Optimization of Extraction Methods and Dyeing Standarization of Nila Leaves (Indigoferatinctoria Linn.) as Natural Dyes

Abstract

Indigosol is commonly used as a synthetic dye to generate blue color. However, synthetic dyes are detrimental to health and environment because they contain heavy metals. Nila plant (Indigoferatinctoria Linn.) contains indican glucoside which produces indoxyl exotic blue gold color and known as indigo. Indigo produce the dull-colored, when applied to cotton material. This study aims to get the optimize extraction method and standard dyeing of nila as cotton material natural dye, in order to generate sharper blue color. Nila leaves were extracted by variation time of maceration at 12, 24, 36, 48 hours and variation boiling temperature at 70, 80, 90 °C in aquadest, with pH 11 and 13. The indigo level was measured using spectrophotometer at λ 611 nm. The optimal result were applied to prima and primissima cotton material and then tested in fade resistance to leaching with staining scale (SNI-08-0285-1998) and color depth with spectrophotometer method with λ 380 - 780 nm. This study showed that in maceration and boiling method, pH significantly affected the indigo level. The treatment of 12-hour maceration at pH 11 and boiling at 80-90°C at pH 11 were the most optimal treatment to produce sharp blue color, both in prima and primissima cotton material. The best scale of fade resistance was 3-4, which was indigo extract with 12-hour at pH 11 in the maceration method and applied in primissima cotton. It can be concluded that maceration method generates sharper dye than the boiling method in primissima cotton material.