The indigo leaf powder dye which it prepares from the fresh leaves of Polygonum tintorium and the manufacturing and dyeing method

摘要

PURPOSE: A powdered dye using Polygonum tintorium leaves and a preparation method thereof are provided to exhibit high storage stability. CONSTITUTION: A method for preparing a powdered dye using Polygonum tintorium leaves comprises the following steps of: preparing Polygonum tintorium leaves; squeezing the leaves to obtain a Polygonum tintorium leaf extract; and freeze-drying the Polygonum tintorium leaf extract and pulverizing it to obtain powder. In the freeze-drying step, the Polygonum tintorium leaf extract are freeze-dried at the temperature of - 75C ~ -85C in a freeze-drier.