Method for removing oligomers in preparation process of regenerated polyester filament yarn melt

Abstract

The invention relates to a method for removing oligomers in the preparation process of regenerated polyester filament yarn melt, and belongs to the field of spinning. The method comprises the following steps that S1, regenerated polyester bottle flakes are dried; S2, the regenerated polyester bottle flakes are molten; S3, the viscosity of a high-decomposition polymer molecular chain is reduced; S4, primary filtration is carried out on regenerated polyester melt; S5, negative pressure film drawing is carried out; S6, suction separation is carried out; and S7, filtering and collecting are carried out, wherein the S1 comprises the following steps that S1a, the treated bottle flakes are conveyed into a boiling type pre-crystallizer for pre-crystallization, part of the oligomers is removed andcollected through a cyclone dust separator after being heated to form a particle solid state; and S1b, the pre-crystallized bottle flakes enter a drying tower to be dried. After improvement, the fullpackage rate is improved by 10%, and the defective rate is reduced by 5%.

Description

technical field [0001] The invention relates to a method for removing oligomers during the preparation process of recycled polyester filament melt, belonging to the field of spinning. Background technique [0002] Using waste polyester mineral water bottles and edible oil bottles as raw materials for recycled polyester, the whole bottle is cleaned, crushed, friction washed, dried, dried, melted and recycled to replace virgin polyester to produce high-quality polyester filaments. However, due to the fact that the recycled polyester raw materials are fully rubbed and washed, some low-molecular substances still remain. For example, the glue used for the label of the old polyester bottle, the sugar and grease substances in the old polyester bottle and the residual cleaning agent in the washing process are attached to the polyester raw material and are difficult to remove. After high temperature melting, various residual substances It is converted into oligomers and mixed in the...

AI Technical Summary

Problems solved by technology

[0005] The influence of the presence of oligomers: If the oligomers are not removed in time during the melt preparation process, the viscosity of part of the melt will be reduced after a period of high temperature, resulting in uneven melt viscosity

Furthermore, it causes instability in the production during the spinning process, which in turn affects the intrinsic quality of the final product

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