MANUFACTURING METHOD OF POLYESTER GREY YARN HAVING EXCELLENT FLATNESS, INCREASING QUALITY AND BEING LIGHT

摘要

PURPOSE: A manufacturing method of polyester grey yarn and dip cord is characterized by minimizing pore between filaments after twisting and weaving, controlling infiltration and diffusion of an adhesive composition to reduce stiffness of the dip cord and to increase utility rate of tenacity and reducing content of the adhesive composition to reduce a production cost. CONSTITUTION: Polyester grey yarn manufactured by a directly spinning draw method or a warp draw method is obtained by the steps of: preparing liquid polymer melted polyester solid-phase polymerized chip; discharging the liquid polymer through a base having 1.2-15 of flattening; quenching the discharged polymer on a hood-heater having 250-350deg.C and 120-400mm of length and an insulating board having 70-400mm of length on 0.01-0.10sec. of detention period; and then spinning the quenched undrawn yarn at 500-1000m/min. of spinning velocity in a draw ratio of 4.5-7.0 times on 0.5-12% of relaxation ratio at 200-245deg.C of heat-treating temperature. A drawn yarn thereof has over 0.2050 of birefringence ratio, over 45% of crystallinity and 1.2-5.5 of flattening.