Project Database

Indigo Dye Removal From Cotton Denim Waste

Due to the growth in world population, textile production and consumption are continually increasing, therefore a higher amount of pre- and post-consumer textile waste has been accumulated. Reuse and recycling of textile waste can save the use of raw materials, energy and water consumption, chemicals and auxiliaries and waste water treatment. Denim is fast selling apparel throughout the world. Currently, there are many denim companies in the world. Denim is a kind of cotton warp-faced twill that is characterized by indigo dying and only the warp is dyed. The aim of this project is to develop a physical method for removing those indigo dye color, so that the denim waste can be more easily reused or re-dyed. Specifically, the objectives of this project are to:

• Develop a physical method with the use of high temperature water and activated carbon (AC) for removing the indigo blue color from cotton denim.
• Conduct experiments to optimize the conditions of parameters in the method for achieving a target decoloring efficiency ≥ 98% as defined by K/S measurement.
• Characterize the mechanical strength of the decolored and the original cotton.
• Develop a decoloring process and a pre-industrial scale system based on the method.
• Estimate the operating cost and perform sustainability impact assessment.

Project No. (ITC) ITP/051/19TP
Project Type Platform
Project Co-ordinator Dr. CHAN Alex
Research Institute The Hong Kong Research Institute of Textiles & Apparel Limited
ITF Amount HK$ 7,804,000
Start Date DD/MM/YY 2020-03-31
Completion Date DD/MM/YY 2022-03-30
Arvind Limited
GAP International Sourcing Ltd.