Comparison of Hair Damage Based on Treatment Timing During Iron Permanent Wave Procedure

The study investigated the optimal timing for applying hair conditioner during an iron permanent wave process to minimize hair damage. Four hair samples were treated at different times, and their tensile strength, hydration, thickness, and cuticle condition were analyzed using Atomic Force Microscopy. The sample treated in the middle of the process showed superior results, with 3% higher tensile strength than early-treated, 11% higher than late-treated, and 16% higher than untreated samples. It also had the lowest moisture loss rate and the healthiest cuticle appearance. This research suggested that mid-treatment application of conditioner could effectively reduce hair damage.