POST-TREATING METHOD OF TETRAFLUOROETHYLENE POLYMER THERMALLY PRETREATED

摘要

PURPOSE: To obtain through continuous steps a tetrafluoroethylene polymer which has a high bulk density and a good flow behavior by imparting an impact stress to be generated by the mutual collision of fine particles to a tetrafluoroethylene polymer under the acceleration action of a high-speed gas-jet current at a specific temperature. CONSTITUTION: A tetrafluoroethylene polymer which is preliminarily treated to be half-molten is subjected to an impact action to be generated substantially exclusively by the mutual collision of fine particle under the acceleration action of a high-speed gas-jet current at 1 or more, at a temperature of +80 deg.C or lower. To perform this process, various commercial-type jet mills of different constructions are best suited. This polymer fine particle is dispersed into a diffusive gas-jet current at 1 or more which flows at such a high speed as about 50-1000 m/sec and these particles run into each other by the high speed and disturbance of the gas current. A gaseous medium which creates the gas-jet current to be used as acceptable is all of the gases of various kinds which behave inertly against the tetrafluoroethylene polymer to be treated and especially a compressed air is used.