Kinetics of Dyeing Cotton Fabric with Fusticwood

The dyeing of textile fabric with natural dyes has received considerable interest in recent years, due to its environment-friendly nature. The dyes usually possess lower toxicity, and are less prone to cause allergic reactions. Fusticwood, the dye used in this project, is a classic natural dye. The dyestuff, which was purchased as bark shavings, comes from the heartwood of a tropical tree related to mulberry, and provides different colors based on the mordant used. This project will attempt to determine the kinetics of dyeing cotton fabric with the Fusticwood extract, as well as how the kinetics are affected by factors such as temperature, initial dye concentration and mordant.

Dye was obtained from the bark through multiple extractions. Cotton fabric was mordanted with Alum powder overnight. In the early kinetic studies, the fabric was immersed in the dye and samples were taken over a period of 24 hours, but data from these studies revealed that the adsorption process took place primarily within the first four hours. As such, studies hereinafter focused on the first four hours of the dyeing process. Initial studies found that the absorption peak of Fusticwood dye was 324 nm, where absorption values were linearly proportional to the concentration of the dye. Kinetic studies on the first four hours of dyeing were performed at 35°C and 50°C. Initial results show second and third order kinetics. Future studies will look at statistical methods of verifying the model and go on to examine the possible factors affecting the kinetics.