Use of single fibre fatiguing experiments to understand breakage in textured hair part 2: Testing panellists hair

Abstract Objective The previous article in this series demonstrated how single fibre fatigue testing produces a simple and logical explanation as to why breakage is such a problem for consumers with very curly textured hair. The intent of this current paper was to extend this study to hair of varying curl types. Methods Single fibre fatigue testing was utilized to further provide insight into the differing tendencies for breakage in hair of different curl types. Hair was procured from many panellists in both New Jersey, USA and Cape Town, South Africa. Results In general, results showed progressive negative trends in each of the three identified areas of concern with increasing curl type. Namely, fibres tended to break under fewer fatiguing cycles, exhibited higher premature failure and will encounter higher fatiguing stresses. A surprising outcome of this testing was a huge variability in the tendency for breakage among panellists' hair within any given curl type. A high propensity for breakage may be interpreted as the hair being damaged as a result of the panellists' habits and practices; but certain samples were seen to be remarkably breakage resistant. An unexpected correlation was noted between the characteristic lifetime and the modulus of hair in any given curl type. Conclusions Results show the compounding effect of three contributing parameters which each yield progressively increasing detrimental effects with increasing curl type. Yet, the variability in breakage properties in any given curl type is highly noteworthy. While this work sheds light on the reasons for a high breakage propensity in textured hair, it unexpectedly reveals how certain individuals have remarkable breakage resistant hair.