US2872702A

US2872702A - Apparatus for lacing spinning tubes

Info

Publication number: US2872702A
Application number: US622928A
Authority: US
Inventors: Dunlap William; Henry J Mcdermott
Original assignee: American Viscose Corp
Current assignee: Akzo Nobel UK PLC
Priority date: 1956-11-19
Filing date: 1956-11-19
Publication date: 1959-02-10
Anticipated expiration: 1976-02-10

Description

Feb. 10, 1959 w. DUNLAP EI'AL APPARATUS FOR LACING SPINNING mass Filed Nov. 19, 1956 2,872,702 APPARATUS FOR LACING SPINNING TUBES William Dunlap, Boothwyn, and Henry J. McDermott,

'Collingdale, Pa., assignors to American Viscose Cor- The invention relates to the spinning of artificial filaments, and more particularly to the method and apparatus or initially lacing freshly formed filaments at the start of the spinning procedure.

In the conventional manufacture of artificial filaments by the viscose process, a spinning solution is extruded under pump pressure through the apertures of a spinneret and into a liquid spin bath where the filaments are set. A departure from this conventional procedure has been to withdraw the freshly formed filaments from the liquid spin bath througha vertically disposed tube which extends from the spinneret to a point above the spin bath level. With this manner of filament withdrawal, a flow of spin bath is induced through the tube in the same direction as the filament travel, thus insuring that fresh spin bath liquid is continuously supplied to the filaments as they are extruded. While this modified manner of filament spinning, generally referred to in the art as vertical tube spinning, has resulted in greater productivity and in improved filament quality, it has also created a problem of satisfactorily lacing the initially formed filaments at the start of the spinning operation.

In the usual practice of vertical tube spinning, the extrusion pump is placed in operation after which the spinneret is immersed into the spin bath. Since the spinning solution is continuously being extruded from the spinneret, a mass of filaments is formed and tends to remain well below the spin bath surface. A hook is then utilized to pull this filament mass upwardly through the tube for the initial lacing of the spinning apparatus. It is apparcut that this lacing procedure depends almost entirely upon the skill and speed of the operator, and in addition involves the risk of tube and spinneret obstruction by fragments broken away from the filament mass. Further, while being immersed within the spin bath, the spinneret may not be entirely filled with spinning solution, but may contain a small volume of air which permits en try of the liquid spin bath into the spinneret and cause the filament forming material to coagulate along the spinneret face or within its apertures. In view of these difiiculties, it is a primary object of the present invention to provide a generally new and improved method and apparatus for initially lacing the freshly formed filaments at the start of the spinning procedure.

Another object is to provide a method of buoyantly lacing freshly formed filaments through a vertical spinning tube.

Still another object is the provision of a flexible cap or cover capable or snugly embracing a spinneret to protect the same and which is adapted to assist in lacing the filaments at the tart of the spinning operation.

A further object is to provide in the spinning of artificial filaments, a method wherein the initially extruded spinning solution alone or in combination with a small volume of air iscontained in a compressed state at the spinneret face and assists in buoyantly lacing the freshly formed filaments through a vertical tube at the start of the spinning. operation.

. trough 15 containing a liquid spin bath 17.

Patented Feb. 10, 1959 A still further object is the provision of a spinneret cap or cover for use in floatably lacing freshly formed filaments within a spin bath, and which may be adjusted to vary its degree of buoyancy.

These and other objects and advantages of the invention will be apparent from the following description and accompanying drawing in which:

Figure 1 is a vertical section of a portion of a filament spinning apparatus illustrating one embodiment of the present invention at the startof the spinning operation;

Figure 2 is an enlarged fragmentary section of a portion of the apparatus shown in Figure l; and.

Figure 3 is a view similar to Figure 2 illustrating a second embodiment of the invention at an intermediate stage during its lacing travel.

Generally, the invention relates to a method and apparatus for initially lacing freshly formed filaments at the start of the spinning procedure, and includes a buoyant cap or cover which is flexibly and snugly embraced over the spinneret face before the same is positioned within a liquid spin bath and in alignment with the lower'end of a vertically disposed spinning tube. Once spinning is commenced, the extruded filament forming material collects within the cap, along with any air which may be contained within the spinneret. In view of the continuous and positive pumping action on the spinning solution, the extruded material, and any contained air, is compressed until the frictional resistance between the contacting surfaces of the cap and the spinneret is overcome. At this time, the cap leaves the spinneret and, in view of the buoyant nature of the cap and the compressed state of the material and air contained therein, tloatsupwardly through the tube to the spin bath surface. This floating movement of the cap creates an initial flow of spin bath in an upward direction which, when combined with the force exerted by the compressed spinning solution and air within the cap, serves to lace the leading ends of the filaments through the vertically disposed tube. It will be noted that the spinneret is protected from the liquid spin bath during its initial immersion and that the freshly formed filaments are rapidly carried upwardly to the spin bath surface with little or no accumulation thereof within the vertically disposed tube. At the slower production speeds, the spinning solution and air collected within the cap does not apparently undergo compression to a sufiicient degree, and thus it is desirable to employ a cap having a closed air chamber to increase the buoyant characteristic thereof.

With reference to the drawing, Figure 1 illustrates a conventional apparatus for use in spinning artificial filaments and includes a spimreret 7 connected by the coupling nut 9 to One end of a rounder 11, which in turn is supplied with spinning solution under pump pressure from a suitable source, not shown. The rounder is swingably supported at 13 for movement to and from the In its operative position as shown in Figure 1, the rounder 11 is supported on a bracket 19, fixed to the trough wall, and is in alignment with the lower flared end of a vertically disposed tube 21 which rests on the nut 9 and extends upwardly to a point above the level of the spin bath 17. The tube 21 is maintained in desired aligned position by the spacers 23 which are slidably mounted within annular brackets 25 secured to the spinning apparatus. After leaving the spin bath, the filaments are passed about the godets 27 which function in the known and conventional manner.

In accordance with the present invention, the spinneret, before being immersed, is enclosed by a cap or cover 29 formed of a buoyant material with at least its side .wall possessing some resilience to enable the same to snugly embrace the spinneret. Thus, the embodiment of the invention shown in Figure 2 includes a cylindrical side wall 31 and an end wall 33. The internal diameter of the cap is slightly less than the external diameter of the spinneret 7 necessitating a stretching of the wall 31 as the cap is positioned on the spinneret to insure good frictional engagement between the contacting surfaces of these parts. In addition, the length of the cap 29 is such as to provide a small area or pocket between the spinneret face and the end wall 33 within which the initially extruded spinning solution and air can collect as heretofore described. Since the cap 29 is applied before the rounded is immersed within the spin bath, it effectively prevents the entry of the liquid spin bath into the spinneret and thereby protects against the possibility of the filament forming material coagulating along the spinneret face or within its apertures. Once the rounder is disposed in operative position, the tube 21 is lowered into rest position on the nut 9, as illustrated in Figure 1. As in the conventional vertical tube spinning apparatus, the peripheral configuration of the nut 9 and the flared lower end of the tube 21 cooperate to form suitable openings through which a uniform and continuous supply of fresh liquid spin bath can flow upwardly into and through the tube 21 during the spinning process.

During the filament forming procedure, the mass of filament forming material initially extruded, along with any air contained within the spinneret, collect within the area between the spinneret face and the cap end wall 33, as represented by the characters 35 and 37 in Figure 2. With each delivery stroke of the conventional positive acting metering pump, the mass of spinning solution 35 and the collected air 37 are subjected to increased compression until they exert a pressure on the cap wall 33 sufficient to overcome the frictional engagement between the contacting surfaces of the cap wall 31 and the spinneret 7. As heretofore mentioned, the buoyant effect of the material from which the cap is formed and the contained volume of air 37, taken with the compressed state of the spinning solution mass 35 all contribute in rapidly lacing the freshly formed filaments upwardly through the tube 21. The freshly formed filaments are all units at their leading ends into a single glob formed by the mass 35 which coagulates during its upward travel through the spin bath and thus delivers the filaments to the spin bath surface in a form which enables the operator to easily grasp the same with great assurance that all filament ends will be simultaneously laced.

When spinning artificial filaments at slow speeds, it appears that the cap is ejected from the spinneret before the mass of spinning solution 35 and the contained volume of air 37 are sufficiently compressed so that the cap and filaments move upwardly through the tube at a relatively slow rate. At this reduced rate of upward movement, there is an increased tendency for the cap 29 to flutter and wedge within the tube 21, possibly due to the alteration in the flow pattern of the spin bath through the tube 21, with the risk that the freshly formed filaments will accumulate at the lower end of the tube and obstruct proper spinning. Under these circumstances, it is desirable to employ the modified lacing structure 39 shown in Figure 3 which incorporates a closed chamber 41 to increase the buoyancy of the lacing device. This embodiment shown in Figure 3 includes a cylindrical side wall 43, a fixed end wall 45 and a movable wall in the form of a plug or plunger 47 which is capable of being slidably teleseoped within the air chamber 41 to vary the volume of air contained therein. As illustrated, the fixed wall 45 is spaced from the lower end of the side wall 43 and thus the lower end 49 of the lacing device 39 corresponds both in structure and function to the cap 29 heretofore described. An elongated extension 51. projects from the plug 47 and serves both as a handle for use during the lacing procedure and as a means for adjusting the plug within the chamber 41.

In use, the lower end 49 of the structure shown in Figure 3 is applied to the spinneret in the same manner as the cap illustrated in Figures 1 and 2. Once the pressure on the mass of spinning solution 53 and air 55 collected between the spinneret face and the wall 45 is sufficient to move the structure 39 away from the spinneret, the lacing device and the freshly formed filaments are rapidly moved upwardly through the tube 21 in the same manner as heretofore described.

In view of the elongated nature of the second described embodiment, there is no tendency for the same to wedge within the tube 21, and it is apparent that the plug 47 may be accurately adjusted within the chamber 41 to provide the buoyant effect best suited for the particular production speed being employed.

With both embodiments of the invention described, it is evident that the freshly formed filaments are laced through the vertically disposed tube 21 in an efficient and highly reliable fashion. Further, the protection of the spinneret effected by the lacing structures disclosed gives full assurance that the spinneret will be free from coagulated materials which would obstruct the flow of spinning solution therethrough. The

lacing devices

29 and 39 may be formed with any suitable buoyant and resilient materials, with particularly satisfactory results being obtained in using polyethylene.

It is seen from the above description that the objects of the invention are well fulfilled by the method and apparatus described. The description is intended to be illustrative only and it is to be understood that changes and variations may be made without departing from the spirit and scope of the invention as defined by the appended claims.

We claim:

1. In the production of regenerated cellulose artificial filamentary material wherein viscose is extruded through a spinneret submerged within a spin bath to form filamentary materials which are passed through a vertically disposed tube to the spin bath surface, the method of lacing the freshly formed filaments through the vertically disposed tube including the steps of containing at the spinneret face and out of contact with the spin bath an initially extruded volume of viscose, compressing the contained volume of "iscose, and finally releasing the compressed volume of viscose into the spin bath at the lower end of the vertically disposed tube and allowing the same to pass upwardly through the tube as a glob to which the freshly formed filamentary materials are attached.

2. In the production of regenerated cellulose artificial filamentary material wherein viscose is extruded through a spinneret submerged within a spin bath to form filamentary materials which are passed through a vertically disposed tube to the spin bath surface, the method of lacing the freshly formed filaments through the vertically disposed tube including the steps of containing at the spinneret face and out of contact with the spin bath an initially extruded volume of viscose along with any air carried by the spinneret, compressing the contained volume of viscose by confirmed extrusion of viscose through the spinneret, and finally releasing the compressed volume of viscose and air into the spin bath at the lower end of the vertically disposed tube and allowing the same to buoyantly pass upwardly through the tube as a glob to which the freshly formed filamentary materials are attached.

3. In the production of regenerated cellulose artificial filamentary material wherein viscose is extruded through a spinneret submerged within a spin bath to form filamentary materials which are passed through a vertically disposed tube to the spin bath surface, the method of lacing the freshly formed filaments through the vertically disposed tube including the steps of containing an initially extruded volume of viscose and any air carried by the spinneret within a buoyant cap frictionally disposed over the spinneret, comprising the contained volume of viscose and air by continued extrusion of viscose through the spinneret until the friction between the cap and spinneret is overcome, and allowing the cap and compressed volume of viscose and air to buoyantly rise through the vertically disposed tube to the spin bath surface and carry therewith the freshly formed filamentary materials.

4. In the production of regenerated cellulose artificial filamentary material wherein viscose is extruded through a spinneret submerged within a liquid spin bath, the method of protecting the spinneret from premature coagulation of viscose within and along the spinneret face including the steps of frictionally disposing a cap over the spinneret face before the spinneret is submerged within the spin bath, submerging the covered spinneret within the spin bath and causing the extrusion of viscose therethrough, containing the initially extruded volume of viscose and any air carried by the spinneret within said cap, and continuing extrusion of the viscose through the spinneret until the cap is ejected therefrom.

5. A method as defined in claim 4 wherein said cap is buoyant and assists in floatably elevating the freshly formed filamentary materials to the spin bath surface.

6. A method as defined in claim 4 wherein said cap includes an air chamber, the size of which may be varied to alter the buoyancy thereof.

7. In the production of regenerated cellulose artificial filamentary material wherein viscose is extruded through a spinneret submerged within a spin bath to form filamentary materials which are passed through a vertically disposed tube to the spin bath surface, a method for protesting the spinneret from premature viscose coagulation along its face and for lacing the freshly formed filaments through the vertically disposed tube including the steps of frictionally disposing a buoyant cap over the spinneret face before the same is submerged within the spin bath, submerging the spinneret within the spin bath and in alignment with the lower end of the vertically disposed tube, causing viscose to be extruded through the Spinneret and be contained within the cap along with any air carried by the spinneret, compressing the initially extruded volume of viscose by continued extrusion of viscose until the friction between the cap and spinneret is overcome, and allowing the cap and the compressed volume of viscose and air to buoyantly lace upwardly through the vertically disposed tube to the spin bath surface.

8. A protective cap for use with a spinneret including a tubular member, one end of said tubular member being adapted to resiliently engage with the annular wall of a spinneret, a wall formed integrally with and positioned within said tubular member at substantially right angles to its axis, said last-mentioned wall being located between the ends of said tubular member, a movable closure disposed within said tubular member and cooperating with said last-mentioned wall to provide an air chamber, said closure frictionally engaging with the internal wall of said tubular member to provide a hold tight seal therebetween and being adapted for adjustment relative to said lastmentioned wall to vary the size of the air chamber and the resulting buoyancy of the cap.

9. In combination with a spinneret having an annular wall and a perforated face across one end thereof, a protective cap including a resilient annular wall having a smooth internal surface frictionally engaging with the annular wall of said spinneret, a wall secured to the an nular wall of said cap and extending in a plane substantially parallel to the perforated face of said spinneret, and means cooperating with at least the annular wall of said cap to provide a closed buoyant air chamber, said cap annular wall having an internal diameter slightly less than the external diameter of the spinneret annular wall.

10. In an apparatus for making artificial filaments by extruding a filamentforming material into a liquid spin bath, a spinneretfor extruding the filament-forming material into the spin bath as a plurality of individual streams, said spinneret having an annular wall and a perforated face across one end thereof, and a protective cap formed of material which is buoyant in the liquid spin bath and including a resilient annular wall having a smooth internal surface frictionally engaging with the annular wall of said spinneret and an end wall formed integrally with said cap annular wall and extending across one end thereof in a plane substantially parallel to the perforated face of said spinneret, said cap annular wall having an internal diameter slightly less than the external diameter of the spinneret annular wall.

Taylor May 15, 1934 Dorough Apr. 15, 1941 Patent No 2372,7091 February l0, 1959 William Dunlap et al printed specification or appears in the that the said Letters It is hereby certified that err ng correction and of the above numbered patent requiri Patent should read as corrected below.

.d em of snugly line 65,

"rounded" reed ed m united column 4 line 75 Column 1, line 63, for "or snugly res for "teIt reed w start column 3, line 12 for me rounder line 42, for "units" re for comprising" read are compressing e Signed and sealed this 2nd day of June 1959u (SEAL) Attest:

KARL AXLINE ROBERT C. WATSON Commissioner of Patents Attesting Oificer