A kind of spinning method of the high-viscosity polyester melt that reduces oligomer

Abstract

The invention relates to a spinning method of oligomer-reduced high-viscosity polyester melt in the technical field of chemical fiber production, which transports the high-temperature melt after viscosity increase to the spinning mechanism through a multi-stage screw pump; the screw The temperature of the high-temperature melt at the output end of the pump is 285±5°C; a mixer is installed after each stage of the multi-stage screw pump, and the low-temperature melt is input into the mixer through the bypass input port, and mixed with the high-temperature melt in the mixer , reduce the temperature of the high-temperature melt, so that the temperature of the output melt of each stage mixer is 280±5°C; output the melt to the spinning mechanism through at least two stages of screw pumps and mixers for spinning, and the screw pumps step by step Pressurization, the melt temperature at the front end of the spinneret is 285±5°C, and the melt pressure is 12‑16Mpa. This method can effectively reduce the flow rate of the melt, reduce the chance of shear temperature rise, and at the same time, eliminate the influence of shear temperature rise through mixing and cooling, thereby reducing the generation of cyclic oligomers and ensuring the spinning quality.

Description

technical field [0001] The invention relates to the technical field of chemical fiber production, in particular to a spinning method of high-viscosity polyester melt. Background technique [0002] In the prior art, during the polyester spinning process, the high-viscosity melt PET usually needs to be heated and maintained at 285±5°C for transportation. During the transportation process, the inside of the melt will heat up due to shearing. Finally, the high temperature will lead to the production of high-melting cyclic oligomers. The melting point of the cyclic oligomers is as high as 310 ° C. It does not melt at the temperature of polyester melting and heating, which directly affects the life of the melt filter. The clogging of the filter holes will also affect the life of the spinneret and the final spinning quality. An effective way to reduce shear heating is to reduce the flow velocity, but the decrease in flow velocity will inevitably lead to a decrease in efficiency. ...

AI Technical Summary

Problems solved by technology

[0002] In the prior art, during the polyester spinning process, the high-viscosity melt PET usually needs to be heated and maintained at 285±5°C for transportation. During the transportation process, the inside of the melt will heat up due to shearing. Finally, the high temperature will lead to the production of high-melting cyclic oligomers. The melting point of the cyclic oligomers is as high as 310 ° C. It does not melt at the temperature of polyester melting and heating, which directly affects the life of the melt filter. It will lead to clogging of the filter holes, and will also affect the life of the spinneret and the final spinning quality

An effective way to reduce shear heating is to reduce the flow velocity, but the decrease in flow velocity will inevitably lead to a decrease in efficiency. Melt 285±5℃ is a difficult problem in this field

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