The Study Of Pretreatment Auxiliaries And Technology For Thick And Heavy Cotton Woven Fabric

As one of the most important link in textile printing and dying processing, the pretreatment of cooton fabric has gained much attention from the textile printing and dying field at the beginning. With the long-term efforts of the specialists and scholars, this important process is having great changes and revolutions, it has began to go from traditional torm which is high temperature, concentrated alkali, power-wasting and water-wasting as early as a few decades ago. Among the lots of research achieve-ments, the application of enzyme technology and the hydrogen peroxide activation system gained the biggest one in the way to lower temperature,reduce alkalias well as minimize time, high efficiency and specifity of the enzyme make it very effective in lowering temperature and reducing alkalias. It also can protect the fabric from damages while gain the textile satisfactory White degree and wettability. The hydrogen peroxide activation system is make up of hydrogen peroxide and hydrogen peroxide activator, the hydrogen peroxide activator can help the hydrogen peroxide get a higher decomposition rate even under lower temperature. This can reduce the temperature of bleaching very much.The history of enzyme studying has been decades, at present, the technology is quite mature and has been used in practical production, but for the practical production always lags behind the scientific research, there is many difficultise for the enzyme technology to be popular, like the equipment updating, technology revolution and so on. Moreover, although the enzyme is very efficient for blending and knit fabrics, it can’t lead to a good effect in fabrics which has more impurities and which is more thick and tight. The hydrogen peroxide activation system is still at the stage of theoretical research, it takes time to put it into application.The main research object of the issue is thick and heavy cotton fabric, the main goal of the experiment is to explore one feasible low temperature and energy-conservation pretreatment technology for the thick and heavy cotton fabric. For the enzyme is not efficient in thick and heavy cotton fabric pretreatment, this issue still regards the caustic soda as the main scouring agent, studying the auxiliaries reloventse to pretreatment on the base of traditional caustic soda/hydrogen peroxide technology. Fisrt we classify the commercial auxiliaries, such as:penetrating agent, emulsifier, metal ion chelating agent, hydrogen peroxide activator, ect, make sure that each has one focused function; then, we study them to choose those ones with excellent performance and compound them; finally we optimize the applying technology and study the performance of the compound, explore its function in lowering temperature and the amount of alkali as well as in shoten the processing time. The research results show that:(1) led by AEC9-Na, the alcohol ether acid ester surfactants has the lowest critical micelle density, but the surface tensionits of its aqueous solution is the highest. Led by rapid panetrant T and rapid panetrant TF-107, sulfonic acid salt surfactants has the bset wetting permeability in low alkali concrete solution, but they can stand high alkali concrete. Led by AEP, alcohol ether phosphate ester surfactant has the best high temperature alkali resistance, and is suilt to be composed.(2) the best HLB of the emulsifiers which are used in scouring is between10.35-11.35, near10.75. The emulsifiers have the bset effect to remove the impurity in this range. The polyethylene glycol ethers surfactants whose backbones have branched chains has excellent wetting abilities as well as emulsifying property, its effect is better than linear polyethylene glycol ethers surfactants(block polyethylene glycol ethers surfactants) and the ones containing benzene ring substituents. The experiment determines the best scouring process:NaOH40g/L,AEP3g/L, iso-tridecanol polyoxyethylene ether5g/L, gather oxygen b(c)ene block polymer3g/L, WF2g/L, a dip a rolling, keeping60℃for90min, hot-water rinsing, cold-water rinsing.(3) Bleach the fabric after scouring, using the method of GLM-univariate analysis, study the influence which the dosage of the low-temperature scouring and bleaching agent, pH and temperature act on bleach bypass. Through analyzing the data, we can conclude that the best bleaching process is:JFC2g/L, low-temperature scouring and bleaching agent5g/L, pH=9.5, two dips two rollings, keep80℃for60min, hot-water rinsing, cold-water rinsing.(4) Compared to tradional pretreatment agents, the home-made new-type pretreatment agents is more suiltble for continuous pad steam pretreatment, the latter one performs better in infusion process. While in same pretreatment process, the home-made new-type pretreatment agents can gain the fabric better quality, the home-made new-type pretreatment agents dosen’t perform well in cold-batch process, but when combined with econtrol, the fabric can gain satisfactory pretreating effect.