Study On The Process Of Water Saving Reduction Washing For Polyester Fabric

After polyester and its blended fabrics are dyed with disperse dyes,the caustic soda and the sodium hyposulfite are generally used for reduction and washing.The process is cumbersome and more complicated,the energy consumption,water consumption and time-consuming are high.At the same time,when using the sodium hyposulfite,it is easy to produce odor and dust,affect the working environment,sodium hyposulfite exposure to the air will gradually lose the ability to restore.The reduction washing agent HY used in this project has a strong reducing ability and can completely remove the dyestuffs on the surface of the fabric to obtain the desired color fastness.Experiments show that,compared with the traditional sodium hyposulfite and caustic soda reduction washing process,the color fastness to rubbing and dry/wet rubbing fastness after reduction washing are all improved,and the effect of reducing washing agent HY on the shade of the fabric is not great.The use of this product after washing and washing does not require acid neutralization,and can reduce the number of liquid discharges,so it can greatly shorten the operation time,reduce water consumption,electricity consumption,gas consumption,and chemicals,reduce production costs,and achieve environmental protection and fee reduction requirements.First of all,this article selected the disperse black ECO,disperse scarlet GS,disperse dark blue EX-SF and disperse yellow SE-RL four kinds of dyes to carry on the experiment,after dyeing finished polyester drainage to carry on the reduction and washing,the result shows that the reducing washing agent HY is at the weakly acidic condition of 5-6 has a good reduction washing effect,and the washing fastness and rubbing fastness are superior to those of the sodium hyposulfite and caustic soda reduction washing process.The reduction washing agent HY is suitable for reducing and washing at acidic conditions.According to the above experimental results,the reduction washing agent has a better reduction and washing effect under acidic conditions.Therefore,eight kinds of disperse dyes are used for polyester dyeing,and it is not necessary to directly perform the reduction and washing in the dyeing liquor after dyeing the polyester.At this time,the pH of the dye solution is adjusted to 5-6.Experiments were conducted under different conditions of reducing agent dosage,reducing washing time and temperature.The results showed that the amount of reducing agent HY was 1.5-2.5g/L,the reduction time was about 20 min,the reduction temperature was 90-95°C,and excellent color fastness was obtained.Through the above eight kinds of dyes,three dark dyes are selected: disperse black ECO,disperse scarlet GS,and disperse dark blue EX-SF,and add high-efficiency detergent TC in the reduction washing process to reduce one-time water washing through a single variable experiment to find the process recipe.The results showed that the net lotion had a certain removal effect on the floating color of the fabric surface and could effectively clean the floating surface of the fabric.The amount of the detergent is 1.5-2.5g/L.Compared with no detergent,the color fastness is improved,and the rubbing fastness can be improved.After the reduction,it only needs to be washed once,which saves energy.Orthogonal experiments were conducted on the three dark dyes dispersed in black ECO,disperse red GS and disperse dark blue EX-SF to optimize the washing process.The results showed that the formula for the reduction and washing process of the dispersed black ECO was as follows: reducing agent HY dosage 2g/L,temperature 90°C,time 20 min,net detergent amount 1.5g/L,washed once after reduction,and the stain fastness was 3-4 grade,wet rubbing fastness 4 grade;Disperse Blue EX-SF reduction washing process formula: reducing agent HY dosage 2g/L,temperature 90°C,time 20 min,net detergent dosage 1.5g/L,after reduction washing once,the staining fastness is 4 grade and the wet rubbing fastness is 4 grade;the formula of the reducing and washing process of disperse red GS is: reducing agent HY dosage 2g/L,temperature 85°C,time 15 min,net detergent dosage 2.5g/L,washed once after reduction,stain fastness is 4 grade and wet rubbing fastness is 4-5 grade.Finally,using the above process to set out the test,through the test,compared with the traditional sodium hyposulfite-caustic soda reduction washing process,the reduction washing agent HY can achieve the purpose of saving water,eliminating a drainage process,eliminating the need for washing,stain fastness improved by half,rubbing fastness improved by half.