Production of polychlorotrifluoroethylene textiles

Claim 1

PROCESS FOR MAKING FINE FILAMENTS AND MULTI-FILAMENT YARNS FROM POLYCHLOROTRIFLUOROETHYLENE RESINS WHICH COMPRISES HOT DRAWING A MOLTEN FREELY EXTRUDED FILAMENT OF POLYCHLOROTRIFLUORETHYLENE ELAVING AN EXTRUSION DIE FROM 75 TO 200 TIMES ITS ORIGINAL LENGTH WHILE SUBJECTING SAID ARTICLES TO A TEMPERATURE WITHIN THE RANGE FROM ABOUT 300*C. TO ABOUT 500*C., COOLING THE HOT DRAWN FILAMENT TO BELOW THE SOFTENING POINT OF THE RESIN, THREAFTER STEETCHING THE DRAWN FILAMENT FROM ABOUT 200% TO ABOUT 700% OF ITS LENGTH WHILE AT A TEMPERATURE WITHIN THE RANGE FROM ABOUT 50*C., TO ABOUT 150*C., AND ANNEALING THE STRETCHED ARTICLE BY BRIEFLY EXPOSINGTHE SAME TO TEMPERATURES OF ABOUT 150*C. TO 200*C. UNDER CONDITIONS PREVENTING SHRINKAGE IN EXCESS OF 20% OF SAID STRETCHED ARTICLE, SAID POLYCHLOROTRIFLUORETHYLENE HAVING ESTIMATED MOLECULAR WEIGHTS IN THE RANGE FROM AROUND 25,000 TO AROUND 75,000 AND HAVING MELT VISCOSITIES AT 230*C. OF AT LEAST 0.5 MEGAPOISE.