PROCESS FOR THE CONTINUOUS PRODUCTION OF VISCOSE RAYON YARNS HAVING HIGH DEGREE OF WHITE

摘要

Process for the continuous production of viscose rayon yarns having a high degree of white, comprising extruding the viscose solution into a coagulating bath, drawing and coagulating the extruded filaments in said bath, and advancing said filaments in a substantially helical path while they undergo the treatments required for the production of a finished yarn, characterized in that it comprises effecting, after the filaments have been withdrawn from the spinning bath, a completion of the coagulation in a manner described hereinbefore until a coagulation index not higher than 1 has been attained, and a treatment with water having a non-alkaline pH, until the content of the following elements in the yarn has been reduced to values not higher than the following ones : total sulphur 0.2%, sulphur bound as sulphides 0.02%, elementary sulphur 0.6%, iron 40 ppm, zinc ppm, Pb 30 ppm.