Soft Gaskets, Soft Gasket Material

Soft Gaskets

Stockwell Elastomerics manufactures custom soft gaskets from various soft gasket materials to customer specification. “Soft gasket” is a relative term; for heavy industrial applications a 40 durometer rubber may be considered a soft gasket material, but in an electronics application, a 40 durometer rubber would be considered hard.

Typical solid rubber gaskets range from 10 – 70 durometer on the Shore A scale. In order to make even softer materials, common polymers are expanded into open and closed cell rubber materials. Neoprene, silicone, EPDM, fluorosilicone and other rubber compounds can be chemically expanded to introduce air pockets. This is analogous to adding yeast to dough to make it rise. These air pockets make sheet materials even softer.

Expanded rubber materials are available in a variety of densities and firmness. The hardness or firmness is commonly measured by Compression Force Deflection (CFD) as opposed to durometer. CFD is a measurement of pressure at 25% deflection per ASTM D 1056.

Compression Force Deflection

Stockwell Elastomerics has applied the ASTM D1056 CFD test to a range of soft gasket materials to give a relative sense of hardness.

MaterialDescriptionCFD @ 25% (psi)
BF-2000Ultra Soft Open Cell Silicone Foam1.6
BF-1000Extra Soft Open Cell Silicone Foam2.5
PORON, 4790-92Extra Soft Open Cell PORON (urethane)2.6
PORON, 4701-30Very Soft Open Cell PORON (urethane)3.2
R10480SSoft Closed Cell Silicone Sponge6
R10470MMedium Closed Cell Silicone Sponge10
R10490MFluorosilicone Closed Cell Sponge13.3
SE201010 Durometer Liquid Silicone Rubber (LSR)25.2
SE202020 Durometer Liquid Silicone Rubber (LSR)48.2
Vibration Dampening Pads

More detailed information about soft gasket materials, including compression curves, cycle testing and short term stress relaxation, is available upon request for most materials offered by Stockwell Elastomerics.

Contact Stockwell Elastomerics for Soft Gaskets and Soft Gasket Materials

Contact Us for further assistance with custom soft gaskets and soft gasket material.