Dyeing Of Cellouose Fibers With Acid Dyes

Acid dyes is often used in dyeing process of protein fiber, due to the lack of affinity between it and cellulose fiber, it is not generally used for cellulose fiber dyeing. In this thesis, cotton knitted fabric is modified by cationic agent which makes acid dyes can be adsorpted fiber and fixed on fiber, so as to enlarge the range of dyes used in dyeing cellulose fiberes and solve the environment problem cuased by adding neutral electrolyte in the dyeing process of cellulose fiberes with reactive or direct dyes, at the same time dyeing cellulose fiberes with acid fluorescence dyes could increase the varieties of fluorescent fiber and meet the needs of market.Cationic modification of cellulose fibre is introducing cationic groups through reaction between modifying agent and functional groups on the cellulose fiber molecular, in this way, it improves the dyeing rate of anionic dyes; makes low-salt or salt-free dyeing with direct dye or reactive dye true; reduces the pollution due to water discharge to the environment. High acid dyes on the dyeing rate and color bright can also be carried out on the modified cellulose fiber dyeing, especially dyed with acid fluorescent dyes on cellulose fibre which can be applied in the field of chemical industry, textile, medicine, etc.This thesis adopts the cellulose fiber modifier KC to modify the cotton knitted fabric and focus on study the dyeing behavior of modified cotton. First of all, the modification effects of concentration of modifying agent are studied by testing the Zeta potential on modified cationic fabric surface, elements content analysis and the modification process is optimized by testing the dyeing K/S value and the evaluation of color fastnesse. Second, the optimum dyeing process with acid fluorescent dyes is determined by studying impact of different dyeing pH value, time, temperature on the K/S value of dyed fabric, the influence of the R value, color fastness. Third, Lananset series acid dyes are used to dye modified cotton, the optimum dyeing process conditions are determined by studying the impact of different dyeing pH, time, temperature, etc on the K/S value of dyed fabric, the influence of the R value, color fastness, further to the acid dye cotton fabric dyeing process in thermodynamics and dynamics research, to explore the cation modifier used in accelerating mechanism of acid dyes to dye cotton. Results showed that modified cotton fabric dyed with acid dyes exhibited high color performance, The dyeing percentage of cotton knitted fabric dyed by trichromatic dyes could reach more than95%, higher K/S value and color fastness for all levels3-4above. At the same time, the use of acid fluorescent dyes of modified cotton fabric dyeing can also obtain good dyeing effects,such as the K/S value of cotton knitted fabric dyed with acid brilliant red can reach6.349, the K/S value of cotton knitted fabric dyed with acid brilliant yellow can reach4.593, and remarkable fluorescence effects.