METHOD FOR MANUFACTURING POLYETHYLENE TEREPHTHALATE DRAWN FIBER, POLYETHYLENE TEREPHTHALATE DRAWN FIBER, AND TIRE CORD

摘要

The present invention relates to a method for manufacturing a drawn fiber, which enables the manufacture of a polyethylene terephthalate drawn fiber which causes little degradation in strength during a tire-manufacturing process, such as a tire vulcanization process, and which exhibits superior strength and stability in form and has a large filament size of 2000 deniers or higher. The present invention also relates to a polyethylene terephthalate drawn fiber and to a tire cord obtained by the method. The method for manufacturing the polyethylene terephthalate drawn fiber comprises: a step of melt-spinning, at a speed of 2500 to 4000 m/min, polymers containing 90 mol % or more of polyethylene terephthalate and having a terminal carboxy group (-COOH) content of 20 to 30 eq/106g, so as to form an undrawn fiber having a filament size of 2000 deniers or higher; and a step of drawing the undrawn fiber at a draw ratio of 1.4 to 2.4.