Dyeing of Polyester Using Natural Colorant from Melastoma malabathricum L.

Abstract

Nowadays, interests on natural colorant have increased as the public are more aware and concern to environmental-related issues. In the continuing replacement of synthetic colorant, applications of natural colorant have extended to synthetic fibres. In this study, Melastoma malabathricum L. was extracted through boiling and ultrasound-assisted extraction (UAE). The colorant from UAE was dried in an oven before being converted into powder form using ball mill grinder. The colorant produced was dyed on polyester fabric at 85 °C. The polyester fabric was treated with sodium hydroxide as an alkaline treatment and chitosan prior to dyeing in an attempt to increase the dye uptake. The evaluation of the dyed fabrics was measured using colour spectrophotometer and tested for washfastness. Samples dyed using the UAE method gave lower value of L* which indicate higher dye uptake and darker colour. The fabric which was treated with sodium hydroxide gave deeper shade in comparison with the fabric treated with chitosan. The ratings for colourfastness to washing were between 3 and 5 which show moderate to good range.