Study On Indigo Foam Dyeing Of Cotton Yarn

As a kind of water saving and energy saving environmental protection technology,it is particularly important to upgrade the technology of denim dyeing and finishing industry with high pollution and high emission.This paper discusses the screening of foam system and foaming process of indigo dye,as well as the dyeing effect and dyeing property of cotton yarn under different indigo foaming dyeing conditions,through the orthogonal experiment was adopted to get the best technology of foam indigo dyeing.Compared with the traditional indigo dyeing,the results show that foam indigo technology has obvious advantages in water saving,energy saving,dyeing performance and so on.Indigo foam multiple dyeing cotton yarns with/without oxygen were compared with traditional indigo multiple dyeing cotton yarns,it is considered that the effect and properties of indigo foam dyed with yarn in the anaerobic environment can achieve the effect of indigo traditional dyeing process or even better.This topic is mainly developed from the following aspects.Firstly,the stability of colorless foam system was studied..Sodium dodecyl sulfate,sodium dodecyl benzene sulfonate and Tween 80 were selected as foaming agents,while citric acid,dodecyl alcohol and sodium alginate were selected as stabilizers.The influence of foaming process on foam system and the influence of indigo concentration on foam system were discussed.The results showed that when the foaming system was sodium dodecyl sulfate and citric acid,the foaming system had the best performance.When the temperature was 30-60 ?,the foaming system fluctuated greatly,and the foaming speed had little influence on the foaming system.With the increase of foaming time,the foaming system gradually stabilized.In order to understand the influence of the concentration of indigo dye on the performance of foam systems with/without oxygen,the performance,density and liquid p H of the two foams with/without oxygen were compared.,showed that there was no significant difference in foam density and p H of foam liquid,but the foam performance decreased first and then increased gradually with the increase of indigo concentration,showing a "rigid" transition of foam.As an indispensable dye for denim,indigo is different from reactive dye and cannot be directly soluble in water.Therefore,the reduction ratio of indigo is optimized,the process parameters of indigo reduction are determined,According to the optimum conditions of indigo reduction,the dyeing process of foam indigo was optimized.The results showed that when the dyeing temperature was 60 ?,the dye reduction time was25 min,and the dyeing time was 1s,the foam indigo dyeing scheme was the best.When the indigo foam dyeing process reached the same K/S value as the 5 g/L traditional dyeing process,the required concentration of indigo dye was 14 g/L.By comparing the two processes,The results show that the foam technology is better in saving water and saving energy,and the yarn dyeing efficiency is about 10 times that of the traditional process.The twist,single yarn strength,hairiness and appearance of the dyed yarn show absolute advantages.As for denim fabrics,the unique blue and white retro style is loved by everyone after washing,in order to get this kind of style,the most main is the indigo dyed cotton yarn on ring dyeing effect,the factory to get ring dyeing effect often adopts the traditional process to dye cotton yarn many times,In order to avoid the oxidization of the reduced indigo,nitrogen was chosen to protect it and enhance the dye penetration..The multiple dyeing of yarn with/without oxygen foam technology at different concentrations was compared with traditional technology.Indigo was attached to the yarn surface by infrared characterization,and the ring dyeing effect of yarn was observed under the microscope.The results show that with the increase of dyeing times,the K/S value increased gradually,the twist of yarn,single yarn strength are decreased,Compared with the three processes,when the dyeing times are all three times,the concentration of indigo dye required by the aerobic foam process is 4 times that of the traditional process,and the color fastness and ring dyeing effect are similar.The surface of the yarn is smoother than that of the traditional dyeing process.The concentration of indigo dye required by the anaerobic foam process is about 3 times that of traditional process,and the color fastness and ring dyeing effect are better.The penetration effect of dyes is better,and the yarn surface damage is similar to that of the traditional dyeing process.