The Wrap

Dec 15 2015


  • Author: Trefar Evans

This 1-Minute Science Experiment Will Change the Way You Think About Your Hair

As any scientist who works with hair can tell you, hair and water have a love-hate relationship. On the one hand, water is an integral part of hair’s structure and some degree of moisture is essential for keeping it healthy and happy. But on the other, too much water can have a detrimental effect.
Seems counterintuitive, right? What’s important to understand is that water has a unique ability to penetrate hair and plasticize its fibers—which, in essence, means making them weaker.

So while a small amount of water is no problem, the longer your hair remains wet, the greater the potential for breakage. In fact, lab studies have suggested that the tendency for fiber breakage in hair with a high water content is thousands of times higher than when this level is low1,2,3. Keeping hair too wet for too long can, in fact, cause more breakage that “damaging” treatments such as bleach, perms and relaxers.

But don’t take it from scientific journals or diagrams (or even me!). Try these two quick DIY science experiments to understand exactly how vulnerable your hair is when it’s wet—and why drying it quickly and gently is of utmost importance.

The Strength Test

What You’ll Need: 2 hair fibers (that are about the same size) and a glass of water.
What to Do: Drop one fiber into the water glass let the other one remain dry. Once the first fiber has been immersed for about a minute, take it out of the glass and lay it next to the dry fiber. Dry off your fingers, then slowly and carefully stretch the dry fiber until it ultimately breaks. Then, do the same thing with the wet fiber.
What You’ll Notice: After just 60 seconds of immersion, the wet fiber will take considerably less force to break. This explains why rubbing wet hair with a rough cotton towel can so easily cause breakage.

The Texture Test

What You’ll Need: 2 hair fibers (that are about the same size) and a glass of water.
What to Do: Repeat the steps in the experiment above, only this time, rather than stretching the hair fibers until they break, slide your dry fingers back and forth across each fiber, paying attention the difference in texture.
What You’ll Notice: The wet fiber will feel considerably rougher, due to its exposure to water. This explains why wet hair is more susceptible to snags and tangling, and must always be treated with compassion.

1) T.A.Evans, Fatigue Testing of Hair – A Statistical Approach to Hair Breakage, Journal of Cosmetic Science, 60, 599-616, Nov/Dec, 2009
2) T.A. Evans, Measuring Hair Strength, Part 2: Fiber Breakage, Cosmetics & Toiletries, Vol. 128(12), 854-859, December 2013
3) T.A. Evans, Chapter 8 – Hair Breakage, In Practical Modern Hair Science, TA Evans & RR Wickett Ed., Allured Books, 2012.