Preparing method for ordinary-pressure positive-ion dyeable polyester fiber

Abstract

The invention relates to a preparing method for an ordinary-pressure positive-ion dyeable polyester fiber. The preparing method includes the steps that dimethyl isophthalate-5-sodium benzenesulfonate,ethylene glycol, a catalyst and an anti-ether agent are mixed to be subjected to an ester exchange reaction, the reaction is end, then ethylene glycol and sodium ethylene glycol are added, modulationis carried out, then terephthalic acid, ethylene glycol and a catalyst are mixed, and the mixture is subjected to an esterification reaction; the modulated product after the ester exchange reaction is end and polyethylene glycol are added into an esterification reaction system reaching the end point of the esterification reaction, condensation polymerization is carried out, and spinning melt is obtained; the spinning melt is measured, extruded, cooled, subjected to oil applying, stretched, subjected to heat setting and wound, and the ordinary-pressure positive-ion dyeable polyester fiber is prepared. According to preparing method, generation of impurities in the polyester-fiber production process is reduced, pressure rising of a spinning assembly and a filter is reduced accordingly, the service cycle of the polyester fiber is prolonged, the continuity and the safety of the whole production process are guaranteed, and the preparing method has the good economic value and popularizationvalue.

Description

technical field [0001] The invention belongs to the field of polyester spinning, and relates to a preparation method of normal pressure cationic dyeable polyester fiber. Background technique [0002] Due to the high crystallinity, high degree of orientation and high glass transition temperature of PET fibers, it is often difficult for dyes to diffuse into PET molecules under the condition of normal pressure and no carrier, which makes it difficult to dye PET fibers. Therefore, the dyeing of PET fibers It needs to be carried out under high temperature and high pressure or in the presence of a carrier. Cationic dye-dyeable PET chip (CDP) is a copolymer formed by introducing a third component into the macromolecular chain of PET, which overcomes the shortcomings of polyester that is not easy to dye, and has become the next best choice for bright and semi-dull PET. Another important PET variety after slicing, the third component generally contains a strongly acidic sodium sulfo...

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Problems solved by technology

[0004] However, there is a major problem in the production process of this product: due to the addition of the third component in the CDP melt, its apparent viscosity is relatively high, and the impurities generated during the production process also increase accordingly, causing pressure on some spinning components and The pressure difference of the filter rises quickly, and at the same time, carbonized coke is formed on the inner wall of the pipeline. These carbonized coke adhere to the inner wall of the pipeline, which is easy to cause blockage of the pipeline system and is not easy to be removed, which brings great difficulties to the dredging of the pipeline. In addition, in the process of producing this kind of fiber, the service life of the filter is greatly reduced, generally only one week, while the service life of some other spinning components is generally only 10 days, so it needs to be cleaned and replaced frequently. Wire components, which will not only increase operating costs, but also affect the continuity and safety of the entire production process