HIGH TENACITY POLYESTER GREY YARN HAVING FLAT CROSS-SECTION, EXCELLENT ADHESION AND UTILITY RATE OF TENACITY, AND MANUFACTURING METHOD OF DIP CORD

摘要

PURPOSE: A manufacturing method of dip cord and polyester grey yarn having a flat cross-section 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 is obtained by the steps of: preparing polyester solid-phase polymerized chip having over 0.8dl/g of inherent viscosity; melting the polyester chip at 270-300deg.C of spinning temperature to manufacture liquid polymer; discharging the liquid polymer through a base having 1.2-15 of flattening; and then spinning the polymer at 2000-3500m/min. of spinning velocity in a draw ratio of 1.4-3.4 times. The polyester grey yarn has over 30% of crystallinity, over 6.0g/d of strength, a maximum shape stability of 20% and 1.2-5.5 of flattening. Dip cord is obtained by twisting the polyester grey yarn in the maximum total draw ratio of 5% and dipping the yarn at 230-260deg.C of heat-treating temperature for 30-50seconds. The dip cord has over 5.9g/d of strength, a maximum shape stability of 9.0% and over 90% of utility rate of tenacity based on the grey yarn.