Polymeric Dye Retarders for Acrylic Fibers

Abstract

This paper describes a new approach to dye retardation wherein fibers containing ionic dye sites are treated with polyelectrolytes of opposite charge. The polymeric material coats the fiber and reduces the rate of dye uptake. Experi mental data obtained with a continuous dye-bath analyzer are presented to clarify the mechanism of polyelectrolyte retardation of cationically dyeable acrylics, and extend the concept to anionically dyeable fibers. Practical applica tions are described using a polycationic retarder to give level dyeing, union dyeings, or tone-on-tone effects with several types of acrylic fibers. A special advantage of these retarder systems over conventional retarders is that they do not interfere with development of crimp in bicomponent fiber and thus do not alter fabric aesthetics.