Chemical Texture Services: Permanent Waving and Relaxing
The chemistry in one line
Both perming and relaxing break disulfide bonds, reshape the hair, then rebuild the bonds. Perms reduce with ammonium thioglycolate (alkaline, pH around 9 to 9.6, self-heating) or glyceryl monothioglycolate (acid, lower pH, needs external heat, slower and gentler). Relaxers straighten with sodium hydroxide (lye, very high pH), no-lye calcium hydroxide products, or ammonium thioglycolate thio relaxers.
Perm procedure
Consult and test for metallic salts; shampoo without conditioner; examine the scalp. Wrap on the rod size and shape that matches the target curl, using end papers so ends are never fishhooked. Alkaline perms are processed without added heat and checked with a test curl; acid perms need heat. Rinse thoroughly, blot, then neutralize - the neutralizer is an oxidizer that rebuilds the bonds and stops the reduction. If neutralizing is incomplete the hair stays weak and can re-curl or break. Remove rods, rinse, condition.
Wrapping styles matter: croquignole wraps from ends to scalp with overlapping, spiral wraps around the rod, piggyback for long hair. Base placement and rod direction govern volume and movement.
Relaxer procedure
Protect the scalp with base cream, apply to new growth only, smooth without abrading, rinse completely, then shampoo repeatedly with neutralizing shampoo and verify the pH. Pulling relaxer through previously relaxed hair is the classic cause of breakage.
Traps
- Relaxing over a relaxer instead of new growth.
- Skipping or shortening neutralization.
- Perming hair with poor elasticity, or within days of another chemical service.
Rule of thumb
Reduce, reshape, oxidize. If the rebuild step is rushed, the whole service fails - no exceptions.