Research On The Process Characteristic Parameters And Influencing Factors Of Supercritical Fluid Dyeing

The technology of supercritical dyeing can significantly reduce the need of water, energy and the wastewater which is needed to deal with. The influence of operation parameters to dyeing effect and the confirming about the proper operation parameters have been the focus of research to the scholars. At present, the research method about supercritical dyeing is divided into two kinds which are experiment and simulation. This paper using both experiment and simulation methods, through the study about the operation parameters in supercritical dyeing, we can get the influence about operation condition and the proper value about them, all of them can provide design reference to the practical application of supercritical dyeing.The main contents of this paper are as follows:(1) Based on the theory of finite element and tubular charging condition this paper established a2D dyeing mass transfer model, Using this model to calculate the dyeing effect of fiber materials along the radial and axial direction.(2) By changing the characteristic parameters of the model, this paper has investigated the influence of dyeing time, fiber thickness, fluid flow and the size of reaction kettle to the dyeing effect. The result is found that:the increase of dyeing time and fluid flow can not only improve the dye absorption, but also reduce the dyeing heterogeneity of the fiber materials.(3)The supercritical dyeing device with cycle system has been set up. The supercritical carbon dioxide is used as medium, ethanol is used as cosolvent, the dyeing effect of PET has been investigated. This paper has studied the influence of pressure, temperature, cosolvent, fiber thickness to the dyeing depth of K/S and friction color firmness. The results are indicated that:the increase of temperature and pressure can improve the dye absorption and reduce the dyeing heterogeneity of the fiber materials. When use ethanol as cosolvent, the dyeing effect at the surface of fiber is observably increased. But the impact of it is declined rapidly when the thickness is increased. Though the increase of pressure can improve the dye absorption, but it can not ensure the friction color firmness, in this condition, the rise of temperature can improve the dyeing effect and at the same time make the friction color firmness stay steadily.(4) To study the natural fiber dyeing properties, the experiment device which established in this paper is used and using the cotton as dyeing object. Through the change of temperature, pressure, dyes, cosolvent, the dyeing effect of cotton in the supercritical fluid is studied. It is found that:the choice of the dyes has observably influence to the dyeing effect. In this paper, when add water as cosolvent the alkaline dyes and disperse dyes are showed good dyeing effect, the dye diffusion effect can be observably improved when the cycle system is added, and the dyeing uniformity can be also improved.