Abstract: The generatrix of cyan dye ink in reactive digital printing is a copper phthalocyanine type structure, which has poor substantivity and low fixation rate. In order to solve this problem, the paper adjusted the process formula and optimized it by orthogonal experiment. The research results show that replacing sodium bicarbonate with sodium carbonate and adding sodium sulfate in the formula can significantly improve the fixation rate of the cyan dye ink. The optimized process formula is as follows: 0.3% of sodium carbonate, 1% of sodium sulfate, 10% of urea, at 102 ℃ steaming temperature for 10 min. The optimized process formula is also applicable to several other digital printing reactive dye ink colors, improving the fixation rate, having less affection on the tensile breaking strength of the fabric. But the tearing strength is slightly reduced.

Key words: digital printing; cyan dye ink; orthogonal test; fixation rate