The Physical Properties of Silicone O Rings

O rings are used in thousands of applications and must endure a range of conditions. These include high or low temperatures, chemicals, abrasion and movement.

Silicone o rings have excellent flex and fatigue life, ozone and UV radiation resistance, are physiologically neutral and have insulating properties. These compounds are typically reddish orange in color.

High Temperature Resistance

The physical properties of silicone o rings remain stable at high temperatures, making them ideal for use in applications with extreme temperature fluctuations. The material also resists UV damage and corrosion as well as oil, chemicals, solvents, and ozone. The only drawbacks to using these seals are low tensile strength and poor tear and wear resistance.

Silicone o rings are typically red or orange in color. They offer a wide operating temperature range between -100°C and 400°C. They can handle static or dynamic applications and are very versatile, able to hold sealing pressure in a variety of environments. They are also resistant to water and steam, ozone, air, engine and transmission oils (VMQ), animal and vegetable greases, and brake fluid.

Depending on the application, selecting the right o ring can be difficult. When choosing an o-ring, you must consider the operating conditions, chemical compatibility, temperature, durometer, and size. In addition, you need to ensure that the o ring will be able to resist abrasion, compression set, and environmental factors.

ESP has extensive experience in working with o-rings and can assist you with choosing the best material for your application. Contact us today to get started.

Chemical Resistance

Chemical resistance is the ability of a material to withstand exposure to chemical substances over an extended period of time without degradation and without the chemical substance permeating the surface. This characteristic is often determined by the temperature of the chemicals and the concentration. Chemicals Silicone o rings with lower temperature and concentration will degrade faster than those with higher temperatures and concentrations.

Silicone is a naturally inert material that does not react with many chemical substances. This makes it an excellent choice for sealing applications that involve the interaction of chemicals. Silicone is also very versatile and can be used in a variety of industries. It has been found to be very effective in the food, pharmaceutical, jewelry and automotive industry.

The main ingredients in silicone are silicon atoms and oxygen atoms. This gives it a unique structure that makes it more resistant to high temperatures than other elastomers. It is also highly resistant to ozone and UV radiation. Silicone is also known for its excellent flex and fatigue life, insulating properties and physiological neutrality. It can be compounded to meet a variety of standards and specifications including FDA, USP Class VI, USDA, 3-A and Canada AG.

Choosing the right o ring for your application requires consideration of all its characteristics. The type of seal your equipment needs will determine the best material. Marco offers a wide range of standard and custom o rings in various materials to suit any need. Contact a sales consultant or engineer to discuss your specific needs.

Flow Properties

The elasticity of silicone o rings enables them to conform and fill gaps in sealing surfaces. This quality also makes them ideal for use in compression force applications. It is also a highly durable material that can resist acids, alkali, ozone, and UV light. It is easy to handle and can be molded into custom shapes for a precise fit. Additionally, it can be color matched to any RAL or Pantone number for an attractive aesthetic.

Silicones are a group of polymers that contain oxygen, hydrogen, Silicone O Rings – Supplier and carbon in combination with other elements to produce specialized compounds. They are FDA-approved and medical compliant, making them a popular choice for pharmaceutical and food industry seals. They are also inert and do not leach into flavors or cause cytotoxic reactions. Silicones are also resistant to less-penetrating radiation such as ultraviolet and soft X-rays.

There are a variety of elastomers that can be used to manufacture O-rings. Nitrile (NBR) o rings are popular because they provide excellent chemical resistance, good flexibility, and low compression set. NBR is not recommended for use with concentrated detergents or chemicals, petroleum based oils, brake fluid, diluted salt solutions, and high molecular weight chlorinated aromatic hydrocarbons.

EPDM o rings are another widely used material due to their excellent thermal stability and chemical resistance capabilities. Like nitrile, EPDM is not recommended for use in acid-based or petroleum based fluids or with saturated steam. Viton o rings, also known as fluorocarbon rubber, are another common option for high-performance O-rings. Viton can be produced with different monomer compositions and levels of fluorine, which results in improved low-temperature, high-pressure, and chemical resistance properties.

Flexibility

Silicone o rings are flexible and retain their flexibility in one of the widest temperature ranges of all elastomers. They are also soft and durable. They can resist many fluids, such as gasoline, ketones and water. They can withstand temperatures up to 220degC (480degF) and down to -73degC (-100degF).

The flexibility of silicone is a result of its chemistry. Inside the o ring are small molecules called monomers, that form into long chains of polymers. These polymers are coiled up randomly, when the material is stretched they elongate without breaking and when the o ring is no longer being pulled or stretched the chains return to their coiled-up state.

This gives the o ring its stretchiness and ability to rebound from compression. This is important for a good seal and can reduce wear, friction and energy loss. It is a great choice for high-pressure applications where the seal needs to be soft, pliable and resilient.

Although silicone o rings are very soft they are very durable and have some of the best resiliency of all o-ring materials. They are resistant to heat, ozone and corona as well as oils, chemicals and solvents. They are FDA compliant and have very low levels of leachables and extractables, making them suitable for use in food and beverage processing. They are less prone to installation damage and can be protected with a Teflon sleeve.