Is Silicone Sponge the Right Material for Your Application?

As gasketing and sealing demands grow more complex, especially in industries like aerospace, medical, electronics, and automotive, engineers need materials that can withstand environmental extremes, compress without degrading, and meet strict regulatory standards. These are all things that silicone sponge excels at. 

Silicone sponge is a versatile, high-performance material that is often the best choice when a seal needs to perform in a wide range of temperatures, resist long-term compression, or remain chemically stable in challenging environments. Combined with a pressure-sensitive adhesive (PSA) and precision-converted into custom parts, silicone sponge becomes an ideal solution for demanding gasketing and sealing applications. 

What is silicone sponge, and when it makes sense to choose it for your gasketing application? 

What Is Silicone Sponge?

Silicone sponge is a closed-cell elastomeric material made from silicone rubber, but it differs significantly from solid silicone rubber or traditional silicone foam. Unlike the foam materials, which are typically open-cell and allow air and moisture to pass through, silicone sponge has a closed-cell structure. This means each cell is encapsulated, making the material inherently more resistant to fluid and gas penetration. 

Compared to solid silicone, silicone sponge is lighter, more compressible, and better suited to cushioning and vibration isolation. Where solid silicone offers excellent strength and tear resistance, silicone sponge offers superior flexibility, energy absorption, and compressibility, making it the better option in many gasketing scenarios. 

The result is a material that combines the high-performance characteristics of silicone rubber with the conformability and resilience of a sponge, making it ideal for sealing, cushioning, and insulating applications across multiple industries. 

What Make Silicone Sponge Ideal for Gaskets?

Silicone sponge is valued not only for its compressibility but also for its exceptional physical and chemical stability. These properties make it uniquely suited for gaskets in demanding environments: 

Temperature Resistance

Silicone sponge performs reliably in both low and high temperatures, typically ranging from -100°F to 450°F. It’s a natural fit for applications that experience temperature cycling, thermal shock, or extreme heat, all of which are common in aerospace, automotive, and industrial equipment. 

Compression Set Resistance

One of the most critical properties for gasket performance is how well a material resists compression set, which is the permanent deformation that occurs after a gasket has been compressed for a long period.  Most closed cell foams suffer significant deformation after being compressed over time.  Silicone sponge offers excellent resistance to compression set, which allows it to maintain its sealing force overtime and helps prevent leaks or mechanical failure. 

UV, Ozone, and Weather Resistance

Because of its molecular structure, silicone sponge is highly resistant to degradation from ultraviolet light, ozone exposure, and oxidation. This makes it suitable for outdoor environments or equipment exposed to direct sunlight or fluctuating weather conditions. 

Moisture Sealing

Thanks to its closed-cell structure, silicone sponge acts as an effective barrier against water, vapor, and other contaminants. It’s widely used in IP-rated enclosures and weatherproof seals, particularly in electronics and telecommunications. 

Low Toxicity and Regulatory Compliance

Silicone sponge is inert, odorless, and non-toxic. It is available in grades that meet FDA, UL 94, and RoHS standards, making it suitable for use in medical devices, food processing equipment, and other regulated environments. 

Vibration Dampening and Shock Absorption

The sponge-like structure of the material helps to cushion delicate components and absorb vibrations. This protects sensitive equipment from impact or mechanical stress, especially in mobile or high-vibration applications. 

Where are Silicone Sponge Gaskets Used?

Silicone sponge is used across industries where performance and durability are paramount. Typical applications include: 

  • Electrical enclosures and junction boxes: for weather-resistant seals and insulation 

  • Residential and commercial oven sealing and thermal management 

  • Aerospace and defense: for high-performance seals in extreme operating environments 

  • Medical devices: for clean, non-reactive gasket materials that meet regulatory standards 

  • Outdoor lighting and signage: for long-lasting weatherproof gaskets 

  • Automotive lighting and trim: for dust, moisture, and vibration control 

  • EV Battery construction for sealing, thermal management, and shock absorption 

  • Cleanrooms and lab equipment: for chemically inert, contamination-free sealing 

When to Choose Silicone Sponge Over Other Gasketing Materials

Silicone sponge is not always the most economical material, but in certain applications, it’s the best option. Consider using silicone sponge when: 

  • High temperature performance is a requirement 

  • Sealing against water, dust, and outdoor conditions is needed 

  • Weight reduction is important (silicone sponge is lighter than solid silicone) 

  • The gasket will be compressed and released repeatedly over its service life 

  • The application must meet strict regulatory or compliance standards (UL 94 V-0, FDA, etc.) 

  • Inert material required for in food, medical, or skin exposure. 

  • Resistance to UV, ozone, and other harsh chemicals and solvents. 

  • Long-term sealing reliability is critical to performance or safety 

PSA Backing Change the applications of Silicone Sponge Gaskets

Applying a pressure-sensitive adhesive to one side of the silicone sponge significantly improves how it performs during assembly and installation. PSA-backed silicone sponge: 

  • Enables peel-and-stick application, eliminating the need for mechanical fasteners or liquid adhesives 

  • Speeds up assembly by allowing operators to quickly align and secure parts 

  • Improves placement precision, especially for small or complex gasket geometries 

  • Helps hold the gasket in place during multi-part assembly processes 

  • Is available with permanent, repositionable or temporary adhesives, depending on application needs 

  • Can be matched with a wide range of liner options to suit manual or automated application 

Custom Converting Capabilities for Silicone Sponge

At Engineered Materials Inc., we offer a full suite of converting services to turn raw silicone sponge into high-performance, production-ready gasket parts. Our capabilities include: 

  • Die Cutting: we can produce precision-shaped gaskets in high volumes with tight tolerances. Die cutting is ideal for repeatable designs in automotive, medical, and industrial applications. 

  • Slitting: we offer custom-width rolls or continuous strips of PSA-backed silicone sponge, ideal for sealing extrusions or automated installations. 

  • Laminating: our laminating capabilities allow us to apply PSA to silicone sponge and combine it with liners, films, or foils to create custom multi-layer materials tailored to specific needs. 

  • Waterjet Cutting: this method is especially effective for thick or dense silicone sponge materials, allowing clean, burr-free edges and complex part geometries without heat distortion. 

  • Laser Cutting: laser cutting provides ultra-precise part outlines and is ideal for prototyping or low volume runs where design flexibility is essential. 

  • Knife Cutting: also known as flash cutting, this technique g works extremely well for large format part shapes, lower volume runs, or where optimizing material cost is important. 

  • Kiss-Cut Parts on Rolls: for high-speed assembly lines, we offer kiss-cut gasket parts on rolls with easy liner removal. This format is ideal for automated or pick-and-place systems. 

  • Material Sourcing and Consultation: we assist in sourcing high-performance grades of silicone rubber, sponge, and foam including UL-rated, FDA-compliant, or specialty formulations for unique applications. 

How to Design PSA-Backed Silicone Sponge Gaskets

Getting the most from your silicone sponge gasket starts in the design phase. Remember that it’s important to: 

  • Match material thickness to your compression gap: over-compression or under-compression can compromise seal integrity. 

  • Choose an adhesive based on surface energy: not all adhesives perform well on low-energy plastics or metals. Select the right formulation for your surface. 

  • Account for environmental factors: consider exposure to heat, UV, chemicals, and humidity. 

  • Involve your converter early: sharing CAD files, prototypes, or application requirements helps identify the best converting method and material configuration. 

  • Test performance in the field: always validate your gasket in its intended operating environment before full-scale production. 

Find Silicone Sponge Parts for Your Application Today

At Engineered Materials Inc., we help engineers and manufacturers turn silicone sponge into production-ready gasket solutions that meet exacting standards. Whether you’re in the prototyping phase or scaling for full production, our team is ready to support your next project. Contact us today to learn more about our material sourcing, converting capabilities, and how we can help optimize your gasket design. 

Matt Tempelis