FEP vs. PTFE Chemical Resistance

FEP vs. PTFE Chemical Resistance

When choosing materials for industrial applications, especially for those that would come in direct contact with chemicals, factors such as the chemical resistance of FEP and PTFE prove to be essential. FEP and PTFE belong to the fluoropolymers family, which is known for its chemical inertness. However, these two polymers can have specific features that make one of them more appropriate for definite application.

What is FEP?

FEP stands for Fluorinated Ethylene Propylene, a fluoropolymer used for its chemical stability, high heat stability, and low electrical conductivity. FEP offers a combination of the benefits of moldability and flexibility. It is widely applied in cable insulation, lining tanks, and protective coatings for various industrial parts. Additionally, FEP is commonly used in lined pipes, 90-degree elbows, and 45-degree elbows.

What is PTFE?

PTFE (Polytetrafluoroethylene) is the most chemically resistant material available. It is highly inert to the majority of chemicals, including acids, bases, and solvents. PTFE is the material of choice in pharmaceutical, chemical processing, food processing, and aerospace industries because of its extreme resistance to corrosion, high temperatures, and adverse chemical agents. PTFE is also widely used in Lined Reducing Tee, Instrument Tee, Cross, Lined Concentric Reducer, Eccentric Reducer, and Reducing Flange.

Key Differences Between FEP and PTFE Chemical Resistance:

Temperature Range: PTFE can withstand temperatures up to 260°C (500°F), while FEP typically handles temperatures up to 205°C (400°F).

Chemical Resistance: FEP and PTFE are almost equally immune to most chemicals, but PTFE has a slightly better performance in terms of high-temperature resistance and highly reactive chemicals such as concentrated acid and alkalis.

Flexibility: FEP is easier to process than PTFE and offers more flexibility; hence it is better suited to applications that would require bending and shaping.

Ease of Processing: FEP is easier to mold and form than PTFE, which requires specialised processing equipment due to its high melting point.

Cost: FEP is more affordable than PTFE, thus in a situation where severe chemical resistance is not needed, FEP is the preferred option.

Mechanical Strength: PTFE usually has superior mechanical characteristics such as tensile strength and better wear resistance than FEP.

Conclusion

Both FEP and PTFE are chemically resistant which makes them suitable for use in chemically aggressive conditions. PTFE has excellent features in chemical inertness and high-temperature capability; on the other hand, FEP has better flexibility, ease of processing and economics. The decision to use FEP or PTFE will depend on certain factors, such as the operating temperature, chemical resistance, and cost. To understand which of the materials is most suitable for your particular application, you must know the differences in chemical resistance and other properties.

FEP vs. PTFE Chemical Resistance

by Galaxy Thermoplast Pvt. Ltd. time to read: 2 min
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