The Preparation of Traditional Fermented Iron Solution and Its Effect on the Tannate-Dyed Fabric Properties

This article discusses the traditional method of preparing a fermented iron solution and its application to myrobalan-treated silk and cotton fabrics. A chemical reaction for the preparation of a fermented iron solution, along with the development of a black colour on myrobalan-treated fabrics, is also discussed. The surface colour strength and other colour parameters of myrobalan-treated silk and cotton fabrics dyed with a fermented iron solution containing varying proportions of scrap iron, and mordanted with commercial ferrous sulphate solutions of different concentrations, are also assessed. It is observed that myrobalan-treated silk and cotton fabrics dyed with fermented iron solution containing 75 g of scrap iron and molasses produce the highest shade depth. The surface colour strengths are much higher for the traditional method of producing iron-tannate black colour than those of ferrous sulphate, in the concentration tested. The tenacity of myrobalan-treated cotton and silk fabric, when dyed with fermented iron solution, where 75 g of scrap iron is used, is maximum. However, twelve months of storage weaken the fibre substrates. An attempt is also made to minimise the loss of strength in black iron-tannate-dyed fabric after applying a weak organic basic salt following the dyeing and washing process. It is observed that the black iron-tannate-dyed silk and cotton fabrics treated with sodium acetate in the concentrations tested and stored for twelve months show better retention of tensile strength than the untreated black iron-tannate-dyed silk and cotton fabrics.