Hair Volume: Hair Reshaping The process most people use to reshape the hair strand is wet setting to increase curvature or set a shape in your hair. The basic process is to wet the hair by either shampooing or applying a wet styler. Shampooing works best because the surfactants help the water penetrate the hair shaft really well. Once the hair is wet it is redried into shape either by air drying on rollers or heat drying with a blow dryer and a round brush. Why does this work? Your hair has three primary bonds responsible for its shape: 1. Salt hair bonds - temporary and easy to rearrange because they are water dependent. When you wet your hair, the water inserts itself between the salt bonds - breaking them. When you dry out the water, the salt bonds reform in whatever shape the hair is arranged in. The effect is temporary - as soon as the hair is wet, the bonds will break and go back to their original configuration. 2. Disulphide hair bonds - permanent and can only be changed through chemical processing (e.g. perming, relaxing, etc.). 3. Hydrogen hair bonds - temporary and easy to rearrange because they are water dependent. Function the same way as salt bonds. The illustrations below show the three types of hair bonds at work. Initial Reading: Illustration shows hair volume before experiencing 80% relative humidity in 80-degree F for one hour. After One Hour: Illustration shows impact of 80% relative humidity in 80-degree F for one hour on hair volume. How can hair styling products help? Wet stylers like mousse and gel help the reshaping process in two ways: 1. They help rewet the hair so that there is water available to loosen up the hydrogen bonds. 2. Their styling polymers help hold the hair strands together in place until the strand is completely dry and the set is complete. What about heat styling? Curling irons work on the same principle - even on dry hair. The water embedded in the hydrogen and salt bonds mobilizes from the action of heat - allowing the bonds to be reshaped. Watch out for humidity attack! Water in the air as humidity can also penetrate your hair shaft and loosen up those hydrogen bonds you worked so hard to create. Note the effects of humidity in the images at right. Hair Science Advice The best way to prevent "humidity attack" is to use hairspray on your finished hairstyle. The hold polymers in hairspray are the most humidity resistant polymers around. That's because hairspray polymers are not soluble in water alone- the water must be mixed with surfactants, like shampoo, to weaken hairspray bonds.
