METHOD FOR MANUFACTURING FLUOROPLASTIC TAPE AND APPARATUSES FOR MANUFACTURING PELLET AND FOR EXTRUDING FLUOROPLASTIC TAPE Russian patent published in 1997 - IPC

FIELD: chemical engineering and polymer plastics. SUBSTANCE: invention relates to processing polytetrafluoroethylene and may find use when manufacturing ring gaskets and insertions in mechanical engineering and transport. In particular, when manufacturing fluoroplastic tape, pellets are pressed from non-compacted paste. The latter is preliminarily shaped as different-diameter layers with different content and composition of filler to yield annular pellet with completely or partially separated in diametrical direction layers. Then, a set of fluoroplastic tapes with functional layers is simultaneously extruded. To that end, head with replaceable nozzle having combination shaped cuts and moving rod with flats coupled with nozzle cuts is used. Number of flats corresponds to that of nozzle shaped cuts. The latter are disposed uniformly on nozzle perimeter. In addition, once tape is heat treated, it is sized by way of replacing nozzle with different size of shaped cuts. Apparatus for manufacturing pellet in the process of manufacturing fluoroplastic tape is provided with conical thrust rings and a set of different- diameter spacer pipes. Thrust rings are placed on inner surface of lower plunger. Spacer pipes have fixing rings and closure fittings. Socket and cartridge have openings for releasing air from paste being compacted. EFFECT: improved design and enhanced efficiency of process. 5 cl, 6 dwg