PORON® 4701-30 Very Soft Supported
PORON 4701-30 is a very soft cellular polyurethane foam from the Soft Seal Series, cast directly onto a 0.05 mm (2 mil) clear PET film. The material delivers a typical CFD of 34 kPa (5.0 psi) at 25% deflection, density of 320–400 kg/m³ (20–25 lb/ft³), and compression set of 4% max at 23°C and 10% max at 70°C. Thermally, conductivity is 0.076 W/m·°C. Compliant with UL 94 HBF (File E20305), FMVSS 302, CSA HBF (File 188149), and UL JMST2 (File MH15464), with recommended constant use to 90°C (194°F).
Key Properties
- Compression Force Deflection — Typical: 34 kPa (5.0 psi) @ 25% deflection (ASTM D3574-95)
- Compression Set, % max @ 70°C (158°F): 10 (ASTM D3574-95 Test D)
- Hardness, Shore O: 8–16 Min/Max (ASTM D2240-97)
- Density: 320–400 kg/m³ (20–25 lb/ft³) (ASTM D3574-95, Test A)
- Thermal Conductivity: 0.076 W/m·°C (0.53 BTU·in/hr·ft²·°F) (ASTM C518-98)
- Recommended Constant Use Temperature (Max.): 90°C (194°F)
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Physical Properties — PORON® Foam
| Property | Value | Test Method |
| Color (Code) | Black (04) | — |
| Density | 320 (20) – 400 (25) kg/m³ (lb/ft³) | ASTM D3574-95, Test A |
| Density Tolerance | ± 10% | ASTM D3574-95, Test A |
| Thickness | 0.79–2.36 mm (0.031–0.095″) | — |
| Thickness Tolerance — Foam > 0.79 mm (0.031″) | ± 15% | — |
| Thickness Tolerance — Foam < 0.79 mm (0.031″) | ± 0.08 mm (0.003″) | — |
| Compression Force Deflection — Typical | 34 kPa (5.0 psi) | ASTM D3574-95; 0.51 cm/min, 25% deflection |
| Compression Force Deflection — Range | 21–55 kPa (3–8 psi) | ASTM D3574-95; 0.51 cm/min, 25% deflection |
| Compression Set, % max @ 23°C (73°F) | 4 | ASTM D3574-95 Test D |
| Compression Set, % max @ 70°C (158°F) | 10 | ASTM D3574-95 Test D |
| Compression Set — Autoclaved 5 hrs @ 121°C (250°F) | 58 (8.4) kPa (psi) | ASTM D3574-95 Test J / Test D |
| Hardness, Durometer Shore O — Min/Max | 8 / 16 | ASTM D2240-97 |
Electrical & Thermal Properties
| Property | Value | Test Method |
| Dielectric Strength | 1,969 kV/m (50 V/mil) | ASTM D149-97a |
| Dielectric Constant K’ (“DK”) @ 22°C, 50% RH | 1.75 | ASTM D150 |
| Dissipation Factor tan D (“DF”) | 0.05 | ASTM D150-98 |
| Volume Resistivity | 3.1 × 10¹¹ ohm·cm (1.22 × 10¹¹ ohm·in) | ASTM D257-99 |
| Surface Resistivity | 5.9 × 10¹¹ ohm/sq | ASTM D257-99 |
| Thermal Conductivity | 0.076 W/m·°C (0.53 BTU·in/hr·ft²·°F) | ASTM C518-98 |
| Coefficient of Thermal Expansion | 2.3–3.1 × 10⁻⁴ in/in/°C (1.3–1.7 × 10⁻⁴ in/in/°F) | — |
Flammability & Outgassing
| Property | Value | Test Method |
| Flammability — UL 94 HBF | Pass† | UL 94 HBF (File E20305) |
| Flammability — FMVSS 302 | Pass | FMVSS 302 |
| Flammability — CSA Comp HBF | Pass | CSA (File 188149) |
| UL Gasketing & Sealing | Pass | UL JMST2 (File MH15464) |
| Fogging | Pass | SAE J-1756, 3 hrs @ 100°C (212°F) |
| Outgassing TML, % — 320 (20) / 400 (25) kg/m³ | 1.0 / 1.3 | ASTM E595-93, 24 hrs @ 125°C, < 7 kPa |
| Outgassing CVCM, % — 320 (20) / 400 (25) | 0.1 / 0.2 | ASTM E595-93 |
| Outgassing WVR, % — 320 (20) / 400 (25) | 0.3 / 0.6 | ASTM E595-93 |
Environmental & Temperature Resistance
| Property | Value | Test Method |
| Recommended Constant Use Temperature (Max.) | 90°C (194°F) | — |
| Recommended Intermittent Use Temperature (Max.) | 121°C (250°F) | — |
| Embrittlement Temperature | -51°C (-60°F) | ASTM D746-98 |
| Cold Flexibility @ -40°C (-40°F) | Pass | MIL-P-12420D 1991 |
| Moisture Absorption, % Weight Gain (Typical) | 2 | AMS 3568-95, High Humidity |
| Water Absorption — 320 (20) / 400 (25) kg/m³ | 9 / 14 | ASTM D570-95, % Weight Gain |
| UV Resistance | Good | ASTM G53-96 |
| Ozone Resistance | Pass | GM 4486P-95 |
| Corrosion Resistance | Pass | AMS 3568-91 |
| Mildew / Bacteria Resistance | Good | ASTM G21 |
| Staining | No Stain | ASTM D925 |
Supporting Material — Clear Polyester Film (PET) 0.05 mm (2 mil)
| Property | Value | Test Method |
| Density | 1395 kg/m³ (87.1 lb/ft³) | ASTM D1505 |
| Tensile Strength — MD | 3.5 × 10⁶ kPa (500,000 psi) | ASTM D882 |
| Modulus — MD | 2.1 × 10⁵ kPa (30,000 psi) | ASTM D882 |
| Yield Strength (F5) — MD | 1.0 × 10⁵ kPa (15,000 psi) | ASTM D882 |
| Ultimate Elongation | 150% | ASTM D882 |
| Coefficient of Friction A/B (Kinetic) | 0.40 | ASTM D1894 |
| Shrinkage — MD, % (TD) | 1.2 (0.0) | 39 min @ 150°C (302°F) |
Compliance
- UL 94 HBF — Compliant (File E20305)†
- FMVSS 302 — Compliant
- CSA HBF — Compliant (File 188149)
- UL JMST2 (Gasketing & Sealing) — Compliant (File MH15464)
† 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.
- Soft seals and gaskets for low-pressure sealing
- EMI / environmental sealing
- Vibration dampening and cushioning
- Electronics assembly
- Automotive interior sealing
Common industries: electronics, automotive, EMI / environmental sealing, and aerospace.
PORON 4701-30 is a very soft, ultra-conformable cellular polyurethane foam within the PORON Soft Seal Series, cast onto a 0.05 mm (2 mil) clear polyester (PET) film for easy handling. At 320–400 kg/m³ density and 34 kPa (5.0 psi) typical CFD at 25%, it is firmer than the ultra-light 4701-15 but significantly softer than standard gasket foams.
It is designed for low-pressure sealing, gasketing, vibration dampening, and cushioning applications — including automotive interior sealing and electronics assembly — where high conformability and good UV, ozone, and corrosion resistance are required.
The material is rated UL 94 HBF (File E20305), FMVSS 302, CSA HBF (File 188149), and UL JMST2 (File MH15464). Additional performance includes: dielectric strength 1,969 kV/m (50 V/mil), dielectric constant K’ 1.75 at 22°C/50% RH, volume resistivity 3.1 × 10¹¹ ohm·cm, coefficient of thermal expansion 2.3–3.1 × 10⁻⁴ in/in/°C, pass for fogging per SAE J-1756, outgassing TML 1.0/1.3% (at 320/400 kg/m³), CVCM 0.1/0.2%, WVR 0.3/0.6% per ASTM E595-93.
Environmental: moisture absorption 2% typical (AMS 3568-95), water absorption 9/14% at 320/400 kg/m³ (ASTM D570-95), UV resistance good (ASTM G53-96), ozone resistance pass (GM 4486P-95), corrosion resistance pass (AMS 3568-91), mildew/bacteria resistance good (ASTM G21), no staining (ASTM D925), cold flexibility pass at -40°C (MIL-P-12420D 1991). The 0.05 mm (2 mil) clear PET supporting film delivers the same mechanical properties as listed across the PORON Soft Seal Series.
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), FMVSS 302, CSA HBF (File 188149), and UL JMST2 (File MH15464).
What differentiates PORON 4701-30 from the 4701-15, 4701-40, or 4701-41?
4701-30 is the very soft supported grade — cast on 0.05 mm PET film — with a density of 320–400 kg/m³ (20–25 lb/ft³) and a 34 kPa (5.0 psi) typical CFD at 25%. It is considerably firmer than the ultra-light 4701-15 (15 kg/m³, 2.00 kPa typical CFD) but has the broadest environmental and compliance documentation in the Soft Seal supported line, including UL 94 HBF, FMVSS 302, CSA, UV/ozone/corrosion/mildew resistance, fogging, and outgassing (ASTM E595-93). The 4701-40 and 4701-41 are unsupported grades, offering maximum flexibility without a backing film.
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, low compression set means the foam continues to maintain its seal against dust, moisture, and EMI over the service life of the assembly. 4701-30 delivers 4% max at 23°C and 10% max at 70°C per ASTM D3574-95 Test D, and also passes autoclave compression set at 121°C (250°F) — supporting service in environments that undergo sterilization cycles.
What is the operating temperature range for PORON 4701-30?
Recommended constant use temperature is 90°C (194°F) maximum; recommended intermittent use temperature is 121°C (250°F) maximum. Embrittlement temperature is -51°C (-60°F) per ASTM D746-98, and cold flexibility passes at -40°C (-40°F) per MIL-P-12420D 1991.
Is PORON 4701-30 suitable for UL, automotive, and aerospace environments?
Yes. The material is compliant with UL 94 HBF (File E20305), FMVSS 302, CSA HBF (File 188149), and UL JMST2 (File MH15464). Fogging passes SAE J-1756, ozone passes GM 4486P-95, corrosion passes AMS 3568-91, and cold flexibility passes MIL-P-12420D.
How should PORON 4701-30 be specified?
Specify grade (PORON 4701-30), density (320 kg/m³ or 400 kg/m³), thickness (within 0.79–2.36 mm range), color (Black, Code 04), support (0.05 mm clear PET film), CFD range, compliance requirements (UL 94 HBF, FMVSS 302, CSA, UL JMST2 as applicable), dimensional tolerances, and finished format.
