Cyclic Combing of Untreated and Bleached Human Hair: Analysis of the Time-Dependent Breakage of Hair Through Recording the Formation of Fiber Fragments

This study examines the effects of cyclic combing on untreated and bleached human hair, focusing on hair fragment formation over 5,000 cycles. It finds that bleached hair produces more fragments due to higher friction and fragility, while conditioner treatments significantly reduce fragment numbers by decreasing friction, particularly in untreated hair. The study uses a model based on the Voigt–Kelvin equation to describe fragment formation kinetics and suggests that initial fragment release can predict hair resilience to combing. The findings highlight the impact of bleaching and conditioning on hair fragility and propose using "grooming or combing resilience" to describe hair performance during grooming.