DYE ACCESSIBILITY OF RAYON AND SYNTHETIC FIBERS

Abstract

Dye accessibility of fiber depends on the magnitudes of the following factors:1. The surface area through which the dye passes into the fiber.2. The speed by which the dye migrates in the fiber.3. The inner volume υ (cc. per lg dry fiber) in which the dye exists.4. The dissociation energy E of the dye-fiber-complex.As (1) and (2) can be calculable when E is known, the author starts the studies from obtainingE. When in the hot and very dilute direct dye solution the sizes of the dye particles are very small and homgeneous, there holds the next relation. (dissociation energy of a dye particle from the dyed fiber) (cal/ particle) Here k: Boltzmann's constant, T: absolute temperature, m0: number of dye particles in the initial dye bath, m: number of dye particles in the equilibrium reaching dye bath, υ: volume of the dye bath.The dyeing experiments are as follows.Materials to be dyed; viscose rayon, cuprammonium rayon, Vinylon (appolyvinylformal fiber), and polyvinylalcohol fiber. Temperature: 80°C Period: 3 hrs. Liquor ratio: 1/250. Dyes: Benzopurpurine 4BKX Chrysophenine NS Naphthamine Blue 12B (all purified). Dye concentration: 0.001%(Wt) (Benzopurpurine 0.003%) NaCl concentration: 0.001%(Wt) (Benzopurpurine 0.0003%) The results are:Under the same dyeing condition E of Vinylon is found to be greater than that of cellulose fiber. but smaller than that of polyvinylalcohol fiber.