Chemours in the Semicon Manufacturing Industry
Components fabricated from Teflon™ PFA HP Plus have extremely smooth surfaces. This chart contains images of the inner walls of extruded tubing. The images were developed using Atomic Force Microscopy (AFM).
The surfaces of components manufactured from these polymers are characteristically mirror smooth. In order illustrate structure on the surface, these images were amplified in the vertical dimension 80 to 100 times (the base dimensions are not a square). At this high amplification, an impression of the spherulitic structure can be seen in the sample of Teflon™ PFA HP.
Spherulitic structure at the surface
Additional AFM images of components of Teflon™ PFA HP and PFA HP Plus are shown above, measured over a larger range of dimensions, 10 square microns to 90 square microns. In these images the vertical dimension (out of the page) is amplified 25X to allow an indication of the structure at the surface.
Viewing the top row of images from left to right gives an indication of the spherulitic structure of Teflon™ PFA HP.
In contrast, even at this level of amplification, the lower row of images of Teflon™ PFA HP Plus shows the uniform, fine grained structure of this fluoropolymer, even over this wide range of dimensions.
Engineers often use root-mean-square (RMS) measurements, or other measurements of asperity to gauge the comparative smoothness of materials…although this type of measurement has much less relevance in the commercial applicability of polymer surfaces than it has to that of metal surfaces.
The above chart shows RMS measurements made on extruded tube samples over a very large range of dimensions.
Notice, again, that in the range of 10 to 90 square micron image sizes the rolling spherulitic structure of PFA HP is apparent, while over all dimensions the smooth, fine regular structure of PFA HP Plus repeats itself.
Another consequence of the Chemours technology incorporated into Teflon™ PFA HP Plus is enhanced transparency. The spherulites formed in components fabricated from Teflon™ PFA HP Plus have a narrow mean size distribution resulting in less scattering of light and more component transparency.
This is most apparent in tubing / pipe, and less apparent in thicker sections such as fittings.
Better visual clarity is valuable in operations to monitor whether or not process fluid is flowing.