The invention discloses a production technology for
indigo cotton
yarn. The production technology comprises the steps of blowing,
carding, first drawing, second drawing, third drawing, roving,
spinning and post
processing, and specifically comprises the steps that firstly,
indigo dye
coating is molten to be prepared into a leuco body for use; secondly, preprocessed cotton is put into the
indigo dye
coating, the temperature is increased to 35 DEG C at a speed of 3 DEG C / min, temperature keeping is conducted for 30 min, the temperature is increased to 120 DEG C at a speed of 2 DEG C / min,
dyeing continues to be conducted for 20 min, the temperature is decreased to 40 DEG C at a speed of 3 DEG C / min, and the cotton is taken out; thirdly, blowing,
carding, first drawing, second drawing, third drawing, roving and
spinning are conducted on the dyed cotton so that the cotton can be spun into cotton
yarn for use; fourthly, post
processing is conducted on the dyed cotton
yarn, and post
processing comprises drafty oxidation for 5 min, soaping and stoving,
soap washing liquor is formed by adopting
anhydrous sodium carbonate of 2 g / L and standard
soap flakes of 5 g / L, the temperature is 60 DEG C, time is 20 min, and
soap boiling, washing and stoving are conducted on the oxidized fabric.