Patent GB-787598-A (GB)
Title: Improved method and a device for the manufacture of artificial threads from a spinning solution by means of coagulation
IPC: D01D5/06
Filed: 1955-05-20
Abstract: <PICT:0787598/IV (a)/1> <PICT:0787598/IV (a)/2> A wet spinning device comprises a cup-shaped multi-hole spinneret mounted at the end of a spinning solution supply pipe in such a manner that its axis is vertical and its face directed downwards, at least the lower portion of the spinneret projecting into the air and not being surrounded by a tube or being submerged in a bath of coagulating liquid.  The spinneret is without the usual "hat-brim" and the spinneret and the end of the pipe are connected to one another in such a manner as to provide a smooth continuous cylindrical surface without excrescences or sudden changes in diameter.  The upper portion of the spinneret and/or the lower portion of the spinning solution supply pipe are surrounded by an outer pipe concentric with and spaced from the spinneret and/or the lower portion of the spinning solution supply pipe, and means are provided for supplying coagulating liquid to the annular space between the outer pipe and the spinneret and/or spinning solution supply pipe so as to cause the coagulating liquid to flow out of a narrow annular orifice between the lower end of the outer pipe and the lower end of the spinning solution supply pipe or upper portion of the spinneret, and then to flow downwards over the lower vertical portion of the spinneret at a predetermined rate which is lower than that of the bundle of filaments extruded from the spinneret, at least in the first portion of their path of travel from the latter, e.g. in at least the first 10 cm. of this path. Coagulation of the filaments may be incomplete in the stream of coagulating liquid and may be completed by thereafter passing the filaments through a coagulation bath.  As shown in Fig. 1, a viscose supply line 1 is provided with a spinneret plate holder 2 having a spinneret plate 3.  A wider tube 4 for supplying the coagulating liquid is mounted round the tube 1 by means of the collar 5 and a conical sleeve 7 is detachably mounted (as by screwing) on the bottom of the tube 4.  Between the bottom of sleeve 6 and the tube 1 there is an annular slit or clearance 7 through which coagulating liquid may flow out of the tube 4 and along the spinneret plate holder 2 to the spinneret plate 3.  The position of the tube 1 with respect to the tube 4 may be adjusted by means of set screws 8 so that the width of the annular slit 7 is uniform.  Coagulating liquid is supplied through inlets 10 to a reservoir 9 and thence flows over a cylindrical dam 11 and holes 12 into the tube 4.  As shown in Fig. 2, the spinneret plate holder 2 is screwed on to the bottom of the spinning solution supply tube 1, an annular washer 14 being provided to render this joint liquid-tight.  The coagulating liquid supply line 10 is directly connected to the tube 4 and the conical sleeve 6 is screwed on to the bottom of the tube 4.  It terminates in a ring 15 which surrounds the spinneret holder 2 but does not extend to its lower end.  The bottom of the ring 15 is conically ground to form a sharp edge 16 on the inner side so as to facilitate the flow of the coagulating liquid through the annular slit 16.  Washers 17, 18 are provided for sealing the connection between the tube 4 and the sleeve 6, and spacers 19 are provided for correct centring of the tube 1 in the ring 15. The joint between the upper portion of the outer tube 4 and the inner tube 1 is sealed by means of the adjustable packing gland 20, 21, 22.  Specification 664,829 is referred to.