Human's natural hair color comes from the existence of melanin granule. The mechanism of hair color forming in melanocyte is that Eu-melanin or Phaeo-melanin granular chrome are polymerized by tylosinase enzymatic reaction, an autoxidation process. Ty...
Human's natural hair color comes from the existence of melanin granule. The mechanism of hair color forming in melanocyte is that Eu-melanin or Phaeo-melanin granular chrome are polymerized by tylosinase enzymatic reaction, an autoxidation process. Tylosinase, of which precursor is tylosin, is oxidized into dopachrome by hydration of tylosin from dopa as well as by circulation of cyclodopa in dopa-quinone and another oxidation process. Eu-melanin, a brown-black chrome, leading to indole from dopachrome, goes through 5,6-DIH and then quickly converted.
But Phaeo-melanin, a yellow-red chrome, is formed via 5-S or 5-S-CD or 2-S-CD by cysteine from dopachrome, and by involvement of glutathione, a -SH compound, or cysteine. Thus, spontaneous hair color depends on the concentration of Eu- and Phaeo-melanin. The simplest method to change some parts or the entire of natural chrome of hair is ommission or disappearance of melanin chrome. The use of hydroxide lightens melanin contribution pigments, and oxidative hair dyes making brighter than resulted hair color do dying in alkaline condition of pH 9∼10.
A color material that can fix a color onto natural or synthetic fibers or other objects is called dye. Most of vegetable dies applied to natural dye materials use leaves, stem, fruit and flower, heartwood, and bark. The original color of sap extracted from plants is not used as it is, but each unique pigment enables color fixing. Even though dyes are from the plants of a kind, the color varies to growth environment, growth time, part of the plant, and season. This is a demerit for the reproducibility of color, and is a merit in that basic color can be varied more variously by use of mordant even in the same salt solutions.
Dying process of natural dye is composed of refining, bleaching, pigment extracting, fixing, washing, and drying. Washing is a process to identify fastness and color degree. Mordant is such a reacting material to fix a color mordant when pigments are not deposited on to fiber, and a neutral metal compound that substitutes hydrogen and metal through neutralization of acid and base. In case dye is not directly colored on the fiber, salts such as Cr and Al, and metal mordant materials such as alum, green vitriol, and tannin could be used to fix the wanted color by color fixing process to elevate fastness against sunlight and laundry.
In this study, 14 year old girls's virgin hairs which have never been treated with permanents or coloring were used as primary samples. The primary samples were decolored twice in for each 20 minutes. This decolored samples of brightness level 8∼9 were used as secondary samples. Henna was used as experiment group, and 5 color series of control group; gardenia in yellow color series, moxa in brown color series, sappan plant in purple color series, and indigo plant in blue color series, safflower in red color series were comparatively analyzed with henna group.
Polarization microscope was used to measure the thickness of hair. And, tensile strength by KS K 0409, wash off fastness by KS K0403, complex fastness to sweat and sunglight by KS K 0701, and color by L*a*b color space method were measured.
In hair thickness experiment, secondary samples were more swelled than primary samples. Comparing control plant colored hairs with henna colored hairs, gardenia colored hairs were more contracted, but moxa colored hairs were swelled. Sappan plant, safflower, and indigo plant colored hairs were the same in hair thickness. In tensile strength, colored hairs were reduced in it than primary hairs, but henna in blue color series had similar strength to that of primary samples. Among the botanical dye stuffs, the largest drop in tensile strength compared to primary hairs occurred in gardenia colored hairs, on the contrary, indigo plant colored hairs made the lowest drop.
Wash off fastness on chrome disappearance was the lowest in safflower plant colored hairs, and very excellent in indigo plant colored hairs, with grade 4. Coloration of hair which is animal fiber group was compared with that of silk and cotten in botanical unicellular group, as contamination(silk) and contamination(cotten). Contamination(silk) group had lower value in henna colored hairs of blue color series but contamination(cotten) group did in sappan plant colored hairs. Plant colored hairs in control plant group other than these made excellent coloration in level 4∼5. In complex fastness(sweat + sunlight) experiment, moxa, sappan plant, and indigo plant colored hairs made excellent performance of level 4~5 both in acidic and alkaline condition. Safflower colored hair had level 3 both in acidic and alkaline condition, the lowest in the hairs in control plant group.
In color resolution experiment, henna colored hairs had L, the highest level in brightness, but in control group, L of gardeinia and sappan plant colored hairs hand lower L than henna colored hair in their groups. Moxa, indigo plant, and safflower colored hairs in control plant group had higher L than henna colored hairs. Gardenia yellow colored hairs had higher +b value by 46% than henna colored hairs and safflower colored hairs in control plant group also had higher +a value by 17% than henna colored hairs.
In the comparison of hair thickness, gardenia in control plant group, a weak acidic dye in pH 5, contracted the once swelled hairs after coloring secondary decolored hair samples with gardenia chrome. In moxa, hairs were thickened as coordinate bond of dye molecules centering on Fe in the iron solution used as mordant reduce metal cohesion. In secondary hairs relative to the primitive hairs, loss of granular melanin chrome and inter filling materials bring about drop in tensile strength. This indicated that in the comparison between henna and other control plants, tensile strength of other control plants were lower than that of henna. Study results similar to this has not been reported yet, so it needs further study.
Indigo plant colored by oxidation and reduction method was the very excellent in laundry complex fastness(sweat plus sunlight), and the control plants other than safflower also proved good dye on the whole. In color, yellow gardenia and red safflower colored hairs had higher yellow and red color content, respectively than henna colored hairs. Sappan plant had excellent coloring power but in complex fastness(sweat plus sunlight), it was weaker than other control plant colored hairs. In sharpness that represents chroma, other control plant colored hairs had higher color degree than henna colored hairs.
On the whole, control plant colored hairs had lower values in tensile strength but higher values in thickness, wash off fastness, complex(sweat plus sunlight) fastness, and color degree. From the experiment results, hair quality of primitive hairs bossed the condition and reaction of secondary hairs. Different hair thickness measurement proved this, which suggested that various hair measurement of the primitive hairs were different was proved. Plant dye materials in the realm of nature increase hair thickness when coloring, or contracts once-swelled hairs by permanent or coloring, depending on dyes.