PROCESSO DI POST-TRATTAMENTO DI POLIMERI TETRAFLUOROETILENICI PRE-TRATTATI TERMICAMENTE CON MIGLIORAMENTO DEL COMPORTAMENTO ALLO SCORRIMENTO E POLVERE DI POLIMERO POST-TRATTATA IN TAL MODO.

摘要

In a process for aftertreating thermally presintered polymers of tetrafluoroethylene the optionally comminuted powders are subjected, at temperatures below +80 DEG C., to the action of a gas jet mill. Preferred starting materials are tetrafluoroethylene polymers containing a small proportion of a modifying monomer. By the aftertreatment the bulk density and the flow index of the powders are considerably improved without a noticeable disintegration taking place. The aftertreated powders are used in the first place for the manufacture of shaped articles in extrusion devices with automatic feeding means.