Fibers and polymers

 

Colorimetric Analysis of the Stability of Annatto Dye in Solution and It’s Use in the Dyeing of Polyester Fibers

Summary:

                   Nowadays, the alarming issues that the chemical industries are facing include the sustainability and the reduction in the amount of waste produced. In case of textile industries, its biggest cause is the use of synthetic dyes instead of natural dyes. The sense of natural dyes has been used from the middle ages. They can be obtained from roots, berries, bark, leaves and woods. But, they have some kind of disadvantages such as difficulty in reproducing colors, standardization of recipes for dyeing, restricted color range, and low levels of solidity. In addition, natural dyes are sensitive to light and heat, extra care must be taken in their use. On the other hand, synthetic dyes have greater tinctorial power, lower cost, have resistant against light, pH and temperature conditions, good solubility, wide range of color shades and fiber fastness. These features are also the reason for their use in textile industries. But, there come some restrictions. Chemical dyes of azo group cause skin and lung diseases to humen. Therefore, researches have been made on the search for alternative dyes from natural resources with the aim of minimizing these harmful impacts.

                  Annatto is one of oldest known natural colorants. It has almost all the properties of a dye. It presents biodegradability, low toxicity and is environmental friendly. It has yellow-orange pigment and is abundant in carotenoids such as bixin. It has also uses in cosmetics, as a food coloring agent and antioxidant. It is more stable and has an attractive color. It is also sensitive to light and heat. But, extra care must be taken in its use.

                  Polyester (PES) is a synthetic fiber used in production of fabrics. This fiber has excellent properties, such as comfort, attractiveness, thermal retention, air permeability and low in cost. It has tensile traction and chemical resistance.

                 The synthetic dyes are not environmentally benign. Therefore, their replacement with natural dyes must be study. The behavior of annatto dye in PES fiber dyeing was investigated by parameters of color and solidity.