Patent GB-802282-A (GB)
Title: Improvements in method and apparatus for producing novel artificial yarn
Inventor: HOFMANN HUGO
IPC: D01D5/06
Filed: 1956-01-17
Abstract: <PICT:0802282/IV (a)/1> <PICT:0802282/IV (a)/2> In the production of composite filament bundles of regenerated cellulose by the funnel stretch-spinning process, at least one filament bundle component is slubbed at random intervals and at least one filament bundle component is unslubbed, the individual filament bundle component being formed by extruding a viscose or cuprammonium cellulose spinning solution into a common coagulating bath which does not completely coagulate the filaments and therefore leaves them still in a gel or tacky condition, at least one of the filament bundle components having individual filaments of higher denier than the filaments of the other filament bundle components.  The individual filament bundle components are separated from contact with each other and are discharged from the common coagulating bath through separate funnel outlets, the filaments of higher denier having a longer path of travel in their respective funnel(s) than the other filaments and the volumetric rate of flow of the coagulating liquid from the longer funnel(s) being greater than that from the shorter funnel(s).  The bundle(s) of higher denier filaments are caused to pile up temporarily beneath their funnel outlet(s) while the other bundle components are passed on without being first caused to pile up, and thereafter all the filament bundles are brought together, while the filaments are still tacky, by means of a filament uniting device in the absence of cellulose regenerating acid, and the composite filament bundle so formed is collected while subjecting it to the action of an acid cellulose regenerating bath.  As shown in Figs. 2 and 4, the spinning solution is delivered under pressure from the manifold 20 through lead-in tube 22 to the head-space 11 above the spinneret 14 which has two sets of orifices, those in the area 13 being larger than those in the area 15 so that the filaments issuing through the holes 13 will be of higher denier than those issuing through the holes 15.  At the same time coagulating liquid from the manifold 52 is delivered to the inlet tube 34 by means of the tube 54 and is distributed by means of the passage 30 and openings 31, from which it flows upwardly through the interior 27 of the glass cylinder 18 until it overflows into the open upper ends 361, 381 of the spinning funnels 36, 38.  The upper ends 361, 381 are flattened on one side abut each other and terminate just below spinneret 14 to receive the two separate bundles of filaments issuing from the spinneret.  Attached to the lower ends of the funnels 36, 38 by means of flexible coupling members 40, 42 are funnel nipples 48, 50, of which the latter is longer and has a larger nipple opening, thus causing more coagulating liquid to be siphoned through funnel 36 to handle the higher denier filaments 56 extruded into this funnel and to deposit them in a flat tilted surface 60 disposed beneath the funnel.  The take-up rate is such as to permit a temporary pile-up 57 of the filaments and, since they are only partially coagulated and still sticky, nubs or slubby portions are formed on the yarn at irregular random intervals.  Instead of the flat surface 60, a dished receptacle may be placed beneath the funnel nipple 50, the vertical distance between the receptacle and the nipple being adjustable.  The pile of filaments then floats on the coagulating liquid which is discharged into and overflows from the receptacle, producing smaller and more closely spaced slubs than when the flat tilted surface 60 is used.  Yarn filament bundle 58 is led under guide rod 621 and both bundles 58, 56 are led over guide rod 64 and through uniting guide member 66, where the two partially coagulated filament bundles are united into one composite yarn tow in the absence of cellulose regenerating acid, to insure thorough adhesion of the two filament bundles.  From the uniting guide member 66 the composite bundle is led through the reciprocating guide 68 and then to the take-up reel 70.  As the yarn is taken up on reel 70 it is subjected to an acid regenerating bath, the acid being allowed to dribble on to the surface of the skein and being taken up through the medium of a trough-like tongue member 69 secured beneath guide 68.  More than two funnels for the production of unslubbed filaments may be used with at least one funnel designed to produce slubby filaments, the funnels in this case also having a common coagulating bath.  Specifications 460,626, 491,038, 495,555 and U.S.A. Specifications 2,065,175, 2,154,893 and 2,251,247 are referred to.