This study examined primary chemical damage of hair in the process of colored and bleached and secondary hair damage after hair styling. Then, physical heat treatment was conducted with hair and rinsing and washing was repeated to investigate the effects of the use of shampoo, heat of hair dryer, and magic straight and iron tools which are repeated daily on hair damage.
Next, to examine a treatment effect in the repeated damage process, alginate, green tea seed oil, and gray mullet extract which could influence protein, fat, and vitamin A, and water of hair were treated to hair.
1. As a result of tensile strength and elongation testing to measure physical change of hair, in the repeated process of chemical colored and bleached, tensile strength became 2.26 gram force (gf)(virgin hair), 1.82 gf (bleached hair), and 1.71 gf (colored hair) and elongation became 48.9% (bleached), 46.82% (colored), and 41.27% (virgin).
2. For the alginate treatment group, in physical re-damage process after chemical damage, tensile strength showed a 13.20% increase in the colored hair but a 13.94% decrease in the virgin hair and a 4.41% decrease in the bleached hair compared to no treatment sample. Elongation showed a 9.60% increase in the colored hair but a 14.04% decrease in the virgin hair and a 8.29% decrease in the bleached hair compared with no treatment sample. It should be noted that although the alginate sample felt softer and much smoother than the no treatment sample, it is greatly influenced by humidity in atmosphere and may become sensitive to dry weather in season. For cuticle morphology, cuticles were peeled, marking became unclear, interval was irregular, and even some had holes. The alginate group was decreased in peeling and separation of cuticle compared with the no treatment group, suggesting improvement effect. It may partly because alginate coats a cuticle surface and acts as cement in irregular cracking parts, resulting in decreased peeling.
3. For the green tea seed oil treated group, in physical re-damage process after chemical damage, tensile strength showed a 4.24% increase in the virgin hair, a 1.88% decrease in the colored hair, and a 15.72% increased in the bleached hair. Elongation showed a 0.46% increase in the virgin hair but a 4.27% decrease in the colored hair and a 1.7% decrease in the bleached hair. For cuticle change, although the green tea seed oil treated group showed more stable improvement effect than the no treatment group, many unknown substances were adhered with too much oil in the sample.
4. For the gray mullet extract treated group, in physical re-damage process after chemical damage, tensile strength showed a 8.49% decrease in the virgin hair and a 9.43% increase in the colored hair but there was no change in the bleached hair. Elongation showed a 3.19% increase in the virgin hair and a 3.51% increase in the colored hair but a 3.71% decrease in the bleached hair compared with no treatment sample. The gray mullet extract treated group was more stable in cracking than the no treatment group. In hair after bleached, a cuticle boundary was clearly improved, but cuticle separation appeared.
Finally, further study should be conducted with natural hair products which can improve qualitative damage with different concentration of quantitative components.