Nettle biofibre bleaching with ozonation

Abstract

The nettle plant is an industrial crop, different parts of which can be used as food, fodder, and as a raw material for different product purposes in cosmetics, medicine, industry, biodynamic agriculture, and textiles. Nettle fibre usage provides bio-degradable, renewable, sustainable, and eco-friendly textile production and requires low energy consumption during production. However, the natural colour of nettle fibre is beige, cream, or light-brown. In this study, bleaching of 100% natural nettle fibre fabric with ozonation was explored. Apart from ozonation alone, ozonation in the presence of ultrasonic homogeniser activation, conventional bleaching with various bleaching agents, bleaching with a laccase enzyme, and their sequential applications with ozonation (conventional bleaching, then ozonation, followed by laccase enzyme bleaching, and then ozonation) were also investigated. Whiteness, tensile strength, hydrophilicity, and chemical oxygen demand (COD) values were determined and compared. Ozone bleaching led to less strength loss in comparison to hydrogen peroxide bleaching. Higher oxycellulose formation resulted in higher strength loss in the case of peroxide bleaching in comparison to ozone bleaching. Ozone bleaching for nettle fibre fabrics could be used as a viable alternative to hydrogen peroxide bleaching due to its effectiveness, lower application temperature, lower application time, and less environmentally harmful nature.