Foam Silicone Sheet: Closed Cell, Medium Density
ElastaPro makes foam silicone sheet with closed cells in medium density. This material is gray in color and has a smooth finish on both sides. The standard width is 19”, and the maximum roll length is 33”. ElastaPro can slit foam silicone sheet at various widths, and we can apply a pressure sensitive adhesive (PSA) to help you speed installation.
Data Sheet: Medium Density Silicone Foam
What is Foam Silicone Sheet?
A foam silicone sheet is a lightweight, compressible material made from silicone elastomer that’s expanded into a cellular structure. During manufacturing, gas or a blowing agent forms uniform cells within the silicone, creating a resilient foam with the temperature stability and durability of solid silicone rubber.
Foam silicone sheets provide engineers with a versatile sealing and cushioning material that performs reliably under compression, thermal cycling, and environmental exposure. They are available in open-cell and closed-cell formats, allowing for design flexibility based on sealing and permeability requirements. ElastaPro offers closed cell materials.
Properties of Foam Silicone Sheet
Foam silicone combines the desirable features of silicone rubber—thermal resistance, flexibility, and chemical stability—with the cushioning of a foam. Key engineering properties include:
- Wide temperature range: -55°C to +200°C continuous, short-term up to +230°C.
- Low compression set: Excellent recovery, even after long-term compression.
- Lightweight construction: Reduces component weight while maintaining structural integrity.
- Environmental durability: Resistant to UV, ozone, and weathering.
- Chemical compatibility: Performs well in contact with oils, coolants, and process chemicals.
- Dielectric insulation: Maintains electrical isolation in sensitive assemblies.
- Dimensional stability: Retains shape and thickness over long-term service.
These features make foam silicone sheet materials an essential component for high-performance gaskets and thermal insulation systems in demanding industries.
What is Medium-Density Closed-Cell Silicone Foam Sheet?
A medium density closed cell silicone foam sheet is a type of silicone foam engineered to balance compressibility and mechanical strength. “Medium density” typically refers to foam materials in the range of 15–25 lb/ft³ (240–400 kg/m³).
The closed-cell structure means that each cell is sealed off from its neighbors, preventing the passage of air, water, or other fluids. This structure provides watertight sealing with minimal compression, making it ideal for outdoor and environmental sealing applications.
Medium-density closed-cell silicone foam is used when engineers require a reliable, durable seal that resists environmental ingress, vibration, and thermal extremes—especially in enclosures, lighting systems, and vehicle assemblies.
Key Benefits of Closed Cell Silicone Foam Sheet in Medium Density
Choosing a medium density closed cell silicone foam sheet provides several performance advantages:
- Superior sealing: Prevents moisture, air, and dust intrusion in enclosures and housings.
- Excellent compression and recovery: Maintains sealing force and shape across multiple cycles.
- Thermal stability: Reliable performance from -55°C to +200°C.
- UV and ozone resistance: Long service life in outdoor or exposed environments.
- Low outgassing: Suitable for electronics, optics, and aerospace.
- Chemical resistance: Tolerates automotive fluids, lubricants, and cleaning agents.
- Durability: Maintains mechanical and sealing properties after long-term stress and vibration.
For engineers designing IP-rated or weatherproof assemblies, medium density closed-cell silicone foam sheets provide consistent sealing performance under dynamic conditions.
Specifications for Medium-Density Closed Cell Silicone Foam Sheet
While properties can vary by manufacturer, medium-density closed-cell silicone foam sheets typically meet or align with the following specifications. For more information about ElastaPro products, see Data Sheet: Medium Density Silicone Foam.
| Property | Typical Value/Range |
| Density | 15–25 lb/ft³ (240–400 kg/m³) |
| Compression Deflection @ 25% | 5–14 psi (35–97 kPa) |
| Compression Set (22 hr @ 100°C) | <10% |
| Tensile Strength | 90–150 psi (620–1030 kPa) |
| Elongation at Break | 80–150% |
| Water Absorption | <1% by weight |
| Operating Temperature | -55°C to +200°C (short-term to +230°C) |
| Flame Resistance | UL 94 V-0 or equivalent (depending on grade) |
| Color | Gray, black, red, or custom |
Important: Engineers should always consult technical data sheets to confirm that a given material grade aligns with application-specific environmental and regulatory requirements.
Properties for Closed Cell Medium-Density Silicone Foam Sheet
Several material properties make closed cell medium-density silicone foam sheets uniquely suitable for industrial and aerospace sealing:
- Compression Deflection: Indicates how easily the foam compresses—important for sealing under low clamping force.
- Compression Set Resistance: Measures the foam’s ability to recover after compression cycles.
- Thermal Conductivity: Provides thermal insulation for temperature-sensitive assemblies.
- Flame Resistance: Many grades meet UL 94 V-0 or equivalent aerospace standards.
- Electrical Insulation: Excellent dielectric strength for electronic enclosures.
- Dimensional Stability: Withstands expansion or contraction across temperature swings.
These properties ensure consistent performance, long seal life, and reduced maintenance for systems that experience vibration, temperature variation, and environmental stress.
Applications for Foam Silicone Sheet
Foam silicone sheets, especially in medium-density closed-cell grades, are used in a wide range of engineering applications:
- Electronics and Enclosures: Weatherproof gaskets for EMI/RFI shielding and IP-rated sealing.
- Automotive and Transportation: Lighting gaskets, door seals, and vibration isolators exposed to heat and UV.
- Aerospace and Defense: Lightweight, flame-resistant seals compliant with FAR 25.853 and MIL-DTL specifications.
- Industrial Equipment: Environmental seals and vibration pads for pumps, compressors, and control panels.
- Energy and Power Systems: Battery insulation, inverter seals, and shock absorption.
- Medical and Life Sciences: Biocompatible cushioning and seals for reusable equipment.
In all these applications, medium density closed cell silicone foam sheet provides a durable, flexible, and long-lasting sealing solution that withstands mechanical and environmental challenges.
Ask ElastaPro for Medium Density Closed Cell Silicone Foam Sheet
A medium density closed cell silicone foam sheet offers engineers a high-performance balance of strength, compressibility, and environmental resistance. With its superior sealing ability, thermal stability, and chemical durability, it is an ideal choice for enclosures, transportation systems, aerospace equipment, and other critical applications where reliability and longevity matter.
Whether you’re designing an electronic enclosure that needs to pass IP67 testing or a gasket that must survive years of outdoor exposure, closed cell medium density silicone foam provides dependable performance across extreme environments.
Contact us to request a quote or for more information.
