| abstract |
A high speed process for producing polyester filaments, in which process the formation of fluffs and the occurrence of filament breakage are very slight and a package having a good winding appearance can be stably obtained, by melt spinning polyester filaments at a taking-up speed of 3000 m/minute or more, while applying an aqueous emulsion of an oiling agent to the filaments, the oiling agent includes 50% by weight or more of a monobasic acid ester of a C10-18 aliphatic monocarboxylic acid with a C4-18 aliphatic monohydric alcohol and having an average molecular weight of 300 to 500; 1 to 15% by weight of a polyoxyalkylene glycol copolymer having an average molecular weight of 1,000 to 30,000; and 0.1 to 3% by weight of an organic siloxane compound and/or a fluoroalkyl (C3-18) group-containing compound. |