PFA (per-fluoro-alkoxy )

PFA – per-fluoro-alkoxy – is a fully fluorinated co-polymer of TFE, (tetra-fluoro-ethylene) and per-fluoro-vinyl–ether. TFE is one chemical compound, but the per-fluoro-vinyl-ethers are actually a large family of chemical compounds. In practice, the synthesis of PFA involves only the methyl, ethyl and propyl per-fluorinated vinyl ethers and by blending these in different percentages, different classes of PFA’s can be created.

Unlike PTFE, PFA is melt processible so can be extruded and injection moulded as well as transfer moulded. It is less densely white than PTFE but less clear than FEP. PFA can withstand temperatures almost as high as PTFE and higher than FEP or ETFE. It has very good chemical resistance and much better flex crack resistance than even modified FEP’s. PFA also gives better creep resistance than PTFE. PFA’s slip properties are almost as good as those of PTFE. PFA has similar dielectric constant to PTFE but higher dielectric strength and dissipation factor.

PFA is used to line pipes, vessels, valves, fittings and heat exchangers, to provided resistance to attack by aggressive chemicals. It is also used to make tubing, sleeving, and injection moulded parts. Other major applications are electric cable coating and wafer carriers in the semiconductor industry.

Our standard grades P2J, P12J and P16J, are of a very high purity but for some applications, eg semi-conductors, a very low level of fluoride or metal ions is required. This is often known as ‘ultra-high purity’ and is achieved by fully fluorinating, (or ‘end-capping), the terminal groups on the molecular chains. Our grades P2J E, P12J E, and P16J E have been modified in this way.