22—Measurement of the Extent of Delustring of Filament Fabrics

This paper completes the theory of the method of measuring the extent of “delustre” by describing, and discussing, in relation to structure, the ref1ection of plane-polarized light by filament yarns and fabrics and the effect of delustring on the depolarization.The characteristics of the depolarization are interpreted by dividing the total reflection (in the manner described in the previous paper) into the regular reflection (upper surface and internal), the irregular reflection, and the delustre-scattered reflection. The depolarization of each is considered in terms of a “polarized” component and a “depolarized” component of the reflection.The conclusions drawn provide additional support for the interpretations of reflections in terms of structure put forward in the previous paper and show that the use of polarized light increases the sensitivity of the method of measurement of delustre.