Silicone vs EPDM

EPDM

EPDM (Ethylene Propylene Diene Monomer) is a synthetic rubber commonly used in automotive and constructive industries but has a disadvantage of having a lower heat resistance.

Silicone

Silicone is an inorganic polymer used in many industries and applications with the advantage that it can withstand extreme temperatures and keep its physical properties. Silicone is safe to use in the food and beverage industry.

How is Silicone Manufactured?

Depending on the type of silicone being used there are numerous ways to manufacture it. Silicone can come in three forms: LSR (Liquid Silicone Rubbers), RTV (Room Temperature Vulcanisation), HTV (High Temperatur Vulcanisation)

Technical Comparison

  • Temperature – EPDM has a max temperature of 130°C compared to silicone which can reach temperatures of 230°C and 270°C for high-temperature silicones.
  • Elongation – Silicone is seen as the stretchier rubber hence why it is used as vacuum membranes and has a tear resistance and elongation of up to 800% and can stay flexible up to -60°C.
  • Oil Resistance – both materials are prone to swelling
  • Environmental Resistance – Both EPDM and Silicone can withstand general weathering, Ozone, and UV
  • Tear Strength – EPDM is seen as the more durable rubber

Maximum Hot and Cold Temperatures for EPDM and Silicone

Hot Cold
+130°C EPDM starts to degrade -40°C EPDM reaches brittle point
+230°C Silicone starts to degrade -60°C Silicone reaches brittle point

Varying temperatures (hot or cold) have negative effects on all rubbers, particularly when heated.

silicone-heat-diagram

It is important to choose the right material

Silicone is superior when it comes to needing mechanical strength under intense heat and cold resistance as well as being flame resistant. It is important to look at all of the factors that these materials will be subjected to when looking to choose what rubber will be used.

To learn more about Silicone, click here.

To learn more about EPDM, click here.

Viton® O-Rings

logo-vitonViton® (fluorocarbon rubber, FFKM) has excellent resistance to high temperatures, ozone, oxygen mineral oil, synthetic hydraulic fluids, fuels, aromatics and many organic solvents and chemicals making it a good choice for an o-ring material.

Viton® is a synthetic rubber and fluoropolymer elastomer, which is commonly used in O-rings and molded or extruded products. There are four families of Viton® polymers, with a varying fluorine content between 66% and 70%. There are the main grades are A (Dipolymers of VF2/HFP); B (Terpolymers of VF2/HFP/TFE); F (Terpolymers of VF3/HFP/TFE); and specialty types (such as GLT, GBLT, GFLT & Viton® Extreme).

Low-temperature resistance is normally not favorable and for static applications is limited to approximately -15°F (-26°C) although in certain situations it is suitable down to -40°F(-40°C). Under dynamic conditions, the lowest service temperature is between 5°F and 0°F (-15°C and -18°C).

Gas permeability is very low and similar to that of butyl rubber. Special fluorocarbon compounds exhibit an improved resistance to acids, fuels, water, and steam.

Viton_V91A_ORings

Attributes

  • Excellent Heat Resistance
  • Excellent resistance to oils and chemicals
  • Low compression set
  • Good fuel resistance
  • Excellent ozone and weather resistance (oxidation, sun, climat conditions, fungus, mold)

Applications

  • Engine oil seals
  • Fuel systems
  • High-Temperature Seals
  • Petrochemical Systems

Seal & Design is a leading supplier of Viton® O-rings and custom molded seals. We offer both genuine Viton® and standard fluorocarbon materials for general-purpose and high-performance applications. Selecting the type of Viton® that best fits your application is important, but it isn’t complicated, and help is available from Seal & Design. We also offer gaskets made out of Viton®.

For more information visit Seal & Design’s Website.

O-Ring Inspection Equipment

In many critical applications (including automotive, aerospace, and life support, among others), 100% dimensional inspection of o-rings is often required. Seal & Design has a host of inspection machines that are dedicated to 100% inspection of o-rings and other seals, to ensure each individual part meets all drawing dimensions and other measurable specifications.

Also called vision systems, these machines use camera stations with either infrared or white light to measure any particular dimension of an o-ring that is deemed to be critical to function. From ID and OD to concentricity and ovality, our equipment measures and sorts parts quickly and efficiently. Seal & Design is home to a variety of inspection equipment, from machines dedicated specifically to o-rings and round parts, to machines that can measure virtually any shape.

Inspection RoomTo prevent any cross-contamination of the 100% inspected parts, bagging machines are attached directly to the inspection equipment. This allows for precise automatic bagging/sealing of parts, with customer required information including part numbers, quantities, and batch information printed directly onto the bags. From start to finish, the time it takes to inspect and bag an o-ring is often less than 10 seconds.

These inspection machines are just another component of Seal & Design’s World Class production facility, which is certified to ISO/TS 16949:2009 as well is ISO 9001:2008.

Learn more about Seal & Design’s o-ring offerings.

Simriz FFKM

With Simriz® Perfluorelastomers,  Process Seals offers the processing industry the High-End solution in materials technology for sophisticated applications regarding media and temperature stability.

Simriz® features wide chemical stability, similar to that of PTFE, combined with the rubbery properties of an elastomer. Specially for the processing industry, Simriz® makes a complete product range of high class FFKM material available which set new standards regarding operational safety and durability. Apart from the Simriz® compounds for standard and high temperature applications, FDA and USP Class VI compliant versions are available which are optimally designed for use in food and beverage and pharmaceutical production.

General properties:

  • Universal stability like PTFE with the elastic advantages of an elastomer
  • High reliability for static and dynamic applications
  • Extremely high stability in aggressive media
  • Highly stable when used in polar and non-polar media, even at high concentration and temperature
  • Temperature range from -10 °C to +325 °C (Special types)
  • Reliable properties even with frequent temperature changes

Visit Seal & Design to find out more information.

Peek high performance plastic

peek

PolyEtherEther-Ketone, or PEEK, is a high performance thermoplastic material that offers chemical and water resistant properties to seals. Peek seals are manufactured with peek material, and operate at much higher temperatures than other seals.  Seal & Design peek seals can be used consistently to a temperature of 500F without losing any physical properties, and since they are made with thermoplastic materials, they can be heated, cooled, and heated again without degradation. When high temperature and high pressure demand a high performance thermoplastic seal, peek seals meet the needs of various applications. A low co-efficient of friction, and a high wear resistance without lubricants, peek seals are insoluble in solvents such as oils, salts, and acids. Since the properties and materials that peek seals are manufactured from are important to their performance, peek seal materials must resist hardening, and maintain a long service life.

Seal & Design can provide custom peek seals that ensure optimal fluid control while eliminating leakage of your specific products. Our seals are engineered for static and dynamic applications and we utilize the latest research, technologies, and finest materials to provide our customers with optimum performance during demanding application conditions. Our peek sealing products include o-rings, lip seals, piston rings, wipers, and wear rings.

Aflas O-rings and Gaskets

AFLAS_280LR

As a copolymer of tetrafluoroethylene (TFE) and propylene (P), TFE/P provides a unique combination of chemical, heat, and electrical resistance. Chemically, TFE/P resists both acids and bases, as well as steam, amine-based corrosion inhibitors, hydraulic fluids, alcohol, and petroleum fluids. TFE/P is also resistant to ozone and weather. TFE/P typically retains its remarkable chemical resistance even in high temperatures (up to 450° F / 232° C), and tests have shown that electrical resistance actually improves with heat exposure.

The first TFE/P compound to be commercially marketed was Aflas. In a sense, Aflas defined the initial boundaries for base-resistant materials. There are varying grades of Aflas, each with their own molecular weight. Most molded and extruded products are made from Aflas 150P, which has a molecular weight of about 130,000. In comparison, Aflas 100H has a molecular weight of 200,000 and is typically used where high pressures are to be sealed, such as in oil field applications. TFE/P compounds are also widely used in the chemical processing, automotive, and aerospace industries.