Optimization of dyeing conditions for bamboo-cotton blended fabrics: A study on temperature sensitivity, chemical and mechanical properties, and environmental performance

Bamboo fibre is a regenerated cellulose renowned for its eco-friendly profile and comfort, but its dyeing processes often involve environmentally harsh conditions. We present a systematic optimization of reactive dyeing for 100 % bamboo, 100 % cotton and a 70/30 cotton-bamboo blended fabric, focusing on the critical role of temperature. Fabrics were dyed with CI Reactive Black 5 at 50 °C, 60 °C and 70 °C, and evaluated for colour performance, mechanical properties and environmental impact. The key finding was that a dyeing temperature of 60°C delivered the optimal balance for all fabrics, maximizing colour yield (K/S) and dye fixation while minimizing fibre damage and environmental effluent load. The 70/30 cotton-bamboo blend emerged as a superior sustainable alternative, outperforming pure cotton with an 8–10 % higher colour yield, 25–35 % greater water absorbency and significantly reduced shrinkage. Furthermore, the blend demonstrated a substantial environmental advantage, reducing wastewater Total Dissolved Solids (TDS) by 20–25 % and Chemical Oxygen Demand (COD) by 10–15 % compared to pure cotton. Mechanically, the blend successfully combined the high dye affinity of bamboo with the structural stability of cotton, resulting in enhanced bursting strength and pilling resistance. Our research establishes an eco-friendly dyeing protocol for bamboo-cotton blends, confirming their potential as high-performance textiles that align with sustainable manufacturing goals. • Optimal dyeing at 60°C: Achieves 93 % fixation and K/S= 23.0 for bamboo-cotton blends. • 70/30 blend excels: 8–10 % higher color yield, 25–35 % more absorbency vs. cotton. • Eco-friendly benefits: Reduces TDS by 20–25 % and COD by 10–15 % in effluents. • Enhanced durability: Superior pilling resistance, abrasion resistance, and stability. • Sustainable textile solution: Lowers water pollution and energy use in production.