TOWARDS TECHNICAL DEVELOPMENT OF NATURAL DYES FOR THE TEXTILE INDUSTRY IN KENYA: A CASE STUDY OF Bixa orellana.L SOLVENT EXTRACT.

Abstract

The aim of the study is to report the dyeing of textile fibres using the natural dyes extracted from the seeds of Bixa orellana Linn. Natural dyes derived from plant materials have proved to be important alternatives to the use of synthetic dyes in the textile industry. Dyes extracted from annatto (Bixa orellana.L) seeds were used in this study. Bixa orellana.L is a tropical plant cultivated in coastal region of Kenya. Its seeds are covered by a red resin which contains a number of carotenoid compounds that constitute the main colouring agents; Bixin and Norbixin are the predominant colouring compounds. Annatto colouring compounds can be identified by (GC-MS) technique. Analyses of the essential oils were carried out using GC, GC-MS and GC co-injection (of some of the available essential oils with authentic samples).GC and GC co-injection were performed on capillary gas chromatograph Hewlett Packard (HP) 5890 A Series II equipped with a split-less capillary injector system, cross-linked Hewlett Packard Ultra Methyl Silicone (50m length, 0.22m internal diameter, 0.33μm Carbowax film thickness) capillary column and flame ionization detector coupled to Hewlett Packard 3396 series II integrator (fig 13 and 14). Hydrogen gas was used as a source of fuel, while nitrogen gas flowing at a speed of 0.8ml/min was used as carrier gas. Before the sample was injected a compensation run was made for a period of one hour. The dye was then used to dye cellulosic fibre by Exhaustion method. Dyeing was carried out using mordants through pre and post mordant in order to compare the fastness properties of the dye. Reflectance curves of the dyed materials were made using GretagMcBeth colour Eye 700 A0spectrophotometer. From the results, the plant studied is a promising dye-yielding plant and produces a yellow orange colour.It could be exploited as a source of textile dyes and an economic plant. Additionally provide more in depth knowledge on behavior of annatto dyes and dyed cotton textile fibres.