This is one of the most important properties of hair. Because of its elasticity, hair can resist forces that could change its shape, its volume or its length. Its elasticity lets it spring back to its original form without damage.
When healthy hair is wetted and stretched, it can increase in length by up to 30% and still return to its original length when it is dried. Stretching it more than this will tend to damage it, however, leading to permanent lengthening and even breaking.
The elasticity of hair depends on the long keratin fibres in the cortex. Chemical treatments of hair such as perming and bleaching can alter the cortex after repeated damage, and change the hair's elasticity. Hair with poor elasticity will stretch only to a limited extent. It will not curl, it will break easily when it is groomed and it cannot be permed satisfactorily.Both natural sunlight and artificial ultraviolet light break down chemicals in the hair and damage its elasticity in the same way that bleaching does, though to a much lesser degree.
A stylist must always examine the elasticity of a client's hair before deciding on any chemical procedure.
When healthy hair is wetted and stretched, it can increase in length by up to 30% and still return to its original length when it is dried. Stretching it more than this will tend to damage it, however, leading to permanent lengthening and even breaking.
The elasticity of hair depends on the long keratin fibres in the cortex. Chemical treatments of hair such as perming and bleaching can alter the cortex after repeated damage, and change the hair's elasticity. Hair with poor elasticity will stretch only to a limited extent. It will not curl, it will break easily when it is groomed and it cannot be permed satisfactorily.Both natural sunlight and artificial ultraviolet light break down chemicals in the hair and damage its elasticity in the same way that bleaching does, though to a much lesser degree.
A stylist must always examine the elasticity of a client's hair before deciding on any chemical procedure.