Abstract: Polylactic acid (PLA) fiber and polyester (PET) fiber belong to polyester fibers which general be dyed in disperse dyes. Because of the molecular structure and chemical properties of the two kinds of fibers were different, the same dyeing would be shown the color difference phenomenon in fibers. Dyeing PLA, PET fiber with 15 typical disperse dye in papers. The experiment through the dye in the fiber color characteristic value and maximum absorption wavelength showed that significant color different phenomenon in the two kinds of fibers and dye in the PLA fiber produced light effect, and light effect of anthraquinone type and heterocyclic azo type was weaker, anthraquinone type or heterocyclic azo type disperse dye was suitable for PLA, PET woven fabric or blended fabric dyeing. Analysis of the mutual adaptability of PLA, PET and dyes had been given in papers and the dyes suit for PLA/PET blend system was put forward. The result of papers had certain theoretical guiding significance for practice dyeing and the suitable dyes of PLA, PET woven fabric or blended fabric.

Key words: solubility parameter, PLA, PET, disperse dye, color