Central Composite Design Approach for Optimization of Extraction and Dyeing Conditions of Marigold Colorant

Abstract

Marigold flowers are used in many Asian countries for various occasions, rituals and offerings. A considerable amount of unused marigold flowers is wasted while the used ones also pose problems in disposing off. Central composite design of experiment was used to optimize the extraction and dyeing conditions of natural dye from marigold flowers. The effect of pH of the extraction medium, extraction time and material to liquor ratio was investigated. It was found that pH and liquor ratio had statistically significant effect on dye extraction, whereas the effect of time, within the range used in this study, was not found to be significant. Optimum dye extraction was obtained in acidic pH of the extraction medium at lower liquor ratio. Temperature and time dyeing are the most influential factors among many other parameters including amount of salt and material-to-liquor ratio. Cotton fabric dyed with the optimized dye extract, showed very good washing and light fastness properties but poor wet crocking fastness.