Perfluoroalkoxy (PFA) Polymer Resin is a type of fluoropolymer with the properties almost similar to that of Polytetrafluoroethylene (PTFE). But it is melted using conventional injection molding and screw extrusion techniques. PFA coatings share the useful properties of PTFE as coefficient of friction and non reactivity but are easily formable.
PFA offer similar properties to that of FEP but is considered more of a premium resin. PFA coating is ideal when extended services are required in hostile environments involving chemical, thermal and mechanical stress.
Properties of PFA :
- High melting strength
- Stability at high processing temperatures
- Excellent crack resistance
- Excellent stress resistance
- Low coefficient of friction
- More than 10 times flex life of FEP
PFA coating is not degraded by systems that are commonly encountered in chemical processes. It is inert to strong mineral acids, inorganic bases, inorganic oxidizing agents, salty solutions including some organic compounds as organic acids, anhydrides, aromatics, aliphatic hydrocarbons, alcohols, aldehydes, esters, ethers, chloro carbons, fluorocarbons and some combinations of the above.
PFA coatings that are applied on carbon steel or stainless steel have a continuous service temperature ranging between -60˚F to 400˚F. A primer is compulsory before applying the PFA coating. There is a little bit of draw back for PFA coatings, if ones damaged, they cannot be repaired.