Investigation Of Low Temperature Peroxide Bleaching System And Its Application In The Pretreatment Of Cotton Yarns

The pretreatment of cotton yarn needs to be treated for a long time under the condition of high temperature and high alkali concentration,so the cotton fiber is easily damaged.At the same time,it needs to consume a lot of energy,which brings a serious obstacle to the energy saving and pollution reduction in enterprise.In order to solve the problems above,XTA / XQC / H2O2 low-temperature oxygen-bleaching auxiliary system composed of self-made hydrogen peroxide low temperature catalyst XTA,self-made high-efficient scouring agent XQC and oxidant H2O2 was studied in this paper.And the system was applied to the pre-treatment process of cotton yarn.Pretreatment technology of low temperature on cotton yarns(Low temperature pretreatment technology)were explored through the basic performance test,process optimization,pilot test and production experiment.The use of this pretreatment technology can improve the right-first-time rate,save the energy consumption and ensure the pre-treatment effect of cotton yarn can up to standard and bring feasible green production program to the enterprise.The low-temperature oxygen bleaching system studied in this paper is consisted of low-temperature hydrogen peroxide catalyst XTA,high-performance scouring agent XQC and oxygen bleaching grade H2O2.When this system is used in conjunction with chelating agent XB,the pretreatment of cotton yarns can be carried out at 70°C.The mixed solution of XTA and XQC(1: 1)was neutral.It has good alkali resistant stability and strong permeability,so it can catalyze the decomposition of hydrogen peroxide at 70°C to bleach the cotton fiber.Through the experiment,the optimum technological parameters of Low temperature pretreatment was determined.The optimum process parameters are XTA 0.8g/L,H2O28g/L and incubated at 70°C for 60 min,then drain the treatment solution,and XB 1g/L at 70°C for 15 min.Using the optimized low temperature pretreatment to treat the cotton yarns,the whiteness and hairiness of the cotton yarns can reach 78% and 13 cm respectively,which is consistent with the traditional pretreatment.Though the breaking strength reduction is 9% lower than the traditional high temperature oxygen bleaching pretreatment process,it can still meet the following production requirements.And the low temperature process did not change the fiber composition O/C ratio,the fiber surface is smoother than the traditional process,the crystallization of 0.24% higher than the traditional process.After dyeing,the cotton yarn using low temperature pre-treatment process can get the same color with the traditional process,and the color fastness can reach 4.5.After using low temperature process,the cotton yarn has better levelling property,the right-first-time rate in actual use is improved,and the indicators of the finished cloth can comply with a standard.Using the low temperature pretreatment can save energy effectively.It can save 33.33% of the treatment temperature and save 21.6% of the steam at least,which is equivalent to 1 ton of cotton yarn processing as well as 0.356 tons of standard coal.That achieved the goal of energy conservation indeed.