| Natural dyes which was extracted from houttuynia cordata plant,commonly used as Chinese herbal medicine,was not for the fabric dyeing,but also can improve the safety performance of fabric,especially for infaint fabrics.It’s also can reduce the cost of wastewater treatment and conducive to emission reduction.Therefore,a detailed study on the extraction,preparation,purification,dyeing and anti-ultraviolet effect of natural dyes of houttuynia cordata were made in this paper.Water,ethanol,ethyl acetate,methanol were used as extractant in this paper.In order to extract houttuynia natural dyes,extraction times on the extraction efficiency of Houttuynia cordata were discussed.The mixed solvent,water and ethanol,was proved as the best extraction solvent by measuring the absorbance of the extract,the K/S value and color characteristics of the dyeing fabric,and the FTIR test of the dyed fabric.According to the single factor analysis,the best process was got when the ethanol volume fraction was 40%,the pH value of the extract was 9,the extraction temperature was 60 ℃,the extraction time was 60 min,the material ratio was 1:45.On the basis of the optimal process,one time of extract was better.At the same time,ultrasonic extraction was used to extract the natural dyes of Houttuynia cordata and the water was taken as the extractant.The absorbance of the extract,the K/S value and color characteristics of the dyed silk fabric were measured.The results showed that when the extraction ratio was 1:40,the extraction pH was 8,the extraction power was 370 W,and the extraction temperature was 50℃ could get the darkest shadow.The dye powder and purification methods of different extraction methods were analyzed in this paper.When it was extracted by ethanol and dried by spraying,meanwhile by combining with the result of SEM,TG and FTIR test of the dye powder,and the K/S,L.a.b value analysis of dyed fabric we could get the best process of making dye powder.Anhydrous ethanol and polyamide adsorption resin were used to purify the dye.The absorbance of different components and the K/S,L.a.b value of the dyed fabrics were tested.The results showed that both processes could improve the purity of the dye,but the loss of dye was large and the fluctuation of shadow was obvious.The stability of the dyestuff was relatively sensitive to the metal ions,pH and storage condition.While the thermal stability and reproducibility of the dyeing were better.Pre-mordanting,meta-mordanting and post-mordanting were used as three kinds of dyeing methods in this paper,Ferric sulfate,Zinc sulfate,Copper sulfate,Alum were selected as mordants.Cotton,Modal,Viscose,Silk and Wool fabric were dyed.The K/S,L.a.b values,UPF,UVB and color fastness of above fabrics were test.The result showed that the pre-mordanting dyeing method was best in Cotton,Modal and Viscose fabric,the color fastness were reach 3-4 or more except the light fastness(only 1-2);The meta-mordanting dyeing method was best in wool and silk,the dyed fabric color fastness can reach 3 or more;Through ultraviolet resistant test we could see the fabrics dyed with Houttuynia cordata have good anti-ultraviolet capability.Took Silk fabric for example,the effects of dye concentration,dyeing time,dosage of mordant and salt concentration on the dyeing process were analyzed in this paper.The results showed that when the dye concentration was 10%(o.w.f),dyeing time was 100 min and the dosage of Alum was 1g/l,we could get a better dyeing effect.While the effect of Na2SO4 was not obvious. |
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