GB149296A - Improvements in and relating to method for the production of masses or solutions free from air and other gases - Google Patents

Abstract

149,296. Borzykowski, B. Aug. 13, 1917, [Convention date]. Apparatus for making filaments and films; cellulose solutions, processes for making filaments, films, &c. from. -Fluid masses or solutions to be used for the manufacture of artificial threads, films, &c., more particularly solutions of viscose and copper-oxide-ammonia - cellulose, are freed from air and excess of volatile solvent by allowing the solution to flow as a film over a surface located within an exhausted and hermetically-sealed vessel, the material being conveyed from the vessel into an airexhausted system including a supply pipe, head, or nozzle from which the material is projected into coagulating- baths &c., so that contact of the air-feed solution with air up to the moment of use is obviated. By separating air &c. from the solution, the formation of air bubbles and other difficulties connected with the appearance, strength, and coagulation of the thread, film, &c. are avoided. To facilitate the handling and filtering of the solution, there may be added an excess of an indifferent volatile solvent, the excess being afterwards removed during the vacuum treatment, and recovered. The material to be treated is contained in a receptacle 1 and passed through preliminary filters 1<a>, 1<b>, to exhausted chambers 2, 3. These chambers are provided with cone-shaped plates B, B<1>, over which the solution flows as a film, afterwards flowing down the walls of the chambers. When full, the chambers are put into communication with final filters 9, 10 and the spinning-tube 12, all of which have been previously exhausted; when these parts are filled with the solution as is seen by the passage of the latter into the vacuum chamber C, the connexion 16 is closed; the forcing of the solution through the spinning-nozzles 14 is then started by putting air pressure on the material in the receptacles 2, 3 or by gravity &c. For continuous operation the receptacles 2, 3 are worked alternately. The vapours passing to the vacuum pump 27 are preheated if necessary in a preheater 22, and when discharged from the pump are passed to a condenser 29.