Study On Dyeing Technology And Mechanism Of Bamboo Bundle

At present,the single color of bamboo,fewer types of dyes used in bamboo,and immature dyeing process have always restricted the multi-functional application of bamboo.This thesis uses moso bamboo bundles as raw materials and uses two kinds of red,yellow and blue dyes(acidic and reactive)to dye the bamboo bundles.The effect of dyeing process on the dye uptake and light fastness of the bamboo bundles is studied.In addition,the light discoloration law and influencing factors of the dyed bamboo bundles were explored,and the dye uptake,apparent color and lightfastness of the acid and reactive dyed bamboo bundles were comprehensively compared and analyzed.Using scanning electron microscopy,Fourier infrared spectroscopy and other methods to characterize two kinds of dyed bamboo bundles at the microscopic level,and analyze the dyeing kinetics of bamboo bundles,revealing the dyeing mechanism.The main research conclusions are as follows:(1)When dyeing bamboo bundles with acid dyes,increasing the temperature,extending the time and lowering the p H value can effectively increase the dyeing rate of the bamboo bundles.The light fastness grade corresponding to each factor level is clarified,and it can be seen that the light fastness of the dyed bamboo bundle increases with the increase of temperature,and first increases and then decreases with the extension of time.Through the comprehensive analysis of the above conclusions,it is concluded that the best dyeing processes for the three acid dyes are:acid red(90?,10 h,0.5%,p H=4),acid yellow 100?,6 h,0.7%,p H=4),acid blue(90?,10 h,0.3%,p H=4).The light time is controlled as a single variable.It can be seen that the color difference of the acid dyed bamboo bundles increases with the prolonging of the light time.Analyze the lightness(?L*),red-green index(?a*),yellow-blue index(The correlation between?b*)and the total color difference(?E*)shows that acid red dyed bamboo bundles?a*has the most significant linear effect on?E*,and acid yellow and blue dyed bamboo bundles have the most significant linear effect on?E*.*The linear effect is the most significant,and the R² obtained by the linear equation is greater than 0.85.(2)When dyeing bamboo bundles with reactive dyes,the dye uptake rate increases with the increase of dyeing temperature,dyeing time and the concentration of sodium sulfate,and increases with the decrease of dye liquor concentration.The light fastness grade corresponding to each factor level of the reactive dye dyeing process is clarified,and it can be seen that the light fastness first increases and then decreases with the extension of the dyeing time.Comprehensive analysis of the above conclusions,it is concluded that the best dyeing process for three colors of reactive dyes is:5 h,0.7%,70 g·L^-1,dyeing temperature:reactive red and reactive blue(90?),reactive yellow(80?).The light time is controlled as a single variable.It can be seen that the color difference of the bamboo bundles dyed with reactive dyes increases with the prolonged light time.The three chromaticity indexes(?L*,?a*,?b*)and the total color difference(?E*)are analyzed It is concluded that the?a*of reactive red dyed bamboo bundles has the most significant linear effect on?E*,and the?b*of reactive yellow and blue dyed bamboo bundles has the most significant impact on?E*linearity.The linear equation is obtained The R² is greater than 0.97.(3)By comparing the dye uptake rate of acid dyes and reactive dyes,it is concluded that the dye uptake rate of reactive red is 30%higher than acid red,reactive yellow is 6%higher than acid yellow,and the dye uptake rate of reactive blue is about 36 higher than acid blue.%.Refer to the scoring rules for shooting and compare the light fastness of bamboos dyed with different dyes.It is concluded that the light fastness of bamboo bundles dyed with reactive dyes is overall higher than that of acid dyes.Test the light fastness grades under the best technology of different dyes.The light fastness grades of acid red,yellow and blue dyed bamboo bundles are:4,3.5,3.5,and reactive red,yellow,and blue are:Level 4,Level 4.5,Level 3.5.Chromaticity measurement of different dyed bamboos shows that the lightness value L*and red-green index a*of reactive red dyed bamboo are 27.01 and 17.10,respectively,acid red is 25.83 and 15.90,and other indicators are close;the lightness value of reactive yellow dyed bamboo is L*and The yellow-blue index b*is 29.93 and 13.21,respectively,acid yellow is 32.82,18.20,and the color saturation is close;the yellow-blue index b*and color saturation C*of reactive blue dyed bamboo are-2.96 and 3.61,respectively,and acid blue is-8.62,8.79.The specific performance is:the color of bamboo bundles dyed with reactive red is brighter than acid red,the color of bamboo bundles dyed with acid yellow is more pure and brighter than reactive yellow,and the color of bamboo bundles dyed with acid blue is more pure and brighter than reactive blue.(4)Infrared spectroscopy analysis of the bamboo bundles before and after dyeing with acid and reactive dyes showed that the functional groups of the bamboo bundles dyed with acid dyes did not change significantly.The carbonyl groups of the bamboo bundles dyed with reactive dyes were significantly reduced.The analysis shows that acid dyes and bamboo The bundle did not chemically combine,and the reactive dye and the bamboo bundle had a nucleophilic substitution reaction or an affinity elimination addition reaction.Scanning electron microscope observation of the two types of dyed bamboo bundles shows that the microstructure of the acid dye-stained material is rougher than that of the undyed material.The inner wall surface of the catheter becomes rough,and the pores in the inner wall of the catheter are blocked to varying degrees and trapezoidal pores.Decrease,indicating that the dye is effectively attached to the bamboo bundle;a large number of dye particles have been gathered on the surface of the bamboo bundle tube and the fiber dyed with reactive red,and the bamboo bundle dyed with reactive yellow and blue dyes has a weaker sense of pore boundaries on the tube..The dyeing kinetic analysis of bamboo bundles shows that as the dyeing temperature rises,the equilibrium dye uptake rate of bamboo bundles gradually increases,and temperature has a greater influence on the dye uptake rate of bamboo bundles dyed with reactive yellow and blue dyes;The temperature corresponds to a longer half-dyeing time and a smaller dyeing rate constant.This is mainly because the equilibrium dyeing rate of the three dyes at different temperatures is quite different.