POLYESTER THREAD FOR AN AIR BAG AND PREPARATION METHOD THEREOF

The present invention relates to a polyester thread usable for fabric for an air bag, and particularly, to a polyester thread for an air bag in which the polyester thread has a degree of crystallization of 43% to 55%, an amorphous orientation factor (AOF) of 0.2 to 0.8, and a long period fiber grating of 140Ǻ to 180Ǻ, and to a preparation method thereof and to fabric for an air bag produced from the polyester thread. The polyester thread of the present invention has high strength and high elongation property, and thus provides excellent storability, form stability and air blocking effects and simultaneously minimizes impact being applied to a vehicle occupant and protects the vehicle occupant in a safe way when used as fabric for an air bag.