Patent GB-697957-A (GB)
Title: Improvements in or relating to a method of treating a tow of filaments or threads ina limited space
Inventor: KEGGIN JAMES FARGHER
IPC: D01D10/04
Filed: 1950-03-21
Abstract: A continuous tow of filaments, e.g. artificial filaments made from solutions of vegetable seed globulins or phosphoproteins, is introduced, together with a treating liquid having a specific gravity lower than that of the tow, into the inlet end of a portion of a tube having a lower surface which is inclined downwardly in the direction of travel of the tow and of the liquid, and the speed of the liquid and the inclination of the tube are so arranged that a desired quantity of tow collects in folds or loops on the inclined lower surface of the tube and that the treated tow, which is continuously withdrawn from the treating liquid at the exit end of the tube, has been in contact with the liquid for a desired period of time.  The inclined tube may extend downwardly into a constant-level trough so that <PICT:0697957/IV (a)/1> the treating liquid will keep the trough filled up to the constant level as it leaves the lower end of the tube.  Alternatively, the inclined portion of the tube may lead into an upturned portion from the upper end of which the tow is withdrawn and the liquid flows away.  The lower surface of the inclined portion of the treating tube may be inclined at an angle of 5-45 degrees to the horizontal.  In an example, a ripened solution of peanut globulin in an aqueous solution of caustic soda and sodium sulphite is extruded into a coagulating bath of dilute sulphuric acid containing sodium sulphate to form a tow of 15000 filaments.  The tow 1 is taken up on godet 2 and passes to godet 3 from which it passes vertically downwards into a constant level feed cone 4.  It is there picked up by a relaxing solution, e.g. a concentrated solution of sodium sulphate, which carries it through tube 6 and glass cone 7 into the inclined tube 8 which forms one arm of a bent tube.  The speed of the liquid through tube 6 is controlled by the difference in levels of the liquid in cone 4 and the overflow at the end of the other arm 9 of the bent tube.  On entering tube 8, the tow forms a loose column against the lower surface of the tube and is removed from the exit end of arm 9 by godet 10.  The relaxed filaments of the tow may subsequently be subjected to treatment to render them resistant to hot dilute acid and salt solutions.ALSO:Apparatus for treating a continuous tow of filaments with a liquid having a specific gravity lower than that of the tow comprises a constant level feed cone at the inlet end of a treatment tube or tube system through which both the liquid and the untensioned tow are caused to travel in the same direction, the inlet portion of the tube leading to another portion which is substantially wider than the narrowest part of the inlet portion; the wider portion of the tube has a bottom internal surface which is inclined downwardly to such an extent and is of such a length that the tow advances along that surface in folds, and the exit end of the tube, from which the tow is continuously withdrawn, is at a lower level than the liquid level of the feed cone.  The <PICT:0697957/IV (c)/1> sloping bottom surface of the tube may be at 5-45 degrees to the horizontal.  As shown, a tow 1, consisting of 15,000 filaments obtained by extrusion and coagulation of a solution of groundnut globulin, travels from godet 3 into the constant level feed cone 4 where it is picked up by a treatment liquid which enters the cone through pipe 5.  The tow is carried by the liquid through tube 6 and glass cone 7 to the inclined arm 8 of a bent tube, the other arm 9 of which is upturned vertically.  The tow forms a loose column of folds as it slips over the lower surface of arm 8.  It is removed continuously by a godet 10.  Instead of constructing the tube with an upturned exit arm, it may extend downwardly into a constant level trough so that the treating liquid will keep the trough filled up to the constant level as it leaves the lower end of the tube.