Hair fiber characteristics and methods to evaluate hair physical and mechanical properties

Abstract

The hair thread is a natural fiber formed by keratin, a protein containing high concentration of sulfur coming from the amino acid cystine. The main physical proprieties of the hair depend mostly on its geometry; the physical and mechanical properties of hair involve characteristics to improve: elasticity, smoothness, volume, shine, and softness due to both the significant adherence of the cuticle scales and the movement control (malleability), as well as the easiness of combing, since they reduce the fibers static electricity. The evaluation of these effects on hair may be carried out by several methods, as: optical and electron microscopy, mechanical resistance measuring, shine evaluation and optical coherence tomography (OCT).Uniterms: Hair/properties/evaluation. Hair fibers/properties/evaluation. Hair fibers/characteristics. Optical coherence tomography/analytical application. Optical microscopy/analytical application. Electron microscopy/analytical application O cabelo é uma fibra natural formada por queratina, uma proteína composta por teor elevado de enxofre proveniente da cistina. As propriedades principais do cabelo dependem de sua geometria, estrutura física. Características físicas e mecânicas das fibras capilares envolvem propriedades que melhoram: elasticidade, maciez, volume, maleabilidade, facilidade para o ato de pentear e brilho. A avaliação de tais propriedades do cabelo pode ser obtida por métodos diversos, como: microscopia óptica e eletrônica, mensuração da resistência mecânica, determinação do brilho e tomografia por coerência óptica (OCT).Unitermos: Cabelo/propriedades/avaliação. Fibras capilares/propriedades/avaliação. Fibras capilares/ características. Tomografia por coerência óptica/aplicação analítica. Microscopia óptica/aplicação analítica. Microscopia eletrônica/aplicação analítica.

Pollution Damage and Protection of Asian Hair

“…The contact angles of the bleached hair in both the exposed and control groups did not differ significantly with the initial contact angle after pre-treatment. According to our analysis, this is because most of the 18-MEA was lost due to the hair bleaching process [13]. But the contact angle of the virgin hair gradually decreased throughout the experiment.…”

“…More damage will make hair more hydrophilic, leading to more tangled wet hair and a higher wet combing force. Therefore, undamaged or healthy hair has the lowest wet combing force [13]. As shown in Figure 2, the wet combing work of the control sample after the third and sixth cycles were basically the same as the initial sample after pre-treatment, which indicates that surfactants and solvents do not damage the hair and increase wet combing work.…”

“…Both hair cuticle and protein damage will have adverse effects on dry combing. In particular, raised cuticles will cause an uneven hair surface, leading to increased friction between the comb and hairs [3,13]. 2.…”

Friction and Surface Temperature of Wet Hair Containing Water, Oil, or Oil-in-Water Emulsion

“…Although the water composition decreased, the frictional force on the hair was almost constant; the frictional coefficient was 0.3 at 5 and 300 min after the beginning of the evaluation. Previous studies showed that the friction coefficient of the wet hair is higher than that of dry hair, because the hair surface structure changes by the contact with water 19 . However, in the present study, the friction coefficient for the wet hair including water is equivalent to that of the dry hair.…”

Re-Evaluation of Bovine Fiber Biomass as Exploitable Keratinous Bio-Resource for Biomedical and Industrial Applications

“…At first, the diversion into AFRPCs showed some great prospects; however, the problem of great anisotropy in their properties makes it difficult to develop AFRPCs with desired engineering properties [22] [23].…”