Studies on Color-Strength-Related Parameters and Compatibility for Dyeing of Cotton Fabric with Binary Mixtures of Jackfruit Wood and Other Natural Dyes

Abstract

Varying proportions of binary mixtures of aqueous extracts of jackfruit wood (JFW) with other natural dyes like manjistha (MJ), red sandalwood (RSW), marigold (MG), sappan wood (SW), and babool (BL) have been used to dye bleached cotton fabric premordanted with 20% myrobolan and then 20% aluminium sulphate applied in sequence. Binary combinations of JFW with each of the other five extracts named above have been evaluated for color strength (K/S value), coefficient of variation for color strength, and other related color parameters, such as brightness index (BI), changes in hue (ΔH), metamerism index (MI), and total color differences (ΔE). The compatibility of these binary mixtures was assessed by a conventional method of analysis of ΔC versus ΔL plots and K/S versus ΔL plots for progressive depth of shade produced by varying time and temperature profile, as well as by varying total concentrations of the binary mixture of dyes taken in equal proportion. A simple method of assessing relative compatibility rating (RCR) of pairs of dyes has been proposed, where a new empirical index called color difference index [(ΔE × ΔH) / (ΔC × MI)] has been postulated and corresponding relative compatibility ratings (5 = excellent, 4 = good, 3 = average, 2 = poor, 1 = worst, and 0 = noncompatible) have been determined. The results of this newer system of compatibility rating are in agreement with the results of the conventional methods of ΔC versus ΔL or K/S versus ΔL plots. The order of the relative degree of compatibility of these binary mixtures of natural dyes applied on premordanted cotton is JFW: MJ >JFW: RSW ≥ JFW: BL ≥ JFW: MG >≫ JFW: SW