GB215851A - Improvements in and in connexion with the manufacture of viscose silk - Google Patents

Abstract

215,851. Moriondi, C. Feb. 20, 1923. Cellulose xanthates, processes for making filaments from.-The sulphuric acid content of the precipitation bath used in the manufacture of viscose silk is maintained constant by electrolysis of the bath either in the precipitation vessel or in a separate storage tank through which and the precipitation vessel the bath is circulated. For the electrolysis the vessel which is preferably constituted of iron covered with ebonite as described in Specification 18269/08, [Class 70, India-rubber &c.] is provided with a separate compartment B in which is placed the cathode K and from which caustic soda or potash is withdrawn; the compartments are separated by a porous diaphragm D preferably of porous ebonite as described in Specification 200,577. [Class 70, India-rubber &c.]; the anode A is of thin nettings or strips of platinum or platinum-iridium, or of lead peroxide and constructed in a manner similar to that adopted for the plates of secondary batteries: the cathode is preferably a combination of iron gratings or wire nettings, and is placed near to the diaphragm. To prevent diffusion of the gas produced at the anode A into the precipitating bath C, the anode may be placed in a separate compartment C<1>, separated from the bath C by a diaphragm D<1> of a highly porous material, which may be provided with holes D<2> below the level of the anode. Hydrogen and oxygen may be collected from the cathode and anode compartments.