Part 8 What happens to curly hair when it is straighter with heat?

The fascinating realm of hair science!

When curly hair is straightened with a high heat flat iron, a series of complex physical and chemical transformations occur. Here's a step-by-step breakdown of the process:

1. Initial Hair Structure: Curly hair has an elliptical cross-sectional shape, with the cuticle layer overlapping in a zig-zag pattern. This unique structure contributes to its natural curl and texture.

   
   

2. Heat Application: When a high heat flat iron is applied to curly hair, the heat energy penetrates the hair shaft, causing the cuticle layer to lift and separate. This allows moisture to escape, leading to a temporary loss of elasticity.

   
   

3. Denaturation of Keratin: The high heat causes the keratin proteins within the hair shaft to denature, or unwind. This unwinding process disrupts the hair's natural curl pattern, allowing it to be reshaped.

   
   

4. Reorganization of Disulfide Bonds: The heat energy also breaks and reorganizes the disulfide bonds between keratin molecules. These bonds are responsible for maintaining the hair's natural shape and texture. When they are reorganized, the hair can be reshaped into a straighter configuration.

   
   

5. Temporary Reformation of Hair Structure: As the flat iron is moved along the hair shaft, the heat causes the cuticle layer to re-form in a new, straighter configuration. The hair's natural curl pattern is temporarily overridden, resulting in a straighter appearance.

   
   

6. Cooling and Setting: When the heat is removed, the hair begins to cool, and the new shape is set in place. The reorganized disulfide bonds and re-formed cuticle layer help maintain the straightened shape.

   
   

However, it's essential to note that repeated use of high heat styling tools can cause permanent damage to curly hair, including:

• Protein degradation: Excessive heat can break down keratin proteins, leading to weakened hair.

• Moisture loss: High heat can strip the hair of its natural moisture, causing dryness and brittleness.

• Cuticle damage: The constant lifting and re-forming of the cuticle layer can lead to cracks and damage, making the hair more prone to breakage.

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To minimize damage, it's crucial to use a heat protectant, keep the temperature reasonable (below 400°F/200°C), and avoid using high heat styling tools too frequently.

Thank you Venice !