Study On Low Temperature Environmental Soaping Process Of Dyed Fabrics

Reactive dyes are widely used in cellulose fiber due to their advantages of simple process,diverse chromatography and low price.But in the dyeing process,reactive dyes will be hydrolyzed in the alkaline bath,some reactive dyes hydrolysis rate as high as 20~40%.Due to its similar adsorption and diffusion properties,hydrolyzed reactive dyes are easy to be adsorbed on the fiber surface,which will seriously affect the fastness of textiles.The problem of waste water treatment and energy waste caused by repeated washing to improve fastness is becoming more and more serious and needs to be solved.In order to study the problem of staining,the definition of activity is generalized.The concept of “activity” coefficient of hydrolyzed dyes is proposed to simplify the evaluation process.Staining experiments were simulated with completely hydrolyzed dyes.The properties of 12 kinds of surfactants were evaluated under different temperature and dosage conditions,and the spatial and three-dimensional structures of 12 kinds of surfactant hydrophobic components were calculated by quantum chemical calculation of Gaussian.The influence of the surfactant structure on the antistain performance was analyzed by combining the "activity" coefficient and spatial structure.The results show that the addition of a planar structure similar to the parent structure of reactive dyes into the hydrophobic components of anionic and non-ionic surfactants can increase the adsorption of surfactants to dyes and enhance the anti-stain performance of surfactants.The adsorption of dyes by polymeric surfactants can be increased by introducing a plane structure similar to that of reactive dyes into the hydrophobic component of polymeric surfactants or introducing a certain threedimensional structure into the solvent chain.Explore low temperature,environmental protection anti-soaping technology.By measuring the activity coefficient,the anti-staining properties of 5 kinds of efficient soap lotion were evaluated.Two kinds of soap lotion with best anti-staining properties were screened to explore the soap washing technology.The low-temperature water-saving soaping technology was explored by changing the soaping temperature,the number of soaping and washing times under the condition of small bath ratio.The results showed that the optimal process was as follows: after dyeing,drain off water,for two soaping baths,one warm bath at 40℃,one cold bath,soaping agent 2g/L,bath ratio 1:10,soaping time of 20 minutes,and the soaping fastness of cotton fabric could be improved by one level after washing.With the continuous development and wide application of polyester fabric,the reductive cleaning process of polyester dyed with disperse dyes has attracted more and more attention.In particular,the ultrafine polyester and polyester/spandex fabrics dyed with disperse dyes must be improved by reducing cleaning due to the particularity of their fabrics.The traditional process will use caustic soda and sodium disulfite which will bring safety risks,waste water COD burden and other problems.With the introduction of national policies and the enhancement of people’s awareness of environmental protection and safety,this problem needs to be solved urgently.In order to obtain a more environmentally friendly reduction cleaning process,four reducing agents(sodium bisulfite,sodium hydrosulfite,sodium metabisulfite and sodium thiosulfate)were used to explore the environmental reduction cleaning process in combination with the anti-staining detergents.Under the condition of small bath ratio,the difference between traditional reduction cleaning process and semi-reductive cleaning and semi-soaping process was compared by changing the washing process.The results showed that the optimal process was as follows: after dyeing,put the water out,first carry out a reduction cleaning,then one soap washing,and finally a cold wash.The reduction cleaning formula was sodium bisulfite 1g/L,bath ratio 1:10,temperature 80℃,washing time 20 minutes;The soap washing formula is 1g/L,bath ratio 1:10,temperature 80℃,washing time 20 minutes.After washing,the soaping fastness of micro-polyester and polyester/spandex fabrics can be improved by half a stage.