35 Congresso Brasileiro de Cosmetologia, São Paulo, 13-15 Junho 2023-Poster

Albarici, V. C.; Ramos, N. C. B. S; Dini, A. X. P.; Ferreira, M. M.,Hercolino,C. V.; Ribeiro, N. A.; Gonçalves, V. P; Pinheiro, A. S.

Introduction: Hair fiber surface condition is one of the attributes that is firstly identified by consumers upon touching hair. The friction reduction is directly linked, microscopically, to the increase in softness on the fibers surface, which includes a decrease of roughness and the closure of cuticular layers. Macroscopically, it is also necessary that a lower degree of aggregation and interaction exist between fibers. Objective: The purpose was to assess the macro and microscopic hair surface characteristics of different ethnical origins utilizing the techniques of microscopy, combability and sound analysis.

Materials and Methods: Natural hair tresses of straight, wavy, curly and kinky curvatures were used. The scanning electronic microscopy was realized on 5 fibers of each hair type. An equipment with electronic sensors that traduce fibers roughness on sound intensity was used. Combability measurements were conducted using the universal test equipment, in which the tresses were submitted to a passing through a fixed comb. Results and Discussion: According the obtained results, the superficial hair fibers roughness showed equal mean values between the hair groups studied, i.e., the hair with different curvatures showed similar damage degree. The combability analyses showed a crescent energy with the increase hair of curvature. These results are corroborate with sound analyses, on which with the increase of hair curvature there is an increase of sound intensity, indicating a higher friction of fibers with the electronic sensors. Conclusions: The microscopic results analyzed showed that the natural hair of different curvatures showed similar roughness results. However, the macroscopic analysis demonstrated that the responses of energy to combing and sound intensity are also associated with the interaction between the fibers and their aggregation, being therefore, factors that impact on the friction of the hair. Thus, it can be concluded that the combination of macroscopic and microscopic analysis is fundamental for a robust analysis of the surface conditions of the hair.