The Research On Complex Dyeing Of Natural Dyes And Its Application On Wool Fabrics

Nowadays,people pay more attention to their health,and the study found that a lot of synthetic dyes is irritable to sensitive skin,and even lead to skin disease and cancer, especially the disperse and acid dyes.However,the natural dyes are non-toxic and pollution-free,and become unique.Because of their environmental friendly characters,natural dyes will help to solve the serious pollution problem of textile printing and dyeing industry,and become the hot spots and direction of research of the related people and businesses.While at the mean time,vegetable dyes have many weaknesses such as:the incomplete color kinds of the vegetable,the rare cold color and the difficulty on match of the vegetable dyes,etc.This paper will try to solve those problems with complex dyeing.This paper studied dyeing vegetable dyes on wool fabric with complex dyeing method(over dyeing and one-bath dyeing). Firstly,the Indigo naturalis is oxidated by hydrogen peroxide which replace of air oxidation.Then dyeing Cathamus yellow on the sample which dyed by the Indigo naturalis by the over dyeing method.Finally dyeing wool fabric with the mixture of Natural Green and Cathamus yellow by the one-bath dyeing method.Different green could be obtained by the above two related complex methods.The major results and conclusions of the experiments as follows:(1) The results of hydrogen peroxide oxidation indicate that the concentration of hydrogen peroxide,pH value,temperature and time of oxidation can affect the sample's K/S value.And the concentration and temperature are the major factors.According to the K/S value,we obtain ideal hydrogen peroxide oxidation crafts:7ml/l as concentration of hydrogen peroxide,5 as pH value of oxidation solution,40℃as oxidation temperature and 30min as time of oxidation.The effect of the hydrogen peroxide oxidation is better than air oxidation.The K/S value is bigger, the dyeing fastness is better.And the reproducibility of hydrogen peroxide oxidation is also good.(2) We could obtain green color by dyeing Cathamus yellow over the Indigo naturalis.The concentration of the dyes and mordant can affect the a value.The sample after mordant treated can show green,but the not processed can not.The change range of a value will be -6～-14 by changing the concentrations of dyes and mordant concentration.Through the Orthogonal experiment,we can know the influence of the factors.According to the a value,we also can obtain the optimization crafts:6%as concentration of Cathamus yellow, 30%as concentration of Indigo naturalis,4%as concentration of Al-mordant.(3) Through the results of one-bath dyeing of Natural Green and Cathamus yellow,we could know that the concentration and the ratio of Natural Green and Cathamus yellow,pH value,temperature and time of the dyeing could affect the dye-uptake and the a value.In the process of one-bath complex dyeing,Cathamus yellow is the major factor of dye-uptake,and Natural green is the major factor of a value.We can obtain different green color from Natural Green's green color.The change range of a value will be 0～-14.To sum up,through the above two complex dyeing methods,we could obtain different kinds of green color,which could establish a foundation for enriching the color options and solving the difficult issues on matching of the vegetable dyes.