Microfluorometric Studies of the Distribution of Finishes on Fibers and Yarns

Abstract

A microfluorometric method is presented for studying the distribution of finishes on textile substrates. The method is based on the effect of microenvironment (such as microviscosity and micropolarity ) in preserving the excited states of fluorescent tracer molecules introduced into the finish. Different methods for introducing tracers into finishes are described, with a critical appraisal of their merits. Fluorescence intensity is shown to be related to the thickness of the finish film up to about 3 μm. Above this, the intensity levels off due to autoquenching effects. Various microfluorometric scanning modes suitable for studying filaments, yarns, and fabrics are described, and their relevance to the nature of the distribution of finish is discussed in detail. The importance of selecting an appropriate tracer is illustrated by applying the method to an autofluorescent substrate.