Extraction of Natural Dyes from Turmeric (Curcuma longa) and their Application on Polylactic Acid Fiber

This research presents an eco-friendly approach towards Response Surface Methodology (RSM). The current study is based on the optimization of the dyeing process of biodegradable polylactic acid (PLA) fiber using with natural dyes of turmeric extractions by using Soxhlet extraction technique. The dyeing process was carried out by using Daelim Starlet III, which is an infrared dyeing machine. Three independent variables were selected, including pH, time, and temperature. According to the standard test protocols, dyed samples were evaluated for color strength (K/S), CIELab values, fiber tenacity, and fiber elongation. ANOVA test results of the Linear Model exhibited that the model terms have a significant effect on K/S and the physical strength of fiber. Moreover, the observed values were in agreement with the predicted values and the suggested equation model was satisfactory and accurate. A temperature of 100 °C with pH 5 and time duration of 30 minutes in the dyeing process were observed to achieve optimum dyed PLA fibers, exhibiting appreciable strength and elongation. Lastly, dyed fibers exhibited satisfactory color fastness ratings. Index Terms: color strength, exhaustion, natural dyeing, polylactic acid fiber, turmeric