PROCEDIMENTO PER LA PRODUZIONE DI POLVERI COLORANTI

A method for producing dyestuff powders by spray drying a dye dispersion or solution characterized in that the spray drying is effected using a spray dryer comprising a drying room with an inlet for the introduction of hot air into the drying room and an outlet for the discharge of hot air with dyestuff powders from the drying room, an atomizer for spraying the dye dispersion or solution therethrough positioned at the upper part of the drying room and an accelerating means for increasing the velocity of the hot air. The production parameters are controlled so that the temperature at the inlet is between 110 DEG and 260 DEG C., the temperature at the outlet is between 60 DEG and 80 DEG C. and the velocity of hot air at the position just under or around the atomizer is between 5 and 80 m/sec.