Salt-free cold pad batch dyeing method for uncooked and unbleached cotton fibers

Abstract

The invention provides a salt-free cold pad batch dyeing method for uncooked and unbleached cotton fibers, and belongs to the field of cotton fiber printing and dyeing. The salt-free cold pad batch dyeing method includes putting reactive dye and alkaline substances in a mixed solution of an alcoholic organic solvent-water system to obtain dyeing liquid; putting the uncooked and unbleached cotton fibers in the prepared dyeing liquid, and performing padding by a double-dip-double-nip method; rolling the dyed uncooked and unbleached cotton fibers on a rolling machine, wrapping the rolled uncookedand unbleached cotton fibers with a plastic film, and performing rotating and stacking; after stacking, performing soaping, hot water washing, cold water washing and drying. The method has the advantages that the characteristics of high dyeing speed and high dyeing rate of the dye in an ethanol-water system are combined, the uncooked and unbleached cotton fibers can be quickly dyed by the reactive dye under the action of high permeability of ethanol according to a padding method, the dyed cotton fibers can be covalently bonded with hydroxyl groups on cellulose slowly under the condition of normal-temperature stacking to carry out dyeing, and the color fixation rate of the reactive dye in the alcoholic organic solvent-water system is increased under normal temperature conditions.

Description

Technical field [0001] The invention belongs to the field of cotton fiber printing and dyeing, and particularly relates to a salt-free cold pad-batch dyeing method of uncooked and bleached cotton fiber. Background technique [0002] Cotton fiber has become the most used natural cellulose fiber for textiles due to its strong hygroscopicity, comfortable wearing and easy dyeing. However, because the surface of cotton fiber contains impurities such as pectin, wax, cotton seed hull, and lignin, the cotton fiber dyeing process Among them, the active groups on the dye molecules easily react with the hydroxyl groups on the cellulose, which affects the dyeing performance of cotton fibers. Because the active groups on the dye molecules have high chemical bond fastness to the cellulose, the side chains of the cellulose fibers are macromolecular. The hydroxyl groups on the fabric make the fabric fibers negatively charged in the solution, and the water-soluble groups contained in the reactive...

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Problems solved by technology

[0003] In order to avoid the reaction of active groups on dye molecules with chemical bonds of cellulose and improve the utilization rate of dyes, at present, in the dyeing process, a large amount of inorganic salts are mainly added to dyes, such as adding salt to increase dyeing rate, or in dyeing Pre-treatment of cotton fiber with concentrated alkali at high temperature consumes a lot of energy and water resources in the process of treatment, and discharges a large amount of waste liquid, which not only wastes resources, but also causes serious water and soil pollution due to a large amount of saline-alkali discharge. Salinization problem, causing serious pollution to the environment

[0004] Chinese Patent Authorization Announcement No. CN103556449B, the title of the invention is a cotton-type textile cold pad-batch pretreatment method, which adopts the method of changing the cotton-type textile cold-pad-batch process route and the preparation of lye and bleaching solution in the cotton-type textile cold pad-batch process Method, the cotton-type textiles are sequentially pad-rolled with lye mixed with a high proportion of alcoholic organic solvent and sodium hydroxide, and with bleaching solution mixed with a high proportion of alcoholic organic solvent and hydrogen peroxide, and then subjected to cold pad-batch pretreatment, which greatly To a certain extent, the water consumption is reduced and the treatment effect is improved, but it is mainly the pretreatment of cotton-type fabrics through the cold pad-batch method, that is, desizing, scouring and bleaching, and does not dye cotton-type fabrics

[0005] Chinese Patent Publication No. CN103498348A, the name of the invention is a salt-free and low-alkali dyeing method that shortens the dyeing time of reactive dyes. The method adopts mixing the dyed textiles with lye in a high proportion of alcohol organic solvent and a small amount of water with the dye The method of dyeing in the resulting dye solution, although this method shortens the dyeing time of reactive dyes, realizes salt-free dyeing and reduces the amount of alkali agent, but its disadvantage is that the method of exhaust dyeing needs to be carried out at a higher temperature

Although this method solves the problem of large amount of salt and water used in the traditional pad dyeing process, its disadvantages are that the method needs to dry the cotton textile, the process is complicated, and there is a high temperature in the color fixing process after the dyeing process. higher defect

Although this method has less water consumption, low energy consumption, and improves the utilization rate of dyes, its disadvantage is that there is a defect of high temperature in the color fixing treatment after the dyeing process.

[0008] From the existing traditional dyeing process, it can be found that although in the prior art, the problem of more water consumption and salt consumption is solved by adopting the ethanol-water system, and the pad dyeing solves the problem of not needing to be immersed in a water bath for a long time, but In the color fixing process, it still needs to be carried out at a higher temperature, and it is often necessary to add other solutions in the pretreatment to improve the utilization rate and dyeing rate of the dye, so it is necessary to provide a method to simplify the operation process while improving the color fixing process

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