Abstract: In this paper, the nano-carbon black was added to PET chips by melt spinning method to prepare flame-retardant polyester fiber. The effects of nano-carbon black on the flame-retardant properties of polyester fibers were investigated. Results indicated that when the addition amount of nano-carbon black was 1.0%, the fiber had the best flame retardancy; after the introduction of nano-carbon black, the ignition time of the polyester fiber was prolonged, the heat release rate and the total heat release amount were significantly reduced; the thermal stability of the flame-retardant polyester fiber is better than pure polyester fiber; the nano-carbon black promotes the char formation of the polyester fiber, which can improve the continuity and compactness of the carbon layer on the surface of the fiber after burned, thereby isolating the heat and oxygen, so as to enhance the flam e retardancy of the fiber.

Key words: nano-carbon black; polyester fiber; melt spinning; flame retardant