Analysis of Jean's Dyeing by Pretreatment and Dyeing in One-bath

Jean fabrics are increasingly expensive nowadays. "Batch-dyeing" is an important part in jeans-like fabrics, which is not used in traditional jeans production process, while using conventional "batch-dyeing" process of cotton fabrics (desizing, scouring, bleaching and dyeing step by step). Jean's dyeing of vat dye by pretreatment and dyeing in one-bath was studied in this paper. The optimum conditions were obtained by selecting H2O2 elimination agent and controlling parameters of pretreatment and dyeing. That is: H2O2(30%) 1g/L, NaOH 15g/L, Na2SiO3 2g/L, JFC 1g/L, scouring agent 2g/L, indigo blue 2.5%, sodium hydrosulfite 4g/L, scouring and bleaching at 80 degrees C for 60min, then dip-dyeing and oxidation for 10 times. Comparing the process of pretreatment and dyeing in one-bath with traditional one, the former can get a similar performance on dyeing. In addition, the former process shows advantages such as short time, high efficiency, low energy consumption and reduced sewage emission.