Ultrasound Dyeing of Polyester Using Natural Colorant from<i> Melastoma malabathricum l.</i>

Abstract

This paper reports on the application of natural dyes on polyester fabric. Melastoma malabathricum l. was extracted using conventional method of boiling for an hour. Plain lightweight 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 dye extract of Melastoma malabathricum l. was applied on the polyester fabric at 85°C for an hour by exhaustion dyeing and 40 minutes for ultrasound dyeing. The colors of the dyed fabrics were measured using colour spectrophotometer and evaluated for washfastness. Ultrasound dyeing gave deeper colour shades to the fabric even though dyeing was conducted at lower temperature for 40 minutes. The alkaline treated fabrics dyed using ultrasound gave lower value of L* which indicate higher dye uptake and darker colour. The ratings for colourfastness to washing were between 4/5 to 5.