Research On Dye Concentration Analysis Of Successive Vats Dyeing Based On UV-Vis Spectroscopy

To achieve the reuse of dyestuff, traditional successive vats dyeingtechnology calculates the amount of dye supplement only through experience,and problems of big color differences, nonstable color shades are brought.With the advantages as high sensitivity, rapid detection, and nondestructivetesting, ultraviolet-visible spectrometry is suitable for dye concentrationanalysis. By measuring the residual liquid dye concentration of successivevats dyeing, precise guidance for the dye supplement can be provided, tomake the dyeing real-time controlled, repeat dyeing color consistent, andpromote the recycle of dyestuff.According to this request, method to analysis the concentration of dyebased on ultraviolet-visible spectroscopy is proposed by this paper, and isapplied to the link on dye supplement of successive vats dyeing. After theabsorbancies of single, mixed dye samples are detected, dye concentrationsare quantitative analysed by spectrophotometric method and chemometricsmethod concentration modles. The effects of this paper are tested by thedyeing sample tests. In this paper, the main research contents and conclusionsare as follows:(1) According to the need of dye concentration modeling analysis, theabsorbance detection platform is built. The spectral characteristics of lightsources, dyestuff are qualitative analysed, the confidence interval ofinstrument is calculated, and126,121,60concentration samples are preparedfor single, double, triple component dyes.(2) Single-component dye concentrations are analysed by the method ofleast squares, and the single-wavelength integral value as the independentvariable has the best performance. The mean deviation (Bias) is no more than3.7%, and the standard deviation of prediction (SEP) is3.790-4.201. Doublecomponent mixed dyes are analysed by the dual wavelength method, and theBias is no more than4.4%, the SEP is3.681-5.274. The triple component dyes are analysed by the simultaneous equations method, and the Bias is nomore than5.1%, the SEP is4.602-5.561. The experimental results show thatspectrophotometric method can achieve the dye concentration analysis, buthas slightly larger deviation and is unstable.(3) The SMLR model is utilized to analyse single-component dyes, and theBias is less than3.1%, the SEP is within3.4. Double component mixed dyesare analysed by the SMLR model, and their Bias is less than3.2%, SEP iswithin4.0. The PLS model is utilized to analyse triple component dyes, andthe Bias is less than1.4%, the SEP is within1.6. The experimental resultsshow that the chemometrics method to extract the characteristic wavelengthis more scientific, the model is more reliable, and the prediction results aremore accurate and stable.(4)The influence of commonly used auxiliaries on dyes’ spectral curvesis qualitative analysed. The dyeing sample tests of successive vats dyeing areconducted and the samples are color measured. The results show that themethod of this paper significantly improves the vats’ color differences,increase the vats’ number, and improve the fabric’s color stability.