The structure and bleaching/dyeing behaviour of hair sampled from people of various ages were investigated to provide guidance for wig‐making. Hair surface and cross‐sectional morphology were investigated by scanning electron microscopy, whereas the number density and size of melanin granules were evaluated by transmission electron microscopy. The suitability of hair for dyeing was determined by the trade‐off between the fracture strength and lightness of bleached samples. Hair collected from 26‐year‐olds showed the highest number density and the lowest size of melanin granules, thus featuring the lowest mechanical strength reduction and the highest lightness increase after bleaching. The optimal bleaching conditions for such hair were identified as bleaching time = 80 minutes, hydrogen peroxide (H₂O₂) concentration = 60 mL/L, and bleaching temperature = 75°C. Considering its resilience to damage and favourable dyeing behaviour, hair sampled from 26‐year‐olds was concluded to be most suitable for wig‐making. Thus, the present research provides guidance for the selection of raw materials for wig‐making.

中文翻译：

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年龄对头发结构和漂白/染色行为的影响

研究了从各个年龄段的人那里取样的头发的结构和漂白/染色行为，为假发制作提供了指导。通过扫描电子显微镜研究了头发的表面和横截面形态，而通过透射电子显微镜评估了黑色素颗粒的数量密度和大小。头发是否适合染色取决于漂白样品的断裂强度和亮度之间的权衡。从26岁开始收集的头发显示出最高的密度和最低的黑色素颗粒大小，因此漂白后机械强度降低最低，亮度增加最高。确定此类头发的最佳漂白条件为：漂白时间= 80分钟，过氧化氢（H ₂ O₂）浓度= 60 mL / L，漂白温度= 75°C。考虑到其对损坏的抵抗力和良好的染色性能，从26岁的人群中取样的头发被认为最适合制作假发。因此，本研究为假发制作原料的选择提供了指导。