Silicone O Rings Are FDA Approved and Used in Food Processing Equipment
Silicone o rings are FDA approved and are used in food processing equipment. They work well in high and low temperatures and have resistance to chemicals, alcohol, water, and oils.
This class of synthetic elastomer is made by adding pendant organic groups such as methyl, phenyl, and vinyl to silicon atoms. This allows for a variety of properties and compositions to be achieved.
Durability
Whether it’s in medical, pharmaceutical, automotive, semiconductor or electronics applications, the right O-ring material can ensure functionality and prevent equipment failure. Wyatt Seal works closely with engineers to identify the best O-ring sizes, colors and shapes to match their application’s unique specifications.
Silicone can withstand extreme temperatures without damage, even in dynamic applications. It also resists ozone, UV exposure and weathering. It holds up to petroleum fluids, vegetable oils, steam and alcohol, while remaining odorless and non-toxic.
Other durable O-ring materials include Buna (Nitrile), FKM or Viton (Vinyl-Methyl Methacrylate) and EPDM (Ethylene Propylene Diene Monomer). Silicone o rings Viton is a saturated rubber with good extreme temperature properties, while offering chemical resistance as well. It performs well in oil and ozone applications, is more resistant to degradation due to weathering and ozone, and can be sterilized using ETO (ethylene oxide). However, it does not have good tear and abrasion resistance and low tensile strength, so it is better suited for static rather than dynamic applications. For these reasons, it is often used in conjunction with nitrile O-rings.
Temperature Resistance
Silicone operates well within a wide temperature range, from minus 75-degrees to 400-degrees. It has good resistance to ozone, UV radiation and physiologically neutral and is a great choice for seals that must operate in harsh environments. It also has a high flex life and is easy to install. It is not recommended for dynamic applications because of its low tensile strength and abrasion resistance. It does not do well with brake fluid, oily metals, mineral or vegetable oils, high molecular weight chlorinated aromatic hydrocarbons, ammonia solvents or superheated steam.
Nitrile o rings have good chemical and thermal stability, but they are not compatible with certain types of automotive fuels. It is also not recommended for use in contact with strong acids or oxidizers.
VMQ o rings are made of an elastomer that is composed of silicon, oxygen and hydrogen with additional additives for specific properties such as low toxicity or high temperature resistance. VMQ can be formulated to meet the needs of different industries such as food and medical, where the material is FDA approved and does not produce an odor or taste.
Chemical Resistance
A seal, whether it’s an o-ring or any other type of gasket, must be able to resist a wide range of chemicals and environmental conditions. Engineered Seal Products stocks a wide variety of silicone (VMQ) O-rings that have the chemical resistance needed to do the job.
Silicones are able to operate well in temperatures from -84 to 232 degrees Celsius and are resistant to weathering, UV radiation and ozone. They also have good resistance to engine and transmission oils, animal and vegetable fats, brake fluid and diluted salt solutions. They can also be compounded to be electrically conductive or flame retardant for EMI applications.
Unlike many other elastomeric materials, silicone has an inorganic backbone composed of silicon and oxygen atoms. These atoms bond to create a strong structure that is resistant to high temperatures and chemical attack, making it a great choice for O-rings. However, it does have some limitations, including poor tear and abrasion resistance as well as high gas permeability, so it is not recommended for dynamic applications. Fortunately, it is available in a wide variety of colors and formulations to suit different needs.
Moisture Resistance
Water and moisture can affect Silicone O Rings – Supplier o-rings by making them swell, which can cause them to break apart or not seal correctly. Silicone is a great choice for these applications because it doesn’t allow the o-ring to absorb too much water. This helps it resist cracking and deterioration that can result in leaks.
VMQ is a food grade silicone polymer that is FDA-approved and has no odor or taste, which makes it ideal for medical and other industries where this is important. It is also resistant to animal and vegetable oils, grease, ozone, and oxidative environments. It can be used with several lubricants, including Skydrol hydraulic fluid and high molecular weight chlorinated aromatic hydrocarbons.
VMQ O-rings can be made with a variety of coatings to increase their resistance to various environmental conditions. Coatings can protect them from ozone, improve their low-temperature tolerance, and even provide fire resistance. They can be produced with platinum catalyzers for better flexibility and low volatile matter, which makes them suitable for medical systems that require these properties. Alternatively, they can be peroxide or perfluoroalkoxy-copolymer cured for greater flexibility and higher abrasion resistance.
Tensile Strength
Silicone (VMQ) o rings are a good choice for static sealing applications. They provide an excellent range of working temperatures, are odorless and non-toxic and will not grow mold. They are also able to resist ozone, corona and UV radiation, mineral and vegetable oils, diluted salt solutions and fire resistant hydraulic fluids. VMQ is not recommended for use in acids, EP fluids, fuels, gear oils or benzene.
Unlike some other elastomers, silicones are not sensitive to weathering and have an outstanding ozone resistance. They are also able to hold their own in environments with specific acid and alkali elements.
It is important to note that while silicone has an impressive list of beneficial properties, it should not be used in dynamic applications as it lacks tensile strength and tear/abrasion resistance. In these cases, other rubber o-ring materials like nitrile or Viton may be more suitable. Our team would be happy to help you determine which is right for your application. Contact us here to get started.