Final answer:
A steam vapor dryer helps to open the hair's cuticle, allowing moisturizers and oils to penetrate the hair shaft. Moisturizers contain occlusives and humectants, ingredients that respectively form a barrier and absorb moisture to nourish and hydrate hair.
Step-by-step explanation:
A steam vapor dryer infuses water hydration, opening the cuticle layer of the hair shaft and enabling nourishing, moisturizers, and botanical oils to penetrate deeply into the cortex layer. Moisturizers often include ingredients such as occlusives and humectants. Occlusives form a barrier to keep moisture from escaping, while humectants absorb water either from the air or by drawing moisture from the dermis into the epidermis.
The hair's cuticle layer can be likened to a plant's cuticle, which prevents water loss by being impermeable. Similarly, the steam process in hair treatment opens the cuticle to allow moisture and oils to enter the hair shaft to hydrate and nourish it. A well-moisturized hair shaft can prevent water loss and maintain the hair's flexibility and strength.