Denaturation of the protein in the hairProtein in human hair consists of elements of cystine, which is a compound that has an element asamamino sulfide, in a fairly high percentage of the amount. Disulfide bridge of cystine-SS-is one of the main factors responsible for the various forms yangbertanggung of our hair. Straight or curly hair because the keratin molecule containing bridges disulfidayang make mampuuntuk maintain certain forms.Rebonding process involves a chemical process that changes the structure of the protein in the hair. Rebonding process produces permanent changes in the affected hair applications. But the new hair that grows from the root hair rambutakan still have the original form. So, instead of straightening hair rebonding using only ordinary physical treatment, but also using chemical treatments that alter the structure of the protein in the hair permanently. Rebonding process through a process that uses heat pencatokan. Heating resulted in breaking the bonds making up proteins, such as hydrogen bonds break.