The Study On Dyeing Properties And Shade-Darkening Of Fine-Denier Polyamide With Reactive Dyes

Polyamide, commonly known as nylon, is a kind of synthetic fibre which is first appeared as a commodity. It has excellent chemical stability and the character of redressing, non-ironing, dimension stability, little shrinkage and bearing climate. Products made of polyamide exhibit good elasticity, high strength and wearability, durability, little proportion, no moth-eaten, etc, which are loved by multitudinous consumers. Fine-denier polyamide fibres not only have these characteristics, but also suppleness, chubbiness, good pendency, strong elegant feeling, good breathing and comfortableness, and have the sense of quality and function that natural fibre does not have, which make fine-denier polyamide fibre good wearability. But because of the structure characteristics of fine-denier polyamide fibre:The diameter of fibre is small, whose fibrous specific surface area of per weight is large, it is determined that dyeing on fine-denier polyamide fibre has many difficulties.This article is mainly based on reactive dyes to study the dyeing technology on fine-denier polyamide from choosing dyestuffs, determining dyeing process and adding special auxiliary.In this paper, three bi-functional cotton reactive dyes and one wool reactive dye are used to dye on fine-denier nylon. The results show that reactive dyes with bi-vinyl sulphone and a-Bromoacrylamido are suitable for nylon dyeing, which have higher dye-uptake and fixation.According to SERF values, Unisol Red W-PV, Yellow W-DF, Navy Blue W-DR have similar dyeing process. For the built-up property of these dyestuffs, when the dye concentration is between3and4percent, the brightness value hardly reduces significantly. Furthermore, the built-up property of Unisol Black GN is also investigated, it is found that when the dye concentration is above14percent, the brightness value does not change any more.Effect of wet heat setting on dyeing behaviors and structure and morphology is studied in this article. It is found that, the color yield of hot water-setting fabrics is the highest among three various presetting, and it is doubled than unsetting fabric at130℃for45minutes. A small difference in the setting temperature in the hot water-setting can lead to obvious color difference.Three methods, which is pretreated with chitosan, covered with low refractive index resins, sol-gel technology, are finished to fine-denier nylon fabrics. The results show that, the nylon was pretreated with chitosan and then dyeing, whose deepening effect is better than finished with low refractive index resin. Black dyed samples pretreated with chitosan are treated by aqueous silica sol, which turned out that the dark effect is the best when silica concentration is3%and dipping time is45minutes.Other application of the sol-gel technology, for example ultra-violet cutting, was also discussed in this paper as well. Experimental results showed that nylon fabrics treated by aqueous titanium sol results in good ultra-violet cutting. The UPF of fabrics can achieve24.92after the sol- gel treatment by the mixed sol of Si/Ti=1:5, and UV transmittance dropped substantially. Compared with fabrics treated by pure aqueous silica sol, the whole curve moves20nm to long wavelength direction, and the ultra-violet absorption of UVB band declines significantly.