STUDIES ON RESIN FINISHING FOR CELLULOSIC FABRICS

Abstract

The study deals with the resistance of methylene-linkage to dilute hydrochloric acid, formed between adjacent cellulose chain molecules by formaldehyde treatment in the presence of acidic catalyst, by investigating the amount of the liberated formaldehyde, the alterations of mechanical properties of fibers, yarns and fabrics, and the direct dye affinity by dyeing the cross-section of fibers, and by observation of the fiber surface by the electron microscope.Viscose spun rayon fabrics and filament yarns were treated similarly as in the previous reports (Part I, IV, and V), that is 5min. immersion in the solution containing 12gr H•CHO and 0.1gr HCl in 100ce, and 10min. heating at 120°C. Then, those were washed 30min. in the distilled water at 90_??_95°C., and rinsed thoroughly by cold water, and then dried. Those formalized cellulose were treated in the dilute hydrochloric acids of various concentration at 90±2°C., for 30min, long.The combined formaldehyde was hardly broken up by the treatment with HCl 0.2gr/100cc, however, it was gradually liberated with increased acid concentration. Those phenomena were not affected by the heating during the formalizing treatment of cellulose. The formalized fibers were destroyed on their surface by the dilute acid, therefore, as the acid concentration increases, the direct dye affinity of the treated fabrics increase gradually, while for inner portion of their fibers no change could be recognized until their concentration was increased to over 1.3gr/100cc.The strength of the formalized fiber was little altered with acid treatment described here, but the strength of the yarns and fabrics, was slightly recovered in the case of very low acid concentration, and reduced in the higher concentration.