IMPREGNATION OF BLEACHED JUTE YARNS WITH SYNTHETIC RESINS. PART II. EFFECT OF PRETREATMENTS AND BLEACHING PROCESSES ON THE WET-STRENGTH OF RESIN-TREATED YARNS

CHEMICAL LABORATORY, BOSE INSTITUTE, CALCUTTA

It has been found that the level of lignin content regulates the improvement of wet-strength. other conditions remaining the same. I he low r the lignin content of the bleached yarns, the better is the improvement obtained on impregnation with resins. If the lignin content fails too low, the yarns disintegrate in contact with water, thereby making the use of aqueous solutions cf resins impossible. Chlorite bleaching gives a better improvement of wet-strength after resin treatment than sodium hypochlorite or bleaching powder, due to hemicellulosen remaining more or less in tact. Pretreatment of yarns with 2% sodium carbonate or with rectified spirit containing 2% pyridine gives satisfactory improvements.