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PORON vs. Silicone for Sealing, Gasketing, and Cushioning
- October 03, 2025
Engineers often compare PORON® to silicone when choosing materials for sealing, gasketing, or cushioning. In general, PORON is recommended for applications that require indoor dust sealing and soft, durable cushioning, especially when long term compression recovery is essential. Typically, silicone is recommended for outdoor applications, or when high temperature, fluid resistance, and regulatory approvals are necessary.
For an in depth comparison, consider the following factors.
- Material Types – PORON is a microcellular urethane foam with an open cell structure. Silicone is available in solid, sponge and foam materials. Cellular silicones (silicone sponge and silicone foam) can have an open cell or closed cell structure.
- Compression and Cushioning – PORON is exceptionally soft and conformable. With its ultra low compression set, PORON maintains its thickness and can rebound even after many years. Cellular silicones have good rebound but typically have a higher compression set. This makes silicone better for structural seals than for cushioning, one of the main applications for PORON.
- Sealing Capabilities: PORON is ideal for dust and particle sealing, but it’s not as effective against liquids because of its open cell structure. Closed cell silicones seal against dust, water, and air. They can be used in IP rated enclosures.
- Temperature Resistance: Most grades of PORON withstand temperatures from -40°C to 90°C, but some grades can withstand high temperatures up to 120°C. Most silicones withstand temperatures from -60°C to 200°C, and some specialty grades withstand even higher temperatures.
- Environmental Resistance: PORON is best suited for indoor applications and is sensitive to sunlight, ozone, and prolonged exposure to moisture. Silicone can be used in either indoor or outdoor environments. It resists sunlight, ozone, moisture, and some chemicals.
- Durability and Aging: PORON is recommended for long term indoor cushioning, such as with electronics or automotive interiors. However, it can degrade faster outdoors. Silicone offers excellent long term stability both indoors and outdoors.
- Applications: PORON is used in indoor electronics, automotive interiors, and with some medical devices and wearables. Silicone is used in outdoor enclosures and under-the-hood automotive applications. FDA approved silicones are used in food and beverage applications, and USP Class VI silicones are required for some medical applications.
- Cost: Generally, PORON® is a lower cost material. Silicone typically costs more, especially in specialty or medical grades.
The table below summarizes some of differences between PORON and silicone:
| Property | PORON | Silicone |
|---|---|---|
| Material Type | Urethane foam (open cell) | Solid, sponge, or foam |
| Compression Set | Very low (excellent resistance) | Low to moderate |
| Cushioning | Very soft, gap filling | Moderate (sponge is softer) |
| Dust Sealing | Excellent | Very good |
| Liquid Sealing | Poor | Excellent (closed cell sponge) |
| Temperature Range (Typical) | -40°C to 90°C | -60° to 200°C |
| Environmental Resistance | Limited UV/ozone | Excellent UV/ozone/weather |
| Durability | Best indoors | Excellent indoors and outdoors |
Contact Stockwell Elastomerics for more information and help with material selection for custom gaskets and pads.
PORON® is a registered trademark of Rogers Corporation.