Ethylene Propylene Diene Monomer, or EPDM for short, is a synthetic rubber composed of the substances mentioned in the name. Because they have great resistance to environmental variables including ozone, UV rays, and general weathering, they are utilized for a wide range of applications and industries.
However, they are most typically employed in the automotive and construction industries for various seals. With a life expectancy of more than 50 years, EPDM material is known for its exceptional durability and excellent elastic qualities, even at extremely low temperatures of -40 °C. This material also resists ripping and abrasion. Another extremely adaptable material, EPDM offers a variety of installation methods, such as mechanical attachment, complete adhesion, or ballasting.
Together with silicone, silicone is an inorganic polymer made of carbon, hydrogen, and oxygen. Silicone finds widespread use in a wide range of sectors and applications, including food & beverage, aerospace, rail, and automotive. Although silicone rubber has several benefits, its ability to withstand high temperatures is what makes it most popular and widely utilized.
Silicone and it’s Tolerance with Rubber.
High temperature silicone grades can tolerate temperatures as high as 270°C, although silicone remains stable and retains its physical characteristics up to 230°C (446°F), in contrast to EPDM. Silicone is utilized in the food and beverage industry as dairy tubing, gaskets and seals on food machinery, and vending tubes in drink machines because it is not only excellent in intense heat but also considered a sterile elastomer.
The temperature resistance of a rubber is critical in applications with varied temperature ranges. Choosing the wrong rubber might induce melting, deformation, and/or brittleness, all of which impact the material’s physical qualities and, most likely, cause failure. EPDM has a maximum temperature of 130°C (266°F), which is much lower than silicone’s. Silicone can withstand steady temperatures of 230°C (446°F) and up to 270°C (518°F) for specific high temperature silicone grades.
How Heat Affects EPDM vs How Heat affects Silicone
A scientist put Epdm and Silicone together to test how they work and these were the results:
EPDM RESULTS
At 100°C, the EPDM sample shrank by 17%, to 48mm. A surprise finding, given that the datasheet said the temperature limit was 130°C. At 125°C, the shrinkage continued, but it was more severe, with a 52% reduction from its original size to 28mm. Finally, at 150°C, the EPDM had reduced by 1mm, indicating that 125°C was the temperature at which the material experienced severe deformation.
SILICONE RESULTS
The silicone samples exhibited no shrinking after being exposed to the same temperatures as the EPDM. All silicone rubber samples remained at 58mm when removed from the oven, demonstrating silicone’s stability at high temperatures.
Similarities of EPDM and SILICONE
- Offer good weather resistance.
- are great electrical insulators.
- Maintain flexibility down to approximately -50°C/-58°F.
- Stand up to some chemicals To varied degrees,
- have an excellent compression set.
- Are widely used as water-system seals, O-rings, hoses, and membranes.
- Can be polished to a very smooth surface.
- Are flame retardant.
- Can withstand high temperatures to varied degrees.
That’s where their similarities end, though. Let’s have a look at the benefits each material provides.
Disadvantages of EPDM
You should also avoid using EPDM with oils, greases, hydrocarbon fuels, strong acids, or halogenated solvents. Finally, EPDM has a lower life expectancy than Silicone, which means it will need to be replaced more frequently depending on the application.
Advantages of EPDM
EPDM’s advantages stem from its stable, saturated polymer backbone structure. EPDM is the most water resistant of all rubbers, which is why it is widely used in outdoor applications and as a roofing material. EPDM withstands extreme weather conditions like sleet and snow. Another reason for its employment outside, particularly in construction, is its outstanding abrasion and tear resistance, as well as its ability to withstand the damaging effects of weathering, ozone, and UV light exposure.
EPDM also provides strong electrical resistance. Its chemical qualities make it ideal for electrical insulation and gaskets. It is resistant to polar solvents, including water, acids, alkalis, and phosphate esters. EDPM is excellent at withstanding steam and both low and high temperatures, although silicone can endure even higher temperatures. The material has a low compression set, so it will not lose its resilience under prolonged strain.
Advantages of Silicone
Silicone is food-safe. It’s an extremely adaptable substance due to its chemistry and the numerous ways in which it may be manipulated. As a result, it opens up many possibilities. Perhaps its most enticing feature is its capacity to withstand extremely high temperatures, which makes it particularly desirable for masking applications. Manufacturers will give varied melting points based on their experience and requirements; however, silicone can normally withstand temperatures up to 232°C/450°F. Compare this to EPDM’s 148°C/300°F.
On the bright side, silicone is resistant to vehicle brake fluids, but EPDM is not. Silicone has an excellent compression set that is even lower than EPDM.
Disadvantages of Silicone
Silicone has strong tensile strength but poor abrasion resistance. It is worth noting that it can be designed to improve tear resistance. Also, avoid usage if the item will come into contact with steam exceeding 121°C/249°F, hydrocarbon fuels, alkalis and acids, trichloroethylene, or aromatic hydrocarbons.
Places Where Silicone and EPDM Can Function
Silicone and EPDM have a wide range of applications. Both rubbers are suitable for certain applications, but they cannot satisfy all roles. Here are some examples in which silicone and EPDM are equally viable.
- Silicone and EPDM are extensively used in the automobile industry due to their stability and ability to withstand high temperatures.
- Silicone and EPDM are also resistant to extreme weather, UV radiation, and ozone, which are all possible concerns in the automotive industry.
- EPDM and silicone are used in the building and construction industries as door and window seals, gaskets, O-rings and hoses due to their elastic qualities, flexibility and durability.
- Electronics: Both silicone and EPDM are effective insulators. Examples of uses include gaskets and electrical insulators for power delivery cables.
Areas Where Only EPDM Can be Used
EPDM can be utilized in the following specific areas: -HVAC: EPDM is used in the heating, ventilation, and air conditioning (HVAC) industry due to its low electrical conductivity, ability to reduce vibration, and thermal expansion.
-It is commonly found in grommets, drain tubes, and gaskets. EPDM helps to reduce noise and vibration in consumer appliances that make a lot of noise.
Industrial Rubber Gasket
While gaskets are generally affordable components, it is critical to select the appropriate gasket material for your individual application. Most gasket failures occur because the material is inappropriate for the environment. So, before selecting either EPDM or silicone rubber as a gasket material, you need first analyze how these elements may influence gasket performance:
-Abrasion
-Pressure
-Temperature
-Electromagnetic interference
-Chemicals, UV, and Ozone
CONCLUSION
EPDM and silicone are commonly used seal and gasket materials in both molded and extruded applications. EPDM is popular because of its ability to withstand weathering, wetness, and aging in outdoor applications. It is recognised as an affordable material for a wide range of industries.
Silicone is very resistant to sunlight and oxidation, as well as a suitable electrical insulation material. It has a great compression set and can endure high temperatures. Silicone is not suggested for applications that need abrasion, rip, and cut resistance, as well as high tensile strength.
EPDM and silicone are color stable, ozone resistant, and flexible at low temperatures. EPDM is more resistant to alkalis and acids than other materials, although neither is suggested for resistance to oil or petrol.