Silicone Gaskets

Stockwell Elastomerics manufactures custom silicone gaskets from silicone in its various forms, including solid silicone, expanded silicone sponge and silicone foam. Stockwell Elastomerics also injection molds platinum cured liquid silicone parts and gaskets, and compression molds specialty gaskets from electrically conductive silicone and chemical resistant fluorosilicone.

What is a Silicone Gasket? What is a High Performance Silicone Gasket?

A silicone gasket provides a mechanical seal to fill the space between surfaces in a device. It is the silicone material or part used to close a gap between parts (ingress or egress). Silicone gaskets can be made from a variety of types of silicone, including: solid silicone, silicone foam, silicone sponge, molded silicone, and 3D printed silicone. Silicone gaskets are available in a range of colors, durometers, chemistries, and with various additive packages. They can also be made to be compliant with a variety of industry standards, including: ASTM, AMS, MIL, UL, RoHS, REACH, FDA, and USP Class VI.

Additional properties of high performance silicone gaskets include:

• Range of thermal / electrical conductivity or insulation
• UV and ozone resistant
• Consistent mechanical performance over a wide range of temperatures
• Good compatibility with a wide variety of other materials

Solid Silicone Gaskets

Solid silicone gaskets are manufactured by die cutting or waterjet cutting parts from continuous roll sheet materials or molded sheets. Solid silicone rubber offers a wide hardness range, from 10 – 70 durometer on the Shore A scale. The low durometer silicone gaskets (10A, 20A, 30A) offer excellent environmental sealing with relatively low closure force. Solid gaskets in the mid to higher durometer range require higher closure forces; these are commonly used on metal enclosures or rigid enclosures with a suitable bolt pattern to properly compress a firm gasket. Stockwell Elastomerics injection molds and compression molds solid silicone seals with custom cross-sections for improved sealing integrity for water submersion requirements.

At a Glance: Solid Silicone Gaskets

• Good for heavy water sealing and submersion
• Wide durometer range (10 – 70 Shore A)
• Wide temperature range
• UV and ozone resistance
• Can be die cut or waterjet cut
• Acrylic or silicone adhesives are available
• Gaskets can be molded

Silicone Sponge Gaskets

Silicone sponge gaskets are soft in comparison to solid silicone gaskets, though there is some cross-over at the low durometer solids and the firm grades of silicone sponge. The firmness of silicone sponges is commonly defined by compression force deflection in a psi (pounds per square inch) range compressed 25%. 2 to 5 psi compression force deflection is considered soft, whereas 14 to 20 psi is considered firm. The closed cell structure make silicone sponge an excellent product for environmental seals such as NEMA 4 and IP64 and IP65. Silicone by nature performs well under UV and is mechanically stable over a broad temperature range, often considered for high temperature gaskets and low temperature gaskets.

At a Glance: Sponge Silicone Gaskets

• Good for heavy water spray sealing when properly compressed
• Closed cell, prevents wicking
• Soft gasket allows for sealing with low closure force
• Wide temperature range (-100°F to 500°F)
• UV and ozone resistance
• Can be die cut or waterjet cut
• Acrylic or silicone adhesives are available

Silicone Foam Gaskets

Silicone foam gaskets are closely related to silicone sponge gaskets. However, they typically use platinum cure liquid silicone, and are cast onto a smooth liner giving them a smooth skin. Silicone foam products can range in cell structure from very open cell to mostly closed cell. The open cell silicone products can be used for dust seals or shock/vibration gaskets. The mostly closed celled silicone foam can be used for environmental seals. Gaskets made from silicone foam would be considered to be both high temperature gaskets and low temperature gaskets due to silicone’s mechanical stability in temperature extremes. Silicone is also very stable by nature under UV. BISCO® silicone foams are certified by Underwriter Laboratories (UL) to have a flame rating of UL 94V-0 making them an excellent choice for electrical enclosure gaskets.

At a Glance: Sponge Foam Gaskets

• Good for water spray sealing when properly compressed
• UL 94V-0 flame rated, UL 50 rated
• Soft gasket allows for sealing with low closure force
• Wide temperature range (-67°F to 392°F)
• UV and ozone resistance
• Can be die cut or waterjet cut
• Acrylic or silicone adhesives are available

Injection Molded Silicone Gaskets

Molded silicone seals with round or custom cross-sections are often required for heavy wash down (IP66 or NEMA 4) or water submersion requirements. Liquid silicone rubber (LSR) enables very small cross sections, down to .030″, to be molded in durometers from 10 to 70 Shore A. With injection molded liquid silicone rubber, parting line flash can be reduced to ensure sealing integrity. Request our helpful Liquid Silicone Touch brochureto assist in designing enclosure seals.

At a Glance: Injection Molded Silicone Gaskets

• Good for heavy water spray and submersion
• Wide durometer range (10 – 70 Shore A)
• Molding allows for custom three dimensional parts
• Wide temperature range (-67°F to 392°F)
• UV and ozone resistance