| 摘要 |
535,867. Artificial silk, processes, treating. CELLULOSE HOLDINGS, Ltd. Jan. 2, 1940. No. 118. Convention date, Feb. 8, 1939. Drawings to Specification. [Class 2 (ii)] Elongated articles of regenerated cellulose are continuously produced by the coagulation and decomposition of cellulose xanthates ; they are then heated in the presence of water vapour to complete the decomposition and to remove the volatile impurities before the de-sulphurizing treatment takes place. The process is applied to the production of films, filaments and tubing of viscose which may be cast or extruded into a liquid containing a strong mineral acid or an acid salt to effect the coagulation and decomposition ; or two separate baths may be used to effect coagulation and decomposition separately. The articles are then passed through a heated atmosphere containing water vapour, preferably steam; the temperature for this step of the process is maintained at 70‹ C. or higher. The articles are then passed in a sinuous path around rollers in baths for the usual treatments of desulphurizing, purifying, bleaching, dyeing and softening.
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