EPDM vs. Viton

Attribute	EPDM	Viton
Chemical Resistance	Excellent	Excellent
Temperature Range	-50°C to +150°C	-20°C to +200°C
Hardness	40-90 Shore A	70-95 Shore A
Tensile Strength	10-20 MPa	10-20 MPa
Elongation at Break	200-600%	100-300%
Compression Set	Good	Good
Abrasion Resistance	Good	Excellent

Introduction

When it comes to choosing the right material for various applications, it is essential to consider the specific attributes and characteristics of each option. In the world of rubber materials, EPDM (Ethylene Propylene Diene Monomer) and Viton (a brand of fluoroelastomer) are two popular choices. Both EPDM and Viton offer unique properties that make them suitable for different applications. In this article, we will compare the attributes of EPDM and Viton, exploring their strengths and weaknesses in various areas.

Chemical Resistance

One of the critical factors to consider when selecting a rubber material is its resistance to chemicals. EPDM exhibits excellent resistance to a wide range of chemicals, including acids, alkalis, and polar solvents. It can withstand exposure to ozone, steam, and water, making it a popular choice for outdoor applications and sealing systems. On the other hand, Viton offers exceptional resistance to aggressive chemicals, fuels, oils, and solvents. It is highly resistant to degradation from acids, bases, and oxidizing agents, making it ideal for applications in the chemical and automotive industries.

Temperature Range

Another crucial aspect to consider is the temperature range in which the rubber material can perform effectively. EPDM has a broad temperature range, with a typical operating range of -50°C to +150°C (-58°F to +302°F). It can withstand both high and low temperatures without losing its flexibility or physical properties. Viton, on the other hand, offers an even wider temperature range, with a typical operating range of -20°C to +200°C (-4°F to +392°F). This makes Viton an excellent choice for applications that require resistance to extreme temperatures, such as aerospace and automotive industries.

Compression Set Resistance

Compression set resistance refers to a material's ability to recover its original shape after being compressed. EPDM exhibits good compression set resistance, allowing it to maintain its sealing properties over extended periods. It can withstand repeated compression and decompression cycles without significant loss of performance. Viton, on the other hand, offers excellent compression set resistance, making it suitable for applications where long-term sealing performance is critical, such as gaskets and O-rings in industrial machinery.

Tensile Strength and Tear Resistance

Tensile strength and tear resistance are essential attributes to consider, especially in applications where the rubber material will be subjected to mechanical stress. EPDM has good tensile strength and tear resistance, allowing it to withstand moderate mechanical loads. It can resist tearing and deformation, making it suitable for applications such as weatherstripping and seals. Viton, on the other hand, offers superior tensile strength and tear resistance compared to EPDM. It can withstand high mechanical loads and is often used in applications where resistance to tearing and abrasion is crucial, such as seals in heavy machinery and chemical processing equipment.

UV and Weather Resistance

For outdoor applications, the resistance of the rubber material to UV radiation and weathering is vital. EPDM exhibits excellent UV and weather resistance, making it suitable for outdoor applications such as roofing membranes, window seals, and automotive weatherstripping. It can withstand prolonged exposure to sunlight without significant degradation. Viton, on the other hand, offers good UV and weather resistance but is not as resistant to prolonged sunlight exposure as EPDM. It is more commonly used in indoor applications or in environments where UV exposure is limited.

Fluid Compatibility

Fluid compatibility is a crucial consideration when selecting a rubber material for sealing or fluid handling applications. EPDM is compatible with a wide range of fluids, including water, steam, alcohols, and diluted acids. It is not recommended for use with oils, hydrocarbons, or strong acids. Viton, on the other hand, exhibits excellent compatibility with aggressive fluids, including oils, fuels, solvents, and chemicals. It is widely used in applications where resistance to aggressive fluids is essential, such as fuel systems, chemical processing, and oil refineries.

Cost

Cost is often a significant factor in material selection. EPDM is generally more cost-effective compared to Viton. EPDM is widely available and has a lower price point, making it a popular choice for applications where cost is a primary consideration. Viton, on the other hand, is a premium material and tends to be more expensive. However, the higher cost of Viton is justified by its exceptional chemical resistance and high-temperature capabilities, making it a preferred choice in industries where performance is paramount.

Conclusion

EPDM and Viton are both excellent rubber materials with unique attributes that make them suitable for different applications. EPDM offers excellent chemical resistance, a broad temperature range, and good compression set resistance, making it ideal for outdoor applications and sealing systems. Viton, on the other hand, provides exceptional resistance to aggressive chemicals, a wider temperature range, and superior tensile strength and tear resistance, making it a preferred choice in demanding environments. When selecting between EPDM and Viton, it is crucial to consider the specific requirements of the application and choose the material that best aligns with those needs.