Substrate Color Prediction through Active Monitoring of the Exhaustion Dyeing Process

Abstract

Nowadays, the monitoring and control of the exhaustion dyeing processes is still done in a reactive and indirect fashion. The monitoring focusses on variables that influence the output of the dyeing process, such as temperature, pH and electrolytes concentration. This approach is more reactive than preventive, since it does not proactively detect deviations in the dyed substrate color that are caused by other process variables.The aim of this work is to develop a customized system that could actively monitor and predict the color of the dyed substrate after washing. This involves mathematical models and integration of a USB 4000 spectrophotometer and T300 dip probe made by Ocean Optics, which collects, analyzes and process the data from dyeing solutions. Validation tests performed with direct dyes and 100% cotton fabrics showed a good correlation with the real results, especially after 60 minutes of dyeing. For all the tested dyes, applied alone and combined, the color differences (ΔE94) between the measured and the predicted color were equal or less than 0.70 and 1.52 respectively.