| Summary: | 碩士 === 逢甲大學 === 紡織工程所 === 95 === This dissertation reports the experimental results related to the synthesis of polytetrafluoroethylene (PTFE) film using variable processing parameters with three different lubricant contents, as well as the effects of these processes on the surface structure and physical properties of the film.
The experiment contained two parts: the first was to investigate the effects of lubricant on drawing the PTFE film, and the second was to determine the impact of heat treatment on the film. The results indicate that:
(1) When there was no sufficient lubricant mixed with the PTFE powder (e.g. 20%), the PTFE film produced by calendering prior to the drawing process was almost impermeable. In order to maintain good permeability, the lubricant content needs to be sufficiently high (e.g.25% or 30% ).
(2) When the PTFE film was stretched at 250℃ to 2 to 8 times of its original width, the drawing process gradually enlarged the existing micro-pores on the surface of the film, and concomitantly created interconnected fibrils and nodes, thus improving the permeability of the film. The effect was most pronounced at 8 times of stretching, with the microstructure disappearing gradually when the stretch was over 12 times of the original width.
(3) After the PTFE film was heated at 385℃ for 4 seconds, the microstructure of the film became denser; the treatment also made the film stronger, and better resistant to deformation, while maintaining its excellent permeability.
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