Progressive Hair Straightening Using an Automated Flat Iron: Function of Silicones

The study explored the use of an automated flat iron for progressive hair straightening, focusing on the role of silicones. The iron controlled hair temperature, contact force, and gliding speed, with tests conducted on undamaged curly hair at temperatures between 120°C and 175°C. Results showed irreversible straightening was achieved, influenced by temperature and ironing cycles. Birefringence data indicated straightening was linked to reduced microfilament organization. Silicone treatment did not alter microfilament denaturation but improved straightening quality by enhancing fiber alignment. The study suggested that ironing at around 154°C could balance speed, performance, and hair integrity, offering a potential method for permanent hair smoothing without chemicals.