What is the Difference Between PTFE, FEP and PFA?
Dec 9, 2020
With many types of fluoropolymers available, it can prove challenging to work out what is the best option. There are subtle variances in the structure of PTFE, FEP and PFA and they all offer something different but what are the main differences between these three materials?
Polytetrafluoroethylene is also known as PTFE and was one of the first synthetic fluoropolymers to be made. It is ideal for creating coatings that have non-stick properties which makes it ideal in applications such as cooking or food manufacturing. As it is hydrophobic it has a high level of electronegativity which means that liquids will not affect it.
FEP is also known as Fluorinated Ethylene Propylene and it has different properties when compared to that of PTFE. However, it does have non-stick properties which again makes it suitable for use in applications where residues or oils are likely. FEP does have a softer makeup when compared to that of PTFE and that means that it can melt at a lower temperature which means that it is not suitable in applications that are exposed to high temperatures. Along with this, it is also transparent while it is resistant to sunlight and UV which makes it suitable for use in applications that are exposed to the elements.
Known as Perfluoroalkoxy, PFA has alkoxy substitutes that mean that the polymer can be melt-processed. However, it also differs from a molecular level as it has a smaller chain length than other fluoropolymers. It is extremely durable which makes it suitable for use in demanding application. It is also the preferred option when it comes to choosing a material that requires high chemical resistance as well as high purity and low stiffness while it is also extremely durable when it comes to resisting weathering. It has a lower melting temperature when compared to PTFE while it has great insulation properties and is UV resistant which also adds to its durability.