Fluorinated Ethylene Propylene (FEP) tubing is a type of fluoropolymer tubing that is valued for its unique combination of properties. Here are some key aspects of FEP tubing:

1. Chemical Resistance: FEP is highly resistant to a wide range of chemicals, including acids, bases, and solvents. This makes it suitable for use in environments where chemical exposure is a concern, such as in laboratories or industrial settings.
2. Thermal Properties: FEP can withstand temperatures from as low as -200°C up to approximately 200°C. It also has a lower heat shrink temperature compared to PTFE, which makes it easier to process in applications like catheter manufacturing.
3. Electrical Properties: FEP exhibits excellent dielectric strength, which is the ability to resist electrical breakdown. This makes it suitable for use in electrical insulation applications.
4. Transparency and UV Resistance: FEP is a clear, transparent material, allowing for the visualization of fluid flow when used in tubing applications. It is also UV resistant, which is beneficial for outdoor applications.
5. Low Friction and Non-Stick Surface: The surface of FEP tubing is extremely smooth and has low friction properties. This non-stick surface is useful in applications where easy cleaning or the prevention of material buildup is important.
6. Moisture Absorption: FEP absorbs very little moisture, which ensures stable performance in humid environments and reduces the risk of hydrolytic degradation.
7. Biocompatibility: In medical applications, FEP's biocompatibility is a significant advantage. It does not react with human tissue and is safe for use in various medical devices.
8. Flexibility and Durability: FEP tubing is more flexible than PTFE, making it easier to handle and install. It is also durable, with good resistance to tearing and cracking.
9. Gas Permeability: FEP is relatively permeable to gases, which can be either an advantage or a limitation, depending on the application.
10. Applications: Beyond medical use in catheters, FEP tubing is used in the chemical industry, in fluid handling systems, in the aerospace industry, and in electrical insulation applications.

Fluorinated Ethylene Propylene (FEP) was invented by DuPont and was first introduced in 1960. DuPont, a prominent American chemical company, is well-known for developing numerous synthetic polymers, including other fluoropolymers like Teflon® (PTFE). FEP was developed as part of the company's extensive research into perfluorinated polymers and has since become a widely used material in various industries due to its unique properties.

The first practical use of Fluorinated Ethylene Propylene (FEP) tubing was primarily in the aerospace and electrical industries. Due to its high resistance to heat, chemicals, and electrical current, FEP tubing quickly found applications as an insulator for wiring, especially in environments where wires could be exposed to harsh chemicals or extreme temperatures.

In the aerospace industry, the need for materials that could withstand the demanding conditions of flight and space exploration made FEP an ideal choice. It was used to protect and insulate wiring in aircraft and spacecraft where reliability and performance under extreme conditions were crucial.

Additionally, FEP tubing was used in various electrical applications. Its excellent dielectric properties made it suitable for wire insulation, particularly in situations requiring high-temperature resistance and chemical stability.

Over time, the use of FEP tubing expanded into other industries, including the medical field, where its biocompatibility and clarity made it suitable for applications such as catheter manufacturing. However, its initial adoption was driven by the aerospace and electrical industries, capitalizing on its unique properties for demanding applications.

Cost: FEP tubing tends to be more expensive than other types of plastic tubing. This cost factor can be a significant consideration in budget-sensitive projects or in applications where large quantities of tubing are required.

Mechanical Strength: Although FEP has good tensile strength, it is not as strong or rigid as some other materials, such as metal tubing. This can be a limitation in applications requiring high mechanical strength or structural support.

Gas Permeability: FEP is somewhat permeable to gases, which might be a drawback in applications where gas containment is crucial, such as in certain laboratory or industrial settings.

Thermal Conductivity: FEP has low thermal conductivity, which can be a disadvantage in applications where heat transfer is needed.

Environmental and Health Concerns: The production and disposal of fluoropolymers, including FEP, raise environmental and health concerns. The manufacturing process involves chemicals that can be harmful if not managed properly. Additionally, concerns about the persistence and potential toxicity of fluorinated compounds in the environment have been raised.

Limited Temperature Range: Although FEP can handle a wide range of temperatures, it is not suitable for extremely high-temperature applications. It has a lower melting point compared to some other high-performance plastics like PTFE.

Not Suitable for Some Solvents: While FEP is resistant to many chemicals, there are certain solvents and reactive chemicals that can affect it. It is important to ensure compatibility with the specific chemicals it will be exposed to in any given application.

Flexibility Issues: While FEP is more flexible than PTFE, it might not be flexible enough for certain applications that require highly flexible materials.