Abstract: After slenderizing Process, the surface morphology, internal structure, and other physical and chemical properties of human hair and wool isometric protein fibers would occur to some extent changes. The human hair fibers scale layer completeness after slenderizing and replies state after unsetting retraction were systemic studied by Herbig reaction,compared the human hair fibers modification after slenderizing process,thereby explore human hair fibers slenderizing mechanism. The resultsindicated that Slenderizing process caused human hair fibers scale layers greatly modified,the higher the strain rate,the greater modification,after stretching-setting human hair fibers had greater modification;also found that scale layers and the scales below layer reactions to the stretching treatment had a great difference,stretching and no setting fiber scale layers occured irreversibility changes.

Key words: human hair, slenderizing, scale layer, Herbig reaction