Abstract:

In order to grasp the dyeing properties of the indigo, promote success rate of the production, and calculate the cost of the dyeing process, two groups of experiment were carried out in the rope dyeing machine, effect of yarn density on the dye uptake of indigo and effect of dyeing VAT on the dye uptake of indigo. The yarns were impregnated with dyeing solutions for 26s at 30oC, and oxidized for 75s，the pressure was 7.0 MPa. The dye-uptake of the drying sample yarns were tested and analyzed. The results show that，when the dosage is: indigo 2.0g/L, caustic soda 3.0g/L, sodium hyposulfite 1.32g/L, pH 11.88,oxidation-reduction potential -785mV, electrical conductivity 64.2μS/cm, the dye-uptake reduced with the increasing of the yarn density. Under the same depth, the dye uptake is inversely proportional to the square root of the yarn density .The dye-uptake increased with the increasing of the dyeing VAT, but the growth rate decreased.