Heat, Compression & Tension: The Principles of Flat Ironing

The reason most stylists want a HOT flat iron comes from their technique. It’s important to understand the 3 factors that come into play to get a perfect flat iron pass.

Heat – Correct temperature for the hair type

Compression – Smoothes the cuticle

Tension – Stretching the hair

Heat breaks the hydrogen bonds – Compression smoothes the cuticle down – Tension pulls the bonds apart to allow them to cool in their new smooth, flat position.

The problem is that most stylists do not do one of the 3 factors correctly so they turn up the heat to compensate for this.

PROBLEM: If the compression isn’t correct, the cuticle isn’t smooth enough – they do not get the look they want so they bump up the heat

SOLUTION: On more resistant hair, move your hand closer to the plates to get more compression

PROBLEM: If there isn’t enough tension, the bonds do not slip enough – they do not get the look they want so again they turn up the heat

SOLUTION: When flat ironing (especially on resistant hair) follow a boar bristle brush… especially one of our oval “round” brushes. This gives the ability to get maximum tension on the hair to pull the hydrogen bonds apart and allows them to cool in their new flat state.

If you think about it, it’s the same thing we do to the di-sulfide bonds in perms. The perm solution breaks the bonds and we wrap the perm with tension over the rods to get the new shape.

Same concept… Different bonds… Different tools!

I use the perm comparison when I am speaking with stylists. It just reinforces something that they already know but have probably not paid attention to.