Hair straightening works by altering the chemical structure of the hair strand, specifically the bonds that determine its natural curl or wave pattern. This process typically involves the application of chemicals to break or loosen these bonds, allowing the hair to be reshaped into a straight form. Once straightened, the bonds are then reset, either chemically or with the help of heat, to maintain the new, straight shape.
The fundamental principle is targeting the hair's disulfide bonds (also known as cysteine bonds), which are strong chemical links within the hair protein (keratin) that provide structure and hold the hair's shape. By manipulating these bonds, the natural pattern can be changed.
Different straightening methods utilize specific processes to achieve this:
Types of Chemical Straightening
According to the reference, two primary methods involve chemical manipulation of hair bonds:
-
Japanese/Thermal Reconditioning (Yuko/Rebonding):
- This is described as a non-coating treatment.
- It involves applying a chemical solution that loosens the cysteine bonds in the hair.
- This chemical is typically left on for a specific time, often 15-20 minutes.
- Following the chemical application, heat is applied to restructure the bonds into a straight type. This heat is crucial for setting the new shape.
-
Relaxers/Chemical Straightening:
- This method uses chemical relaxers.
- These chemicals directly break hair's disulfide bonds.
- Breaking these bonds significantly weakens the hair's natural structure, allowing it to be combed into a straight position.
- A neutralizer is then applied to stop the chemical process and reform the bonds in their new, straight configuration.
The Process in Simple Terms
Think of the chemical bonds in your hair like tiny rubber bands holding the protein chains together in a specific pattern (curly or wavy).
- Chemical Application: A straightening chemical is applied. This chemical acts like scissors, either loosening (thermal reconditioning) or cutting (relaxers) those rubber bands.
- Reshaping: With the bonds loosened or broken, the hair is no longer held firmly in its original pattern. It can then be combed or pulled straight.
- Resetting:
- For thermal reconditioning, heat (often from a straightening iron) is used to help the loosened bonds reconnect in the new, straight shape.
- For relaxers, a neutralizer chemical is applied to allow the broken bonds to reform in the straight position.
Comparison Table
| Feature | Japanese/Thermal Reconditioning | Relaxers/Chemical Straightening |
|---|---|---|
| Bonds Affected | Loosens Cysteine bonds | Breaks Disulfide bonds |
| Key Tool | Chemical solution followed by Heat (e.g., flat iron) | Chemical relaxer followed by Neutralizer |
| Process Time | Chemical applied for ~15-20 minutes, then heat applied | Chemical applied, bonds broken, then reset |
| Treatment Type | Non-coating treatment | Chemical treatment |
Ultimately, both methods manipulate the fundamental building blocks of hair structure to permanently or semi-permanently change its shape from curly or wavy to straight.
