Biduri (Calotropis gigantea) leaves extract as natural dyes and ultraviolet protector applied on silk fabric with an exhaust dyeing method

Abstract

Biduri (Calotropis gigantean) leaves extract can be natural dyes and ultraviolet protector agents on the silk fabric. In this research, silk fabric with ultraviolet protection performance was developed using biduri leaves extract in a simple dyeing process. This study aimed to obtain a colored silk fabric from biduri leaves extract with good UV protection properties. The methodology consisted of the extraction process using an aqueous method, dyeing process with exhaust dyeing method, and post mordanting with several mordant. Evaluation of dyeing results included color strength (K/S), color brightness (L*), color direction (a*, b*), ultraviolet protection factor (UPF), and durability after washing. The result showed brightness was inversely proportional to the color strength, and the direction of the resulting color were greenish and yellowish. Dyeing with dyes from the biduri leaves extract with FeSO4 mordant were effectively reflected by the improvement of the UPF up to 31 from an initial value of 5.4. UPF value after 5 times washing down to 29.2 and at 26.8 washing 10 times. Biduri (Calotropis gigantea) leaves showed a high potential to be utilized as natural dyes and UV protector agents simultaneously on the silk dyeing process.