Study on the standardization of staining data of madder

Purpose The purpose of this paper is to study the standardization of madder dye data to analyze the effective dye concentration of the madder extract. Design/methodology/approach First, a standard curve relating K/S variation to madder dye concentration was obtained. This was derived by comparing dyeing effects on silk and cotton fabrics, which also identified optimal dyeing parameters and the maximum K/S value. Subsequently, madder plants from Anhui, Guangdong and Guangxi provinces were used to dye silk and cotton fabrics with the optimized dyeing parameters. Finally, the corresponding dye content of different madder was obtained from the established standard curve. In addition, the dry and wet rubbing fastnesses of these dyed fabrics were evaluated to further clarify the dye effect. Findings The saturation dye concentration of the standard alizarin dyed cotton fabric is about 2.8 g/L (K/S = 14.79) and the silk fabric is about 2.3 g/L (K/S = 18.62). The standard alizarin dyed color card of silk fabric presents a step change, which has a certain reference role in the grade determination of natural dyes. Originality/value This study provides a novel method for quantitative analysis of dye content in different types of madder dyes.