Of Ptfe Film Fragmented Into Yarn Process And Its Properties

This study puts forward a new kind of technology to produce such high performance PTFE yarns.Influences of draft ratio,twist factor,film thickness on the PTFE yarn quality were investigated in this work first of all.Based on the experiment this paper studies the influence of the comprehensive factors including draft ratio,twist factor,film thickness on the PTFE yarn quality by an orthogonal experiment and the analysis of variance.Then optimum technical parameters of the PTFE yarn were obtained by optimum experiment.That is draft ratio 1.8,twist factor190 and film thickness 40μm.Longitudinal section and cross section of the PTFE yarn spun under the optimizing technology parameters were investigated by scanning electron microscopy.The results show that longitudinal section of PTFE yarn is regular cylinder;cross section is polygon; yarn surface is smooth,not easy to absorb dust and possess self-cleaning function. Friction characteristics of PTFE yarn and the influence of various experimental conditions on the abrasion resistance were studied by friction coefficient determination.The relationship between surfaces characteristics of PTFE yarn and abrasion resistance and self-cleaning of final fabrics was also discussed in this paper.Mechanical properties of PTFE yarn,including tensile and relaxation property,were tested in this paper.The appropriate mechanical model was selected and the relationship between mechanical properties of PTFE yarn and weaving process were also studied in this paper.Thermal properties of PTFE yarn,including thermal transition temperature,thermal stability,heat shrinkage,were tested and analyzed by DSC and TG method.The long term working temperature up to 260℃was obtained through discussing the effect on the performance of PTFE yarn of heat treatment temperature and time.Finally,PTFE fabric and Nomex/PTFE fabric were developed and combustibility of them was studied in this paper.Ignition parameter,heat release parameter,mass loss parameter and smoke parameter were obtained.The results showed that PTFE fabric and Nomex/PTFE fabric had good combustibility,and the combusitibility of PTFE fabric was better than that of Nomex/PTFE.