) |
| Dielectric Strength, kV/mm | IEC 243-1 | 2.3 | 2.4 | 3.4 |
| Volume Resistivity, ohm·cm | IEC 60093 | 1.42 × 10¹³ | 4.18 × 10¹³ | 1.35 × 10¹⁴ |
| Surface Resistivity, ohm/sq | IEC 60093 | 4.29 × 10¹³ | 4.49 × 10¹³ | 1.17 × 10¹⁴ |
Temperature Resistance
| Property | Value | Test Method |
| Recommended Constant Use Temperature (Max.) | 90°C (194°F) | — |
| Recommended Intermittent Use Temperature (Max.) | 121°C (249.8°F) | UL 157 |
| Embrittlement Temperature | -50°C (-58°F) | ISO 974 (E) |
Flammability & Outgassing
| Property | Test Method | 240 kg/m³ (15 lb/ft³) | 320 kg/m³ (20 lb/ft³) | 480 kg/m³ (30 lb/ft³) |
| UL 94 HBF† — Min. Thickness Passed, mm (in) | UL 94 HBF (File E20305) | 4.78 (0.188) | 1.57 (0.062) | 1.14 (0.045) |
| FMVSS 302 — Min. Thickness Passed, mm (in) | ISO 3795 / DIN 75200 | 4.78 (0.188) | 4.78 (0.188) | 4.78 (0.188) |
| FMVSS 302 — Max. Burn Rate, mm/min | ISO 3795 / DIN 75200 | 33 | 91 | 73 |
| UL Gasketing & Sealing | UL JMST2 (File MH15464) | Pass | Pass | Pass |
| Fogging | ISO 6452 / DIN 75201 | Pass | Pass | — |
Compliance
- UL 94 HBF — Compliant (File E20305)† — all three grades at documented minimum thicknesses
- UL JMST2 (Gasketing & Sealing) — Compliant (File MH15464) — all grades
† Designed to meet UL 94 HBF based upon 2022 test criteria. As of 2023, items with nominal density ≥ 15.6 lb/ft³ (250 kg/m³) are no longer eligible to be tested for UL 94 HBF but remain equivalent.
- Enhanced seals and gaskets where standard soft foam sealability is insufficient
- Environmental and EMI sealing
- Cushioning and vibration dampening
- Automotive interior sealing
- Electronics assembly
Common industries: electronics, automotive, and EMI / environmental sealing.
PORON 4701-41 is a soft unsupported cellular polyurethane foam with enhanced sealability compared to the standard 4701-40, designed for demanding sealing, gasketing, and cushioning applications where improved surface conformance and sealability are required. Available in three densities — 240, 320, and 480 kg/m³ — it spans a CFD range of 57 to 247 kPa at 25% deflection, with higher CFD values at each density than the equivalent 4701-40 grade (42, 85, 225 kPa respectively), reflecting the enhanced sealability formulation.
As an unsupported foam, it offers maximum flexibility and conformability without a backing film.
Physical performance by grade: compression set max at 70°C is 1.7% (240 kg/m³), 1.5% (320 kg/m³), and 2.5% (480 kg/m³); dimensional stability is ± 2% max change at 22 hrs @ 80°C in a forced-air oven. Temperature resistance is 90°C (194°F) constant and 121°C (250°F) intermittent per UL 157; embrittlement temperature is -50°C (-58°F) per ISO 974(E).
Electrical performance by grade: dielectric strength 2.3 / 2.4 / 3.4 kV/mm (IEC 243-1); volume resistivity 1.42 × 10¹³ / 4.18 × 10¹³ / 1.35 × 10¹⁴ ohm·cm; surface resistivity 4.29 × 10¹³ / 4.49 × 10¹³ / 1.17 × 10¹⁴ ohm/sq (IEC 60093).
Flammability: UL 94 HBF min. thicknesses are 4.78 mm (0.188″) at 240 kg/m³, 1.57 mm (0.062″) at 320 kg/m³, and 1.14 mm (0.045″) at 480 kg/m³; FMVSS 302 min. thickness is 4.78 mm (0.188″) at all three grades; max burn rates are 33 / 91 / 73 mm/min. UL JMST2 passes across all grades. Fogging passes at 240 and 320 kg/m³ per ISO 6452 / DIN 75201.
Note: Designed to meet UL 94 HBF based on 2022 test criteria. As of 2023, items with nominal density ≥ 15.6 lb/ft³ (250 kg/m³) are no longer eligible to be tested for UL 94 HBF but remain equivalent.
Compliant with UL 94 HBF (File E20305) and UL JMST2 (File MH15464).
What differentiates PORON 4701-41 from the standard 4701-40 or the supported PORON grades?
4701-41 is formulated for enhanced sealability compared to the standard 4701-40. At equivalent densities (240, 320, 480 kg/m³), CFD values are higher (57, 97, 247 kPa versus 42, 85, 225 kPa for 4701-40), reflecting a material that conforms and seals more aggressively under compression. Both grades are unsupported, offering maximum flexibility without a backing film. Where 4701-40 is the standard soft gasket selection, 4701-41 is specified when the application demands superior seal integrity — for example, in tighter or more demanding environmental sealing interfaces.
Why is compression set critical for this material?
Compression set measures the foam's ability to recover its original thickness after sustained compression. For seals and gaskets, a foam that takes a set will fail to maintain its seal against dust, moisture, and EMI over the service life of the assembly. 4701-41 delivers compression set maximums of 1.7% (240 kg/m³), 1.5% (320 kg/m³), and 2.5% (480 kg/m³) at 70°C (158°F) per ISO 1856 Test A.
What is the operating temperature range for PORON 4701-41?
Recommended constant use temperature is 90°C (194°F) maximum; recommended intermittent use temperature is 121°C (249.8°F) maximum per UL 157. Embrittlement temperature is -50°C (-58°F) per ISO 974(E).
Is PORON 4701-41 suitable for UL and automotive environments?
Yes. All three density grades comply with UL 94 HBF (File E20305) at documented minimum thicknesses, and all pass UL JMST2 gasketing and sealing (File MH15464). Fogging passes at 240 and 320 kg/m³ per ISO 6452. Note that FMVSS 302 minimum thickness for all three grades is 4.78 mm (0.188"), which is higher than for 4701-40 at the 320 and 480 kg/m³ grades.
How should PORON 4701-41 be specified?
Specify grade (PORON 4701-41), density (240, 320, or 480 kg/m³), thickness, unsupported construction, compliance requirements (UL 94 HBF, FMVSS 302, UL JMST2 as applicable — with minimum thickness noted), dimensional tolerances, and finished format.
