A Study On One-step Continuous Pretreatment Of Desizing,Boiling, Bleaching And Auxiliary Of Cotton Fabric

Nowadays, most of dye industry prefer choosing the alkaline-oxygen method during the pretreatment process of cotton fabric. That means performing the process of desizing and scouring in a certain concentration of caustic soda liquid, then using hydrogen peroxide to bleach. However, it is inevitable to use amount of caustic soda in both ways, the continuous pad-steam method and cold Dumping, and the processing time is time-consuming. In that case, producing a large number of highly polluted water and consuming large amounts of water and energy resources will be ineluctable too. And production costs will also increase. In order to address this issue, and respond to the21st century national advocating policies, such as energy saving, environmental protection, it is urgent to research and invent a series of energy-efficient environmental-friendly pretreatment process of cotton fabric and auxiliary agent. Without caustic soda, steaming by rolling on fabric desizing baths-step method is one of the most efficient methods to make the pretreatment process of cotton fabric to become more effective, save more energy and be more friend to the environment.This topic is mainly about how to treat the kind of heavy cotton fabric with the back-Cook-bleach a bath continuous method and analyze the relevant auxiliary which is used. To value the effects through testing the fabric’s whiteness, capillary effect, desizing rate, breaking strength and oxidative damage degree after be treated, then amend the results and come up with the best treating conditions.Through the orthogonal experiments, producing a high-efficient scouring agent YJ, which was a compound of anionic surfactant and non-ion surface active agent. It was a kind of light yellow viscous liquid, effective content was36%, pH value was6-7. By a series of performance tests, we found that the scouring agent not only had permeability performance and emulsification scattering effect but also had a certain high temperature resistant performance, alkali resistant and Oxidation-resistant property.The subject also studied the supporting auxiliary KX-10which was a kind of special oxide which contains hydrogen peroxide stabilizer and alkali. And through the orthogonal test we determined the best blend of the auxiliary prescription, which was:special oxide 51.4%, soda24.3%, sodium silicate17%, and ash chelating dispersant (L-1000)7.3%. This pretreatment to cotton fabric could be operated without caustic soda and makes alkali-less process available.After a series of optimization experiments and orthogonal experiments, we obtained the best technological conditions:30%peroxide35g/L, scouring agent YJ15g/L, auxiliary KX-1042g/L, roll rate80%, steaming time could be cut to20min,which simplified the pretreatment operation as much as possible, and short process and time, It was a new environmental-friendly technology.Finally through compared with the traditional pre-treating process of cotton fabric, the test results showed that the fabric’s whiteness, capillary effect, desizing rate and dyeing effect were parallel to traditional effects. But large amount of additive’s dosage caused strength damage and oxidative damage larger than the traditional one.