azmater.com Fluorocarbon rubber offers superior chemical resistance and high-temperature durability compared to acrylonitrile butadiene rubber, making it ideal for diaphragms in aggressive environments. Acrylonitrile butadiene rubber provides better flexibility and cost-effectiveness but lacks the heat and solvent resistance of fluorocarbon rubber.
Table of Comparison
| Property | Fluorocarbon Rubber (FKM) | Acrylonitrile Butadiene Rubber (NBR) |
|---|---|---|
| Chemical Resistance | Excellent resistance to oils, fuels, and chemicals | Good resistance to oils and fuels, limited chemical resistance |
| Temperature Range | -20degC to 200degC (-4degF to 392degF) | -40degC to 120degC (-40degF to 248degF) |
| Mechanical Strength | High tensile strength and durability | Moderate tensile strength, good abrasion resistance |
| Flexibility | Moderate flexibility, maintains shape | High flexibility, suitable for dynamic applications |
| Cost | Higher cost due to superior properties | Lower cost, widely available |
| Typical Applications | Automotive fuel systems, chemical processing diaphragms | Oil seals, fuel handling diaphragms, general-purpose seals |
Introduction to Fluorocarbon and Acrylonitrile Butadiene Rubbers
Fluorocarbon rubber (FKM) possesses superior chemical resistance, high-temperature stability up to 250degC, and excellent aging properties, making it ideal for diaphragm applications in aggressive environments. Acrylonitrile butadiene rubber (NBR), characterized by its strong resistance to oils, fuels, and moderate heat tolerance of around 100degC, offers cost-effective performance for less demanding diaphragm applications. Selection between FKM and NBR for diaphragms hinges on the required chemical exposure, temperature range, and mechanical durability.
Key Properties of Fluorocarbon Rubber (FKM)
Fluorocarbon rubber (FKM) offers exceptional chemical resistance, high-temperature stability up to 200degC, and excellent mechanical strength, making it ideal for diaphragm applications exposed to harsh chemicals and extreme environments. FKM's low permeability to gases and resistance to oils and fuels outperform acrylonitrile butadiene rubber (NBR), which typically exhibits lower heat resistance and reduced chemical stability. The superior aging and weathering resistance of FKM ensure longer diaphragm service life in demanding industrial and automotive settings.
Essential Characteristics of Acrylonitrile Butadiene Rubber (NBR)
Acrylonitrile Butadiene Rubber (NBR) offers excellent resistance to oils, fuels, and other chemicals, making it ideal for diaphragms exposed to hydrocarbons. Its superior tensile strength and flexibility provide reliable sealing performance in dynamic applications, while its temperature resistance typically ranges from -40degC to 120degC. Despite having lower chemical and heat resistance compared to Fluorocarbon rubber (FKM), NBR remains cost-effective and widely used in automotive and industrial diaphragm seals where fuel and oil exposure is frequent.
Chemical Resistance: FKM vs NBR for Diaphragm Applications
Fluorocarbon rubber (FKM) exhibits superior chemical resistance compared to acrylonitrile butadiene rubber (NBR), especially against fuels, oils, and aggressive solvents, making FKM ideal for diaphragms exposed to harsh chemical environments. NBR offers good resistance to petroleum-based oils and fuels but degrades faster when exposed to aromatic hydrocarbons, ketones, and acids, limiting its use in chemically demanding applications. FKM's ability to maintain elasticity and integrity at high temperatures and in the presence of aggressive chemicals ensures longer diaphragm lifespan and reliability in industrial and automotive sealing solutions.
Temperature Tolerance Comparison
Fluorocarbon rubber (FKM) offers superior temperature resistance, typically withstanding continuous exposure from -20degC to 200degC, and intermittent use up to 250degC, making it ideal for high-temperature diaphragm applications. Acrylonitrile butadiene rubber (NBR) usually operates effectively within a narrower range of -40degC to 108degC, limiting its use in environments with higher temperature demands. The enhanced thermal stability of fluorocarbon rubber ensures longer diaphragm lifespan and reliability in extreme heat conditions compared to NBR.
Mechanical Strength and Durability
Fluorocarbon rubber (FKM) offers superior mechanical strength and exceptional durability compared to Acrylonitrile Butadiene Rubber (NBR), making it highly resistant to abrasion, high temperatures (up to 250degC), and chemical exposure, crucial for diaphragm applications in harsh environments. NBR provides good mechanical strength and flexibility with moderate resistance to oils and fuels, but it degrades faster under extreme temperatures and aggressive chemicals, limiting its lifespan in demanding diaphragm uses. The enhanced cross-linking density and molecular structure of FKM result in longer service life and reduced maintenance frequency, optimizing diaphragm performance in industrial and automotive systems.
Compatibility with Fluids and Gases
Fluorocarbon rubber (FKM) excels in chemical resistance, offering superior compatibility with aggressive fluids, oils, fuels, and a wide range of gases, making it ideal for demanding diaphragm applications exposed to harsh environments. Acrylonitrile butadiene rubber (NBR) provides good resistance to petroleum-based oils and fuels but shows limited compatibility with aromatic hydrocarbons, ketones, and certain chemicals. For diaphragms used in applications involving aggressive solvents, high temperatures, or exposure to diverse gases, fluorocarbon rubber ensures enhanced durability and fluid compatibility compared to acrylonitrile butadiene rubber.
Cost and Availability Analysis
Fluorocarbon rubber (FKM) exhibits higher costs due to its superior chemical resistance and thermal stability, making it less economically feasible for large-scale diaphragm production compared to acrylonitrile butadiene rubber (NBR). NBR offers widespread availability and lower material costs, driven by its extensive industrial use in automotive and oil industries, contributing to greater cost-efficiency for diaphragms in general applications. The durability of FKM in aggressive environments justifies its premium price, while NBR remains the preferred choice where budget constraints and moderate chemical exposure are primary concerns.
Common Industry Applications for Diaphragms
Fluorocarbon rubber (FKM) diaphragms excel in high-temperature and chemically aggressive environments, making them ideal for use in automotive fuel systems, chemical processing, and aerospace applications where resistance to oils, fuels, and solvents is critical. Acrylonitrile butadiene rubber (NBR) diaphragms are primarily used in industries requiring resistance to petroleum-based oils and fuels, such as hydraulic systems, pneumatic controls, and fuel handling equipment. Both materials serve essential roles in diaphragm applications, with FKM preferred for extreme chemical exposure and high heat, and NBR selected for cost-effective performance in moderate temperature and oil-resistant conditions.
Choosing the Right Rubber for Diaphragm Performance
Fluorocarbon rubber (FKM) offers superior chemical resistance, high-temperature tolerance up to 200degC, and excellent durability, making it ideal for diaphragms exposed to harsh chemicals and extreme environments. Acrylonitrile butadiene rubber (NBR) provides excellent resistance to oils and fuels with moderate temperature resistance up to 100degC, suitable for less aggressive applications requiring good mechanical properties. Selecting the right rubber depends on operational conditions: FKM is preferred for high-performance, chemically demanding applications, while NBR suits cost-effective solutions with moderate chemical exposure.
Infographic: Fluorocarbon rubber vs Acrylonitrile butadiene rubber for Diaphragm