The Research And Application On Heterotypical Fiber To Improve The Dyeing Properties

An uneven dyeing phenomenan was existed in cashmere fiber due to thestructure and properties difference between the normal cashmere and the heterotypicalfiber in cashmere fiber. The cashmere fiber was dyed with Lanasol and Lanasol CEseries reactive dyestuff for fur through micro-suspending dyeing process, and theproperties of the heterotypical hair were investigated existing in cashmere fiber.The heterotypical hair and the normal cashmere were tested and researchedthrough the X-ray diffraction (XRD), Raman spectrum, atomic force microscope(AFM). It was concluded that the crystallinity of heterotypical hair was higher thanthe normal cashmere as it was found that the crystallinity of heterotypical hair was43.71%, while the crystallinity of normal cashmere was41.77%.The investigation was made about micro-suspending dyeing theory throughtesting the dye liquor’s diameter, the absorption spectrum and the surface tension.From the test results of dye liquor’s diameter and the absorption spectrum it wasfound that the micro-suspending auxiliary could form the dyestuff into aggregation.The aggregation possessed a larger force to fiber and an even dispersing particle sothat it could be absorbed on fibers fast and evenly. Auxiliary WQ-G couldsignificantly reduce the surface tension of dyeing liquor so that the fiber was easy toswell and the dyes liquor was easy to permeate into fiber’s interior. As a result themicro-suspending dyeing process was avail to minimize the dyeing differencebetween the heterotypical hair and the normal cashmere.The micro-suspending dyeing process, including the kind and content ofauxiliary, acid content, soaking time and temperature, was optimized and ascertainedthrough testing the dye uptake, the fixation rate, the breaking strength and elongationat break of the heterotypical hair. The optimized craft was that the formic acid was1.5%(owf), the auxiliary of WQ-G was2.0%(owf),WPN was3.0%(owf), the soakingtime was70minutes under the temperature of90celsius. It was found that themicro-suspending dyeing process could improve the dyeing ability of heterotypicalhair and reduce the dyeing difference between the heterotypical hair and the normalfiber. Through the photo and sight of the dyed heterotypical hair and cashmere, it was found that it was easier to figure out the difference between the two fibers dyed withnavy dyestuff compared to browndyestuff as the dyeing difference was more obviousto make a decision, while the brown dyestuff could provide the heterotypical hairbetter dyeing properties.Compared to traditional dyeing process, it was found from the thermodynamicsanalysis that the dyeing rate in balance of micro-suspending dyeing process washigher. There was no change in the absorption isotherm of micro-suspending dyeingprocess as the isotherm remained Langmuir style, which could illustrated thatmicro-suspending dyeing process didn’t change the absorption mode of dyestuff tofiber.Compared with traditional dyeing process, it was found from the dynamicanalysis that the equilibrium absorption capacity, dyeing rate coefficient and diffusioncoefficient of micro-suspending dyeing process were promoted while its half dyeingtime was reduced. A further investigation about the dynamics between theheterotypical hair and the normal cashmere through micro-suspending dyeing process,it was found that the dying rate constant and the diffusion coefficient of theheterotypical hair were lower than those of the normal fiber, and it cost more time forheterotypical hair to reach dyeing balance. Thus it was known that there was a dyeingproperties difference between the heterotypical hair and the normal cashmere.Compared the alkali solubility and the color fastness of the dyed samples it wasfound that micro-suspending dyeing process did avail to keeping the originalproperties of fiber and the subsequent process as it could provide fiber with a betterfeeling such as smoother, fluffier and better color fastness.Based on the conclusion mentioned above, the micro-suspending dyeing processwas applied to manufacture. Compared with the traditional process, it was found thatthere was not an obvious dyeing difference between the heterotypical hair and thenormal cashmere when dyed through micro-suspending dyeing process.