A method for melt spinning of ss - lactone poly ester fibers

摘要

1,124,240. #-lactone polyester fibres. SHELL INTERNATIONALE RESEARCH MAATSCHAPPIJ N.V. 8 Aug., 1967 [10 Aug., 1966], No. 36369/67. Heading B5B. #-Lactone polyester fibres are produced by melt spinning the molten polyester through a die plate, followed by drawing the freshly extruded and molten fibre in a heated zone to a diameter of between ¢ and SP1/SP/ 40 of the diameter at which it was extruded, the temperature within the heated zone being above the polymer recrystallization temperature, and thereafter quickly cooling the fibre to a temperature below its recrystallization temperature. #- Lactones having a mono- or di-substituted alpha-carbon atom are the preferred polymer, especially ,-dimethyl-#-propiolactone. Preferably the die plate is maintained at a temperature above the extrusion temperature of the polyester, and suitable melt spinning temperatures range between 250-333‹ C. The temperature of the heated zone is suitably 177-305‹ C., and that of the cooling zone preferably below 66‹ C., especially below 38‹ C.