GB859520A - Spinning process and apparatus for the production of artificial filaments - Google Patents

Abstract

<PICT:0859520/IV(a)/1> <PICT:0859520/IV(a)/2> In the wet-spinning of artificial filaments by extruding a spinning solution through spinnerets immersed in a bath of coagulating liquid, the spinnerets are positioned a small distance from a continuously rotated permeable hollow drum which is at least partially immersed in the bath, which flows through the periphery of the drum into its interior, a flow of coagulating liquid thus being generated in the bath so as to urge the freshly formed filaments into contact with the drum, which then transports the filaments through the bath under substantially no tension. As shown in Fig. 1, viscose is delivered by pumps 23 through pipes 19 and filters 20 to spinning nozzles 3 positioned near a driven rotatable drum 4 immersed in coagulating liquid in a tank 1 to which the liquid is supplied through a perforated feed pipe 11 and from which it overflows into the trough 111. Filaments 5 extruded from the nozzles 3 are deposited on the perforated peripheral surface of the drum 4 and carried on that surface through the coagulating liquid almost one complete revolution of the drum before they are withdrawn from the drum by the driven rolls 13, 131, 14, 15, squeezed in the nip between the rolls 14, 15 and transported on to the perforated peripheral surface of the driven drum 41 almost completely immersed in a coagulating liquid contained in a tank 2. After passing round the drum 41 the filaments are withdrawn from the drum over the roll 1311 by the pair of rolls 141 and 151 and then travel over the sets of stretch and guide rolls 16, 17. As shown in Fig. 2, the flat end wall 7 of the drum 4 is axially secured to a driven shaft 25 which is journalled in a stationary member of the apparatus and enters the tank 1 through a liquid-tight stuffing box 26. The other end wall 28 of the drum is provided with an axial opening and is rotatable about a short stationary pipe 8, which is mounted in a wall of the tank 1 and communicates both with the interior of the drum and with a pump chamber 9 containing a centrifugal pump 11 driven by an electric motor 10. Coagulating liquid is drawn by the pump 11 from the interior of the drum and discharged into the chamber 9, from which it returns into the tank 1 through several ports, of which one is shown at 18. The peripheral wall 6 of the drum is perforated, allowing a continuous flow of liquid from the tank 1 into the interior of the drum. When the drum is not completely submerged in the coagulating liquid (as in the case of drum 41 in tank 2 (Fig. 1), the drum is provided with an internal impermeable arcuate shield 12 fixedly mounted on the pipe 8, but rotatably supported in the axial bore 27 of the shaft 25 and fitting snugly against the inner surface of the peripheral wall 6 of the drum. The shield 12 extends circumferentially over and beyond the portion of the wall 6 above the level of the coagulating liquid. The apparatus fo the invention facilitates threading up and enables the filaments to be subjected to a rapid flow of coagulating liquid (and hence rapid and uniform coagulation) without their becoming deformed while still in a plastic condition.