25 Nov Why Whipps, Inc. Utilizes Silicone Over Nitrile

Silicone VS Nitrile

What are they?

Acrylonitrile-butadiene (NBR or nitrile) and silicone both have excellent chemical resistance, but differ in key properties. Nitrile remains flexible down to -50°C (-57°C with special formulations) and can operate up to 100°C (121°C with reduced longevity). Silicone, however, withstands higher temperatures up to 230°C, making it ideal for high-temperature applications. Nitrile excels in hydrocarbon fuel and oil resistance, suitable for automotive uses, but contains phthalate plasticizers unsuitable for food contact. Silicone is food grade, often used in food and water processing equipment. Nitrile has high tensile strength and excellent wear resistance, whereas silicone is poor in abrasion resistance but excels in weathering, UV, and ozone resistance, making it better for outdoor applications. Silicone also undergoes less compression set, making it preferable for long-lasting, reusable seals.

Both silicone and nitrile exhibit excellent resistance to cold temperatures, remaining flexible down to -50 °C, with special formulations of nitrile remaining flexible to -57 °C (at the expense of other physical properties such as wear resistance). Nitrile can operate to 100 °C, or 121 °C with reduced longevity.  Silicone can operate at much higher temperatures, up to 230 °C.  This makes silicone the best choice for high temperature applications.

Both materials are resistant to a range of chemicals.  Nitrile has excellent resistance to hydrocarbon fuels and oils, making it ideal for automotive fuel applications.  Formulations of nitrile containing phthalate plasticizers cannot be used with food or children’s toys.  Silicone, on the other hand, is food grade and is often used in food and water processing equipment.  For any application, it is important to check that the elastomer is resistant to the chemicals it will come into contact with.

Nitrile has high tensile strength and excellent wear and abrasion resistance.  By contrast, silicone has poor abrasion resistance, and for dynamic applications where elastomers must have good wear characteristics, nitrile is a better choice.

Nitrile exhibits poor resistance to weathering, UV and ozone, making it unsuitable for outdoor applications.  Silicone has excellent weathering characteristics and is highly resistant to both ozone and UV.  For outdoor applications, silicone is a clear winner.

While both materials exhibit good compression set, silicone generally undergoes less compression set than nitrile. This makes silicone a better choice in sealing applications where a long-lasting, reusable seal is required.