METHOD FOR PRODUCING INDIGO POWDER FOR DYEING AND INDIGO POWDER FOR DYEING PRODUCED BY THE SAME METHOD

PURPOSE: A manufacturing method of indigo powder is provided to reduce the color separation time of indigo comparison with the existing method, and prevent the generation of strain because of high content of indigo colorant. CONSTITUTION: A manufacturing method of indigo powder comprises: a step of adding water into indigo, crushing the indigo to the size of 1-3 cm, and separating extract by squeezing the indigo to make the moisture content of 6-8%(v/w); a step of filtering the extract; a step of supplying oxygen to make the dissolved oxygen of 30-50 ppm, or oxidizing the indigo extract by adding 3-7% of hydrogen peroxide based on the volume of the indigo extract; a step of separating indigo colorant by centrifuging or precipitating the oxidized extract; and a step of drying the indigo colorant, and crushing the dried colorant.