Abstract:

One-way stretching PTFE（polytetrafluoroethylene）membrane which had been subjected to film-splitting was used as starting material for preparing high-tenacity PTFE filaments, the film-splitting process was adopted for manufacturing the filaments under proper tension, heat treatment including different temperatures and treatting durals, twisting, hot drawing and heat setting. The surface morphology of the resulting filaments was observed by SEM, the melting temperature and crystallinity were tested by differential scanning calorimeter, and mechanical properties were tested by single fiber tensile instrument. The results showed that the lower crystallinity of the filaments caused by heat-treatment led to great improvement of the elongation at break, thus enhancing the drawing ratio. Appropriate heat treatment before making PTFE filament with fiber-splitting method，therefore，is conducive to processing PTFE into sewing threads with high-tenacity and good fineness.