How did ancient people perm their hair?

A perm is to roll wet hair around the core of a T-shirt. Wait for natural drying or heat molding with a hair dryer. Perming is the use of hydrogen bonds in the hair structure to break water. The higher the temperature, the more hydrogen bonds are broken, which means that some hydrogen bonds are rearranged, which will not lead to the complete separation and straightening of molecular chains. First, when it comes into contact with water again, the hair will recover due to the internal force of its original shape, and the hydrogen bond will return to its original position. Anyway, it is a temporary curling method (that is, physical).

burn

At the earliest, tools such as electric tongs or iron bars were used to heat the hair in advance, and then the hair was curled into waves. This method is very harmful to hair quality and has been abandoned with the development of science and technology.

Wood perm

Log perming is the earliest method of winding hair on logs. It turns into curly hair after drying, and your hair curls into waves.