GB514736A - Improvements in or relating to the production of artificial fibres - Google Patents

Abstract

514,736. Artificial fibres. GASTELL, R. SCHREIBER-, and FORMHALS, A. May 13, 1938, No. 14365. [Class 2 (ii)] Artificial fibres are obtained by extruding a filament-forming solution through one or more jets which form one electrode of a high tension electrical circuit, into an electrical field created between the jets and an electrode forming the other pole of the high tension supply. The solution is disrupted by the electrical forces into fine fibres and these are removed from a position between the two electrodes without coming into contact with the other electrode. The filament-forming material may be extruded into an air current substantially at right-angles to the direction of extrusion. The spinning solution may be a solution of cellulose acetate or other cellulose ester in a volatile solvent such as acetone. The electrical connection with the jet-electrode may be made at any convenient point since the solution is a conductor of high-tension electricity. The other electrode may consist of one or more thin wires or knife-edged blades connected to the opposite pole of the high tension supply. The wire may be fixed below but preferably not directly underneath the jets. As shown in Figs. 1 and 4, x1, x4, represent cross-sections of wires forming one of the electrodes and j1, j4, indicate jet electrodes. Preferably, the jet electrodes are made negative. A current of air may be caused to flow between the row of jetelectrodes and the other electrode and substantially parallel to both. As shown in Fig. 5, thin streams of solution are extruded through the orifices in the jets i which form the negative electrode of a high tension electric circuit. The positive electrode is formed by a thin wire x. A current of air is passed between the electrodes from an inlet a. Air and solvent leave the apparatus by the pipe b. The electric current used is a direct pulsating current. The electrical field causes the streams of solution to be split up and formed into fine fibres. The thin wire electrode causes the air in its vicinity to be ionised.. The fibres charged with electricity are attracted towards the wire but when they reach the ionised zone tneir charge is neutralised and then reversed so that they are repelled from the wire. A band of felted fibres is thus formed. This is removed from the apparatus by a winding device u assisted by the air current. The operation may be started by means of a thread arranged to run through the spinning zone in the path taken by the fibre band. If desired, the fibres may be allowed to fall to the floor where they collect as a tangled mass. This may be used as heat insulating material or converted into yarn after carding and other treatments.