Epichlorohydrin rubber vs. silicone rubber for diaphragms - What is The Difference?

Epichlorohydrin rubber offers excellent oil resistance and flexibility, ideal for diaphragms in automotive and industrial applications requiring chemical durability. Silicone rubber provides superior thermal stability and biocompatibility, making it suitable for medical and food-grade diaphragm uses.

Table of Comparison

Introduction to Diaphragm Materials

Epichlorohydrin rubber offers excellent resistance to oils, ozone, and weathering, making it suitable for diaphragms in automotive and industrial applications requiring durability in harsh environments. Silicone rubber excels in high-temperature stability, flexibility, and biocompatibility, ideal for medical and food-grade diaphragms where chemical inertness and thermal resistance are critical. Selection between Epichlorohydrin and Silicone diaphragms depends on specific performance needs such as chemical exposure, temperature range, and mechanical flexibility.

Overview of Epichlorohydrin Rubber

Epichlorohydrin rubber (ECO) is a synthetic elastomer known for its excellent resistance to oil, fuel, and ozone, making it ideal for diaphragm applications in harsh chemical environments. This rubber exhibits low gas permeability and strong chemical stability, ensuring durability and reliable sealing performance under exposure to aggressive fluids. Its balanced flexibility and thermal stability differentiate it from silicone rubber, which offers superior temperature resistance but lower chemical resistance.

Overview of Silicone Rubber

Silicone rubber exhibits exceptional flexibility, chemical resistance, and biocompatibility, making it ideal for diaphragm applications where durability and performance under extreme temperatures are crucial. Unlike Epichlorohydrin rubber, which offers good chemical resistance primarily to oils and fuels, silicone rubber maintains stability across a broader temperature range from -60degC to 230degC and resists UV, ozone, and weathering. These properties ensure longer service life and consistent functionality in medical, food-grade, and industrial diaphragm uses.

Chemical Resistance Comparison

Epichlorohydrin rubber exhibits superior resistance to oils, fuels, and ozone, making it ideal for diaphragms exposed to hydrocarbon-based fluids and outdoor environments. Silicone rubber provides excellent resistance to extreme temperatures and oxidizing chemicals but is less resistant to petroleum oils and aliphatic hydrocarbons compared to epichlorohydrin. For chemical environments involving aggressive solvents, acids, and bases, epichlorohydrin rubber ensures longer diaphragm service life and reduced degradation rates.

Temperature Stability and Performance

Epichlorohydrin rubber offers excellent oil resistance and good low-temperature flexibility but has a limited temperature stability range, generally between -40degC and 120degC, making it suitable for moderate thermal environments in diaphragm applications. Silicone rubber outperforms Epichlorohydrin in temperature stability, maintaining flexibility and sealing performance in extreme temperatures from -60degC up to 230degC, ideal for high-heat or frozen conditions. Silicone rubber also demonstrates superior aging resistance and environmental durability, ensuring longer diaphragm performance in harsh temperature fluctuations.

Mechanical Strength and Durability

Epichlorohydrin rubber exhibits excellent mechanical strength and resistance to abrasion, making it highly durable in demanding environments, especially in fuel and oil applications. Silicone rubber offers superior flexibility and resilience at extreme temperatures but generally has lower tensile strength and abrasion resistance compared to epichlorohydrin. When selecting diaphragm materials, epichlorohydrin provides enhanced durability under mechanical stress, while silicone excels in thermal stability.

Flexibility and Elasticity Differences

Epichlorohydrin rubber offers excellent oil resistance and moderate flexibility, making it suitable for applications requiring durability under exposure to various chemicals. Silicone rubber, however, provides superior elasticity and exceptional flexibility over a broad temperature range, ensuring consistent diaphragm performance in extreme conditions. While Epichlorohydrin excels in chemical resistance, Silicone rubber dominates in maintaining elasticity and flexibility for dynamic diaphragm applications.

Application Suitability in Diaphragms

Epichlorohydrin rubber offers excellent resistance to oils, fuels, and weathering, making it highly suitable for diaphragms in automotive and industrial fluid control applications. Silicone rubber excels in extreme temperature resistance and flexibility, ideal for diaphragms used in food processing, medical devices, and sanitary environments. Selecting between Epichlorohydrin and Silicone rubber depends on operational temperature ranges, chemical exposure, and compliance with industry-specific standards.

Cost Efficiency and Longevity

Epichlorohydrin rubber offers superior resistance to oils, fuels, and weathering, making it a cost-effective choice for diaphragms exposed to harsh chemical environments, with moderate longevity under mechanical stress. Silicone rubber provides excellent flexibility, high-temperature stability, and biocompatibility, extending diaphragm lifespan in extreme temperature applications but often at a higher initial cost. Balancing upfront expenses with long-term durability depends on the specific operating conditions and chemical exposure of the diaphragm's intended use.

Conclusion: Optimal Choice for Diaphragm Use

Epichlorohydrin rubber offers superior resistance to oils, fuels, and weathering, making it ideal for diaphragms in automotive and fuel system applications requiring durability and chemical resistance. Silicone rubber excels in extreme temperature tolerance and flexibility, suitable for medical and food-grade diaphragms where biocompatibility and thermal stability are critical. Selecting the optimal diaphragm material depends on the specific operational environment, with Epichlorohydrin preferred for chemical resistance and Silicone favored for temperature resilience and flexibility.