Patent GB-785893-A (GB)
Title: Improved process and apparatus for the manufacture of artificial threads from spinning solutions
IPC: D01D5/06
Filed: 1955-05-20
Abstract: <PICT:0785893/IV (a)/1> Artificial filaments are wet-spun by extruding a spinning solution such as viscose through a spinneret mounted in and encircled by a spinneret holder which constitutes a guiding body for a stream of coagulating liquid, part of the internal surface of the guiding body being in the same flat plane as the flat face of the spinneret and serving as a guiding or boundary surface for the stream of coagulating liquid.  A second guiding member or body having an internal flat surface parallel with that of the first guiding body and spaced only a short distance therefrom is provided with a trumpet-shaped opening coaxial with the spinneret and leading into a tubular conduit for drawing off the bundle of filaments and discharging the coagulating liquid.  The space between the two guiding surfaces thus forms a duct for the stream of coagulating liquid in the shape of a flat annulus, so that the stream can flow first with increasing linear velocity from all rides radially towards the axis of the spinneret in the plane of the spinneret face and then enter the tubular conduit with the bundle of filaments, thus changing the direction of its path of flow to one normal to the previous direction.  As shown in Fig. 1, spinning solution is supplied to the spinneret 5 through the feed pipe 1 and the tubular conduit 4 in the spinning head 3, and is extruded to form a bundle of filaments which leave the spinneret face 6 and are drawn through the bell-mouthed tubular conduit 7 facing and coaxial with the spinneret.  The coagulating feed liquid flows through the supply pipe 8, annular passage 9, wire gauge screen 10, and annular passage 11, and then radially inwards towards the axis of the spinneret 5 between the flat external surface 12 of the spinneret holder 14 and the flat internal surface 13 of the cup-shaped member 15.  The coagulating liquid finally enters the bell mouth of the conduit 7 and flows through the conduit together with the filaments.  The joints between the various detachably connected portions of the apparatus are rendered liquid-tight by means of rubber sealing rings 16-20. The distance between the surfaces 12 and 13 may be adjusted by means of interchangeable annular distance-pieces 21.  In an alternative form of apparatus the spinneret and spinneret holder are submerged in a bath of coagulating liquid in an uncovered trough, the spinneret axis being perpendicular to a wall of the trough and coaxial with an outlet pipe projecting from the exterior of this wall and communicating with the interior of the trough.  The mouth of the pipe in the wall of the trough is bell-shaped and the flat face of the spinneret and spinneret holder is spaced a short distance from and parallel with the wall of the trough carrying the pipe, so that the coagulating liquid flows radially inwards towards the axis of the spinneret between the wall of the trough and the flat outer surface of the spinneret holder before entering the outlet pipe in the wall of the trough. Specification 394,049, [Group IV], is referred to.