Sponge Silicone

Silicone sponge is a lightweight, closed‑cell elastomer engineered for sealing, cushioning, insulation, and vibration damping in demanding environments. Manufactured as a high-performance cellular material, silicone sponge sheets and rolls provide excellent compression recovery combined with outstanding resistance to temperature extremes, UV, ozone, and environmental exposure.

ElastaPro manufactures medium‑density silicone sponge in continuous rolls up to 1/2” thick and pre-cut sheets up to 2” thick, featuring a fine fabric finish. We can slit our closed-cell silicone sponge to custom widths and apply high-performance pressure-sensitive adhesives (PSA) to accelerate your installation process. Whether your application requires standard commercial stock or strict compliance with aerospace or military specifications, our silicone sponge materials deliver reliable, long-term performance.

Data Sheet

Technical Specifications

Closed Cell Silicone Sponge Data Sheet (ESS11M)

Our medium-density closed-cell silicone sponge is designed to meet strict industrial, automotive, and defense standards. This table compares typical ESS11M physical values to AMS-3195 requirements:

Property	AMS-3195 Requirement	Typical ESS11M Value	Test Method
Density (lbs/cu.in.) – Under 1/4” thick	.025 MAX	.020	ASTM D1056
Density (lbs/cu.in.) – Over 1/4” thick	.020 MAX	.018	ASTM D1056
Compression Deflection (psi)	6–14	11	ASTM D575
Compression Set (22 hrs. @ 212°F)	60% MAX	29%	ASTM D395
Brittle Point (°F)	-67	-103	ASTM D746
Temperature Range (°F)	N/A	-103 to +450	ASTM D573
Water Absorption	5% MAX	PASS	ASTM D471
Tensile Strength (psi)	N/A	100	ASTM D412
Elongation (%)	N/A	200	ASTM D412
Thermal Conductivity (BTU in./hr ft² °F)	N/A	0.6	ASTM F433
Volume Resistivity (OHM-CM)	N/A	10^15	ASTM D257

Material Certifications & Compliance

ElastaPro’s medium-density closed-cell silicone sponge materials meet or exceed the following specifications:

• AMS 3195: Standard specification for aerospace sealing and gasketing applications.

• MIL-R-46089: Military specification for gaskets used in aerodynamic and rain seals on aircraft and missiles.

• ASTM D1056: Standard classification for flexible cellular materials (automotive and general industrial).

• MIL-R-6130: Military specification for environmental seals, gaskets, and blast insulation.

Understanding Silicone Sponge Structures

What is a Closed-Cell Silicone Sponge?

Silicone sponge is produced using a specialized blowing agent during the curing process, creating a uniform, closed-cell structure that traps independent air pockets throughout the elastomer. This architecture yields a highly compressible, lightweight material with minimal water absorption.

Unlike solid silicone sheeting, a silicone sponge compresses easily under low closure forces. This makes it highly effective for sealing lightweight enclosures, plastic housings, and thin-gauge sheet metal doors that could deform under excessive gasket pressure.

Closed-Cell vs. Open-Cell Silicone Sponge

When choosing a cellular material for industrial gaskets, cell structure is critical:

• Closed-Cell Silicone Sponge: The internal cells are completely sealed and isolated from one another. This provides an absolute barrier against moisture, dust, air, and environmental ingress, along with superior compression set resistance.

• Open-Cell Silicone Sponge: The internal cells are interconnected like a cleaning sponge. While highly breathable and excellent for acoustic dampening or open-air cushioning, open-cell configurations are not recommended for weatherproofing or fluid sealing.

Industrial Applications and Benefits

Primary Benefits of Silicone Sponge Sheets

• Low Closure Force Sealing: Soft, conformable structure compensates for uneven mating surfaces and tolerance stack-ups.

• Extreme Temperature Stability: Operates continuously from –60°C to +230°C (–103°F to +450°F).

• Long-Term Resilience: Low compression set ensures gaskets bounce back and maintain sealing integrity after repeated compression cycles.

• Environmental Resistance: Naturally immune to degradation from UV radiation, ozone, extreme weather, and moisture.

Common Engineering Applications

Thanks to its balance of flexibility and rugged durability, silicone sponge sheet stock is cut, slit, or waterjet-fabricated into vital components across multiple industries:

• Enclosure and Cabinet Gaskets: Protecting outdoor electrical enclosures, NEMA boxes, and LED lighting systems from water and dust ingress.

• HVAC Systems: High-temperature door seals and access panel insulation barriers that resist thermal cycling.

• Aerospace & Defense: Aerodynamic skin seals, cabin insulation, and vibration isolation pads compliant with military specifications.

• Electronics & EV Batteries: Soft cushioning pads and micro-vibration dampening layers that protect delicate circuit boards and battery cells.

• Medical & Food Processing: Formulated to meet strict regulatory standards (such as FDA or compliance with cleaning protocols) for sterilization gaskets and hygienic equipment cushions.

Frequently Asked Questions

When should I use a silicone sponge sheet instead of a solid silicone sheet?

Use a silicone sponge sheet when you need an environmental seal but have limited closure force available, or when you are dealing with lightweight, easily warped enclosure materials. Solid silicone sheet is much firmer, heavier, and better suited for high-pressure fluid seals or heavy mechanical wear environments.

Is silicone sponge material inherently waterproof?

Yes, provided it features a closed-cell structure. Because the internal cell walls are unbroken, water cannot penetrate or wick through the material, ensuring a watertight barrier even under low compression forces.

In what formats can I purchase silicone sponge from ElastaPro?

We supply material to distributors, fabricators, and OEMs in multiple commercial formats, including continuous silicone sponge rolls (ideal for high-volume die-cutting or slitting into strips) and thick silicone sponge sheets for deep-cavity gaskets and heavy cushioning applications.