Determination of the relation between the particle size of viscose and the physical properties of the rayon produced: development of a practical method for measuring the change of particle size

Abstract

During the ripening of viscose, changes take place in the constitution of the colloidal solution which can be observed by means of the change in the intensity of the Tyndall light scattered by the solution. The intensity of the scattered light decreases rapidly at first, but more slowly with time, apparently approaching a limiting minimum value. The point at which the intensity measurements become practically constant is in close proximity to the point of optimum spinning conditions and appears to be a more accurate means of locating this point than either the viscosity or the ammonium chloride method. The change observed in this work occurred in a rather narrow range with the apparatus employed. The development of the Tyndall beam as a practical method for measuring the maturity of viscose syrup will therefore require refinements in the apparatus used. On the basis of the results obtained, it is suggested that the colloidal particles of viscose syrup do not coagulate as solid particles but instead aggregate in some loose type of aggregation.