Silicone Products Silicone Sponge Cords

When it comes to sealing and gasketing, sometimes the simplest shape offers the most effective solution. We manufacture high-performance silicone sponge cord designed for reliable, long-lasting performance in a wide range of sealing and cushioning applications. With a round, uniform profile and the resilience of closed cell sponge, these cords offer a flexible and versatile option for industries requiring consistent environmental protection and temperature resistance.

Our extruded sponge cord is available in a variety of diameters, ranging from as small as 0.062” to as large as 2.5”, making it easy to find a size that fits your design requirements. These extruded cords are ideal for filling irregular gaps, creating seals around curved surfaces, or being cut to length for custom gaskets. Their lightweight, compressible structure makes them easy to work with, while their closed-cell construction ensures they resist water absorption and prevent wicking.

Bellofram’s in-house mixing and compounding capabilities allow us to offer materials across all five hardness ranges specified by ASTM D1056. This level of control ensures consistency, repeatability, and tailored performance based on the exact needs of your application. Whether you need a soft, easily compressible cord for delicate components or a firmer option for robust sealing, our manufacturing flexibility delivers.

For industries with strict regulatory and material requirements, our silicone sponge cords meet aerospace-grade standards. We are listed on the qualified products list for Boeing BMS 1-23 and are approved for all three hardnesses of BMS 1-60. This makes our silicone sealing cords well-suited for demanding aerospace, defense, and transportation applications where material traceability and compliance are critical.

These silicone sponge cords also perform well across a wide temperature range, maintaining their properties from -85°F to +400°F. This makes them suitable for both indoor and outdoor use, where exposure to temperature swings, moisture, or environmental contaminants might otherwise compromise performance. Their resistance to UV, ozone, and compression set further enhances long-term durability.

Whether you’re sealing enclosures, insulating components, or absorbing vibration, Bellofram’s extruded silicone cords offer the material integrity and dimensional stability required for complex engineering challenges. Available in standard or custom lengths, these cords provide the reliability needed in high-performance environments, with the flexibility to adapt to a wide range of sealing needs.