Sponge silicone sheet is a lightweight, compressible, and resilient elastomeric material used in a wide range of engineering applications that require sealing, cushioning, insulation, or vibration control. Unlike solid silicone rubber, which has a dense structure, sponge silicone is characterized by a cellular matrix with either open or closed cells. This structure gives it a soft, compressible feel and allows it to conform easily to irregular surfaces while maintaining excellent sealing performance.
This article from ElastaPro answers frequently answered questions (FAQs) about this material
What are the Properties of Sponge Silicone Sheet?
Sponge silicone sheet is typically made from silicone rubber compounded with a blowing agent that creates a uniform cell structure during the curing process. Closed-cell sponge silicone has cells that are not interconnected, allowing it to resist water and fluid absorption. Open-cell sponge silicone, on the other hand, has interconnected pores, making it more breathable but less water resistant. Engineers choose between these types based on whether fluid sealing or air permeability is required.
One of the primary advantages of sponge silicone is its wide operating temperature range. Like other silicone elastomers, it typically performs well from –60 °C to 200 °C, depending on formulation. It remains flexible in cold environments and stable at elevated temperatures, making it suitable for harsh or fluctuating thermal conditions. Additionally, sponge silicone offers excellent resistance to ozone, UV exposure, weathering, and many chemicals.
What are its Advantages?
The compressibility of sponge silicone sheet allows it to form reliable seals with relatively low closure forces. This is particularly important in applications involving lightweight plastic or aluminum enclosures that could deform under excessive gasket pressure. The soft structure can compensate for uneven surfaces, tolerance stack-ups, or warped panels without sacrificing sealing integrity.
Sponge silicone also exhibits excellent recovery after compression, maintaining performance over many cycles. This resilience makes it a preferred choice for gasketing in environments where assemblies may be opened and closed repeatedly. Its low density also reduces weight compared to solid silicone, which can be a valuable advantage in aerospace, automotive, and portable electronic designs.
In addition to sealing, sponge silicone provides effective thermal insulation, vibration damping, and acoustic absorption. These properties make it useful in protecting sensitive components from shock, reducing noise transmission, and improving system reliability.
What are Some Common Applications?
Engineers specify sponge silicone sheet for a variety of applications across industries. It is commonly die-cut or waterjet-cut into gaskets and seals for electrical enclosures, HVAC systems, and outdoor lighting. In transportation and aerospace, it is used to seal access panels, doors, and hatches where flexibility and environmental resistance are critical.
Sponge silicone is also employed in thermal and acoustic management systems, acting as a buffer between vibrating or moving parts. In medical devices, its inertness and softness make it suitable for cushioning and sealing components.
When Do You Use Sponge Silicone Sheet?
Sponge silicone sheet is best used when a soft, conformable, and environmentally resistant material is needed to create a reliable seal under low compression forces. It’s ideal for enclosures exposed to temperature extremes, UV, or moisture. However, it is less abrasion-resistant and not suited for high mechanical wear situations.
In short, sponge silicone sheet combines the unique properties of silicone elastomers with the versatility of a compressible cellular structure. For engineers, it offers an effective solution for sealing, cushioning, and insulating applications where performance and durability must be balanced with softness and flexibility.
Contact ElastaPro for sponge silicone sheet.
