The PTFE film prepared by one-way or two-way stretching method has a spider web-like microporous structure on the surface. The three-dimensional structure has very complex changes such as network connectivity, hole nesting, and channel bending, so it has excellent surface filtering function.
Nano masks produced using PTFE mask film have the characteristics of high barrier efficiency, long service life, lightness and breathability, and are a new direction for the development of masks in the future.
</p