Patent GB-341075-A (GB)
Title: Improvements in processes and apparatus for the dry spinning of solutions of cellulose derivatives
IPC: D01D4/02
Filed: 1929-10-07
Abstract: <PICT:0341075/IV/1> <PICT:0341075/IV/2> <PICT:0341075/IV/3> <PICT:0341075/IV/4> <PICT:0341075/IV/5> Apparatus for making filaments-Relates to means for supplying additional air or other evaporative medium in the vicinity of the spinning jets when dry spinning artificial silk &c. as is described in the parent Specification.  According to one modification, such air is supplied to the interior of the bundle of filaments issuing from the spinning jets.  The air may be supplied through the body of the spinning nozzle as in the form shown in Figs. 1 and 2, or if a gap is left in the ring of spinning orifices constituting the nozzle then as shown in Fig. 5 in which a disc jet is employed, a separate pipe 41 may serve for the air supply, the pipe being pivoted to the nozzle pipe 28 and a stop 44 being provided to determine its movement.  In the former case the spinning jet 16 is of annular form, being held in position together with a section of filter cloth 15 and appropriate packing 17 by means of an external collar 19 and an inner member 25 screwed to the body 7 of the nozzle; this outer member serves for the supply of the additional air, for which purpose air supplied through a pipe 231 and a passage 22 in the body 7, passes through a passage 24 in the member 25, then through inclined radial passages 24a into an annular space from which it is distributed by means of an adjustable spreader 26. The additional air may be directed with respect to the filaments either downwardly, upwardly or radially outwards, but preferably in the direction of movement of the filaments and somewhat outwardly.  The devices above described may be used in conjunction with devices for supplying additional air to the exterior of the bundle of filaments.  According to another modification, applicable to cases in which the filaments are extruded into a counter current of the evaporative medium, the additional air &c. introduced in the vicinity of the jets, is constrained by the provision of a tubular or other collector device that surrounds the filaments, to make intimate contact therewith; the additional air may move in the same direction as the filaments, or opposite thereto.  As shown in Fig. 8 an external perforated ring 53 serves for the supply of additional air which is directed upwards and inwards, and a collector 48 causes this air to make intimate contact with the filaments during its passage to the draw-off pipe 50.  Instead of the ring 53, the additional air supply device may be combined with the spinning nozzle as shown in Figs. 1 and 2. In another form shown in Fig. 9, the collector 56 is mounted on the filter 30, and additional air is supplied downwardly through a perforated pipe 58, the air moving downwardly with the filaments before passing to the draw-off 50.  The amount of additional air may bear any relationship to the total volume passing through the cell, and it is preferred that the supply is controlled in the manner described in Specification 203,092 [Class 2 (ii), Cellulose &c], and employed in respect of the drawoff from the cells.  The additional air may be cold or heated; and it may contain a proportion of solvent vapours.