During a perm procedure, what does wrapping the hair around a rod do?

Wrapping the hair around a rod during a perm procedure is a crucial step in determining the final curl pattern of the hair. When the hair is wrapped around the rod, it takes on the shape and size of that rod, which is essential for creating curls or waves. The rod serves as a mold, allowing the chemical solution applied during the perm process to penetrate the hair shaft and alter the hair's structure in a way that sets the curl.

This shaping is what gives the perm its character—whether it be loose waves or tight curls, the size and type of rod used directly influence the outcome. The perm solution breaks down the disulfide bonds in the hair, and when the hair is wrapped around the rod, those bonds re-form in a new pattern as the hair dries and the solution is neutralized, establishing the desired curl or wave pattern once the rods are removed.

Other options, such as strengthening, conditioning, or moisturizing, while they may be beneficial outcomes of the overall perming process, do not specifically relate to the action of wrapping hair around the rods. Rather, the primary function of the wrapping method is to set the curl pattern effectively.