Derived from standard PTFE, a new product – modified PTFE – is created by co-polymerization with a small quantity of a perfluorinated modifier and reduction of the molecular weight. Although modified PTFE can be processed by the same methods used for standard PTFE, it has a clearly improved profile of properties, such as reduced cold flow and permeation as well as smaller pore volume and a lower stretch void index (SVI).

Modified PTFE is obtained from the monomer, tetrafluoroethylene (TFE) and a modifier (which is perfluorinated as well), perfluoropropylvinylether (PPVE). The shorter molecular chains (compared to PTFE) have a higher tendency to crystallize. This would degrade the mechanical properties of the material. The modifier effectively inhibits crystallization. This means that with modified PTFE it is possible to combine thermoplastic property components – due to the shorter molecular chains – with the good mechanical properties of standard PTFE.

While retaining the positive properties that are typical for PTFE, modified PTFE has additional benefits:

• Cold flow reduced by the factor of 3
• Reduced permeation of chemicals and gases down to half of the PTFE value
• Porosity reduced to half of PTFE’s porosity
• Minimum tendency for pore formation during drawing processes
• Suitable for welding, using special methods