Chemical Texture Services and Relaxing
Chemical Texture Services and Relaxing
This domain covers relaxers and permanent waves: the chemistry of breaking and rebuilding disulfide bonds, product selection, and the neutralizing step.
Core rules
- Relaxers: sodium hydroxide (lye, pH about 12-13), no-lye (guanidine or calcium hydroxide, pH about 9-10), and thio relaxers (ammonium thioglycolate, pH about 9-10).
- Base the scalp and hairline; apply to new growth only; do not overlap previously relaxed hair.
- Smooth, do not scrub, and time precisely. Rinse thoroughly, then neutralize with shampoo at pH 4.5-5.5, lathering several times and leaving the last lather on per the label.
- Permanent waves: alkaline waves (pH 7.5-9.5) and acid-balanced waves (pH 5.5-7.0). Wrap, process, take a test curl, rinse, then neutralize with hydrogen peroxide to rebuild disulfide bonds.
- Retouch relaxers every 6-8 weeks; avoid shampooing or scratching the scalp before a service.
Worked example
A client's relaxer is due and the previous relaxer is 5 inches down the strand. Reasoning: applying product along the whole strand causes overlapping, over-processing, and breakage. You apply to the new growth only, keep the product off the previously relaxed hair, and rinse with the hair flat to avoid tangling.
Traps
- Skipping or shortening neutralization leaves residual alkali that keeps breaking hair.
- "No-lye" is not gentler in every case; it can leave calcium deposits and dryness.
- A test curl is the only reliable processing check; timing alone is not.
- Never relax hair that has been lightened to a high level without a strand test.