Low Temperature Dyeing Process Of Wool Using Reactive Dyes In Redox Systems Combined With Mixed Rare Earth Chlorides

The purpose of the present thesis is to determine the appropriate dye formula andprocess for dyeing wool by reactive dyes in low temperature dyeing bath of redoxsystems combined with rare earth mixture of LaCL3and CeCL3.The three redox systems,hydrogen peroxide/thiourea,hydrogen peroxide/glyoxaland potassium persulfate/thiourea,were screened to conduct wool low temperaturedyeing using reactive dyes,respectively. The single factor experiments were carried outon wool dyeing at low temperature with reactive dyes in the mixed rare earth and theredox systems combined with the mixed rare earth respectively to determine theappropriate range of various factors, such as dyeing holding temperature, dyeingholding time, and so on. Then through the orthogonal test and validation test about thewool dyeing at low temperature in the redox system combined with mixed rare earth, aappropriate formula and process about low temperature dyeing of wool using reactivedyes with the redox system and rare earth was determined as follows:Dyeing formula：Reactive Lanasol dyes (owf):3%Hydrogen peroxide:0.045mol/LThiourea:0.015mol/LRare earth mixture of LaCL3and CeCL3(owf):0.2%Anhydrous sodium sulfate（owf）:2%Albegal B(owf):3%pH:4.9Suitable process conditions：Holding temperature:75℃Holding time:45minBath ratio:1:40The experimental results indicated that compared with conventional dyeing usingreactive Lanasol dyes,the holding temperature of the low temperature dyeing usingreactive Lanasol dyes in hydrogen peroxide/thiourea system with mixed rare earthchlorides decreased20℃,holding time was shortened15min,the dye uptake increased 1.2%and single fiber strength increased2.16CN. Compared with the low temperaturedyeing in hydrogen peroxide/thiourea system,the dye uptake increased0.67%, thetemperature decreased5℃,the holding time was shortened5min and the fiber strengthincreased1.03CN. In comparison with the low temperature dyeing in mixed rare earthchlorides,the temperature decreased10℃,the holding time was shortened5min,thedye uptake increased1.61%and the fiber strength increased0.58cN.The benefits of the wool dyeing quality using the reactive dyes in hydrogenperoxide/thiourea system with the addition of rare earth mixture are to obtain betterwool dyeing quality than that obtained through only the mixed rare earth or redoxsystems, and to result in lower fiber damage, lower holding temperature and lowerholding time than those using conventional dyeing.