Technology for producing direct spinning terylene industrial filaments after liquid state polycondensation of prepolymer

Abstract

The invention discloses technology for producing direct spinning terylene industrial filaments after liquid state polycondensation of prepolymer and belongs to the technical field of spinning. The technology comprises the processes of esterification, prepolycondensation, liquid state polycondensation, and spinning, and is characterized by comprising the following steps of: performing prepolycondensation reaction on esterified ethylene glycol and phthalic acid to prepare a melt with the viscosity of 0.3 to 0.4dl/g, and conveying the melt to a liquid state polycondensation kettle for liquid state polycondensation by using a booster pump; and conveying the melt to a spinning beam for spinning through a gear pump, wherein the inherent viscosity of the polyester melt after liquid state polycondensation is 0.85 to 1.05dl/g. By directly conveying the melt into the liquid state polycondensation kettle for polycondensation and performing the production technology of directly spinning the melt, the production technology for producing the direct spinning terylene industrial filaments after the liquid state polycondensation of the prepolymer shortens the process flow, reduces the production energy consumption and production cost, and solves the technical problem of difficulty in conveying the melt simultaneously.

Description

Technical field: [0001] The invention relates to a production process of directly spinning polyester industrial filaments from a precondensed melt after liquid-phase viscosification, and belongs to the technical field of spinning. Background technique: [0002] For a long time, because the polyester civilian yarn industry has been in a state of low-profit and no-profit operation, and as the thriving polyester industrial yarn in 2007 and 2008, it has become the goal of many polyester civilian yarn companies. Therefore, after 2009, the new production capacity of polyester industrial yarn has been rapid. Expansion eventually led to the current meager profit of polyester industrial yarn. At present, the quality of polyester industrial yarn has been greatly improved, and how to reduce production costs on the basis of ensuring high quality is a key issue in the field of polyester industrial yarn to enhance its own competitiveness. [0003] In the production of polyester industria...

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Problems solved by technology

[0007] 1. From the point of view of the production process, the final polycondensation process, the solid-state polycondensation process, and the screw extruder melting and slicing process consume a lot of energy, and the process is complicated, and there is a certain production consumption. It can be seen that no matter the traditional production method It is still a new technology of liquid-phase viscosifying melt direct spinning, and the production cost pressure is relatively high.

[0008] 2. In the direct spinning production process of liquid-phase viscosified melt, due to the high viscosity of the melt obtained by final polycondensation, it will require a lot of energy to transport such a high-viscosity melt to the liquid-phase viscosified process, including melting Pressure increase, temperature insulation, etc., all of which have certain technical difficulties

[0009] To sum up, in the existing production process of polyester chips, the process of final polycondensation, solid-state polymerization, and the processes of melt spinning of chips into the screw extruder will go through repeated heating, cooling, melt solidification, pellet injection and remelting, etc. process, resulting in a sharp increase in energy consumption. At the same time, the dust, debris and viscosity difference between the inside and outside of the high-viscosity slices during the production process will lead to unstable quality of existing polyester industrial yarn products.

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