Abstract: Method for manufacturing polyester fibers comprising melt-extruding a polymer without increasing an intrinsic viscosity of the polymer during spinning to minimize a reduction of the intrinsic viscosity of the polymer; maintaining a low atmospheric temperature directly below a nozzle to maximize a degree of orientation of undrawn yarn; winding the polymer at 2,000 m/min or more to produce a undrawn yarn, followed by drawing the undrawn yarn through continuous three phases at low temperature. The method has advantages in that high strength and low shrinkage polyester fibers with a uniform fineness and physical properties can be manufactured at high spinning efficiency, without formation of broken filament and curved filament, by preventing formation of a vortex of cooling air with the use of eddy plates directly below a nozzle.

Abstract: Described in the present invention is a polyester multifilament yarn having a high modulus and low shrinkage which provides a treated cord having high tenacity and improved dimensional stability that can be advantageously employed as a fibrous reinforcement material of rubber products such as tires and belts.

Abstract: Described in the present invention is a polyester multifilament yarn having a high modulus and low shrinkage which provides a treated cord having high tenacity and improved dimensional stability that can be advantageously employed as a fibrous reinforcement material of rubber products such as tires and belts.

Abstract: Disclosed is a method for manufacturing polyester fibers comprising the steps of: melt-extruding a polymer without increasing an intrinsic viscosity of the polymer during spinning to minimize a reduction of the intrinsic viscosity of the polymer; maintaining a low atmospheric temperature directly below a nozzle to maximize a degree of orientation of undrawn yarn; winding the polymer at 2,000 m/min or more to produce a undrawn yarn, followed by drawing the undrawn yarn through continuous three phases at low temperature. The method has advantages in that high strength and low shrinkage polyester fibers with a uniform fineness and physical properties can be manufactured at high spinning efficiency, without formation of broken filament and curved filament, by preventing formation of a vortex of cooling air with the use of eddy plates A directly below a nozzle.

Abstract: Disclosed is a process for preparing a high modulus and a low shrinkage polyester multifilament yarn of 1000 deniers or more at a spinning rate of 2,000 m/min or more, comprising the steps of: melt-extruding polyester chips having an intrinsic viscosity of 0.90 to 1.2 through a spinning nozzle and passing polyester chips through a heating zone; quenching melt-extruded yarns with the use of a radial in-to-out quenching method to solidify them; and providing spin finishes to solidified yarns before winding. The industrial polyester multifilament yarns have a coefficient of variation of 4.0% or less in a cross sectional diameter of filaments, and excellent uniformity of fineness. Treated cords formed from the industrial polyester multifilament yarns with high modulus and low shrinkage have an excellent dimensional stability and tenacity, and can be used as reinforcements of rubber goods such as tires.

Abstract: A method for preparing industrial polyester fibers involving melt-spinning polyester chips through a nozzle, oiling the resultant filaments with an aqueous emulsion oiling agent, and producing, from the filaments, multifilament yarn at a speed of 2000-3300 m/min.