foam epdm gasket
When applications demand reliable environmental sealing, flame resistance, and consistent mechanical performance, closed-cell EPDM / Neoprene blends are a proven solution. One of the most widely specified options in this category is the Durafoam™ DK Series, a family of UL-recognized closed-cell sponge rubber materials available in five hardness grades.
At NEDC, we routinely die cut and waterjet cut these materials into precision gaskets, seals, pads, and custom components for electrical enclosures, industrial equipment, and transportation applications.
Material Overview: Durafoam™ DK Series
The Durafoam™ DK Series is a closed-cell Neoprene / EPDM polymeric blend designed to meet demanding sealing and flame-resistance requirements while maintaining flexibility and resilience over a wide temperature range.
All five grades are:
-
UL Recognized to UL 50E, UL 157, UL 508, and UL 94 HF-1
-
CSA Listed to CAN/CSA C22.2 No. 017-92
-
Manufactured to ASTM D1056 sponge rubber classifications
-
Black in color
-
Closed-cell construction for moisture and air sealing
Available Grades & Mechanical Ranges
The DK Series is offered in five progressive firmness levels, allowing engineers to balance compression force, sealing pressure, and durability:
DK1111 (SCE 41 / 2C1)
-
Density: ~6 PCF
-
Compression Deflection (25%): 2–5 PSI
-
Tensile Strength: 75 psi
-
Ideal for very soft, low-load sealing applications
ASTM D1056 2C1C1F1Z, Z= Fungus Resistance per MIL-STD-810 Method 508
DK2121 (SCE 42 / 2C2)
-
Density: ~6 PCF
-
Compression Deflection: 5–9 PSI
-
Tensile Strength: 100 psi
-
Common choice for light enclosure gasketing
ASTM D1056 2C2C1F1Z, Z= Fungus Resistance per MIL-STD-810 Method 508
DK3131 (SCE 43 / 2C3)
-
Density: ~9 PCF
-
Compression Deflection: 9–13 PSI
-
Tensile Strength: 100 psi
-
Balanced sealing force and durability
ASTM D1056 2C3C1F1Z, Z= Fungus Resistance per MIL-STD-810 Method 508
DK4141 (SCE 44 / 2C4)
-
Density: ~10 PCF
-
Compression Deflection: 13–17 PSI
-
Tensile Strength: 125 psi
-
Higher load applications requiring tighter seals
ASTM D1056 2C4C1F1Z, Z= Fungus Resistance per MIL-STD-810 Method 508
DK5151 (SCE 45 / 2C5)
-
Density: ~13 PCF
-
Compression Deflection: 17–25 PSI
-
Tensile Strength: 150 psi
-
Firmest grade for robust mechanical sealing
ASTM D1056 2C5C1F1Z, Z= Fungus Resistance per MIL-STD-810 Method 508
Performance Characteristics of the DK Series
Across all five hardness levels, the DK Series delivers consistent performance:
-
Temperature Range: –40°F to +250°F
-
Water Absorption: ≤5% by weight
-
Elongation: ≥150%
-
Compression Set: ≤25%
-
Ozone Resistance: Pass (ASTM D1171)
-
Oil Resistance: Pass (Fluid Immersion E1)
-
Flame Resistance: UL 94 HF-1 & FMVSS 302 compliant
These properties make the DK Series well-suited for outdoor enclosures, electrical cabinets, HVAC systems, industrial machinery, and transportation equipment.
Precision Die Cutting & Waterjet Cutting
We convert DK Series materials in-house using steel-rule die cutting, and waterjet cutting, depending on part geometry, tolerance, and volume.
-
Die cutting for high-volume, repeatable gasket production
-
Waterjet cutting for thicker materials, complex profiles, and short-run or prototype parts
-
Tight dimensional control for sealing surfaces and bolt-hole alignment
-
Clean edges with no thermal distortion
Whether you need simple rectangular gaskets or complex multi-hole profiles, we can match the material grade to the compression requirements of your application.
Material Selection Support
Because ASTM D1056 defines physical performance rather than polymer chemistry, selecting the right DK grade is about understanding load, deflection, and sealing pressure, not just hardness on paper.
If you’re replacing an existing sponge rubber, upgrading for UL compliance, or dialing in compression force, we can help identify the most appropriate DK Series grade and convert it to your exact specification.