Method for producing polyester industrial yarn by one-step method

Abstract

The invention discloses a method for producing polyester industrial yarn by a one-step method, comprising a solid-phase polymerization step, a fusing spinning step, a stretching and heat shaping step and a winding and forming step. The method is characterized in that: in the solid-phase polymerization step, raw materials with the viscosity of 0.65+ / -0.05dl / g, the content of terminal carboxyl group of 24+ / -3mol / t are cut into pieces and stuck to be materials with the viscosity of 1.035+ / -0.01dl / g, the water content less than or equal to 20ppm and the content of the terminal carboxyl group lessthan or equal to 15mol / t through continuous solid-phase polymerization; in the fusing spinning step, the ratio of the length to the diameter of spinneret orifices of a spinneret plate for spinning is3:1, the deviation ratio of the aperture to the length of the spinneret orifice is + / -0.02, and the spinneret orifices are evenly arrayed in the spinneret plate; in the stretching and heat shaping step, four rollers are adopted for stretching and shaping; and in the winding and forming step, the winding speed is 6,300+ / -500m / min. The polyester industrial yarn can simultaneously achieve the performances of high strength, high modulus and low shrinkage, and has breakage strength more than or equal to 8.2CN / dtex, initial modulus more than or equal to 110N / dtex, the modulus more than or equal to 5.0cn / dtex when 5 percent is stretched and dry heat shrinking percentage less than or equal to 4.1 percent.

Description

technical field [0001] The invention relates to the technical field of polyester industrial yarns, in particular to a method for producing polyester industrial yarns in one step. Background technique [0002] As a rubber skeleton material, polyester industrial yarn is widely used in the fields of tires, conveyor belts, high-pressure hoses and building decoration. Among them, the tire cord fabric used for high-grade passenger tires not only requires the cord fabric to have high strength and high modulus to ensure its low loss performance and reduce the heating phenomenon of the tire during use, but also requires it to have good low shrinkage, which is beneficial to the tire. Forming process and avoid tire side dent phenomenon. [0003] At present, industrialized production of high-strength, high-modulus and low-shrinkage industrial filaments mainly includes spinning and drawing one-step method and two-step method. The one-step method is that the raw material slices (PET sli...

AI Technical Summary

Problems solved by technology

Among them, the one-step method has the advantages of short process flow, high product quality, good benefit and less equipment footprint, so it is better than the two-step method, but the high-temperature spinning, high-temperature and high-stretching spinning process not only affects the performance of the equipment. Very high requirements, such as spinning speed at least 6000 ~ 7000m / min, and because the stretching heat setting is carried out at a higher speed, the heating time of the tow is shorter, the crystal growth is not sufficient, and the requirement of low shrinkage cannot be taken into account

Therefore, due to factors such as equipment reasons and difficult process control, the promotion and application of the one-step method is greatly restricted, especially the products produced cannot simultaneously take into account high strength, high modulus and low shrinkage.

Moreover, its spinning speed is generally below 6000m / min, and the products produced generally cannot reach high modulus.