US3028626A - Wet-spinning apparatus - Google Patents

Description

April 10, 1962 M. SONNlNO WET-SPINNING APPARATUS Filed May 5. 1960 T0 GUIDE ROLL AND NEXT STEP 38 IN PROCESS IS r lo/ I04 I I 26x 2e 52 I 42 42 50 8 4O 76 f 76 64 l 56 FROM SUPPLY SOURCE OF SP/NN/NG' SOLUT/ON INVENTOR. MAR/0 SON/V/NO BY fi/mst .4? A

United States Patent of Maine Filed May 3, 1960, Ser. No. 26,477 9 Claims. (Cl. 18-8) This invention relates broadly to wet-spinning apparatus and, more pmticularly, to such apparatus which permits the spun material to travel upwardly in a coagulating bath without immersion of the spinning head in the bath.

It was known prior to the present invention to arrange the spinning nozzle at the end of a tube and to cause the coagulating liquid comprising the spinning bath to pass through the tube in the direction of travel of the extruded filaments or thread. In many cases, the prior-art practice has involved positioning the tube horizontally and the coagulating liquid was usually arranged to flow from a supply source through the tube in front of which the spinning nozzle or spinnerette had been placed. In the latter arrangement, immediately after extrusion of the spinning solution into the coagulating liquid to form filaments, the coagulating liquid carried the threads with it, and filaments having improved properties were obtained due to the favorable direction of flow of the coagulating liquid. In such cases, the immersion of the spinnerette and the spinning head in the coagulating liquid and the removal of the spinnerette, when it had to be changed, caused no great difficulty except for the tirne lost in draining the assembly.

In the suggestions found in the prior art for so-called upward Spinning the spinning head is immersed in the coagulating liquid. This may not be particularly objectionable when the coagulating liquid is at room temperature or thereabouts, but is objectionable when the liquid coagulant is at a reduced temperature such as, for example, 0 C. or lower and the spinning solution being extruded through the orifices of the spinnerette is at an elevated temperature, e.g., 50 or 60 C. or higher, e.g., up to 80 or 90 C.

The present invention provides new and improved wetspinning apparatus wherein the spinning head and the spinnerette, which together form the spinning assembly, are not immersed in the coagulating liquid with concurrent advantages in heat transfer, cost saving, equipment simplification and efficient and ample distribution of the coagulating liquid. Furthermore, in the apparatus of the present invention, the spinning head is outside of the coagulating liquid. This is a matter of particular importance when the coagulatng liquid is one that is at a temperature of the order of 10 C. to or C. Also, the coagulating chamber for each head is removable without disturbing the performance of the other heads of a particular series. Furthermore, the spinnerette is in such a position that the extruded filaments and the face of the spinnerette can be readily observed. The practical advantages of such a construction will be readily apparent to those skilled in the art, who will also quickly appreciate that the invention provides a long-desired need in the art.

It is, accordingly, a primary object of the present invention to provide an improved wet-spinning apparatus where in the spinning head and the spinnerette are not immersed in the coagulating liquid with the accompanying advantages set forth in the preceding paragraph.

Other advantages of the invention will be apparent to those skilled in the art from the following more detailed description and the single figure of the accompanying draw- The novel features that are characteristic of the inven- "ice tion are set forth in the appended claims. The invention, itself, however, will best be understood by reference to the description which follows, when considered in connection with the accompanying drawing in which the single FIGURE shows a side sectional view of apparatus embodying the invention.

Referring to the drawing, which is merely illustrative of apparatus embraced by the invention, there is shown by way of illustration wet-spinning apparatus embodying the invention and which comprises an elongated chamber 10 having side walls and which is open at its upper end. Within the chamber 10 there is an open-ended spinning tube 12 which has a comically-shaped main body portion 14 and, preferably, an outwardly-flaring mouth 16 at its apex. Such an outwardly-flaring or funnel-shaped mouth obviates or minimizes turbulence as the coagulating liquid 32 overflows into the reservoir 20. Within the chamber 10 there is a wall 18 which joins the upper portion of the spinning tube 12 to the inner, upper part of the chamber 10, thereby sectionally dividing the chamber 10 to form an upper reservoir 20 and a lower reservoir 22. Closure and sealing means 24 are provided for closing and sealing the lower end of the elongated chamber 10 and for supporting a spinnerette 26 in an upward-spinning position. The lower end 23 of the spinning tube 12 is so spaced from the upper part of the closure and sealing means 24 as to form a narrow, annular passageway 30 therebetween. Through this annular passageway coagulating liquid 32 can be introduced into the spinning tube 12 at a level below the face 34 of the spinnerette 26. Means including a conduit 36 are provided for introducing a coagulating liquid into the upper part of the lower reservoir 22 and, also, means including a conduit 38 for withdrawing coagulating liquid. from the lower part of the upper reservoir 20. I

The closure and sealing means 24 advantageously include, as shown in the drawing, a combination of a cap or coupling nut 40, an O-ring sealing member 42 and an end-closing member 44 that can be detachably united to the cap 40 and upon which member the spinnerette 26 can be mounted in an upward-spinning position.

The cap 40 is adapted to fit within the elongated chamber 10 at the lower end thereof, the upper portion 46 of the cap being also adapted to fit within the bottom of the spinning tube 12 and being spaced from the lower end 28 thereof so as to form the aforementioned narrow, annular passageway 30. This cap may be formed, for instance, of nylon, polymerized tetrafiuoroethylene, or of any suitable material which has the desired heatinsulating properties and is resistant to attack by the particular liquids with which it comes in contact.

The cap 40 has a central, vertical opening 48 therein. The upper part of this opening is adapted to receive the spinnertte 26 therein, the side wall(s) of the spinnerette abutting the side wall(s) defining the aforesaid upper part of the opening 48. The lower part of this opening is of larger diameter than that of the said upper part thereof, the wall defining this larger diameter, lower part of the opening 48 being threaded; that is, the cap has an internally threaded portion into which can be screwed the externally threaded upper extension 50 of the end-closing member 44.

The cap 40 also has an annular slot 52 in the broadest part of its outer periphery. This slot has therein an O- ring sealing member 42 which may be formed of neoprene or other plastic or other material capable of functioning as a gasket material and which is impervious to the action of the particular coagulating liquid 32 employed in the use of the apparatus. This Q-ring provides a seal between the cap or coupling nut 40 and the elongated chamber 10.

The end-closing member 44 has an externallythreaded upper extension 50, which has an annular recess 56 in its upper wall and an annular gasket 58 therein adapted to contact the lip 60 of the spinnerette 26. The member 44 can be formed of the same kind or type of material'described above with reference to the cap 4% Means also are provided for coupling the end-closing member 44 to the elongated chamber 10. These means may take the form of a member comprising a bottom wall 62 having a side wall(s) 64 and an extension 50. The extension 50 is provided with the aforementioned recess 56 in which is placed the gasket material 53 comprised, for example, of neoprene rubber or of any other material which is resistant to attack by the spinning solution or dope which is being conducted to the spinnerette 26 through the pipe or conduit 66.

The bottom wall 62 and the extension 50 have a cen tral, vertical opening 68 therein which is aligned with the opening 48 in the cap 49. The wall defining the lower part of this opening 68 is threaded so that the conduit 66 having an externally threaded end or terminal section 72 can be screwed into the threaded opening 68 in the end-closing member 44.

The coupling nut 74 provides means whereby the endclosing member 44 can be tightened at the abutment '76 between said member and the lower part of the elongated chamber 16. This coupling nut also provides means whereby the spinnerette 26 can be locked into place.

The open-ended inlet conduit 36 leads to an opening 78 in the upper part 80 of the side wall of the lower reservoir 22. Means also are provided for feeding a coagulating liquid into the open end 82 of the inlet conduit 36. The open-ended conduit 36 advantageously may have a funnel-shaped mouth 84. The means for feeding a coagulating liquid thereto include, for example, a feed vessel 86 positioned above said funnel-shaped mouth and having side walls 38 and 9t) and a bottom wall 92, which vessel is adapted to receive feed coagulating liquid 32 therein. A tube 94 passes through the bottom wall 92 of said vessel and is adapted to be plugged when the apparatus is not in operation. This tube is vertically aligned with the aforesaid mouth 84 of the inlet conduit 36.

Suitable means also are provided for preventing the coagulating liquid from overflowing from the feed ves- Sol 86. Such means advantageously may take the form of a conduit 96 for carrying excess coagulating liquid from the feed vessel 86 to the discharge vessel or sump 98.

The conduit 96 advantageously may have a funnelshaped mouth 109. The mouth of this funnel is above the normal level of liquid in the feed vessel 86. When this normal level of liquid is excessive, it enters the mouth 100 of the conduit 96 and is connected through this conduit to the discharge vessel or sump 98.

Suitable means (not shown) are provided for recirculating the coagulating liqud from the sump 93 to the feed vessel 86, and for adding make-up liquid coagulant to the latter vessel as and when needed.

In ordinary pilot-plant and commercial operations the feed vessel 86 and the discharge vessel or sump 98 are in the form of long troughs or rectangular vessels with a plurality of spinning assemblies, e.g., 15 to 500 or more, positioned adjacent thereto as indicated in the accompanying drawing. The spinning assemblies may be arranged along one or both sides of such troughs.

In operation, the spinning assembly can be removed for changing of the spinnerette 26 as desired or as may be required; and during this time, after plugging (e.g., with a cork or other stopper) the top of the tube 94, the coagulating liquid will flow from the feed vessel or trough 86 to the discharge Vessel or sump 98 without interfering with the spinnerette change. Once the spinnerette 26 is ready for threading-up, the elongated chamber 10 with its inner, open-ended, conically-shaped spinning tube 12 is connected with the cap or coupling nut 40, and the flow of coagulating solution will begin immediately upon removal of the plug from the top of the tube 94.

In operation, the coagulating solution travels upvardly concurrently with the extruded filamentary material 192 into the conical chamber 194 of the spinning tube 12, which chamber during operation of the apparatus, contains coagulating liquid 32. The conical shape makes possible an increase in the velocity of the coagulating liquid as the freshly coagulated filaments become stronge The filaments that form at the face 34 of the spinnerette 26, are led under moderate tension, after leaving the coagulating bath, to a guide means (e.g., a roll) and thence to the next step in the process.

From the foregoing description it will be noted that the spinning head is outside of the coagulating liquid. This is a matter of considerable practical importance when the coagulating liquid is one which is maintained at a low temperature, e.g., 0 C. and below as is described more fully in, for instance, Cresswell US. Patent No. 2,558,730. It is also to be noted that the spinning chamber for each head is removable without disturbing the performance of the other heads employed in a particular series. Also, the spinnerette is in such a position that the extruded filaments and face of the spinnerette can be observed.

In brief, the wet-spinning apparatus of the present invention provides a new and unobvious arrangement whereby the spinning head is not immersed in the coagulating liquid with the attendant advantages of efficiency in heat transfer, cost saving in operation, equipment simplification and adequate and effective distribution of the coagulating liquid.

The apparatus of the present invention is applicable for use in any wetaspinning operation, but is especially useful in the wet-spinning of a solution of a polymer of acrylonitrile wherein such a solution normally is extruded into a coagulating bath maintained at a temperature below +l0 C., e.g., from --9 C. to '5 C. Such spinning solutions and coagulating baths (as well as other solutions and baths that can be used in practicing the present invention) are described in, for instance, Patents 2,558,730, -731, -732, -733, -735 and -78l; 2,6l4,- 289; 2,777,751; and in the patents referred to in the above-identified patents.

I claim:

1. Wet-spinning apparatus comprising an elongated chamber having side walls and which is open at its upper end; an open-ended spinning tube within said chamber, said tube having a conically-shaped main body portion; a wall within said chamber joining the upper portion of the said spinning tube to the inner, upper part of the chamber, thereby sectionally dividing the interior of the chamber to form an upper reservoir and a lower reservoir; closure and sealing means for closing and sealing the lower end of the said elongated chamber and for supporting a spinnerette in an upward-spinning position such that the face of the spinnerette is in approximately the same horizontal plane as that of the uppermost surface of the said closure and sealing means, the lower end of the said spinning tube being so spaced from the upper part of said closure and sealing means as to form a narrow, annular passageway therebetween, and through which passageway coagulating liquid can be introduced into the lower part of the said spinning tube at a level below that of the face of the said spinnerette; means including a conduit for introducing a coagulating liquid into the upper part of the said lower reservoir; and means including a conduit for withdrawing coagulating liquid from the lower part of the said upper reservoir.

2. Wet-spinning apparatus as in claim 1 wherein the elongated chamber is a cylindrical, elongated chamber and the comically-shaped main body portion of the spinning tube has an outwardly-flaring mouth at its apex.

3. Wet-spinning apparatus as in claim 1 wherein the closure and sealing means for closing and sealing the lower end of the said elongated chamber and for supporting a spinnerette in an upward-spinning position include, in combination, a cap, an O-ring sealing member and an end-closing member that can be detachably united to said cap and upon which member a spinnerette can be mounted in an upward-spinning position.

4. Wet-spinning apparatus comprising a cylindrical, elongated chamber having side walls and which is open at its upper end; an open-ended spinning tube within said chamber, said tube having a conicallyashaped main body portion with an outwardly-flaring mouth at its apex; a Wall within said chamber joining the upper portion of the said spinning tube to the inner, upper part of the chamber, thereby sectionally dividing the interior of the chamber to form an upper reservoir and a lower reservoir each having a side wall; an open-ended inlet conduit leading to an opening in the upper part of the side wall of the lower reservoir; means for feeding a coagulating liquid into the open end of said inlet conduit; an open-ended outlet conduit leading from an opening in the lower part of the side wall of the upper reservoir; a discharge receiver positioned to receive coagulating liquid that flows from the open end of said outlet conduit when the apparatus is in operation; closure and sealing means for closing and sealing the lower end of the said elongated chamber and for supporting a spinnerette in an upward-spinning position such that the face of the spinnerette is in approximately the same horizontal plane as that of the uppermost surface of the said closure and sealing means, the lower end of the said spinning tube being so spaced from the upper part of said closure and sealing means as to form a narrow passageway therebetween, and through which passageway coagulating liquid can be introduced into the lower part of the said spinning tube at a level below that of the face of the said spinnerette, said closure and sealing means including, in combination, a cap, an O-ring sealing member and an end-closing member that can be detachably united to said cap and upon which member a spinnerette can be mounted in an upward-spinning positon.

5. Wet-spinning apparatus as in claim 4 wherein the open-ended inlet conduit has a funnel-shaped mouth and the means for feeding a coagulating liquid thereto include a feed vessel positioned above said funnel-shaped mouth, said vessel having side walls and a bottom wall and being adapted to receive feed coagulating liquid therein; a tube within said feed vessel that passes through the bottom wall thereof, which is adapted to be plugged when the apparatus is not in operation, and which is vertically aligned with the aforesaid mouth of the said inlet conduit.

:6. Wet-spinning apparatus as in claim 5 which additionally includes means for preventing coagulating liquid from overflowing from the said feed vessel.

7. Wet-spinning apparatus as in claim 6 wherein the means for preventing coagulating liquid from overflowing from the feed vessel includes a conduit for carrying excess coagulating liquid from the said feed vessel to the said discharge vessel.

8. Wet-spinning apparatus as in claim 4 which additionally includes a conduit detachably united to the endclosing member of the defined closure and sealing means and through which conduit spinning solution can be passed and thence through a passageway leading to the spinnerette that, in operation, is mounted on said end-closing member in an upward-spinning position.

9. Wet-spinning apparatus comprising a cylindrical, elongated chamber having side walls and which is open at its upper end; an open-ended spinning tube within said chamber, said tube having a conically shaped main body portion with an outwardly-flaring mouth at its apex; a wall within said chamber joining the upper portion of the said spinning tube to the inner, upper part of the chamber, thereby sectionally dividing the interior of the chamber to form an upper reservoir and a lower reservoir; closure and sealing means for closing and sealing the lower end of the said elongated chamber and for supporting a spinnerette in an upward-spinning position such that the face of the spinnerette is in approximately the same horizontal plane as that of the uppermost surface of the said closure and sealing means, the lower end of the said spinning tube being so spaced from the upper part of said closure and sealing means as to form a narrow, annular pasageway therebetween, and through which passageway coagulating liquid can be introduced into the lower part of the said spinning tube at a level below that of the face of the said spinnerette, said closure, sealing and spinnerette-supporting means including, in combination, a cap adapted to fit within said elongated chamber at the lower end thereof and the upper portion of said cap being also adapted to fit within the bottom of said spinning tube and spaced therefrom so as to form the aforementioned narrow, annular passageway, said cap having a central, vertical opening therein, the upper part of said opening being adapted to receive a spinnerette in an upward-spinning position, said spinnerette having a lip, and the lower part of said opening being of larger diameter than that of the said upper part thereof and the wall defining said lower part being internally threaded, said cap also having an annular slot in the broadest part of its outer periphery, said slot having therein an O-ring sealing member, and an end-closing member having an externally-threaded upper extension which is screwed into the internally-threaded portion of the said cap, said end-closing member having a central, vertical opening therein which is aligned with the opening in the said cap, the said extension having an annular recess in its upper wall and an annular gasket therein adapted to contact the lip of the said spinnerette, and means for coupling said end-closing member to said elongated chamber; means including a conduit for introducing a coagulating liquid into the upper part of the said lower reservoir; and means including a conduit for withdrawing a coagulating liquid from the lower part of the said upper reservoir.

References Cited in the file of this patent UNITED STATES PATENTS 827,434 Friedrich July 31, 1906 2,255,594 Berndt Sept. 9, 1941 2,711,559 Lynch June 28, 1955 FOREIGN PATENTS 742,817 Germany May 12, 1943 333,868 Switzerland Dec. 31, 1958 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION April 10, 1962 Patent No. 3,028,626

Mario Sonnino rtified that err-er appears in th tion and that the said Letters Patent e above numbered pet- It is hereby as should reedes ent requiring correc corrected below.

Column 1 line 52, for "coagulatng' read column 3, line 53, for "connected" read conducted signed and sealed this 24th day of July 1962.

(SEAL) Attest: ERNEST w. SWIDER DAVID LADD Commissioner of Patents Atteeting Officer

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