silicone sponge vs silicone foam

silicone sponge vs silicone foam

We see on prints all the time “R10480S Silicone Foam” or “HT-800 Silicone Sponge”. Its clear what the customer is requiring. However- these requirements are slightly incorrect. It should read “R10480S Silicone Sponge” and “HT-800 Silicone Foam”. WIth that said, when I ask customers about this, a common question that the customer may be thinking- “this guy is a pedantic dude”. Not really- but with that said, I thought I’d write a blog discussing the differences between the two.

Whats the Differences between Silicone Sponge, and Silicone Foam?

How its Made? Silicone Sponge vs Silicone Foam

Silicone Sponge is expanded from a play doh like product that is put into presses, or calendars. It moves from a solid mixture to a silicone “sponge” mixture. The play-doh has some strength before being expanded, and cured. The curing occurs through a bleeder cloth to allow air pockets to escape during the expanding process. 

Silicone Foam is expanded from a low viscosity liquid that is cast onto a liner. Any silicone foam you get in roll form will always be on a liner. This is for two reasons:

  1. Its how its made
  2. Silicone Foam is usually not as strong as its silicone sponge counterpart, so its better to be protected/supported by the liner.


Most of the materials differences originate from the ingredients that are used. For example, FDA requirements that can be met, and flame retardancy are both driven by the ingredients that the materials utilize.

Compression Set

-Compression Set is usually better with silicone foam products.

Flame Retardancy Capability

-Most silicone foam products will meet the UL 94 V0 stringent standard. Silicone foam in general is more flame retardant. 

Over Strength Metrics

-Silicone Sponge has a lot better physicals than its silicone foam counterparts. Silicone Sponge has better 

  1. Elongation
  2. Tensile Strength
  3. Tear Strength

Sealing Abilities

Silicone Sponge in general is a much better pressurized seal than silicone foam. Not to say silicone foam doesn’t have its place in environmental seal gaskets but I do usually recommend silicone sponge over silicone foam in general sealing applications.

Common Silicone Sponge Products

R10480S Silicone Sponge | Saint Gobain Performance Plastics

R10480M Silicone Sponge | Saint Gobain Performance Plastics

BISCO RS-770 Silicone Sponge | Rogers Corporation

BISCO RS-720 Silicone Sponge | Rogers Corporation 

Common Silicone Foam Products

Norseal Silicone Foam F12 | Saint Gobain Performance Plastics

BISCO Silicone Foam HT-870 | Rogers Corporation

BISCO Silicone Foam HT-800 | Rogers Corporation

BISCO Silicone Foam HT-840 | Rogers Corporation

More Information

NEDC die-cuts, and waterjet-cuts silicone foam, and silicone sponge gaskets. For more information on silicone sponge OR silicone foam – or you feel you have an application that could utilize it,  please contact

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