Globally, cotton is the largest consumed natural textile fibre and reactive dyes are the most preferred colourants owing to the wide shade gamut, ease of application, achieving acceptable fastness norms and meeting the desired cost economy. Exhaust dyeing is the most common method for cotton knitwear but detrimentally impacts environment due to discharge of large quantity of electrolyte in the effluent stream. The continuous dyeing processes demands regular and bulk orders for mass production or long meterage of same shade to ensure viability of the high capital expenditure. The cold–pad-batch (CPB) method of application is best suited from the ecology as well as the economic aspects but needs critical control over processing parameters to avoid centre to selvedge shade variation.
Global warming, carbon footprint, sustainability and zero liquid discharge are the most widely discussed and critically monitored parameters by the stakeholders of the textile value chain. Cotton is the most widely used textile fibre owing to its abundant agricultural production and characteristic comfortwear properties. However, from the ecological point of view it is considered to be the most water, energy and chemical consuming textile fibre. The wet processing is the most critical and complex part of the cotton knitwear manufacturing and it involves series of processing steps on different machines.
