Spinning method of high-viscosity polyester melts for reducing oligomers

Abstract

The invention relates to a spinning method of high-viscosity polyester melts for reducing oligomers in the technical field of chemical fiber production. High-temperature melts subjected to viscosity increasing are conveyed to a spinning mechanism through multiple stages of screw pumps; the temperatures of the high-temperature melts at the output ends of the screw pumps are 285+ / -5 DEG C; a mixer is arranged behind each of the multiple stages of screw pumps, bypass input ports are used for inputting low-temperature melts into the mixers, the low-temperature melts are mixed with the high-temperature melts in the mixers, the temperatures of the high-temperature melts are reduced and the temperatures of output melts of the mixers of all stages are 280+ / -5 DEG C; and melts are output to the spinning mechanism for spinning through at least two stages of screw pumps and mixers, the screw pumps perform pressurization stage by stage, the temperatures of melts at the front end of a spinneret plate are 285+ / -5 DEG C, and the pressures of the melts are 12-16 MPa. According to the method, the flow rate of the melts can be effectively reduced, the chance of temperature rise caused by shearing isreduced, and meanwhile, the influence of temperature rise caused by shearing is eliminated through mixing cooling, so that the production of the cyclic oligomers is reduced and the spinning quality is guaranteed.

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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