Effects of thermal treatments with a curling iron on hair fiber

Abstract

The effect of curling hair with a curling iron has been investigated. Possibilities of thermal damage with repeated curling according to, and in violation of, the manufacturer's specifications have been studied. The propensity of hair surface to damage depends on the moisture content of the hair, and these experiments have been conducted in both wet and dry conditions, with and without application of tension, and with short or prolonged times. Scanning electron microscopic examination revealed that fibers treated under the dry condition (50% RH) show radial and axial cracking along with scale edge fusion. Similar thermal treatment on wet hair resulted in severe damage of the type described above, as well as bubbling and buckling of the cuticle due to the formation and escaping of steam from the fiber. Fibers subjected to repeated curling in the dry condition show slight increases in tensile mechanical properties, characteristic of a cross‐linked fiber. Fibers treated with conditioners show an improvement in characteristic life, especially in the case of low‐molecular‐weight conditioners, such as CETAB, which can penetrate into the hair fiber (shown by TOF‐SIMS analysis).

Ceramic flat irons: Improper use leading to acquired trichorrhexis nodosa

“…Hair damage is usually noticed as a change in the quality of the hair, dry ends, or flyaway hair. [10][11][12][13][14] If breakage occurs, it can happen anywhere along the length of the hair causing a shaggy or skimpy appearance to the hair. When this occurs, flat iron users may use the device even more frequently to try to tame the broken or uneven appearance of their hair, which leads to more damage (Fig 2).…”

“…15,16 Skin burns can occur in users and, recently, there have been reports that these devices should be considered household hazards because of the risk of accidental skin burns in children. 15,16 Studies have shown that temperatures of 1758C to 2158C for 5 minutes are sufficient to damage most hair; this threshold may be lower if the heat is applied to damp or chemically treated hair 1,[8][9][10]17 (Figs 3 and 4). Proper use of flat irons involves application of the implement to dry hair, and specialized products may be applied to the hair before pressing to help prevent the burning and allow for smoother hair that remains straight longer.…”

“…Proper use of flat irons involves application of the implement to dry hair, and specialized products may be applied to the hair before pressing to help prevent the burning and allow for smoother hair that remains straight longer. 2,10 If there is a temperature setting on the device, it should be set no higher than 1758C or on the low/medium setting. How frequently the flat iron can be used depends on the individual's hair type, but should probably not be used more than one time per week.…”

Exogenous Factors in Hair Disorders

“…However, disregarding the guidelines increases the potential for severe hair damage. Prolonged (10-min) curling of dry hair combined with increased tension led to moderate compression, disintegration, radial cracking and scale edge fusion of the surface cuticular cells, observed by surface microscopy [79] . When repeated curling was applied to wet hair, distortion of cuticle cells with bulges or bumps was formed, most likely due to the explosive release of steam trapped in the wet cuticles [79] .…”

“…Prolonged (10-min) curling of dry hair combined with increased tension led to moderate compression, disintegration, radial cracking and scale edge fusion of the surface cuticular cells, observed by surface microscopy [79] . When repeated curling was applied to wet hair, distortion of cuticle cells with bulges or bumps was formed, most likely due to the explosive release of steam trapped in the wet cuticles [79] . Damage to the fi ber surface as a result of thermal exposure was also refl ected by an increase in combing forces, a technique very sensitive to minute chemical or physical changes in the hair surface [80] .…”