Abstract

A new parameter – Hair Vibrance Factor (HVF) has been developed to determine the comprehensive effects of hair shine and colour intensity. This parameter can be used to characterize the hair colour vibrancy and make new claims on hair dye formulae as well as on after-dye treatments for coloured hair. Experimental results indicated that a hair spray containing PPG-3 Benzyl Ether Ethylhexanoate improved hair shine on various types of coloured hair and made the coloured hair more vibrant.

INTRODUCTION
Hair shine is an important feature of hair appearance, and this attractive visual effect is a key consumer objective in the hair care market. Hair colour intensity is another important attribute for coloured hair. Consumers always want to have their coloured hair appeared bright and striking, or vibrant. Until now, neither a parameter, nor a test method, has been defined and developed to make such quantified “vibrancy” claims.
Lefaudeus and his colleagues have published principles for measuring hair luster (shine) using a Colour Hair Visual Appearance Study System - SAMBA Hair System based on an innovative polarization camera SAMBA (1-2). They have observed that there are two bands on captured coloured hair images: the “Shine” band (first reflection, no colour) and the “Chroma” band (second reflection with colour) (Figure 1). They defined an “Overlapping Coefficient” to describe overlapping degrees between “Shine” and “Chroma” (Figure 2) – the scalar product of the shine distribution and the chroma distribution. We have observed that the overlapping coefficient increases after specific cosmetic treatments an ...