Abstract: A multifunctional frame retardant polyester fiber was prepared by sheath-core spinning method, with its core modified by environmentally friendly phosphorus organic flame retardant G-77 and the sheath subjected to waterproof treatment by using self-made foame-retardant master batch and PVDF, respectively, and the spinning process and functions were discussed. The experimental results revealed that the fiber had improved flame retardant and waterproofing propertis.When compared with the multifunctional flame retardant fiber prepared earlier with inorganic flame retardant agent, the G-77modified multifunctional foame retardant fiber displayed better mechanical properties and spinnability, with the maximum breaking strength up to  4.1646cN/dtex, and the winding speed was controlled in the range between 1000 and 2000 m/min.

Key words: PET, spinnability, sheath-core, multifunction, foame retarding, waterproof