Empirical Study of the Dyeing Behaviour of Polyester/Cotton Blended Fabrics with Disperse and Reactive Dyes Under Nigerian Industrial Conditions

Dyeing of polyester/cotton blended fabrics presents distinct technical challenges due to the different dyeing affinities, swelling characteristics, and optimal dyeing conditions required for each fibre component. This study empirically investigates the dyeing behaviour of 65:35 and 50:50 polyester-to-cotton blended fabrics using simultaneous and two-bath dyeing methods with disperse and reactive dye combinations at a textile finishing plant in Kano State, North West Nigeria. The effects of temperature, dyeing time, dye concentration, carrier chemical addition, and auxiliary concentrations on colour strength, levelness, and fastness properties were systematically evaluated using a central composite response surface design. Dye uptake on each fibre component was assessed by spectrophotometric analysis of residual dyebath liquor. Results demonstrate that simultaneous dyeing of both fibres at 130 degrees Celsius under pressure achieved colour strength within 8 percent of two-bath sequential dyeing values while reducing total process time by 35 percent. Levelness was improved by controlled addition of dyeing retarder at 2 g/L. Reactive dye fixation efficiency averaged 71 percent for cotton component under optimised conditions. Wash fastness of simultaneously dyed 65:35 blend achieved grade 4 to 5 rating for both dye types. The carrier chemical addition of 2 g/L significantly improved disperse dye uptake on polyester at 100 degrees Celsius atmospheric pressure dyeing, enabling carrier-assisted atmospheric dyeing as an energy-saving alternative at 18 percent lower energy consumption than high-temperature pressure dyeing. The study provides validated process parameters for efficient one-bath dyeing of polyester/cotton blends under North West Nigerian textile plant conditions. Keywords: polyester/cotton blend, dyeing, disperse dye, reactive dye, colour strength