DEVELOPMENT OF ENVIRONMENTALLY FRIENDLY WATER-BASED INK USING PALASH (BUTEA-MONOSPERMA) FLOWERS AND GUAR GUM VIA A GREEN PROCESS FOR SUSTAINABLE PRINTING AND PACKAGING APPLICATIONS

Abstract

Natural colourants overtake synthetic colourants as the safer, cleaner, and environmentally friendly option. An attempt has been made to extract the dye from fresh Butea monosperma (Palash) flowers. This study described a sustainable technique for removing the pigment from Palash flowers and using the resulting natural ink ingredients. The ink was blended with guar gum as a binder and sodium carbonate at different concentrations for colour enhancer. The obtained ink was characterized by different modern techniques such as FTIR, FESEM, and rheometer for its molecular interaction, surface morphology, and flowability. The viscosity of the ink varies from 2.16 Pa.s at 0.01 s-1 to 0.022 Pa.s at 1000 s-1 440.0 Pa.s at 0.01 s-1 to 0.22 Pa. s. at 1000 s-1 for PL/GG and PL/GG/SC4 respectively, which has shear thinning properties as essential for painting and printing. The total colour difference was from 28.50 to 79.34; solid content was 6.12% to 9.50%, and glossiness attributes varied from 6.4 to 7.4 for the ink formulation of neat PL/GG up to PL/GG/SC4 (SC 0 to 0.3% w/v). The addition of sodium carbonate enhances the colour properties significantly even after the rub resistance and light fastness test, which suggests that the ink formulated with palash, guar gum, and sodium carbonate persists under different processing conditions during printing and painting on various substrates. The prepared ink is water soluble and harmless, and encouraging with its green production approach, it has applications on packaging films, corrugated sheets, and fresh produce surfaces.