Silicone Orings

Silicone orings are the best choice for static applications requiring resistance to extreme temperatures. They also feature excellent ozone and UV radiation resistance, as well as physiologically neutral and insulating properties.

These molded products wedge between two mechanical parts to create a seal for preventing fluid or gas leakage and keeping out contaminants. Choose from a variety of standard and custom o-ring compounds with various properties and compositions.

Temperature Resistance

Silicone o-rings are excellent at handling extreme temperatures, including very high and low ones. They also withstand exposure to UV light, ozone and weathering conditions well.

The silicone polymer (vinyl-methyl-silicone or VMQ) is used for numerous applications, from medical equipment to jewelry to automotive to aerospace. It’s very good in dry heat, resists ozone and UV radiation well and performs in most chemical environments (though it is limited by its resistance to animal and vegetable oils, alkalis, brake fluids, petroleum-based fuels and hydrocarbon lubricants).

However, silicone has low tensile strength and poor abrasion and tear resistance. It’s also more permeable to gases and steam than other materials, so it shouldn’t be used for dynamic applications that expose o-rings to frequent changes in temperature or pressure. It’s often combined with a lubricant for those purposes. The fluorinated version of silicone, fluorosilicone rubber (FVMQ), demonstrates similar characteristics but offers even better performance in these situations.

Chemical Resistance

Silicone o-rings are very resistant to many chemicals, including most hydrofluoric acid and chlorine. In addition, they are very stable at high temperatures and able to retain their properties under severe environmental Silicone Parts Manufacturer conditions. They also have excellent ozone, UV radiation and atmospheric aging resistance. These characteristics make silicone an ideal material for static, low-pressure applications.

A silicone o-ring is easy to clean and sterilize, which helps reduce the risk of bacteria growth and cross-contamination. These qualities make silicone O-rings especially suitable for food processing equipment. They can even be manufactured in a metal detectable version that is FDA-compliant for use in food production lines.

FVMQ (fluorinated silicone rubber) is a special variation of silicone that adds additional beneficial properties. These include higher maximum service temperature hot air, superior ozone and UV radiation resistance, fuel oil resistance, and improved chemical resistance to mineral acids and fatty oils. It can also be compounded to be electrically resistant and conductive. These features can improve the performance of an o-ring in a number of different environments. However, it is not recommended for dynamic applications, as it has limited abrasion and tear resistance.

Flexibility

Silicone orings are flexible at low temperatures and have excellent heat, ozone, corona resistance, dielectric stability, and resistance to oils, chemicals and solvents. They are also odorless, non-toxic and do not grow mold. They are easy to work with and can be molded easily. They can be compounded to be electrically resistant, conductive or flame retardant.

While silicone can provide a wide variety of properties and functions, some compounds may not be suitable for dynamic applications due Silicone Parts Manufacturer to their low shear and tensile strength. However, the shear and tensile strength of the compound is dependent on the application.

Most silicone O-rings are made from VMQ mixtures and offer good resistance to hot and cold air, water steam, ozone, oxidative environments, animal and vegetable oils and greases, kerosene, engine and transmission oil, brake fluid, diluted sulfuric acid and alkalis. They have excellent ozone, UV radiation and set resistance but do not hold up well to abrasion or shear. Silicone o-rings are the best choice for static applications that require high resistance to extreme temperature ranges and harsh environmental conditions.

Flexural Strength

Silicone is a very soft and pliable rubber that resists high temperatures. This makes it a great choice for sealing in a wide variety of environments, including extreme cold and hot. However, it does not hold up well in dynamic applications due to its low tensile and tear resistance.

The flexural strength of silicone is largely determined by the compound’s structure and manufacturing methods. VMQ silicones are comprised of a central strip, or backbone, of alternating silicon and oxygen atoms. The chemical structure allows for varying organic methyl groups along the backbone to create different compounds with unique properties and applications.

VMQ silicones have one of the widest working temperature ranges of any elastomer, while maintaining their flexibility and low compression set characteristics. They are resistant to oxygen, ozone and UV radiation and are odorless, tasteless and nontoxic. They also offer good chemical resistance to mineral and vegetable oils, brake fluid (non petroleum base), fire resistant hydraulic fluid and high molecular weight chlorinated aromatic hydrocarbons.

Silicone is commonly found in medical, automotive and aerospace manufacturing, but it can be used in a variety of other industries as well. It is particularly useful for applications requiring an inert material that does not react with chemicals or corrode. It is available in a number of FDA-compliant formulations, as well as a metal detectable version that is ideal for food and beverage production lines.

Temperature Tolerance

While most o-rings can withstand a range of temperatures, some materials offer better tolerance than others. To help determine an o-ring’s temperature tolerance, you should know its maximum and minimum working temperatures.

Silicone (VMQ) demonstrates impressive performance at high and low temperatures. It can work at temperatures up to 250degC and some special varieties can handle -100degC. It also resists a wide variety of chemicals, including animal and vegetable oils and water.

This o-ring material also shows great resistance to ozone, sunlight and weathering. This makes it an excellent choice for outdoor equipment and systems.

Silicone o-rings are typically odorless, tasteless and nontoxic. Because of this, they’re ideal for food processing applications. However, you should choose the correct o-ring size for your application to ensure a proper seal. This will prevent fluid and gas loss. Marco offers several different o-ring sizes, shapes and durometers to suit various applications. To find the perfect o-ring, speak with a Marco engineer. Our popular o-ring material family comparison chart is also available to assist in your selection process.