Dilute solution viscometry of single polyester fibers

Efflux times were measured for dilute solutions of short lengths of ten single polyester fibers by micro capillary viscometry using a 50-μl charge. Limiting viscosity numbers (intrinsic viscosities) and molecular weights were calculated for each fiber by a single-point method. Efflux times were measured for three of the fibers after they were subjected to two different laundering procedures and outdoor exposure. The viscometric method was unsuitable for fiber identification but was shown to be highly discriminating for the comparison of fibers of similar commercial origins.