Study On Dyeing Ability Of Natural Plant Dyestuff By Ultrasonic Method

Natural dyes are searched from nature and have small impact on environment in dyeingprocess,besides, many natural dyes are Chinese medicine resources, which have high officinalvalue and beneficial to human body.At present,people pay attention to plant dyestuff becauseof its avirulent, harmless, pollution-free and elegant tonal.From the point of view ofpro-environment, health and ecological,natural plant dyestuff has more advantages thansynthetic dyes.Therefore,it is an inevitable trend that natural dye for will replace chemicaldyestuff.Ultrasonic technology was used in this paper to find a extraction method which is highefficiency, energy saving and can improve the dyeing rate for natural plant dyestuff.Thedyeing ability improvent technology for natural plant dyestuff was studied,extracting anddyeing method were also discussed in this paper. Ultrasonic technology is a widely applied ina broken method with its convenient, rapid, efficient, and safe characteristics.It has theadvantage of improve the dyeing speed and dye uptake,shorten processing time, reduce thefiber damage, improve production efficiency and so on.All of the materials and drugs used inthis experiment are green and pro-enviroment. Water extraction, ultrasonic, enzymatic andenzyme/ultrasonic method were chosen in rubia, cortex phellodendri and gallnut extraction,moreover,different fabrics were dyed in ultrasonic condition, various factors in the process ofextracting were also researched so as to improve efficiency and saving energy.The dye-uptakeamoung the fabrics dyed with different extracting sulotions were compared through theabsorbenc value and△E.Finally dyeing fastness was tested.As the results showed, ultrasonic method could shorten extraction time and improve thedye-uptake.Cotton fabric achieved good apparent depth under the condition of dyeing at80℃for60min by ultrasonic method. When extracting,natural dyestuff extraction yield would beincreased and obviously higher than water extraction, enzymatic extraction and ultrasonicextraction method by adding enzyme.Gallnut could obtain high extraction yield under thecondition of extracting at70℃for60min with pH7. The optimum extracting process for rubiaand cortex phellodendri was:extracting temperature50℃, time60min, pH4.5.Ultrasonic wavecan stay longer and penetrate deeper in plant cell than electromagnetic wave,which is useful for the effective components of plant diffusion and extraction；while biological enzyme acts atthe plant material surface,it can also improve the extract yield by destroying cellwall,reducing the resistance of pigment extracted from the cells. Natural plant dyestuff extractingyield was greatly improved by combining two kinds of technology. The fabrics were dyedwith enzyme/ultrasonic extracted solution under ultrasonic conditions in this experiment, asthe test result shows,the dye-uptake was obviously higher than conventional water bath, thuslow dye-uptake and poor levelling problem for natural plant dyestuff rubia, cortexphellodendri, gallnut etc are solved. In addition, soaping fastness, dry and wet grindingfastness for dyed fabrics in ultrasonic conditions of can be impromoted by one grade.